Factors associated with respiration induced variability in cerebral blood flow velocity.

PubMed Central

Coughtrey, H; Rennie, J M; Evans, D H; Cole, T J

1993-01-01

A consecutive cohort of 73 very low birthweight infants was studied to determine the presence or absence of beat to beat variability in the velocity of blood flow in the cerebral circulation and its relation with respiration. One minute epochs of information included recordings of cerebral blood flow velocity estimated with Doppler ultrasound, blood pressure, spontaneous respiratory activity, and ventilator cycling. Fourier transformation was used to resolve the frequencies present within the one minute epochs and to classify the cerebral blood flow velocity as showing the presence or absence of any respiratory associated variability. A total of 249 recordings was made on days 1, 2, 3, and 7. Forty seven infants showed respiratory variability in cerebral blood flow velocity on 97 occasions, usually during the first day of life. The infants with respiratory associated variability were of lower gestational age and when the respiratory associated variability was present they were more likely to be ventilated and receiving higher inspired oxygen; these associations were shown to be independent of gestational age. There was no significant independent association with brain injury, cerebral blood flow velocity (cm/s), or blood pressure (mm Hg). The findings suggest that artificial ventilation may entrain normal respiratory associated variability in the cerebral circulation but do not provide evidence that it is harmful. PMID:8466269

Intraocular Pressure, Blood Pressure, and Retinal Blood Flow Autoregulation: A Mathematical Model to Clarify Their Relationship and Clinical Relevance

PubMed Central

Guidoboni, Giovanna; Harris, Alon; Cassani, Simone; Arciero, Julia; Siesky, Brent; Amireskandari, Annahita; Tobe, Leslie; Egan, Patrick; Januleviciene, Ingrida; Park, Joshua

2014-01-01

Purpose. This study investigates the relationship between intraocular pressure (IOP) and retinal hemodynamics and predicts how arterial blood pressure (BP) and blood flow autoregulation (AR) influence this relationship. Methods. A mathematical model is developed to simulate blood flow in the central retinal vessels and retinal microvasculature as current flowing through a network of resistances and capacitances. Variable resistances describe active and passive diameter changes due to AR and IOP. The model is validated by using clinically measured values of retinal blood flow and velocity. The model simulations for six theoretical patients with high, normal, and low BP (HBP-, NBP-, LBP-) and functional or absent AR (-wAR, -woAR) are compared with clinical data. Results. The model predicts that NBPwAR and HBPwAR patients can regulate retinal blood flow (RBF) as IOP varies between 15 and 23 mm Hg and between 23 and 29 mm Hg, respectively, whereas LBPwAR patients do not adequately regulate blood flow if IOP is 15 mm Hg or higher. Hemodynamic alterations would be noticeable only if IOP changes occur outside of the regulating range, which, most importantly, depend on BP. The model predictions are consistent with clinical data for IOP reduction via surgery and medications and for cases of induced IOP elevation. Conclusions. The theoretical model results suggest that the ability of IOP to induce noticeable changes in retinal hemodynamics depends on the levels of BP and AR of the individual. These predictions might help to explain the inconsistencies found in the clinical literature concerning the relationship between IOP and retinal hemodynamics. PMID:24876284

A clinical governance framework for blood services.

PubMed

Williamson, L M; Benjamin, R J; Devine, D V; Katz, L M; Pink, J

2015-05-01

The elements of clinical governance, which ensure excellence in clinical care, can be applied to blood services. In this survey, their application in a range of blood providers was gauged, with the aim of identifying best practice and producing a generalizable framework. The Medical Directors of members of the Alliance of Blood Operators surveyed how different elements of clinical governance operated within their organizations and developed recommendations applicable in the blood service environment. The recommendations that emerged highlighted the importance of an organization's culture, with the delivery of optimal clinical governance being a corporate responsibility. Senior management must agree and promote a set of values to ensure that the system operates with the patient and donor at its heart. All staff should understand how their role fits into the 'journey to the patient', and a culture of openness promoted. Thus, reporting of errors and risks should be actively sought and praised, with penalties applied for concealment. Systems should exist to collect, analyse and escalate clinical outcomes, safety data, clinical risk assessments, incident reports and complaints to inform organizational learning. Clinical governance principles from general health care can be applied within blood services to complement good manufacturing practice. This requires leadership, accountability, an open culture and a drive for continuous improvement and excellence in clinical care. © 2015 International Society of Blood Transfusion.

Blood Pressure Measurement: Clinic, Home, Ambulatory, and Beyond

PubMed Central

Drawz, Paul E.; Abdalla, Mohamed; Rahman, Mahboob

2014-01-01

Blood pressure has traditionally been measured in the clinic setting using the auscultory method and a mercury sphygmomanometer. Technological advances have led to improvements in measuring clinic blood pressure and allowed for measuring blood pressures outside the clinic. This review outlines various methods for evaluating blood pressure and the clinical utility of each type of measurement. Home blood pressures and 24 hour ambulatory blood pressures have improved our ability to evaluate risk for target organ damage and hypertension related morbidity and mortality. Measuring home blood pressures may lead to more active participation in health care by patients and has the potential to improve blood pressure control. Ambulatory blood pressure monitoring enables the measuring nighttime blood pressures and diurnal changes, which may be the most accurate predictors of risk associated with elevated blood pressure. Additionally, reducing nighttime blood pressure is feasible and may be an important component of effective antihypertensive therapy. Finally, estimating central aortic pressures and pulse wave velocity are two of the newer methods for assessing blood pressure and hypertension related target organ damage. PMID:22521624

Home blood pressure variability on one occasion is a novel factor associated with arterial stiffness in patients with type 2 diabetes.

PubMed

Fukui, Michiaki; Ushigome, Emi; Tanaka, Muhei; Hamaguchi, Masahide; Tanaka, Toru; Atsuta, Haruhiko; Ohnishi, Masayoshi; Oda, Yohei; Hasegawa, Goji; Nakamura, Naoto

2013-03-01

Recent studies have suggested that not only mean blood pressure but also variability in blood pressure might be related to cardiovascular disease. The aim of this study was to investigate the association between home blood pressure variability on one occasion and markers of arterial stiffness in patients with type 2 diabetes. We investigated the relationship between the s.d. of clinic- or home-measured systolic blood pressure on one occasion and pulse wave velocity (PWV) in 332 patients with type 2 diabetes, and we evaluated whether the SD of clinic- or home-measured systolic blood pressure on one occasion was an independent determinant of PWV by multivariate linear regression analysis, after adjustment for known risk factors for arterial stiffness, including sex, age, duration of diabetes, body mass index, hemoglobin A1c, serum total cholesterol, triglycerides, smoking status, drinking alcohol, presence of antihypertensive medication, average systolic blood pressure and heart rate. Age, average morning home-measured systolic blood pressure, heart rate and PWV (r=0.259, P<0.0001) were positively correlated with the s.d. of morning home blood pressure on one occasion. Multiple regression analysis demonstrated that age, average morning home-measured systolic blood pressure (P=0.0019), heart rate and the s.d. of morning home-measured systolic blood pressure on one occasion (P=0.0159) were independently associated with PWV. In conclusion, home blood pressure variability on one occasion was correlated with PWV, independent of other known risk factors, in Japanese patients with type 2 diabetes.

Intraocular pressure, blood pressure, and retinal blood flow autoregulation: a mathematical model to clarify their relationship and clinical relevance.

PubMed

Guidoboni, Giovanna; Harris, Alon; Cassani, Simone; Arciero, Julia; Siesky, Brent; Amireskandari, Annahita; Tobe, Leslie; Egan, Patrick; Januleviciene, Ingrida; Park, Joshua

2014-05-29

This study investigates the relationship between intraocular pressure (IOP) and retinal hemodynamics and predicts how arterial blood pressure (BP) and blood flow autoregulation (AR) influence this relationship. A mathematical model is developed to simulate blood flow in the central retinal vessels and retinal microvasculature as current flowing through a network of resistances and capacitances. Variable resistances describe active and passive diameter changes due to AR and IOP. The model is validated by using clinically measured values of retinal blood flow and velocity. The model simulations for six theoretical patients with high, normal, and low BP (HBP-, NBP-, LBP-) and functional or absent AR (-wAR, -woAR) are compared with clinical data. The model predicts that NBPwAR and HBPwAR patients can regulate retinal blood flow (RBF) as IOP varies between 15 and 23 mm Hg and between 23 and 29 mm Hg, respectively, whereas LBPwAR patients do not adequately regulate blood flow if IOP is 15 mm Hg or higher. Hemodynamic alterations would be noticeable only if IOP changes occur outside of the regulating range, which, most importantly, depend on BP. The model predictions are consistent with clinical data for IOP reduction via surgery and medications and for cases of induced IOP elevation. The theoretical model results suggest that the ability of IOP to induce noticeable changes in retinal hemodynamics depends on the levels of BP and AR of the individual. These predictions might help to explain the inconsistencies found in the clinical literature concerning the relationship between IOP and retinal hemodynamics. Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.

[Blood sampling using "dried blood spot": a clinical biology revolution underway?].

PubMed

Hirtz, Christophe; Lehmann, Sylvain

2015-01-01

Blood testing using the dried blood spot (DBS) is used since the 1960s in clinical analysis, mainly within the framework of the neonatal screening (Guthrie test). Since then numerous analytes such as nucleic acids, small molecules or lipids, were successfully measured on the DBS. While this pre-analytical method represents an interesting alternative to classic blood sampling, its use in routine is still limited. We review here the different clinical applications of the blood sampling on DBS and estimate its future place, supported by the new methods of analysis as the LC-MS mass spectrometry.

Genetic and environmental influences on blood pressure variability: a study in twins.

PubMed

Xu, Xiaojing; Ding, Xiuhua; Zhang, Xinyan; Su, Shaoyong; Treiber, Frank A; Vlietinck, Robert; Fagard, Robert; Derom, Catherine; Gielen, Marij; Loos, Ruth J F; Snieder, Harold; Wang, Xiaoling

2013-04-01

Blood pressure variability (BPV) and its reduction in response to antihypertensive treatment are predictors of clinical outcomes; however, little is known about its heritability. In this study, we examined the relative influence of genetic and environmental sources of variance of BPV and the extent to which it may depend on race or sex in young twins. Twins were enrolled from two studies. One study included 703 white twins (308 pairs and 87 singletons) aged 18-34 years, whereas another study included 242 white twins (108 pairs and 26 singletons) and 188 black twins (79 pairs and 30 singletons) aged 12-30 years. BPV was calculated from 24-h ambulatory blood pressure recording. Twin modeling showed similar results in the separate analysis in both twin studies and in the meta-analysis. Familial aggregation was identified for SBP variability (SBPV) and DBP variability (DBPV) with genetic factors and common environmental factors together accounting for 18-40% and 23-31% of the total variance of SBPV and DBPV, respectively. Unique environmental factors were the largest contributor explaining up to 82-77% of the total variance of SBPV and DBPV. No sex or race difference in BPV variance components was observed. The results remained the same after adjustment for 24-h blood pressure levels. The variance in BPV is predominantly determined by unique environment in youth and young adults, although familial aggregation due to additive genetic and/or common environment influences was also identified explaining about 25% of the variance in BPV.

Assessment of Normal Variability in Peripheral Blood Gene Expression

DOE PAGES

Campbell, Catherine; Vernon, Suzanne D.; Karem, Kevin L.; ...

2002-01-01

Peripheral blood is representative of many systemic processes and is an ideal sample for expression profiling of diseases that have no known or accessible lesion. Peripheral blood is a complex mixture of cell types and some differences in peripheral blood gene expression may reflect the timing of sample collection rather than an underlying disease process. For this reason, it is important to assess study design factors that may cause variability in gene expression not related to what is being analyzed. Variation in the gene expression of circulating peripheral blood mononuclear cells (PBMCs) from three healthy volunteers sampled three times onemore » day each week for one month was examined for 1,176 genes printed on filter arrays. Less than 1% of the genes showed any variation in expression that was related to the time of collection, and none of the changes were noted in more than one individual. These results suggest that observed variation was due to experimental variability.« less

High beat-to-beat blood pressure variability in atrial fibrillation compared to sinus rhythm.

PubMed

Olbers, Joakim; Gille, Adam; Ljungman, Petter; Rosenqvist, Mårten; Östergren, Jan; Witt, Nils

2018-02-07

Atrial fibrillation (AF) is associated with an increased risk for cardiovascular morbidity and mortality, not entirely explained by thromboembolism. The underlying mechanisms for this association are largely unknown. Similarly, high blood pressure (BP) increases the risk for cardiovascular events. Despite this the interplay between AF and BP is insufficiently studied. The purpose of this study was to examine and quantify the beat-to-beat blood pressure variability in patients with AF in comparison to a control group of patients with sinus rhythm. We studied 33 patients - 21 in atrial fibrillation and 12 in sinus rhythm - undergoing routine coronary angiography. Invasive blood pressure was recorded at three locations: radial artery, brachial artery and ascending aorta. Blood pressure variability, defined as average beat-to-beat blood pressure difference, was calculated for systolic and diastolic blood pressure at each site. We observed a significant difference (p < .001) in systolic and diastolic blood pressure variability between the atrial fibrillation and sinus rhythm groups at all locations. Systolic blood pressure variability roughly doubled in the atrial fibrillation group compared to the sinus rhythm group (4.9 and 2.4 mmHg respectively). Diastolic beat-to-beat blood pressure variability was approximately 6 times as high in the atrial fibrillation group compared to the sinus rhythm group (7.5 and 1.2 mmHg respectively). No significant difference in blood pressure variability was seen between measurement locations. Beat-to-beat blood pressure variability in patients with atrial fibrillation was substantially higher than in patients with sinus rhythm. Hemodynamic effects of this beat-to-beat variation in blood pressure may negatively affect vascular structure and function, which may contribute to the increased cardiovascular morbidity and mortality seen in patients with atrial fibrillation.

Variability of blood pressure in dialysis patients: a new marker of cardiovascular risk.

PubMed

Di Iorio, Biagio; Di Micco, Lucia; Torraca, Serena; Sirico, Maria Luisa; Guastaferro, Pasquale; Chiuchiolo, Luigi; Nigro, Filippo; De Blasio, Antonietta; Romano, Paolo; Pota, Andrea; Rubino, Roberto; Morrone, Luigi; Lopez, Teodoro; Casino, Francesco Gaetano

2013-01-01

Hemodialysis patients have a high cardiovascular mortality, and hypertension is the most prevalent treatable risk factor. We aimed to assess the predictive significance of dialysis-to-dialysis variability in blood pressure in hemodialysis patients. We performed a historical cohort study in 1,088 prevalent hemodialysis patients, followed up for 5 years. The risk of cardiovascular death was determined in relation to dialysis-to-dialysis variability in blood pressure, maximum blood pressure and pulse pressure. Variability in blood pressure was a predictor of cardiovascular death (hazard ratio [HR] = 1.242; 95% confidence interval [95% CI], 1.004-1.537; p=0.046). Also age (HR=1.021; 95% CI, 1.011-1.048; p=0.049), diabetes (HR=1.134; 95% CI, 1.128-1.451; p=0.035), creatinine (HR=0.837; 95% CI, 0.717-0.977; p=0.024) and albumin (HR=0.901; 95% CI, 0.821-0.924; p=0.022) influenced mortality. Maximum blood pressure and pulse pressure did not show any effect on cardiovascular death. Dialysis-to-dialysis variability in blood pressure is a predictor of cardiovascular mortality in hemodialysis patients, and blood pressure variability may be used in managing hypertension and predicting outcomes in dialysis patients.

Validity and Usefulness of `Wearable Blood Pressure Sensing' for Detection of Inappropriate Short-Term Blood Pressure Variability in the Elderly

NASA Astrophysics Data System (ADS)

Iijima, Katsuya; Kameyama, Yumi; Akishita, Masahiro; Ouchi, Yasuyoshi; Yanagimoto, Shintaro; Imai, Yasushi; Yahagi, Naoki; Lopez, Guillaume; Shuzo, Masaki; Yamada, Ichiro

An increase in short-term blood pressure (BP) variability is a characteristic feature in the elderly. It makes the management of hemodynamics more difficult, because it is frequently seen disturbed baro-reflex function and increased arterial stiffness, leading to isolated systolic hypertension. Large BP variability aggravates hypertensive target organ damage and is an independent risk factor for the cardiovascular (CV) events in elderly hypertensive patients. Therefore, appropriate control in BP is indispensable to manage lifestyle-related diseases and to prevent subsequent CV events. In addition, accumulating recent reports show that excessive BP variability is also associated with a decline in cognitive function and fall in the elderly. In the clinical settings, we usually evaluate their health condition, mainly with single point BP measurement using cuff inflation. However, unfortunately we are not able to find the close changes in BP by the traditional way. Here, we can show our advantageous approach of continuous BP monitoring using newly developing device `wearable BP sensing' without a cuff stress in the elderly. The new device could reflect systolic BP and its detailed changes, in consistent with cuff-based BP measurement. Our new challenge suggests new possibility of its clinical application with high accuracy.

Relationships between blood pressure and health and fitness-related variables in obese women.

PubMed

Shin, Jeong Yeop; Ha, Chang Ho

2016-10-01

[Purpose] The present study aimed to separately compare systolic blood pressure and diastolic blood pressure with health and fitness-related variables among Asian obese and normal weight middle-aged women. [Subjects and Methods] The study included 1,201 women aged 30-59 years. The participants were classified into obese and normal weight groups. The blood pressure and health and fitness-related variables of all participants were assessed. [Results] Significant interaction effects were observed for most blood pressure and health and fitness-related variables between the groups. However, significant interaction effects were not observed for standard weight, basal metabolic rate, and heart rate. Blood pressure showed significant positive correlations with weight, body fat, fat weight, core fat, body mass index, and basal metabolic rate in both groups. Systolic blood pressure was significantly correlated with muscular endurance, power, and agility in the obese group and with VO2max and flexibility in the normal weight group. Diastolic blood pressure was significantly correlated with muscular endurance and power in the obese group and with VO2max in the normal weight group. [Conclusion] The relationships between systolic blood pressure and heart rate, muscle endurance, power, and agility are stronger than the relationships between diastolic blood pressure and these variables.

Impact of baseline systolic blood pressure on visit-to-visit blood pressure variability: the Kailuan study.

PubMed

Wang, Anxin; Li, Zhifang; Yang, Yuling; Chen, Guojuan; Wang, Chunxue; Wu, Yuntao; Ruan, Chunyu; Liu, Yan; Wang, Yilong; Wu, Shouling

2016-01-01

To investigate the relationship between baseline systolic blood pressure (SBP) and visit-to-visit blood pressure variability in a general population. This is a prospective longitudinal cohort study on cardiovascular risk factors and cardiovascular or cerebrovascular events. Study participants attended a face-to-face interview every 2 years. Blood pressure variability was defined using the standard deviation and coefficient of variation of all SBP values at baseline and follow-up visits. The coefficient of variation is the ratio of the standard deviation to the mean SBP. We used multivariate linear regression models to test the relationships between SBP and standard deviation, and between SBP and coefficient of variation. Approximately 43,360 participants (mean age: 48.2±11.5 years) were selected. In multivariate analysis, after adjustment for potential confounders, baseline SBPs <120 mmHg were inversely related to standard deviation (P<0.001) and coefficient of variation (P<0.001). In contrast, baseline SBPs ≥140 mmHg were significantly positively associated with standard deviation (P<0.001) and coefficient of variation (P<0.001). Baseline SBPs of 120-140 mmHg were associated with the lowest standard deviation and coefficient of variation. The associations between baseline SBP and standard deviation, and between SBP and coefficient of variation during follow-ups showed a U curve. Both lower and higher baseline SBPs were associated with increased blood pressure variability. To control blood pressure variability, a good target SBP range for a general population might be 120-139 mmHg.

[Predictors of mean blood glucose control and its variability in diabetic hospitalized patients].

PubMed

Sáenz-Abad, Daniel; Gimeno-Orna, José Antonio; Sierra-Bergua, Beatriz; Pérez-Calvo, Juan Ignacio

2015-01-01

This study was intended to assess the effectiveness and predictors factors of inpatient blood glucose control in diabetic patients admitted to medical departments. A retrospective, analytical cohort study was conducted on patients discharged from internal medicine with a diagnosis related to diabetes. Variables collected included demographic characteristics, clinical data and laboratory parameters related to blood glucose control (HbA1c, basal plasma glucose, point-of-care capillary glucose). The cumulative probability of receiving scheduled insulin regimens was evaluated using Kaplan-Meier analysis. Multivariate regression models were used to select predictors of mean inpatient glucose (MHG) and glucose variability (standard deviation [GV]). The study sample consisted of 228 patients (mean age 78.4 (SD 10.1) years, 51% women). Of these, 96 patients (42.1%) were treated with sliding-scale regular insulin only. Median time to start of scheduled insulin therapy was 4 (95% CI, 2-6) days. Blood glucose control measures were: MIG 181.4 (SD 41.7) mg/dL, GV 56.3 (SD 22.6). The best model to predict MIG (R(2): .376; P<.0001) included HbA1c (b=4.96; P=.011), baseline plasma glucose (b=.056; P=.084), mean capillary blood glucose in the first 24hours (b=.154; P<.0001), home treatment (versus oral agents) with basal insulin only (b=13.1; P=.016) or more complex (pre-mixed insulin or basal-bolus) regimens (b=19.1; P=.004), corticoid therapy (b=14.9; P=.002), and fasting on admission (b=10.4; P=.098). Predictors of inpatient blood glucose control which should be considered in the design of DM management protocols include home treatment, HbA1c, basal plasma glucose, mean blood glucose in the first 24hours, fasting, and corticoid therapy. Copyright © 2014 SEEN. Published by Elsevier España, S.L.U. All rights reserved.

LB01.06: VISIT-TO-VISIT BLOOD PRESSURE VARIABILITY AND CARDIOVASCULAR OUTCOMES IN FELODIPINE EVENT REDUCTION STUDY.

PubMed

Zhang, Y; Zhang, X; Liu, L; Zanchetti, A

2015-06-01

Many antihypertensive outcome trials have shown that visit-to-visit blood pressure variability is correlated closely with clinical outcomes in hypertensive patients. The objective of the study was to investigate the relationship between visit-to-visit blood pressure variability (BPV) and the major cardiovascular outcomes in the Chinese hypertensive patients. Felodipine Event Reduction (FEVER) study was a double-blind, randomized trial on 9711 Chinese hypertensive patients, in whom cardiovascular outcomes were significantly reduced by more intense therapy achieving a mean of 138 mmHg SBP compared with less-intense therapy achieving a mean of 142 mmHg. Visit-to-visit BPV during the follow-up period [defined as standard deviation (SD), coefficient of variation (CV), and average real variability(ARV)] was derived from casual cuff BP measures after six months follow-up until the end of the study. Hazard ratios (HRs), for the incidence of CVD associated with SD, CV, and ARV of SBP and DBP were calculated using Cox proportional hazard models. Overall predictive power [area under receiver operating characteristic (AUC ROC) curve] of the level of blood pressure, blood pressure variability and other baseline characteristics was calculated. In FEVER study, visit-to-visit variability in SBP were significant predictors of subsequent stroke [eg, hazard ratios [HR] for ARV, SD and CV was 1.071 (95% CI: 1.025-1.118), 1.373 (95% CI: 1.159-1.626) and 0.572 (95% CI: 0.451-0,726)]. Visit-to-visit variability in DBP were also showed similar trend [eg, HR for ARV, SD and CV was 1.066 (95% CI: 0.992-1.145), 1.931 (95% CI: 1.435-2.598) and 0.558 (95% CI: 0.438-0,710)]. However, using the analysis of AUC ROC analysis, the risk importance sequence of the stroke events in this cohort was level of SBP, age, level of DBP ARV, SD, sex, CV and treatment. Visit-to-visit blood pressure variability has some effects on the cardiovascular outcomes in the Chinese hypertensive patents in the cohort in

Relationship between Clinic and Ambulatory Blood-Pressure Measurements and Mortality.

PubMed

Banegas, José R; Ruilope, Luis M; de la Sierra, Alejandro; Vinyoles, Ernest; Gorostidi, Manuel; de la Cruz, Juan J; Ruiz-Hurtado, Gema; Segura, Julián; Rodríguez-Artalejo, Fernando; Williams, Bryan

2018-04-19

Evidence for the influence of ambulatory blood pressure on prognosis derives mainly from population-based studies and a few relatively small clinical investigations. This study examined the associations of blood pressure measured in the clinic (clinic blood pressure) and 24-hour ambulatory blood pressure with all-cause and cardiovascular mortality in a large cohort of patients in primary care. We analyzed data from a registry-based, multicenter, national cohort that included 63,910 adults recruited from 2004 through 2014 in Spain. Clinic and 24-hour ambulatory blood-pressure data were examined in the following categories: sustained hypertension (elevated clinic and elevated 24-hour ambulatory blood pressure), "white-coat" hypertension (elevated clinic and normal 24-hour ambulatory blood pressure), masked hypertension (normal clinic and elevated 24-hour ambulatory blood pressure), and normotension (normal clinic and normal 24-hour ambulatory blood pressure). Analyses were conducted with Cox regression models, adjusted for clinic and 24-hour ambulatory blood pressures and for confounders. During a median follow-up of 4.7 years, 3808 patients died from any cause, and 1295 of these patients died from cardiovascular causes. In a model that included both 24-hour and clinic measurements, 24-hour systolic pressure was more strongly associated with all-cause mortality (hazard ratio, 1.58 per 1-SD increase in pressure; 95% confidence interval [CI], 1.56 to 1.60, after adjustment for clinic blood pressure) than the clinic systolic pressure (hazard ratio, 1.02; 95% CI, 1.00 to 1.04, after adjustment for 24-hour blood pressure). Corresponding hazard ratios per 1-SD increase in pressure were 1.55 (95% CI, 1.53 to 1.57, after adjustment for clinic and daytime blood pressures) for nighttime ambulatory systolic pressure and 1.54 (95% CI, 1.52 to 1.56, after adjustment for clinic and nighttime blood pressures) for daytime ambulatory systolic pressure. These relationships were

Alcohol- and light-induced electro-oculographic responses: variability and clinical utility.

PubMed

Marmor, Michael F; Wu, Kathy H C

2005-01-01

The alcohol-induced electro-oculographic (EOG) response has been proposed by Arden as an indicator of retinal pigment epithelial (RPE) integrity. We have evaluated the consistency of the alcohol-EOG with respect to clinical applicability and compared this response to the ISCEV-standard EOG. We recorded, in a group of normal subjects (n=29, 14 men with mean age 42+/-11 years and 15 women with mean age 36+/-13 years), the alcohol response to a single oral dose of ethanol at 160 mg/kg (as 40 proof vodka, drunk in 15 s after 12 h of fasting), followed by an ISCEV-standard EOG 90 min after alcohol administration. Blood alcohol levels were monitored at regular intervals with a breath analyzer. We found a wide range of amplitudes in both light and alcohol responses among participants, from minimal to large values. Subjects had a wide range of blood alcohol concentrations from 0.02 to 0.10%; near the time of the response peak, but there was no relationship between alcohol levels and peak/baseline ratios. In addition, there was no relationship between alcohol peak/baseline ratio and the Arden ratio. Neither the alcohol nor the light response parameters showed any relationship with age or gender. Some of the inter-individual variability in the EOG response to alcohol may reflect variable absorption of oral alcohol. The alcohol-induced EOG has too broad a range of responses to be useful clinically for the one-time evaluation of individual patients. We have similar concerns regarding clinical applications of the standard light-induced EOG.

An artificial pancreas provided a novel model of blood glucose level variability in beagles.

PubMed

Munekage, Masaya; Yatabe, Tomoaki; Kitagawa, Hiroyuki; Takezaki, Yuka; Tamura, Takahiko; Namikawa, Tsutomu; Hanazaki, Kazuhiro

2015-12-01

Although the effects on prognosis of blood glucose level variability have gained increasing attention, it is unclear whether blood glucose level variability itself or the manifestation of pathological conditions that worsen prognosis. Then, previous reports have not been published on variability models of perioperative blood glucose levels. The aim of this study is to establish a novel variability model of blood glucose concentration using an artificial pancreas. We maintained six healthy, male beagles. After anesthesia induction, a 20-G venous catheter was inserted in the right femoral vein and an artificial pancreas (STG-22, Nikkiso Co. Ltd., Tokyo, Japan) was connected for continuous blood glucose monitoring and glucose management. After achieving muscle relaxation, total pancreatectomy was performed. After 1 h of stabilization, automatic blood glucose control was initiated using the artificial pancreas. Blood glucose level varied for 8 h, alternating between the target blood glucose values of 170 and 70 mg/dL. Eight hours later, the experiment was concluded. Total pancreatectomy was performed for 62 ± 13 min. Blood glucose swings were achieved 9.8 ± 2.3 times. The average blood glucose level was 128.1 ± 5.1 mg/dL with an SD of 44.6 ± 3.9 mg/dL. The potassium levels after stabilization and at the end of the experiment were 3.5 ± 0.3 and 3.1 ± 0.5 mmol/L, respectively. In conclusion, the results of the present study demonstrated that an artificial pancreas contributed to the establishment of a novel variability model of blood glucose levels in beagles.

Circadian blood pressure variability in type 1 diabetes subjects and their nondiabetic siblings - influence of erythrocyte electron transfer.

PubMed

Matteucci, Elena; Consani, Cristina; Masoni, Maria Chiara; Giampietro, Ottavio

2010-10-05

Normotensive non-diabetic relatives of type 1 diabetes (T1D) patients have an abnormal blood pressure response to exercise testing that is associated with indices of metabolic syndrome and increased oxidative stress. The primary aim of this study was to investigate the circadian variability of blood pressure and the ambulatory arterial stiffness index (AASI) in healthy siblings of T1D patients vs healthy control subjects who had no first-degree relative with T1D. Secondary aims of the study were to explore the influence of both cardiovascular autonomic function and erythrocyte electron transfer activity as oxidative marker on the ambulatory blood pressure profile. Twenty-four hour ambulatory blood pressure monitoring (ABPM) was undertaken in 25 controls, 20 T1D patients and 20 siblings. In addition to laboratory examination (including homeostasis model assessment of insulin sensitivity) and clinical testing of autonomic function, we measured the rate of oxidant-induced erythrocyte electron transfer to extracellular ferricyanide (RBC vfcy). Systolic blood pressure (SBP) midline-estimating statistic of rhythm and pulse pressure were higher in T1D patients and correlated positively with diabetes duration and RBC vfcy; autonomic dysfunction was associated with diastolic BP ecphasia and increased AASI. Siblings had higher BMI, lower insulin sensitivity, larger SBP amplitude, and higher AASI than controls. Daytime SBP was positively, independently associated with BMI and RBC vfcy. Among non-diabetic people, there was a significant correlation between AASI and fasting plasma glucose. Siblings of T1D patients exhibited a cluster of sub-clinical metabolic abnormalities associated with consensual perturbations in BP variability. Moreover, our findings support, in a clinical setting, the proposed role of transplasma membrane electron transport systems in vascular pathobiology.

ABO blood groups and malaria related clinical outcome.

PubMed

Deepa; Alwar, Vanamala A; Rameshkumar, Karuna; Ross, Cecil

2011-03-01

The study was undertaken to correlate the blood groups and clinical presentations in malaria patients and to understand the differential host susceptibility in malaria. From October 2007 to September 2008, malaria positive patients' samples were evaluated in this study. Hemoglobin, total leukocyte count, and platelet count of each patient were done on an automated cell counter. After determining the blood groups, malarial species and the severity of clinical course were correlated. A total of 100 patients were included in the study, of which 63 cases were positive for Plasmodium falciparum and 37 cases were positive for P. vivax infection and 11 patients had mixed infection. The results of the blood groups showed 22 - 'A' group, 42 - 'B' group, 35 - 'O' group and 1 was 'AB' group. When the clinical courses between different groups were compared using the following parameters for severe infection--a parasitic load of >10/1000 RBCs, severe anemia with hemoglobin < 6 g%, platelet count of <10,000/mm3, hepato or splenomegaly or clinical signs of severe malaria such as fever >101°F and other organ involvement, it was observed that 'O' group had an advantage over other the groups. The difference in rosetting ability between red blood cells of different 'ABO' blood groups with a diminished rosetting potential in blood group 'O' red blood cells was due to the differential host susceptibility. 'O' group had an advantage over the other three blood groups. Based on literature and the results of this study, the diminished rosetting potential in blood group 'O' red blood cells is suggested as the basis for the differential host susceptibility.

Clinical Decision Support Reduces Overuse of Red Blood Cell Transfusions: Interrupted Time Series Analysis.

PubMed

Kassakian, Steven Z; Yackel, Thomas R; Deloughery, Thomas; Dorr, David A

2016-06-01

Red blood cell transfusion is the most common procedure in hospitalized patients in the US. Growing evidence suggests that a sizeable percentage of these transfusions are inappropriate, putting patients at significant risk and increasing costs to the health care system. We performed a retrospective quasi-experimental study from November 2008 until November 2014 in a 576-bed tertiary care hospital. The intervention consisted of an interruptive clinical decision support alert shown to a provider when a red blood cell transfusion was ordered in a patient whose most recent hematocrit was ≥21%. We used interrupted time series analysis to determine whether our primary outcome of interest, rate of red blood cell transfusion in patients with hematocrit ≥21% per 100 patient (pt) days, was reduced by the implementation of the clinical decision support tool. The rate of platelet transfusions was used as a nonequivalent dependent control variable. A total of 143,000 hospital admissions were included in our analysis. Red blood cell transfusions decreased from 9.4 to 7.8 per 100 pt days after the clinical decision support intervention was implemented. Interrupted time series analysis showed that significant decline of 0.05 (95% confidence interval [CI], 0.03-0.07; P < .001) units of red blood cells transfused per 100 pt days per month was already underway in the preintervention period. This trend accelerated to 0.1 (95% CI, 0.09-0.12; P < .001) units of red blood cells transfused per 100 pt days per month following the implementation of the clinical decision support tool. There was no statistical change in the rate of platelet transfusion resulting from the intervention. The implementation of an evidence-based clinical decision support tool was associated with a significant decline in the overuse of red blood cell transfusion. We believe this intervention could be easily replicated in other hospitals using commercial electronic health records and a similar reduction in

Deciphering Sources of Variability in Clinical Pathology.

PubMed

Tripathi, Niraj K; Everds, Nancy E; Schultze, A Eric; Irizarry, Armando R; Hall, Robert L; Provencher, Anne; Aulbach, Adam

2017-01-01

The objectives of this session were to explore causes of variability in clinical pathology data due to preanalytical and analytical variables as well as study design and other procedures that occur in toxicity testing studies. The presenters highlighted challenges associated with such variability in differentiating test article-related effects from the effects of experimental procedures and its impact on overall data interpretation. These presentations focused on preanalytical and analytical variables and study design-related factors and their influence on clinical pathology data, and the importance of various factors that influence data interpretation including statistical analysis and reference intervals. Overall, these presentations touched upon potential effect of many variables on clinical pathology parameters, including animal physiology, sample collection process, specimen handling and analysis, study design, and some discussion points on how to manage those variables to ensure accurate interpretation of clinical pathology data in toxicity studies. This article is a brief synopsis of presentations given in a session entitled "Deciphering Sources of Variability in Clinical Pathology-It's Not Just about the Numbers" that occurred at the 35th Annual Symposium of the Society of Toxicologic Pathology in San Diego, California.

Clinical and Laboratory Potential Predictors of Blood Culture Positivity in Under Five Children with Clinically Severe Pneumonia - Khartoum -Sudan.

PubMed

Salih, Karimeldin Mohamed Ali; El-Samani, El-Fatih; Bilal, Jalal Ali; Eldouch, Widad; Ibrahim, Salah Ahmed

2015-08-01

Blood culture is necessary for appropriate management of clinically severe pneumonia in children under five years of age. However, in limited resource countries it might be unduly costly and waste of valuable time because of the high negative culture rate. This study aims to identify clinical and laboratory parameters that potentially predict a positive blood culture in cases of severe pneumonia. A hospital based study, enrolled 189 cases satisfying the WHO definition of severe pneumonia. Age, gender, clinical history, physical examination, temperature, complete blood count, C-reactive protein, blood culture and Chest X Ray for all the patients were recorded. Forty one patients had positive blood culture giving a prevalence of 21.7%. All variables were used in a dichotomous manner. White Blood Count (WBC) more than 20 000, very high C-reactive protein (C-RP ≥8mg/L) and Temperature more than 40(o)C, had a positive predictive value of 46.1%, 44.3% and 40.0% respectively for a positive culture as well as a Negative Predictive Value of 91.1%, 91.6% and 91.7% respectively. The WBC more than 20 000 and temperature above 40(o)C had a significant association with a positive blood culture. Their adjusted Odds Ratios were 3.9 (95% CI: 1.4-10.90) and 3.1 (95% CI: 1.2-8.4) respectively. This was not the case for C-RP (Odds Ratio=2.2, 95% CI: 0.7-2.2) or positive Chest X Ray (Odds Ratio=1.5, 95% CI: 0.6-3.6). Temperature of more than 40(o)C, Very high C-RP and WBC of more than 20 000 are good indicators of a potential positive blood culture. It is therefore recommended that further research be undertaken to refine these predictors as screening tools before resorting to blood culture. It is also recommended that antibiotic treatment may be initiated on the basis of the high temperature and WBC, while waiting for the culture results.

Higher Blood Pressure Variability in White Coat Hypertension; from the Korean Ambulatory Blood Pressure Monitoring Registry

PubMed Central

Kang, In Sook; Shin, Jinho; Ihm, Sang-Hyun; Kim, Ju Han; Park, Sungha; Kim, Kwang-Il; Kim, Woo-Shik; Kim, Soon Gil; Shin, Gil Ja

2016-01-01

Background and Objectives Blood pressure variability (BPV) was recently shown to be a risk factor of stroke. White coat hypertension (WCH) used to be regarded as innocuous, but one long-term follow-up study reported that WCH increased stroke rate compared to normotension (NT). In this study, we aimed to evaluate the relationship between WCH and BPV. Subjects and Methods We analyzed 1398 subjects from the Korean Ambulatory Blood Pressure Registry, who were divided into NT (n=364), masked hypertension (n=122), white coat hypertension (n=254), and sustained hypertension (n=658) groups. Results Baseline characteristics were similar among groups. The average real variability (ARV), a highly sensitive BPV parameter, was highest in the WCH group, followed by the sustained hypertension, masked hypertension, and NT groups. The results persisted after being adjusted for covariates. The WCH vs. sustained hypertension results (adjusted mean±standard error) were as follows: 24-h systolic ARV, 22.9±0.8 vs. 19.4±0.6; 24-h diastolic ARV, 16.8±0.6 vs. 14.3±0.5; daytime systolic ARV, 21.8±0.8 vs. 16.8±0.6; and daytime diastolic ARV, 16.2±0.6 vs. 13.4±0.5 (p<0.001 for all comparisons). Conclusion From the registry data, we found that subjects with WCH or masked hypertension had higher BPV than NT. However, long-term follow-up data assessing the clinical influences of WCH on stroke are needed. PMID:27275173

Analytical and Clinical Performance of Blood Glucose Monitors

PubMed Central

Boren, Suzanne Austin; Clarke, William L.

2010-01-01

Background The objective of this study was to understand the level of performance of blood glucose monitors as assessed in the published literature. Methods Medline from January 2000 to October 2009 and reference lists of included articles were searched to identify eligible studies. Key information was abstracted from eligible studies: blood glucose meters tested, blood sample, meter operators, setting, sample of people (number, diabetes type, age, sex, and race), duration of diabetes, years using a glucose meter, insulin use, recommendations followed, performance evaluation measures, and specific factors affecting the accuracy evaluation of blood glucose monitors. Results Thirty-one articles were included in this review. Articles were categorized as review articles of blood glucose accuracy (6 articles), original studies that reported the performance of blood glucose meters in laboratory settings (14 articles) or clinical settings (9 articles), and simulation studies (2 articles). A variety of performance evaluation measures were used in the studies. The authors did not identify any studies that demonstrated a difference in clinical outcomes. Examples of analytical tools used in the description of accuracy (e.g., correlation coefficient, linear regression equations, and International Organization for Standardization standards) and how these traditional measures can complicate the achievement of target blood glucose levels for the patient were presented. The benefits of using error grid analysis to quantify the clinical accuracy of patient-determined blood glucose values were discussed. Conclusions When examining blood glucose monitor performance in the real world, it is important to consider if an improvement in analytical accuracy would lead to improved clinical outcomes for patients. There are several examples of how analytical tools used in the description of self-monitoring of blood glucose accuracy could be irrelevant to treatment decisions. PMID:20167171

[The association between blood pressure variability and sleep stability in essential hypertensive patients with sleep disorder].

PubMed

Zhu, Y Q; Long, Q; Xiao, Q F; Zhang, M; Wei, Y L; Jiang, H; Tang, B

2018-03-13

Objective: To investigate the association of blood pressure variability and sleep stability in essential hypertensive patients with sleep disorder by cardiopulmonary coupling. Methods: Performed according to strict inclusion and exclusion criteria, 88 new cases of essential hypertension who came from the international department and the cardiology department of china-japan friendship hospital were enrolled. Sleep stability and 24 h ambulatory blood pressure data were collected by the portable sleep monitor based on cardiopulmonary coupling technique and 24 h ambulatory blood pressure monitor. Analysis the correlation of blood pressure variability and sleep stability. Results: In the nighttime, systolic blood pressure standard deviation, systolic blood pressure variation coefficient, the ratio of the systolic blood pressure minimum to the maximum, diastolic blood pressure standard deviation, diastolic blood pressure variation coefficient were positively correlated with unstable sleep duration ( r =0.185, 0.24, 0.237, 0.43, 0.276, P <0.05). Conclusions: Blood pressure variability is associated with sleep stability, especially at night, the longer the unstable sleep duration, the greater the variability in night blood pressure.

Inhibitory effects of losartan and azelnidipine on augmentation of blood pressure variability induced by angiotensin II in rats.

PubMed

Jiang, Danfeng; Kawagoe, Yukiko; Kuwasako, Kenji; Kitamura, Kazuo; Kato, Johji

2017-07-05

Increased blood pressure variability has been shown to be associated with cardiovascular morbidity and mortality. Recently we reported that continuous infusion of angiotensin II not only elevated blood pressure level, but also increased blood pressure variability in a manner assumed to be independent of blood pressure elevation in rats. In the present study, the effects of the angiotensin type I receptor blocker losartan and the calcium channel blocker azelnidipine on angiotensin II-induced blood pressure variability were examined and compared with that of the vasodilator hydralazine in rats. Nine-week-old male Wistar rats were subcutaneously infused with 240 pmol/kg/min angiotensin II for two weeks without or with oral administration of losartan, azelnidipine, or hydralazine. Blood pressure variability was evaluated using a coefficient of variation of blood pressure recorded every 15min under an unrestrained condition via an abdominal aortic catheter by a radiotelemetry system. Treatment with losartan suppressed both blood pressure elevation and augmentation of systolic blood pressure variability in rats infused with angiotensin II at 7 and 14 days. Azelnidipine also inhibited angiotensin II-induced blood pressure elevation and augmentation of blood pressure variability; meanwhile, hydralazine attenuated the pressor effect of angiotensin II, but had no effect on blood pressure variability. In conclusion, angiotensin II augmented blood pressure variability in an angiotensin type 1 receptor-dependent manner, and azelnidipine suppressed angiotensin II-induced augmentation of blood pressure variability, an effect mediated by the mechanism independent of the blood pressure-lowering action. Copyright © 2017 Elsevier B.V. All rights reserved.

What variables can influence clinical reasoning?

PubMed

Ashoorion, Vahid; Liaghatdar, Mohammad Javad; Adibi, Peyman

2012-12-01

Clinical reasoning is one of the most important competencies that a physician should achieve. Many medical schools and licensing bodies try to predict it based on some general measures such as critical thinking, personality, and emotional intelligence. This study aimed at providing a model to design the relationship between the constructs. Sixty-nine medical students participated in this study. A battery test devised that consist four parts: Clinical reasoning measures, personality NEO inventory, Bar-On EQ inventory, and California critical thinking questionnaire. All participants completed the tests. Correlation and multiple regression analysis consumed for data analysis. There is low to moderate correlations between clinical reasoning and other variables. Emotional intelligence is the only variable that contributes clinical reasoning construct (r=0.17-0.34) (R(2) chnage = 0.46, P Value = 0.000). Although, clinical reasoning can be considered as a kind of thinking, no significant correlation detected between it and other constructs. Emotional intelligence (and its subscales) is the only variable that can be used for clinical reasoning prediction.

What variables can influence clinical reasoning?

PubMed Central

Ashoorion, Vahid; Liaghatdar, Mohammad Javad; Adibi, Peyman

2012-01-01

Background: Clinical reasoning is one of the most important competencies that a physician should achieve. Many medical schools and licensing bodies try to predict it based on some general measures such as critical thinking, personality, and emotional intelligence. This study aimed at providing a model to design the relationship between the constructs. Materials and Methods: Sixty-nine medical students participated in this study. A battery test devised that consist four parts: Clinical reasoning measures, personality NEO inventory, Bar-On EQ inventory, and California critical thinking questionnaire. All participants completed the tests. Correlation and multiple regression analysis consumed for data analysis. Results: There is low to moderate correlations between clinical reasoning and other variables. Emotional intelligence is the only variable that contributes clinical reasoning construct (r=0.17-0.34) (R2 chnage = 0.46, P Value = 0.000). Conclusion: Although, clinical reasoning can be considered as a kind of thinking, no significant correlation detected between it and other constructs. Emotional intelligence (and its subscales) is the only variable that can be used for clinical reasoning prediction. PMID:23853636

Blood pressure variability in man: its relation to high blood pressure, age and baroreflex sensitivity.

PubMed

Mancia, G; Ferrari, A; Gregorini, L; Parati, G; Pomidossi, G; Bertinieri, G; Grassi, G; Zanchetti, A

1980-12-01

1. Intra-arterial blood pressure and heart rate were recorded for 24 h in ambulant hospitalized patients of variable age who had normal blood pressure or essential hypertension. Mean 24 h values, standard deviations and variation coefficient were obtained as the averages of values separately analysed for 48 consecutive half-hour periods. 2. In older subjects standard deviation and variation coefficient for mean arterial pressure were greater than in younger subjects with similar pressure values, whereas standard deviation and variation coefficient for mean arterial pressure were greater than in younger subjects with similar pressure values, whereas standard deviation aations and variation coefficient were obtained as the averages of values separately analysed for 48 consecurive half-hour periods. 2. In older subjects standard deviation and variation coefficient for mean arterial pressure were greater than in younger subjects with similar pressure values, whereas standard deviation and variation coefficient for heart rate were smaller. 3. In hypertensive subjects standard deviation for mean arterial pressure was greater than in normotensive subjects of similar ages, but this was not the case for variation coefficient, which was slightly smaller in the former than in the latter group. Normotensive and hypertensive subjects showed no difference in standard deviation and variation coefficient for heart rate. 4. In both normotensive and hypertensive subjects standard deviation and even more so variation coefficient were slightly or not related to arterial baroreflex sensitivity as measured by various methods (phenylephrine, neck suction etc.). 5. It is concluded that blood pressure variability increases and heart rate variability decreases with age, but that changes in variability are not so obvious in hypertension. Also, differences in variability among subjects are only marginally explained by differences in baroreflex function.

[Correlation between long time systolic blood pressure variability and short time systolic blood pressure in aged population].

PubMed

An, Shasha; Zheng, Xiaoming; Li, Zhifang; Wang, Yang; Wu, Yuntao; Zhang, Wenyan; Zhao, Haiyan; Wu, Aiping; Wang, Ruixia; Tao, Jie; Gao, Xinying; Wu, Shouling

2015-11-01

To investigate the correlation between long time systolic blood pressure variability(SBPV)and short time SBPV in aged population. A total of 752 subjects aged ≥60 years of Kailuan Group who took part in 2006-2007, 2008-2009, 2010-2011 and 2012-2013 health examination were included by cluster sampling method.Long time SBPV was calculated by standard deviation of mean systolic blood pressure measured in 2006-2007, 2008-2009, 2010-2011 and 2012-2013, standard deviation represents short time systolic blood pressure which is derived from 24 hour ambulatory blood pressure monitoring. The observation population was divided into three groups according to the third tertiles of the time systolic blood pressure variability: the first point(<9.09 mmHg (1 mmHg=0.133 kPa)), second point (≥9.09 mmHg, and <14.29 mmHg), and third point (≥14.29 mmHg). Multivariate logistic regression analysis was used to analyze the correlation between long time systolic blood pressure variability and short time systolic blood pressure. (1) The participants' age were (67.0±5.7) years old (284 women). (2) The 24 hours and daytime SSD were (14.7±4.0) mmHg, (14.7±3.5) mmHg, (15.7±4.4) mmHg (P=0.010) and (14.1±4.4) mmHg, (14.2±3.5) mmHg and (15.4±4.6) mmHg (P<0.001) according to the tertiles of long time systolic blood pressure variability, respectively, nighttime SSD were (12.0±4.4) mmHg, (11.8±4.8) mmHg and (11.9±4.9) mmHg (P=0.900). (3) Multiple logistic regression analysis showed that the tertiles of long time SSD was the risk factor for increasing daytime SSD>14.00 mmHg (OR=1.51, 95%CI: 1.03-2.23, P=0.037), but not a risk factor for increasing 24 hours SSD>14.41 mmHg (OR=1.10, 95%CI: 0.75-1.61, P=0.639) and nighttime SSD>11.11 mmHg (OR=0.98, 95%CI: 0.67-1.42, P=0.899). Increased long time SBPV is a risk factor for increasing daytime SBPV.

Ambulatory Blood Pressure Monitoring in Clinical Practice: A Review

PubMed Central

Viera, Anthony J.; Shimbo, Daichi

2016-01-01

Ambulatory blood pressure monitoring offers the ability to collect blood pressure readings several times an hour across a 24-hour period. Ambulatory blood pressure monitoring facilitates the identification of white-coat hypertension, the phenomenon whereby certain individuals who are not on antihypertensive medication show elevated blood pressure in a clinical setting but show non-elevated blood pressure averages when assessed by ambulatory blood pressure monitoring. Additionally, readings can be segmented into time windows of particular interest, e.g., mean daytime and nighttime values. During sleep, blood pressure typically decreases, or dips, such that mean sleep blood pressure is lower than mean awake blood pressure. A non-dipping pattern and nocturnal hypertension are strongly associated with increased cardiovascular morbidity and mortality. Approximately 70% of individuals dip ≥10% at night, while 30% have non-dipping patterns, when blood pressure remains similar to daytime average, or occasionally rises above daytime average. The various blood pressure categorizations afforded by ambulatory blood pressure monitoring are valuable for clinical management of high blood pressure since they increase accuracy for diagnosis and the prediction of cardiovascular risk. PMID:25107387

24-Hour Blood Pressure Variability Assessed by Average Real Variability: A Systematic Review and Meta-Analysis.

PubMed

Mena, Luis J; Felix, Vanessa G; Melgarejo, Jesus D; Maestre, Gladys E

2017-10-19

Although 24-hour blood pressure (BP) variability (BPV) is predictive of cardiovascular outcomes independent of absolute BP levels, it is not regularly assessed in clinical practice. One possible limitation to routine BPV assessment is the lack of standardized methods for accurately estimating 24-hour BPV. We conducted a systematic review to assess the predictive power of reported BPV indexes to address appropriate quantification of 24-hour BPV, including the average real variability (ARV) index. Studies chosen for review were those that presented data for 24-hour BPV in adults from meta-analysis, longitudinal or cross-sectional design, and examined BPV in terms of the following issues: (1) methods used to calculate and evaluate ARV; (2) assessment of 24-hour BPV determined using noninvasive ambulatory BP monitoring; (3) multivariate analysis adjusted for covariates, including some measure of BP; (4) association of 24-hour BPV with subclinical organ damage; and (5) the predictive value of 24-hour BPV on target organ damage and rate of cardiovascular events. Of the 19 assessed studies, 17 reported significant associations between high ARV and the presence and progression of subclinical organ damage, as well as the incidence of hard end points, such as cardiovascular events. In all these cases, ARV remained a significant independent predictor ( P <0.05) after adjustment for BP and other clinical factors. In addition, increased ARV in systolic BP was associated with risk of all cardiovascular events (hazard ratio, 1.18; 95% confidence interval, 1.09-1.27). Only 2 cross-sectional studies did not find that high ARV was a significant risk factor. Current evidence suggests that ARV index adds significant prognostic information to 24-hour ambulatory BP monitoring and is a useful approach for studying the clinical value of BPV. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

Exercise systolic blood pressure variability is associated with increased risk for new-onset hypertension among normotensive adults.

PubMed

Berger, Assaf; Grossman, Ehud; Katz, Moshe; Kivity, Shaye; Klempfner, Robert; Segev, Shlomo; Goldenberg, Ilan; Sidi, Yehezkel; Maor, Elad

2016-06-01

Both resting blood pressure (BP) variability and exercise BP previously showed association with incident hypertension. The aim of the present study was to examine whether visit-to-visit variability in exercise systolic blood pressure (SBP) can predict the risk for new-onset hypertension among normotensive adults. We investigated 6546 normotensive men and women who were annually screened in a tertiary medical center and completed treadmill exercise tests at each visit. Based on the initial three baseline annual visits, long-term intervisit variability of exercise SBP among the three tests was measured using standard deviation (SD) and coefficient of variation for each participant. The rate of newly diagnosed hypertension was measured in different variability levels during 6 ± 3 years of follow-up. Multivariate analysis adjusted for various clinical factors, including resting BP, showed that each 5 mm Hg rise in the SD of exercise SBP resulted in a significant 5% increase in the risk for the development of future hypertension (P = .015). Subjects in the upper exercise SBP SD variability tertile had a 28% (P = .007) increased risk for hypertension during follow-up, as compared with those in the lowest tertile. Similar results were achieved for the assessment of coefficient of variation of exercise SBP. In conclusion, visit-to-visit variability in exercise SBP can predict the development of future hypertension among normotensive individuals. Copyright © 2016 American Society of Hypertension. Published by Elsevier Inc. All rights reserved.

Interferences from blood collection tube components on clinical chemistry assays

PubMed Central

Bowen, Raffick A.R.; Remaley, Alan T.

2014-01-01

Improper design or use of blood collection devices can adversely affect the accuracy of laboratory test results. Vascular access devices, such as catheters and needles, exert shear forces during blood flow, which creates a predisposition to cell lysis. Components from blood collection tubes, such as stoppers, lubricants, surfactants, and separator gels, can leach into specimens and/or adsorb analytes from a specimen; special tube additives may also alter analyte stability. Because of these interactions with blood specimens, blood collection devices are a potential source of pre-analytical error in laboratory testing. Accurate laboratory testing requires an understanding of the complex interactions between collection devices and blood specimens. Manufacturers, vendors, and clinical laboratorians must consider the pre-analytical challenges in laboratory testing. Although other authors have described the effects of endogenous substances on clinical assay results, the effects/impact of blood collection tube additives and components have not been well systematically described or explained. This review aims to identify and describe blood collection tube additives and their components and the strategies used to minimize their effects on clinical chemistry assays. PMID:24627713

Is reducing variability of blood glucose the real but hidden target of intensive insulin therapy?

PubMed

Egi, Moritoki; Bellomo, Rinaldo; Reade, Michael C

2009-01-01

Since the first report that intensive insulin therapy reduced mortality in selected surgical critically ill patients, lowering of blood glucose levels has been recommended as a means of improving patient outcomes. In this initial Leuven trial, blood glucose control by protocol using insulin was applied to 98.7% of patients in the intensive group but to only 39.2% (P < 0.0001) of patients in the control group. If appropriately applied, such protocols should decrease both the mean blood glucose concentration and its variability (variation of blood glucose concentration). Thus, it is logically possible that the benefit of intensive insulin therapy in the first Leuven trial was due to a decrease in mean glucose levels, a decrease in their variability, or both. Several recent studies have confirmed significant associations between variability of blood glucose levels and patient outcomes. Decreasing the variability of blood glucose levels might be an important dimension of glucose management, a possible mechanism by which an intensive insulin protocol exerts its putative beneficial effects, and an important goal of glucose management in the intensive care unit. Clinicians need to be aware of this controversy when considering the application of intensive insulin therapy and interpreting future trials.

Self-monitored blood pressure: a role in clinical practice?

PubMed

Padfield, Paul L

2002-02-01

Electronic self-monitoring of blood pressure is increasing in popularity and most international guidelines on the management of hypertension approve cautious use of the technique in the assessment of potentially hypertensive individuals. A recent editorial in the Archives of Internal Medicine suggested that it was "appropriate to encourage the widespread use of self recorded BP as an important adjunct to the clinical care of the patient with hypertension". Such a statement is based on increasing evidence that self-monitoring of blood pressure gives similar information to daytime ambulatory blood pressure -- a now well-established technology in the management of hypertension. Suggested strategies for the use of self-monitoring of blood pressure include monitoring in individuals whose clinical risk status is low enough that they need not necessarily be given medical therapy simply on the basis of a clinic pressure (i.e. at a 10 year risk of cardiovascular disease below 20%). The threshold for defining 'normotension/hypertension' is now regarded as being broadly similar for ABPM and SBPM and is set at 135/85 mmHg. In a recent meta-analysis of all available studies the average difference between these techniques, using the same patients, is -1.7/1.2 mmHg. There is some evidence that careful use of self-monitoring may improve blood pressure control in patients who are otherwise resistant to care. Self-monitoring of blood pressure has now been shown in at least one major prospective study to predict outcome better than clinic pressures and in that setting it now has equivalence to the use of ABPM. There remain issues regarding the availability of validated devices, the quality of training of patients in their use and the possibility that inaccurate recording might occur, either deliberately or by accident. Self-monitoring of blood pressure may well not give the same readings as carefully measured blood pressure by research nurses but its use is clearly superior to

Effect of induced ruminal acidosis on blood variables in heifers.

PubMed

Marchesini, Giorgio; De Nardi, Roberta; Gianesella, Matteo; Stefani, Anna-Lisa; Morgante, Massimo; Barberio, Antonio; Andrighetto, Igino; Segato, Severino

2013-05-06

Ruminal acidosis is responsible for the onset of different pathologies in dairy and feedlot cattle, but there are major difficulties in the diagnosis. This study modelled the data obtained from various blood variables to identify those that could indicate the severity of ruminal acidosis. Six heifers were fed three experimental rations throughout three periods. The diets were characterised by different starch levels: high starch (HS), medium starch (MS) and low starch, as the control diet (CT). Ruminal pH values were continuously measured using wireless sensors and compared with pH measurements obtained by rumenocentesis. Blood samples were analysed for complete blood count, biochemical profile, venous blood gas, blood lipopolysaccharide (LPS) and LPS-binding proteins (LBP). The regression coefficient comparing the ruminal pH values, obtained using the two methods, was 0.56 (P = 0.040). Feeding the CT, MS and HS led to differences in the time spent below the 5.8, 5.5 and 5.0 pH thresholds and in several variables, including dry matter intake (7.7 vs. 6.9 vs. 5.1 kg/d; P = 0.002), ruminal nadir pH (5.69 vs. 5.47 vs. 5.44; P = 0.042), mean ruminal pH (6.50 vs. 6.34 vs. 6.31; P = 0.012), haemoglobin level (11.1 vs. 10.9 vs. 11.4 g/dL; P = 0.010), platelet count (506 vs. 481 vs. 601; P = 0.008), HCO3(-) (31.8 vs. 31.3 vs. 30.6 mmol/L; P = 0.071) and LBP (5.9 vs. 9.5 vs. 10.5 μg/mL; P < 0.001). A canonical discriminant analysis (CDA) was used to classify the animals into four ruminal pH classes (normal, risk of acidosis, subacute ruminal acidosis and acute ruminal acidosis) using haemoglobin, mean platelet volume, β-hydroxybutyrate, glucose and reduced haemoglobin. Although additional studies are necessary to confirm the reliability of these discriminant functions, the use of plasma variables in a multifactorial model appeared to be useful for the evaluation of ruminal acidosis severity.

Clinical Use and Patentability of Cord Blood

PubMed

Cavusoglu, Turker; Kilic, Kubilay Dogan; Yigitturk, Gurkan; Tomruk, Canberk; Turgut, Mehmet; Uyanikgil, Yigit

2018-03-14

The blood in the umbilical cord that provides the connection between mother and fetus during pregnancy is called cord blood. The blood of umbilical cord which is usually got rid of following birth, is a very rich stem cell source. Cord blood collection gives no harm to the mother and baby. Besides, its allogeneic and au-tologous usage, the most important disadvantage is that the number of cells is insufficient in adults. Today, it is predominantly used for therapeutic purposes for many diseases. The aim of this review is giving a detailed information about groups of stem cells in cord blood and determining the point of clinical use. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Blood Glucose Monitoring Before and After Type 1 Diabetes Clinic Visits.

PubMed

Driscoll, Kimberly A; Johnson, Suzanne Bennett; Wang, Yuxia; Wright, Nancy; Deeb, Larry C

2017-12-23

To determine patterns of blood glucose monitoring in children and adolescents with type 1 diabetes (T1D) before and after routine T1D clinic visits. Blood glucose monitoring data were downloaded at four consecutive routine clinic visits from children and adolescents aged 5-18 years. Linear mixed models were used to analyze patterns of blood glucose monitoring in patients who had at least 28 days of data stored in their blood glucose monitors. In general, the frequency of blood glucose monitoring decreased across visits, and younger children engaged in more frequent blood glucose monitoring. Blood glucose monitoring increased before the T1D clinic visits in younger children, but not in adolescents. It declined after the visit regardless of age. Members of the T1D care team need to consider that a T1D clinic visit may prompt an increase in blood glucose monitoring when making treatment changes and recommendations. Tailored interventions are needed to maintain that higher level of adherence across time. © The Author(s) 2017. Published by Oxford University Press on behalf of the Society of Pediatric Psychology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com

Facebook advertising for participant recruitment into a blood pressure clinical trial.

PubMed

Nash, Erin L; Gilroy, Deborah; Srikusalanukul, Wichat; Abhayaratna, Walter P; Stanton, Tony; Mitchell, Geoffrey; Stowasser, Michael; Sharman, James E

2017-12-01

Recruitment of sufficient sample size into clinical trials is challenging. Conventional advertising methods are expensive and are often ineffective. The effectiveness of Facebook for recruitment into blood pressure clinical trials of middle-to-older-aged people is unknown. This study aimed to assess this by comparing Facebook advertising with conventional recruitment methods from a retrospective analysis within a clinical trial. Conventional advertisements (newspaper, radio and posters) were employed for the first 20 months of a randomized controlled clinical trial conducted in three Australian capital cities from Tasmania, Queensland and the Australian Capital Territory. With dwindling participant recruitment, at 20 months a Facebook advertising campaign was employed intermittently over a 4-month period. Recruitment results were retrospectively compared with those using conventional methods in the previous 4 months. Compared with conventional recruitment methods, Facebook advertisement was associated with a significant increase in the number of participants recruited in the Australian Capital Territory (from an average 1.8-7.3/month; P < 0.05). There was also an increase in Tasmania that was of borderline significance (from 4.0 participants recruited/month to 9.3/month; P = 0.052). However, there was no effect in Queensland (from 6.0 participants recruited/month to 3.0/month; P = 0.15). Facebook advertisement was associated with a significant decrease in the age of participants enquiring into the study (from 60.9 to 58.7 years; P < 0.001). Facebook advertising was successful in helping to increase recruitment of middle-to-older aged participants into a blood pressure clinical trial, although there may be some variability in effect that is dependent on location.

Role of Ambulatory and Home Blood Pressure Monitoring in Clinical Practice: A Narrative Review

PubMed Central

Shimbo, Daichi; Abdalla, Marwah; Falzon, Louise; Townsend, Raymond R.; Muntner, Paul

2015-01-01

Hypertension, a common cardiovascular disease (CVD) risk factor, is usually diagnosed and treated based on blood pressure readings obtained in the clinic setting. Blood pressure may differ considerably when measured in the clinic versus outside of the clinic setting. Over the past several decades, evidence has accumulated on two approaches for measuring out-of-clinic blood pressure: ambulatory blood pressure monitoring (ABPM) and home blood pressure monitoring (HBPM). Blood pressure measures on ABPM and HBPM each have a stronger association with CVD outcomes than clinic blood pressure. Controversy exists whether ABPM or HBPM is superior for estimating CVD risk, and under what circumstances these methods should be used in clinical practice for assessing out-of-clinic blood pressure. This review describes ABPM and HBPM procedures, the blood pressure phenotypic measures that can be ascertained, and the evidence that supports the use of each approach to measure out-of-clinic blood pressure. This review also describes barriers to the successful implementation of ABPM and HBPM in clinical practice, proposes core competencies for the conduct of these procedures, and highlights important areas for future research. PMID:26457954

Patients with Parkinson disease present high ambulatory blood pressure variability.

PubMed

Kanegusuku, Hélcio; Silva-Batista, Carla; Peçanha, Tiago; Silva-Junior, Natan; Queiroz, Andreia; Costa, Luiz; Mello, Marco; Piemonte, Maria; Ugrinowitsch, Carlos; Forjaz, Cláudia

2017-09-01

Patients with Parkinson disease (PD) present blunted nocturnal blood pressure fall and similar ambulatory blood pressure variability (ABPV) measured by standard deviation (SD) and coefficient of variation (CV) compared with healthy subjects. However, these classical indices of ABPV have limited validity in individuals with circadian blood pressure alterations. New indices, such as the average of daytime and night-time standard deviation weighted by the duration of the daytime and night-time intervals (SD dn ) and the average real variability (ARV), remove the influence of the daytime and the night-time periods on ABPV. This study assessed ABPV by SD dn and ARV in PD. Twenty-one patients with PD (11 men, 66 ± 2 years, stages 2-3 of modified Hoehn & Yahr) and 21 matched controls without Parkinson disease (9 men, 64 ± 1 years old) underwent blood pressure monitoring for 24 h. ABPV was analysed by 24 h, daytime and night-time SD and CV, and by the SD dn and ARV. Systolic/diastolic 24-h and night-time SD and CV were similar between the patients with PD and the controls. The patients with PD presented higher daytime systolic/diastolic CV and SD than the controls (10·4 ± 0·9/12·3 ± 0·8 versus 7·0 ± 0·3/9·9 ± 0·5%, P<0·05; 12·6 ± 1·0/9·1 ± 0·5 versus 8·6 ± 0·4/7·5 ± 0·3 mmHg, P<0·05, respectively) as well as higher systolic/diastolic SD dn (10·9 ± 0·8/8·2 ± 0·5 versus 8·2 ± 0·3/7·1 ± 0·2 mmHg, P<0·05, respectively) and ARV (8·8 ± 0·6/6·9 ± 0·3 versus 7·2 ± 0·2/6·0 ± 0·2 mmHg, P<0·05, respectively). In conclusion, patients with PD have higher ABPV than control subjects as assessed by SD d , CV d , SD dn and AVR. © 2016 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

Effects of food or sleep deprivation during civilian survival training on clinical chemistry variables.

PubMed

Ståhle, Lars; Granström, Elisabeth; Ljungdahl Ståhle, Ewa; Isaksson, Sven; Samuelsson, Anders; Rudling, Mats; Sepp, Harry

2013-06-01

To describe clinical chemistry and weight changes after short-term food or sleep deprivation or multiple deprivations during civilian survival training. Data from one baseline-controlled two-period crossover study designed to compare sleep deprivation for up to 50 hours with food deprivation for up to 66 hours (n = 12) and data from regular multiple-deprivations survival training comparing participants (n = 33) with nondeprived instructors (n = 10). Food deprivation was associated with decreased body weight, blood glucose, serum triglycerides, sodium, chloride, and urine pH, and there were increases in blood and urine ketones and serum free fatty acids. Sleep deprivation was associated with a minor decrease in hemoglobin and erythrocyte particle count and volume fraction and an increase in leukocytes. The clinical chemistry and body weight changes associated with food deprivation were qualitatively similar to those observed in fasting obese patients but developed quicker in the survival training setting. Sleep deprivation had few effects on the clinical chemistry profile except for hematological variables. Physicians evaluating clinical chemistry data from patients subjected to short-term food or sleep deprivation should take the physiological state into account in their assessment. Copyright © 2013 Wilderness Medical Society. Published by Elsevier Inc. All rights reserved.

Greater nighttime blood pressure variability is associated with left atrial enlargement in atrial fibrillation patients with preserved ejection fraction.

PubMed

Norioka, Naoki; Iwata, Shinichi; Ito, Asahiro; Tamura, Soichiro; Kawai, Yu; Nonin, Shinichi; Ishikawa, Sera; Doi, Atsushi; Hanatani, Akihisa; Yoshiyama, Minoru

2018-06-13

Left atrial enlargement is an independent risk factor for ischemic stroke in patients with atrial fibrillation. Little is known regarding the association between nighttime blood pressure variability and left atrial enlargement in patients with atrial fibrillation and preserved ejection fraction. The study population consisted of 140 consecutive patients with atrial fibrillation (mean age 64 ± 10 years) with preserved ejection fraction (≥50%). Nighttime blood pressure was measured at hourly intervals, using a home blood pressure monitoring device. Nighttime blood pressure variability was expressed as the standard deviation of all readings. Left atrial volume index was measured using the modified Simpson's biplane method with transthoracic echocardiography. Multiple regression analysis indicated that nighttime mean systolic/diastolic blood pressure and its variability remained independently associated with left atrial enlargement after adjustment for age, sex, anti-hypertensive medication class, and left ventricular mass index (P < 0.01). When patients were divided into four groups according to nighttime blood pressure and its variability, the group with higher nighttime blood pressure and its variability had significantly larger left atrial volume than the group with lower nighttime blood pressure and its variability (46.6 ml/m 2 vs. 35.0 ml/m 2 , P < 0.0001). Higher nighttime blood pressure and its variability are associated with left atrial enlargement. The combination of nighttime blood pressure and its variability has additional predictive value for left atrial enlargement. Intensive intervention for these high-risk patients may avoid or delay progression of left atrial enlargement and reduce the risk of stroke.

[Explore objective clinical variables for detecting delirium in ICU patients: a prospective case-control study].

PubMed

Liu, Xiaojiang; Lyu, Jie; An, Youzhong

2017-04-01

The aim of this case-control study is to explore clinical objective variables for diagnosing delirium of intensive care unit (ICU) patients. According to the method of prospective case-control study, critical adult postoperative patients who were transferred to ICU of Peking University People's Hospital from October 2015 to May 2016 and needed mechanical ventilation were included. After evaluating the Richmond agitation sedation scale score (RASS), the patients whose score were -2 or greater were sorted into two groups, delirium and non-delirium, according to the confusion assessment method for the ICU (CAM-ICU). Then these patients were observed by domestic multifunctional detector for electroencephalographic (EEG) variables such as brain lateralization, brain introvert, brain activity, brain energy consumption, focus inward, focus outward, cerebral inhibition, fatigue, sleep severity, sedation index, pain index, anxiety index, fidgety index, stress index and the cerebral blood flow (CBF) index which was named of perfusion index. Other variables including indexes of ICU blood gas analysis, which was consisted of variables of blood gas analysis, routine blood test and biochemistry, previous history and prognostic outcome was recorded. Binary logistic regression was used for multivariate analysis. Forty-three postoperative patients, who needed intensive care, were included. Eighteen were in delirium group and twenty-five in control group. Excluding the trauma, variables like gender, age, temperature, heart rate, respiratory rate, mean arterial pressure, acute physiology and chronic health evaluationII(APACHEII) score, organ failure, dementia and emergency surgery didn't show any statistical significance between two groups. The trauma in delirious patients increased obviously compared with the control group (33.3% vs. 4.0%, P = 0.031). Except for the brain activity [122.47 (88.62, 154.21) vs. 89.40 (86.27, 115.97), P = 0.034], there were no statistical differences in

Clinical significance of stress-related increase in blood pressure: current evidence in office and out-of-office settings.

PubMed

Munakata, Masanori

2018-05-29

High blood pressure is the most significant risk factor of cardiovascular and cerebrovascular diseases worldwide. Blood pressure and its variability are recognized as risk factors. Thus, hypertension control should focus not only on maintaining optimal levels but also on achieving less variability in blood pressure. Psychosocial stress is known to contribute to the development and worsening of hypertension. Stress is perceived by the brain and induces neuroendocrine responses in either a rapid or long-term manner. Moreover, endothelial dysfunction and inflammation might be further involved in the modulation of blood pressure elevation associated with stress. White-coat hypertension, defined as high clinic blood pressure but normal out-of-office blood pressure, is the most popular stress-related blood pressure response. Careful follow-up is necessary for this type of hypertensive patients because some show organ damage or a worse prognosis. On the other hand, masked hypertension, defined as high out-of-office blood pressure but normal office blood pressure, has received considerable interest as a poor prognostic condition. The cause of masked hypertension is complex, but evidence suggests that chronic stress at the workplace or home could be involved. Chronic psychological stress could be associated with distorted lifestyle and mental distress as well as long-lasting allostatic load, contributing to the maintenance of blood pressure elevation. Stress issues are common in patients in modern society. Considering psychosocial stress as the pathogenesis of blood pressure elevation is useful for achieving an individual-focused approach and 24-h blood pressure control.

Short-term variability of blood pressure and heart rate in hyperthyroidism.

PubMed

Girard, A; Hugues, F C; Le Jeunne, C; Elghozi, J L

1998-06-01

The effect of hyperthyroidism on the short-term memory variability of blood pressure and heart rate was evaluated in 12 untreated hyperthyroid patients during thyrotoxicosis and after a 6 1/2 month treatment designed to achieve a stable euthyroid state. Beat-by-beat finger blood pressure was measured with a Finapres device. The pulse interval, from which pulse rate was derived, was obtained from the blood pressure signal. Due to the significant change in heart rhythm associated with thyrotoxicosis, both pulse interval (taken as a surrogate of heart period) and pulse rate (taken as a surrogate of heart rate) were computed. Power spectral analysis showed a reduction in the overall heart period variability in the supine position in the hyperthyroid compared to the euthyroid state. This effect was observed in the low-frequency (0.005-0.068 Hz), mid-frequency (0.068-0.127 Hz) and high-frequency (respiratory) domains as well, with a significant reduction of the modulus of these bands of 31%, 35% and 47%, respectively. The heart rate spectral modulus also exhibited a reduction of the high-frequency component (31%) in the supine position in the hyperthyroid subjects. These changes in heart rhythmicity corroborate a vagal deficit in hyperthyroidism. In addition, blood pressure spectral power exhibited a significant deficit in the orthostatism-induced mid-frequency systolic blood pressure rise in the hyperthyroid state (64%) compared with the euthyroid state. This observation may reflect a reduced vascular sympathetic activation with standing. The resulting vasodilatation could well contribute to normalize blood pressure in thyrotoxicosis in which cardiac output is increased.

Whole blood flow cytometry measurements of in vivo platelet activation in critically-Ill patients are influenced by variability in blood sampling techniques.

PubMed

Rondina, Matthew T; Grissom, Colin K; Men, Shaohua; Harris, Estelle S; Schwertz, Hansjorg; Zimmerman, Guy A; Weyrich, Andrew S

2012-06-01

Flow cytometry is often used to measure in vivo platelet activation in critically-ill patients. Variability in blood sampling techniques, which may confound these measurements, remains poorly characterized. Platelet activation was measured by flow cytometry performed on arterial and venous blood from 116 critically-ill patients. We determined how variability in vascular sampling site, processing times, and platelet counts influenced levels of platelet-monocyte aggregates (PMA), PAC-1 binding (for glycoprotein (GP) IIbIIIa), and P-selectin (P-SEL) expression. Levels of PMA, but not PAC-1 binding or P-SEL expression, were significantly affected by variability in vascular sampling site. Average PMA levels were approximately 60% higher in whole blood drawn from an arterial vessel compared to venous blood (16.2±1.8% vs. 10.7±1.2%, p<0.05). Levels of PMA in both arterial and venous blood increased significantly during ex vivo processing delays (1.7% increase for every 10 minute delay, p<0.05). In contrast, PAC-1 binding and P-SEL expression were unaffected by processing delays. Levels of PMA, but not PAC-1 binding or P-SEL expression, were correlated with platelet count quartiles (9.4±1.6% for the lowest quartile versus 15.4±1.6% for the highest quartile, p<0.05). In critically-ill patients, variability in vascular sampling site, processing times, and platelet counts influence levels of PMA, but not PAC-1 binding or P-SEL expression. These data demonstrate the need for rigorous adherence to blood sampling protocols, particularly when levels of PMA, which are most sensitive to variations in blood collection, are measured for detection of in vivo platelet activation. Copyright © 2011 Elsevier Ltd. All rights reserved.

Measurement-to-measurement blood pressure variability is related to cognitive performance: the Maine Syracuse study.

PubMed

Crichton, Georgina E; Elias, Merrill F; Dore, Gregory A; Torres, Rachael V; Robbins, Michael A

2014-11-01

The objective was to investigate the association between variability in blood pressure (BP) and cognitive function for sitting, standing, and reclining BP values and variability derived from all 15 measures. In previous studies, only sitting BP values have been examined, and only a few cognitive measures have been used. A secondary objective was to examine associations between BP variability and cognitive performance in hypertensive individuals stratified by treatment success. Cross-sectional analyses were performed on 972 participants of the Maine Syracuse Study for whom 15 serial BP clinic measures (5 sitting, 5 recumbent, and 5 standing) were obtained before testing of cognitive performance. Using all 15 measures, higher variability in systolic and diastolic BP was associated with poorer performance on multiple measures of cognitive performance, independent of demographic factors, cardiovascular risk factors, and pulse pressure. When sitting, reclining, and standing systolic BP values were compared, only variability in standing BP was related to measures of cognitive performance. However, for diastolic BP, variability in all 3 positions was related to cognitive performance. Mean BP values were weaker predictors of cognition. Furthermore, higher overall variability in both systolic and diastolic BP was associated with poorer cognitive performance in unsuccessfully treated hypertensive individuals (with BP ≥140/90 mm Hg), but these associations were not evident in those with controlled hypertension. © 2014 American Heart Association, Inc.

Clinical use of indium-111 labeled blood products

DOE Office of Scientific and Technical Information (OSTI.GOV)

Loken, M.K.; Clay, M.E.; Carpenter, R.T.

1985-12-01

Following the introduction of In-111 oxine as a label for blood cells by McAffee and Thakur in 1976, these procedures have become increasingly important in the practice of nuclear medicine. Of particular interest are studies involving the use of labeled leukocytes for the detection of focal infection. The clinical utility of labeled platelets is less well developed, although the use of platelets to detect the formation of thrombi in blood vessels and on vascular grafts and prostheses is gaining prominence. This report summarizes the techniques presently employed at the University of Minnesota for the labeling of blood products, and theirmore » clinical use. Consideration also is given to the desired expertise and cost factors involved in the labeling of leukocytes and platelets.43 references.« less

Effect of induced ruminal acidosis on blood variables in heifers

PubMed Central

2013-01-01

Background Ruminal acidosis is responsible for the onset of different pathologies in dairy and feedlot cattle, but there are major difficulties in the diagnosis. This study modelled the data obtained from various blood variables to identify those that could indicate the severity of ruminal acidosis. Six heifers were fed three experimental rations throughout three periods. The diets were characterised by different starch levels: high starch (HS), medium starch (MS) and low starch, as the control diet (CT). Ruminal pH values were continuously measured using wireless sensors and compared with pH measurements obtained by rumenocentesis. Blood samples were analysed for complete blood count, biochemical profile, venous blood gas, blood lipopolysaccharide (LPS) and LPS-binding proteins (LBP). Results The regression coefficient comparing the ruminal pH values, obtained using the two methods, was 0.56 (P = 0.040). Feeding the CT, MS and HS led to differences in the time spent below the 5.8, 5.5 and 5.0 pH thresholds and in several variables, including dry matter intake (7.7 vs. 6.9 vs. 5.1 kg/d; P = 0.002), ruminal nadir pH (5.69 vs. 5.47 vs. 5.44; P = 0.042), mean ruminal pH (6.50 vs. 6.34 vs. 6.31; P = 0.012), haemoglobin level (11.1 vs. 10.9 vs. 11.4 g/dL; P = 0.010), platelet count (506 vs. 481 vs. 601; P = 0.008), HCO3- (31.8 vs. 31.3 vs. 30.6 mmol/L; P = 0.071) and LBP (5.9 vs. 9.5 vs. 10.5 μg/mL; P < 0.001). A canonical discriminant analysis (CDA) was used to classify the animals into four ruminal pH classes (normal, risk of acidosis, subacute ruminal acidosis and acute ruminal acidosis) using haemoglobin, mean platelet volume, β-hydroxybutyrate, glucose and reduced haemoglobin. Conclusions Although additional studies are necessary to confirm the reliability of these discriminant functions, the use of plasma variables in a multifactorial model appeared to be useful for the evaluation of ruminal acidosis severity. PMID:23647881

Systolic blood pressure variability in patients with early severe sepsis or septic shock: a prospective cohort study.

PubMed

Tang, Yi; Sorenson, Jeff; Lanspa, Michael; Grissom, Colin K; Mathews, V J; Brown, Samuel M

2017-06-17

Severe sepsis and septic shock are often lethal syndromes, in which the autonomic nervous system may fail to maintain adequate blood pressure. Heart rate variability has been associated with outcomes in sepsis. Whether systolic blood pressure (SBP) variability is associated with clinical outcomes in septic patients is unknown. The propose of this study is to determine whether variability in SBP correlates with vasopressor independence and mortality among septic patients. We prospectively studied patients with severe sepsis or septic shock, admitted to an intensive care unit (ICU) with an arterial catheter. We analyzed SBP variability on the first 5-min window immediately following ICU admission. We performed principal component analysis of multidimensional complexity, and used the first principal component (PC 1 ) as input for Firth logistic regression, controlling for mean systolic pressure (SBP) in the primary analyses, and Acute Physiology and Chronic Health Evaluation (APACHE) II score or NEE dose in the ancillary analyses. Prespecified outcomes were vasopressor independence at 24 h (primary), and 28-day mortality (secondary). We studied 51 patients, 51% of whom achieved vasopressor independence at 24 h. Ten percent died at 28 days. PC 1 represented 26% of the variance in complexity measures. PC 1 was not associated with vasopressor independence on Firth logistic regression (OR 1.04; 95% CI: 0.93-1.16; p = 0.54), but was associated with 28-day mortality (OR 1.16, 95% CI: 1.01-1.35, p = 0.040). Early SBP variability appears to be associated with 28-day mortality in patients with severe sepsis and septic shock.

Patient-Reported Outcomes and Socioeconomic Status as Predictors of Clinical Outcomes after Hematopoietic Stem Cell Transplantation: A Study from the Blood and Marrow Transplant Clinical Trials Network 0902 Trial.

PubMed

Knight, Jennifer M; Syrjala, Karen L; Majhail, Navneet S; Martens, Michael; Le-Rademacher, Jennifer; Logan, Brent R; Lee, Stephanie J; Jacobsen, Paul B; Wood, William A; Jim, Heather S L; Wingard, John R; Horowitz, Mary M; Abidi, Muneer H; Fei, Mingwei; Rawls, Laura; Rizzo, J Douglas

2016-12-01

This secondary analysis of a large, multicenter Blood and Marrow Transplant Clinical Trials Network randomized trial assessed whether patient-reported outcomes (PROs) and socioeconomic status (SES) before hematopoietic stem cell transplantation (HCT) are associated with each other and predictive of clinical outcomes, including time to hematopoietic recovery, acute graft-versus-host disease, hospitalization days, and overall survival (OS) among 646 allogeneic and autologous HCT recipients. Pretransplantation Cancer and Treatment Distress (CTXD), Pittsburgh Sleep Quality Index (PSQI), and mental and physical component scores of the Short-Form 36 were correlated with each other and with SES variables. PROs and SES variables were further evaluated as predictors of clinical outcomes, with the PSQI and CTXD evaluated as OS predictors (P < .01 considered significant given multiple testing). Lower attained education was associated with increased distress (P = .002), lower income was related to worse physical functioning (P = .005) and increased distress (P = .008), lack of employment before transplantation was associated with worse physical functioning (P < .01), and unmarried status was associated with worse sleep (P = .003). In this large heterogeneous cohort of HCT recipients, although PROs and SES variables were correlated at baseline, they were not associated with any clinical outcomes. Future research should focus on HCT recipients at greater psychosocial disadvantage. Copyright © 2016 The American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.

Interpretation of Blood Microbiology Results - Function of the Clinical Microbiologist.

PubMed

Kristóf, Katalin; Pongrácz, Júlia

2016-04-01

The proper use and interpretation of blood microbiology results may be one of the most challenging and one of the most important functions of clinical microbiology laboratories. Effective implementation of this function requires careful consideration of specimen collection and processing, pathogen detection techniques, and prompt and precise reporting of identification and susceptibility results. The responsibility of the treating physician is proper formulation of the analytical request and to provide the laboratory with complete and precise patient information, which are inevitable prerequisites of a proper testing and interpretation. The clinical microbiologist can offer advice concerning the differential diagnosis, sampling techniques and detection methods to facilitate diagnosis. Rapid detection methods are essential, since the sooner a pathogen is detected, the better chance the patient has of getting cured. Besides the gold-standard blood culture technique, microbiologic methods that decrease the time in obtaining a relevant result are more and more utilized today. In the case of certain pathogens, the pathogen can be identified directly from the blood culture bottle after propagation with serological or automated/semi-automated systems or molecular methods or with MALDI-TOF MS (matrix-assisted laser desorption-ionization time of flight mass spectrometry). Molecular biology methods are also suitable for the rapid detection and identification of pathogens from aseptically collected blood samples. Another important duty of the microbiology laboratory is to notify the treating physician immediately about all relevant information if a positive sample is detected. The clinical microbiologist may provide important guidance regarding the clinical significance of blood isolates, since one-third to one-half of blood culture isolates are contaminants or isolates of unknown clinical significance. To fully exploit the benefits of blood culture and other (non- culture

Dietary Nitrate Lowers Blood Pressure: Epidemiological, Pre-clinical Experimental and Clinical Trial Evidence.

PubMed

Gee, Lorna C; Ahluwalia, Amrita

2016-02-01

Nitric oxide (NO), a potent vasodilator critical in maintaining vascular homeostasis, can reduce blood pressure in vivo. Loss of constitutive NO generation, for example as a result of endothelial dysfunction, occurs in many pathological conditions, including hypertension, and contributes to disease pathology. Attempts to therapeutically deliver NO via organic nitrates (e.g. glyceryl trinitrate, GTN) to reduce blood pressure in hypertensives have been largely unsuccessful. However, in recent years inorganic (or 'dietary') nitrate has been identified as a potential solution for NO delivery through its sequential chemical reduction via the enterosalivary circuit. With dietary nitrate found in abundance in vegetables this review discusses epidemiological, pre-clinical and clinical data supporting the idea that dietary nitrate could represent a cheap and effective dietary intervention capable of reducing blood pressure and thereby improving cardiovascular health.

Influences of obstructive sleep apnea on blood pressure variability might not be limited only nocturnally in middle-aged hypertensive males.

PubMed

Shao, Liang; Heizhati, Mulalibieke; Yao, Xiaoguang; Wang, Yingchun; Abulikemu, Suofeiya; Zhang, Delian; Zhou, Ling; Hong, Jing; Li, Nanfang

2018-05-01

In this cross-sectional study, we analyzed the potential association between sleep measures and blood pressure variability. Ninety-three middle-aged hypertensive males, who underwent polysomnography and 24-h ambulatory blood pressure monitoring, were enrolled. Blood pressure variability was assessed by blood pressure standard deviation. Obstructive sleep apnea (apnea hypopnea index ≥ 15) was diagnosed in 52 (55.91%) patients. Mean body mass index and age were 27.77 ± 3.11 kg/m 2 and 44.05 ± 8.07 years, respectively. Hypertensive males with obstructive sleep apnea showed significantly higher 24-h, diurnal, and nocturnal diastolic blood pressure variability, compared to those without obstructive sleep apnea. While total cohort was further divided into two groups using the median of oxygen desaturation index, another indicator for severity of OSA, significant differences were also observed in 24-h, diurnal, and nocturnal diastolic blood pressure variability between two groups with higher and lower oxygen desaturation index. While subjects were also divided into two groups via the mean of sleep stage 1, hypertensive males with sleep stage 1 ≥ 8.1% showed significantly higher diurnal diastolic blood pressure variability than those with sleep stage 1 < 8.1%. Apnea hypopnea index was independently associated with 24-h and nocturnal diastolic blood pressure variability; oxygen desaturation index of 3% with 24-h diastolic, diurnal, and nocturnal diastolic blood pressure; and sleep stage 1 was with 24-h and with diurnal diastolic blood pressure variability in all study subjects. Effects of obstructive sleep apnea on blood pressure variability may not be limited nocturnally.

Improved blood utilization using real-time clinical decision support.

PubMed

Goodnough, Lawrence T; Shieh, Lisa; Hadhazy, Eric; Cheng, Nathalie; Khari, Paul; Maggio, Paul

2014-05-01

We analyzed blood utilization at Stanford Hospital and Clinics after implementing real-time clinical decision support (CDS) and best practice alerts (BPAs) into physician order entry (POE) for blood transfusions. A clinical effectiveness (CE) team developed consensus with a suggested transfusion threshold of a hemoglobin (Hb) level of 7 g/dL, or 8 g/dL for patients with acute coronary syndromes. The CDS was implemented in July 2010 and consisted of an interruptive BPA at POE, a link to relevant literature, and an "acknowledgment reason" for the blood order. The percentage of blood ordered for patients whose most recent Hb level exceeded 8 g/dL ranged at baseline from 57% to 66%; from the education intervention by the CE team August 2009 to July 2010, the percentage decreased to a range of 52% to 56% (p = 0.01); and after implementation of CDS and BPA, by end of December 2010 the percentage of patients transfused outside the guidelines decreased to 35% (p = 0.02) and has subsequently remained below 30%. For the most recent interval, only 27% (767 of 2890) of transfusions occurred in patients outside guidelines. Comparing 2009 to 2012, despite an increase in annual case mix index from 1.952 to 2.026, total red blood cell (RBC) transfusions decreased by 7186 units, or 24%. The estimated net savings for RBC units (at $225/unit) in purchase costs for 2012 compared to 2009 was $1,616,750. Real-time CDS has significantly improved blood utilization. This system of concurrent review can be used by health care institutions, quality departments, and transfusion services to reduce blood transfusions. © 2013 American Association of Blood Banks.

Variability of Uncrossmatched Blood Use by Helicopter EMS Programs in the United States.

PubMed

Karl, Alyssa; Pham, Tiffany; Yanosky, Jeff D; Lubin, Jeffrey

2016-01-01

Some helicopter emergency medical services (HEMS) maintain an independent supply of blood for use during transport, although practice is variable and not well described. We aimed to characterize the blood-carrying practices by HEMS programs across the United States. Online surveys were sent to the leadership of the 261 HEMS programs nationwide listed in the 2011 Atlas and Database of Air Medical Services (ADAMS) database. We examined blood-carrying practices in aggregate, including typical transport time, proportion of scene transports, and local population density. A GIS (Geographic Information System) and multivariable logistic regression models were used to estimate the impact of characteristics of local practice on each program's decision to carry blood. A total of 235 (91%) programs responded to the survey, representing 857 of the 929 (92.2%) HEMS rotor wing aircraft nationwide. Fifty-nine (25.3%) programs independently carried blood. A higher proportion of interfacility transports (OR 1.023; 95% CI 1.010-1.036) and decreased local population density (OR 1.006; 95% CI 1.001-1.011) were associated with increased odds of carrying blood. Transport time (OR 1.006; 95% CI 0.991-1.020) and number of transports (OR 1.000; CI 1.000-1.000) were not associated with a program's blood carrying practices. There was no effect of local practices on a program's decision to carry blood (OR 1.002; 95% CI 0.980-1.026). There is great variability in the utilization of blood by HEMS programs in the United States. Programs that serve more rural areas and programs with a larger percentage of interfacility transports are more likely to independently carry blood.

LB02.03: EVALUATION OF DAY-BY-DAY BLOOD PRESSURE VARIABILITY IN CLINIC (DO WE STILL NEED STANDARD DEVIATION?).

PubMed

Ryuzaki, M; Nakamoto, H; Hosoya, K; Komatsu, M; Hibino, Y

2015-06-01

Blood pressure (BP) variability correlates with cardio-vascular disease as BP level itself. There is not known easy way to evaluate the BP variability in clinic.To evaluate the usefulness of maximum-minimum difference (MMD) of BP in a month compared to standard deviation (SD), as an index of BP variability. Study-1: Twelve patients (age 65.9 ± 12.1 y/o) were enrolled. Measurements of home systolic (S) BP were required in the morning. The 12 months consecutive data and at least 3 times measurements a month were required for including. (Mean 29.0 ± 4.5 times/month in the morning). We checked the correlation between MMD and SD. Study-2: Six hemodialized patients monitored with i-TECHO system (J of Hypertens 2007: 25: 2353-2358) for longer than one year were analyzed. As in study-1, we analyzed the correlation between SD and MMD of SBP. 17.4 ± 11.9 times per month. Study-3: The data from our previous study (FUJIYAM study Clin. Exp Hypertens 2014: 36:508-16) were extracted. 1524 patient-month morning BP data were calculated as in study-1. Picking up data measuring more than 24 times a month, 517 patient-month BP data were analyzed. We compared the ratio to 25 times measured data of SD and MMD, in the setting 5, 10, 15, 20 times measured data. Study-1: SBP, MMD was correlated very well to SD (p < 0.0001, R=0.923). Equation of SBPSD = 1.275+ 0.208xMMD. Study-2: R = 0.884 (P < 0.0001) SBPSD = 2.17+ 0.22xMMD. Study-3: R = 0.842(P < 0.0001), if we used all data measurements > 2 times. If data were extracted (measurements>24 times), correlation was 0.927 (P < 0.0001). The equation of SBPSD = 1.520+ 0.201xMMD. The ratios of SD to 25 times were as follows; 0.956 in 5 times, 0.956 in 10, 0.979 in 15, 0.991 in 20 times. The ratios of MMD to 25 times were as follows; 0.558 in 5, 0.761 in 10, 0.874 in 15, 0.944 in 20. We can assume SD easily by measuring MMD as an index of day-by-day BP variability of a month. The equation

The Accreditation Experience of Clinical Laboratories and Blood Banks in Mexico

PubMed Central

2015-01-01

The accreditation of clinical laboratories and blood banks based on ISO 15189 is now being consolidated in Mexico, and is coordinated by the Mexican accreditation entity innovative strategies, A.C. (ema) and supported by the activities of the committee of clinical laboratories and blood banks. The active participation in working groups formed by the technical committee of clinical laboratories and blood banks in specific areas, has contributed to the formulation of technical documents and criteria of evaluation that strengthen the current accreditation scheme. The national registry of evaluation (PNE) consists of technical experts and evaluators from different disciplines of clinical laboratory; the evaluators actively participate in accreditation assessment, with an ultimate goal to receive training and feedback for continuous improvement of its own performance. PMID:27683498

The Accreditation Experience of Clinical Laboratories and Blood Banks in Mexico.

PubMed

Quintana, Sandra

2015-11-01

The accreditation of clinical laboratories and blood banks based on ISO 15189 is now being consolidated in Mexico, and is coordinated by the Mexican accreditation entity innovative strategies, A.C. (ema) and supported by the activities of the committee of clinical laboratories and blood banks. The active participation in working groups formed by the technical committee of clinical laboratories and blood banks in specific areas, has contributed to the formulation of technical documents and criteria of evaluation that strengthen the current accreditation scheme. The national registry of evaluation (PNE) consists of technical experts and evaluators from different disciplines of clinical laboratory; the evaluators actively participate in accreditation assessment, with an ultimate goal to receive training and feedback for continuous improvement of its own performance.

VISIT-TO-VISIT VARIABILITY OF BLOOD PRESSURE AND DEATH, ESRD AND CARDIOVASCULAR EVENTS IN PATIENTS WITH CHRONIC KIDNEY DISEASE

PubMed Central

CHANG, Tara I.; TABADA, Grace H.; YANG, Jingrong; TAN, Thida X.; GO, Alan S.

2016-01-01

OBJECTIVES Visit-to-visit variability of blood pressure is an important independent risk factor for premature death and cardiovascular events, but relatively little is known about this phenomenon in patients with chronic kidney disease not yet on dialysis. METHODS We conducted a retrospective study in a community-based cohort of 114,900 adults with chronic kidney disease stages 3–4 (estimated glomerular filtration rate 15–59 mL/min per 1.73 m2). We hypothesized that visit-to-visit variability of blood pressure would be independently associated with higher risks of death, incident treated end-stage renal disease, and cardiovascular events. We defined systolic visit-to-visit variability of blood pressure using three metrics: (1) coefficient of variation (2) standard deviation of the mean systolic blood pressure, and (3) average real variability. RESULTS The highest versus the lowest quintile of the coefficient of variation was associated with higher adjusted rates of death (hazard ratio 1.22; 95% confidence interval 1.11–1.34) and hemorrhagic stroke (hazard ratio 1.91, confidence interval 1.36–2.68). Visit-to-visit variability of blood pressure was inconsistently associated with heart failure, and was not significantly associated with acute coronary syndrome and ischemic stroke. Results were similar when using the other two visit-to-visit variability of blood pressure. Visit-to-visit variability of blood pressure had inconsistent associations with end-stage renal disease, perhaps due to the relatively low incidences of this outcome. CONCLUSIONS Higher visit-to-visit variability of blood pressure is independently associated with higher rates of death and hemorrhagic stroke in patients with moderate to advanced chronic kidney disease not yet on dialysis. PMID:26599220

Cord blood clinical processing, cryopreservation, and storage.

PubMed

Elmoazzen, Heidi; Holovati, Jelena L

2015-01-01

Allogeneic umbilical cord blood (UCB) hematopoietic stem cell transplantation has become a crucial advancement in the treatment for a variety of diseases including hematopoietic and non-hematopoietic malignancies, BM failure syndromes, hemoglobinopathies, and metabolic and immunodeficiency disorders. It has been well documented that the success of UCB engraftment is tied to UCB banking processes, and now there are established guidelines for standardization of collection, banking, processing, and cryopreservation for unrelated UCB units with purpose of achieving consistent production of high quality placental and UCB units for administration. In 2011, Canada's Ministry of Health has announced Canada's first national, publicly funded umbilical cord blood bank, which aims to provide altruistic donations for unrelated allogeneic hematopoietic stem cell transplant. In this chapter, we describe specific protocols for clinical processing, cryopreservation, and storage of UCB used by the Canadian Blood Services National Public Umbilical Cord Blood Bank.

Quantification of peripheral and central blood pressure variability using a time-frequency method.

PubMed

Kouchaki, Z; Butlin, M; Qasem, A; Avolio, A P

2016-08-01

Systolic blood pressure variability (BPV) is associated with cardiovascular events. As the beat-to-beat variation of blood pressure is due to interaction of several cardiovascular control systems operating with different response times, assessment of BPV by spectral analysis using the continuous measurement of arterial pressure in the finger is used to differentiate the contribution of these systems in regulating blood pressure. However, as baroreceptors are centrally located, this study considered applying a continuous aortic pressure signal estimated noninvasively from finger pressure for assessment of systolic BPV by a time-frequency method using Short Time Fourier Transform (STFT). The average ratio of low frequency and high frequency power band (LF PB /HF PB ) was computed by time-frequency decomposition of peripheral systolic pressure (pSBP) and derived central aortic systolic blood pressure (cSBP) in 30 healthy subjects (25-62 years) as a marker of balance between cardiovascular control systems contributing in low and high frequency blood pressure variability. The results showed that the BPV assessed from finger pressure (pBPV) overestimated the BPV values compared to that assessed from central aortic pressure (cBPV) for identical cardiac cycles (P<;0.001), with the overestimation being greater at higher power.

Control of end-tidal PCO2 reduces middle cerebral artery blood velocity variability: implications for physiological neuroimaging.

PubMed

Harris, Ashley D; Ide, Kojiro; Poulin, Marc J; Frayne, Richard

2006-02-15

Breath-by-breath variability of the end-tidal partial pressure of CO2 (Pet(CO2)) has been shown to be associated with cerebral blood flow (CBF) fluctuations. These fluctuations can impact neuroimaging techniques that depend on cerebrovascular blood flow. We hypothesized that controlling Pet(CO2) would reduce CBF variability. Dynamic end-tidal forcing was used to control Pet(CO2) at 1.5 mm Hg above the resting level and to hold the end-tidal partial pressure of oxygen (Pet(O2)) at the resting level. Peak blood velocity in the middle cerebral artery (MCA) was measured by transcranial Doppler ultrasound (TCD) as an index of CBF. Blood velocity parameters and timing features were determined on each waveform and the variance of these parameters was compared between Normal (air breathing) and Forcing (end-tidal gas control) sessions. The variability of all velocity parameters was significantly reduced in the Forcing session. In particular, the variability of the average velocity over the cardiac cycle was decreased by 18.2% (P < 0.001). For the most part, the variability of the timing parameters was unchanged. Thus, we conclude that controlling Pet(CO2) is effective in reducing CBF variability, which would have important implications for physiologic neuroimaging.

Improving the clinical management of traumatic brain injury through the pharmacokinetic modeling of peripheral blood biomarkers.

PubMed

Dadas, Aaron; Washington, Jolewis; Marchi, Nicola; Janigro, Damir

2016-11-30

Blood biomarkers of neurovascular damage are used clinically to diagnose the presence severity or absence of neurological diseases, but data interpretation is confounded by a limited understanding of their dependence on variables other than the disease condition itself. These include half-life in blood, molecular weight, and marker-specific biophysical properties, as well as the effects of glomerular filtration, age, gender, and ethnicity. To study these factors, and to provide a method for markers' analyses, we developed a kinetic model that allows the integrated interpretation of these properties. The pharmacokinetic behaviors of S100B (monomer and homodimer), Glial Fibrillary Acidic Protein and Ubiquitin C-Terminal Hydrolase L1 were modeled using relevant chemical and physical properties; modeling results were validated by comparison with data obtained from healthy subjects or individuals affected by neurological diseases. Brain imaging data were used to model passage of biomarkers across the blood-brain barrier. Our results show the following: (1) changes in biomarker serum levels due to age or disease progression are accounted for by differences in kidney filtration; (2) a significant change in the brain-to-blood volumetric ratio, which is characteristic of infant and adult development, contributes to variation in blood concentration of biomarkers; (3) the effects of extracranial contribution at steady-state are predicted in our model to be less important than suspected, while the contribution of blood-brain barrier disruption is confirmed as a significant factor in controlling markers' appearance in blood, where the biomarkers are typically detected; (4) the contribution of skin to the marker S100B blood levels depends on a direct correlation with pigmentation and not ethnicity; the contribution of extracranial sources for other markers requires further investigation. We developed a multi-compartment, pharmacokinetic model that integrates the biophysical

EDUCORE project: a clinical trial, randomised by clusters, to assess the effect of a visual learning method on blood pressure control in the primary healthcare setting

PubMed Central

2010-01-01

Background High blood pressure (HBP) is a major risk factor for cardiovascular disease (CVD). European hypertension and cardiology societies as well as expert committees on CVD prevention recommend stratifying cardiovascular risk using the SCORE method, the modification of lifestyles to prevent CVD, and achieving good control over risk factors. The EDUCORE (Education and Coronary Risk Evaluation) project aims to determine whether the use of a cardiovascular risk visual learning method - the EDUCORE method - is more effective than normal clinical practice in improving the control of blood pressure within one year in patients with poorly controlled hypertension but no background of CVD; Methods/Design This work describes a protocol for a clinical trial, randomised by clusters and involving 22 primary healthcare clinics, to test the effectiveness of the EDUCORE method. The number of patients required was 736, all between 40 and 65 years of age (n = 368 in the EDUCORE and control groups), all of whom had been diagnosed with HBP at least one year ago, and all of whom had poorly controlled hypertension (systolic blood pressure ≥ 140 mmHg and/or diastolic ≥ 90 mmHg). All personnel taking part were explained the trial and trained in its methodology. The EDUCORE method contemplates the visualisation of low risk SCORE scores using images embodying different stages of a high risk action, plus the receipt of a pamphlet explaining how to better maintain cardiac health. The main outcome variable was the control of blood pressure; secondary outcome variables included the SCORE score, therapeutic compliance, quality of life, and total cholesterol level. All outcome variables were measured at the beginning of the experimental period and again at 6 and 12 months. Information on sex, age, educational level, physical activity, body mass index, consumption of medications, change of treatment and blood analysis results was also recorded; Discussion The EDUCORE method could provide a

Symbolic dynamics marker of heart rate variability combined with clinical variables enhance obstructive sleep apnea screening

NASA Astrophysics Data System (ADS)

Ravelo-García, A. G.; Saavedra-Santana, P.; Juliá-Serdá, G.; Navarro-Mesa, J. L.; Navarro-Esteva, J.; Álvarez-López, X.; Gapelyuk, A.; Penzel, T.; Wessel, N.

2014-06-01

Many sleep centres try to perform a reduced portable test in order to decrease the number of overnight polysomnographies that are expensive, time-consuming, and disturbing. With some limitations, heart rate variability (HRV) has been useful in this task. The aim of this investigation was to evaluate if inclusion of symbolic dynamics variables to a logistic regression model integrating clinical and physical variables, can improve the detection of subjects for further polysomnographies. To our knowledge, this is the first contribution that innovates in that strategy. A group of 133 patients has been referred to the sleep center for suspected sleep apnea. Clinical assessment of the patients consisted of a sleep related questionnaire and a physical examination. The clinical variables related to apnea and selected in the statistical model were age (p < 10-3), neck circumference (p < 10-3), score on a questionnaire scale intended to quantify daytime sleepiness (p < 10-3), and intensity of snoring (p < 10-3). The validation of this model demonstrated an increase in classification performance when a variable based on non-linear dynamics of HRV (p < 0.01) was used additionally to the other variables. For diagnostic rule based only on clinical and physical variables, the corresponding area under the receiver operating characteristic (ROC) curve was 0.907 (95% confidence interval (CI) = 0.848, 0.967), (sensitivity 87.10% and specificity 80%). For the model including the average of a symbolic dynamic variable, the area under the ROC curve was increased to 0.941 (95% = 0.897, 0.985), (sensitivity 88.71% and specificity 82.86%). In conclusion, symbolic dynamics, coupled with significant clinical and physical variables can help to prioritize polysomnographies in patients with a high probability of apnea. In addition, the processing of the HRV is a well established low cost and robust technique.

Enumeration of major peripheral blood leukocyte populations for multicenter clinical trials using a whole blood phenotyping assay.

PubMed

Hensley, Tiffany R; Easter, Austin B; Gerdts, Sarah E; De Rosa, Stephen C; Heit, Antje; McElrath, M Juliana; Andersen-Nissen, Erica

2012-09-16

Cryopreservation of peripheral blood leukocytes is widely used to preserve cells for immune response evaluations in clinical trials and offers many advantages for ease and standardization of immunological assessments, but detrimental effects of this process have been observed on some cell subsets, such as granulocytes, B cells, and dendritic cells. Assaying fresh leukocytes gives a more accurate picture of the in vivo state of the cells, but is often difficult to perform in the context of large clinical trials. Fresh cell assays are dependent upon volunteer commitments and timeframes and, if time-consuming, their application can be impractical due to the working hours required of laboratory personnel. In addition, when trials are conducted at multiple centers, laboratories with the resources and training necessary to perform the assays may not be located in sufficient proximity to clinical sites. To address these issues, we have developed an 11-color antibody staining panel that can be used with Trucount tubes (Becton Dickinson; San Jose, CA) to phenotype and enumerate the major leukocyte populations within the peripheral blood, yielding more robust cell-type specific information than assays such as a complete blood count (CBC) or assays with commercially-available panels designed for Trucount tubes that stain for only a few cell types. The staining procedure is simple, requires only 100 μl of fresh whole blood, and takes approximately 45 minutes, making it feasible for standard blood-processing labs to perform. It is adapted from the BD Trucount tube technical data sheet (version 8/2010). The staining antibody cocktail can be prepared in advance in bulk at a central assay laboratory and shipped to the site processing labs. Stained tubes can be fixed and frozen for shipment to the central assay laboratory for multicolor flow cytometry analysis. The data generated from this staining panel can be used to track changes in leukocyte concentrations over time in

Enhanced blood pressure variability in a high cardiovascular risk group of African Americans: FIT4Life Study.

PubMed

Veerabhadrappa, Praveen; Diaz, Keith M; Feairheller, Deborah L; Sturgeon, Kathleen M; Williamson, Sheara; Crabbe, Deborah L; Kashem, Abul; Ahrensfield, Debra; Brown, Michael D

2010-01-01

High blood pressure (BP) levels in African Americans elicit vascular inflammation resulting in vascular remodeling. BP variability (BPV) correlates with target organ damage. We aimed to investigate the relationship between inflammatory markers and BPV in African Americans. Thirty-six African Americans underwent 24-hour ambulatory BP monitoring (ABPM). BPV was calculated using the average real variability index. Fasting blood samples were assayed for high-sensitivity C-reactive protein (hs-CRP), tumor necrosis factor-alpha (TNF-alpha), and white blood cell (WBC) count. Significant associations between hs-CRP and 24-hour systolic variability (r=0.50; P=.012) and awake systolic variability (r=0.45; P=.02) were identified after adjusting for age, body mass index, and 24-hour mean BP. ABPM variables were compared between the hs-CRP tertile groups. In post-hoc analysis, there was a significant difference in 24-hour and awake periods for both systolic and diastolic variability among the groups. TNF-alpha and WBC count showed no associations with ABPM variables. hs-CRP was associated with systolic variability, and higher levels of hs-CRP were related with greater BPV. Higher inflammatory status influences wider fluctuations in systolic BP, which in turn could facilitate early progression to target organ damage independent of absolute BP levels in African Americans.

Significance of blood pressure variability in patients with sepsis.

PubMed

Pandey, Nishant Raj; Bian, Yu-Yao; Shou, Song-Tao

2014-01-01

This study was undertaken to observe the characteristics of blood pressure variability (BPV) and sepsis and to investigate changes in blood pressure and its value on the severity of illness in patients with sepsis. Blood parameters, APACHE II score, and 24-hour ambulatory BP were analyzed in 89 patients with sepsis. In patients with APACHE II score>19, the values of systolic blood pressure (SBPV), diasystolic blood pressure (DBPV), non-dipper percentage, cortisol (COR), lactate (LAC), platelet count (PLT) and glucose (GLU) were significantly higher than in those with APACHE II score ≤19 (P<0.05), whereas the values of procalcitonin (PCT), white blood cell (WBC), creatinine (Cr), PaO2, C-reactive protein (CRP), adrenocorticotropic hormone (ACTH) and tumor necrosis factor α (TNF-α) were not statistically significant (P>0.05). Correlation analysis showed that APACHE II scores correlated significantly with SBPV and DBPV (P<0.01, r=0.732 and P<0.01, r=0.762). SBPV and DBPV were correlated with COR (P=0.018 and r=0.318; P=0.008 and r=0.353 respectively). However, SBPV and DBPV were not correlated with TNF-α, IL-10, and PCT (P>0.05). Logistic regression analysis of SBPV, DBPV, APACHE II score, and LAC was used to predict prognosis in terms of survival and non-survival rates. Receiver operating characteristics curve (ROC) showed that DBPV was a better predictor of survival rate with an AUC value of 0.890. However, AUC of SBPV, APACHE II score, and LAC was 0.746, 0.831 and 0.915, respectively. The values of SBPV, DBPV and non-dipper percentage are higher in patients with sepsis. DBPV and SBPV can be used to predict the survival rate of patients with sepsis.

Blood volume analysis: a new technique and new clinical interest reinvigorate a classic study.

PubMed

Manzone, Timothy A; Dam, Hung Q; Soltis, Daniel; Sagar, Vidya V

2007-06-01

Blood volume studies using the indicator dilution technique and radioactive tracers have been performed in nuclear medicine departments for over 50 y. A nuclear medicine study is the gold standard for blood volume measurement, but the classic dual-isotope blood volume study is time-consuming and can be prone to technical errors. Moreover, a lack of normal values and a rubric for interpretation made volume status measurement of limited interest to most clinicians other than some hematologists. A new semiautomated system for blood volume analysis is now available and provides highly accurate results for blood volume analysis within only 90 min. The availability of rapid, accurate blood volume analysis has brought about a surge of clinical interest in using blood volume data for clinical management. Blood volume analysis, long a low-volume nuclear medicine study all but abandoned in some laboratories, is poised to enter the clinical mainstream. This article will first present the fundamental principles of fluid balance and the clinical means of volume status assessment. We will then review the indicator dilution technique and how it is used in nuclear medicine blood volume studies. We will present an overview of the new semiautomated blood volume analysis technique, showing how the study is done, how it works, what results are provided, and how those results are interpreted. Finally, we will look at some of the emerging areas in which data from blood volume analysis can improve patient care. The reader will gain an understanding of the principles underlying blood volume assessment, know how current nuclear medicine blood volume analysis studies are performed, and appreciate their potential clinical impact.

Renal Blood Flow, Glomerular Filtration Rate, and Renal Oxygenation in Early Clinical Septic Shock.

PubMed

Skytte Larsson, Jenny; Krumbholz, Vitus; Enskog, Anders; Bragadottir, Gudrun; Redfors, Bengt; Ricksten, Sven-Erik

2018-06-01

Data on renal hemodynamics, function, and oxygenation in early clinical septic shock are lacking. We therefore measured renal blood flow, glomerular filtration rate, renal oxygen consumption, and oxygenation in patients with early septic shock. Prospective comparative study. General and cardiothoracic ICUs. Patients with norepinephrine-dependent early septic shock (n = 8) were studied within 24 hours after arrival in the ICU and compared with postcardiac surgery patients without acute kidney injury (comparator group, n = 58). None. Data on systemic hemodynamics and renal variables were obtained during two 30-minute periods. Renal blood flow was measured by the infusion clearance of para-aminohippuric acid, corrected for renal extraction of para-aminohippuric acid. Renal filtration fraction was measured by renal extraction of chromium-51 labeled EDTA. Renal oxygenation was estimated from renal oxygen extraction. Renal oxygen delivery (-24%; p = 0.037) and the renal blood flow-to-cardiac index ratio (-21%; p = 0.018) were lower, renal vascular resistance was higher (26%; p = 0.027), whereas renal blood flow tended to be lower (-19%; p = 0.068) in the septic group. Glomerular filtration rate (-32%; p = 0.006) and renal sodium reabsorption (-29%; p = 0.014) were both lower in the septic group. Neither renal filtration fraction nor renal oxygen consumption differed significantly between groups. Renal oxygen extraction was significantly higher in the septic group (28%; p = 0.022). In the septic group, markers of tubular injury were elevated. In early clinical septic shock, renal function was lower, which was accompanied by renal vasoconstriction, a lower renal oxygen delivery, impaired renal oxygenation, and tubular sodium reabsorption at a high oxygen cost compared with controls.

Individual variability in clinical effect and tolerability of opioid analgesics - Importance of drug interactions and pharmacogenetics.

PubMed

Solhaug, Vigdis; Molden, Espen

2017-10-01

As pain is often a comorbid condition, many patients use opioid analgesics in combination with several other drugs. This implies a generally increased risk of drug interactions, which along with inherent pharmacogenetic variability and other factors may cause differences in therapeutic response of opioids. To provide an overview of interactions and pharmacogenetic variability of relevance for individual differences in effect and tolerability of opioid analgesics, which physicians and other healthcare professionals should be aware of in clinical practice. The article was based on unsystematic searches in PubMed to identify literature highlighting the clinical impact of drug interactions and pharmacogenetics as sources of variable response of opioid analgesics. Cytochrome P450 (CYP)-mediated metabolism is an important process for both clinically relevant interactions and pharmacogenetic variability of several opioids. Concomitant use of CYP inhibitors (e.g. paroxetine, fluoxetine and bupropion) or inducers (e.g. carbamazepine, phenobarbital and phenytoin) could counteract the clinical effect or trigger side effects of analgesics in the same manner as genetically determined differences in CYP2D6-mediated metabolism of many opioids. Moreover, combination treatment with drugs that inhibit or induce P-glycoprotein (ABCB1), a blood-brain barrier efflux transporter, may alter the amount ('dose') of opioids distributed to the brain. At the pharmacodynamic level, it is crucial to be aware of the potential risk of interaction causing serotonergic syndrome when combining opioids and serotonergic drugs, in particular antidepressants inhibiting serotonin reuptake (SSRIs and SNRIs). Regarding pharmacogenetics at the receptor level of pain treatment, the knowledge is currently scarce, but an allelic variant of the μ1 opioid receptor (OPRM1) gene has been associated with higher dosage requirement to achieve analgesia. Drug interactions and pharmacogenetic differences may lead to

Technical Stability and Biological Variability in MicroRNAs from Dried Blood Spots: A Lung Cancer Therapy-Monitoring Showcase.

PubMed

Kahraman, Mustafa; Laufer, Thomas; Backes, Christina; Schrörs, Hannah; Fehlmann, Tobias; Ludwig, Nicole; Kohlhaas, Jochen; Meese, Eckart; Wehler, Thomas; Bals, Robert; Keller, Andreas

2017-09-01

Different work flows have been proposed to use miRNAs as blood-borne biomarkers. In particular, the method used for collecting blood from patients can considerably influence the diagnostic results. We explored whether dried blood spots (DBSs) facilitate stable miRNA measurements and compared its technical stability with biological variability. First, we tested the stability of DBS samples by generating from 1 person 18 whole-genome-wide miRNA profiles of DBS samples that were exposed to different temperature and humidity conditions. Second, we investigated technical reproducibility by performing 7 replicates of DBS again from 1 person. Third, we investigated DBS samples from 53 patients with lung cancer undergoing different therapies. Across these 3 stages, 108 genome-wide miRNA profiles from DBS were generated and evaluated biostatistically. In the stability analysis, we observed that temperature and humidity had an overall limited influence on the miRNomes (average correlation between the different conditions of 0.993). Usage of a silica gel slightly diminished DBS' technical reproducibility. The 7 technical replicates had an average correlation of 0.996. The correlation with whole-blood PAXGene miRNomes of the same individual was remarkable (correlation of 0.88). Finally, evaluation of the samples from the 53 patients with lung cancer exposed to different therapies showed that the biological variations exceeded the technical variability significantly ( P < 0.0001), yielding 51 dysregulated miRNAs. We present a stable work flow for profiling of whole miRNomes on the basis of samples collected from DBS. Biological variations exceeded technical variations significantly. DBS-based miRNA profiles will potentially further the translational character of miRNA biomarker studies. © 2017 American Association for Clinical Chemistry.

Blood lipids, homocysteine, stress factors, and vitamins in clinically stable multiple sclerosis patients

PubMed Central

2010-01-01

Multiple Sclerosis (MS) patients present a decrease of antioxidants and neuroprotective and immunoregulatory vitamins and an increase of total homocysteine (tHcy), cholesterol (CHL), HDL-cholesterol, and of cellular stress markers, variably associated with the different phases of the disease. We compared the blood levels of uric acid, folic acid, vitamins B12, A, and E, tHcy, CHL, HDL-cholesterol, and triglycerides in forty MS patients during a phase of clinical inactivity with those of eighty healthy controls, matched for age and sex. We found higher levels of tHcy (p = 0.032) and of HDL-cholesterol (p = 0.001) and lower levels of vitamin E (p = 0.001) and the ratio vitamin E/CHL (p = 0.001) in MS patients. In conclusion, modifications of some biochemical markers of cell damage were detected in MS patients during a phase of clinical inactivity. PMID:20163740

Effect of postmortem sampling technique on the clinical significance of autopsy blood cultures.

PubMed

Hove, M; Pencil, S D

1998-02-01

Our objective was to investigate the value of postmortem autopsy blood cultures performed with an iodine-subclavian technique relative to the classical method of atrial heat searing and antemortem blood cultures. The study consisted of a prospective autopsy series with each case serving as its own control relative to subsequent testing, and a retrospective survey of patients coming to autopsy who had both autopsy blood cultures and premortem blood cultures. A busy academic autopsy service (600 cases per year) at University of Texas Medical Branch Hospitals, Galveston, Texas, served as the setting for this work. The incidence of non-clinically relevant (false-positive) culture results were compared using different methods for collecting blood samples in a prospective series of 38 adult autopsy specimens. One hundred eleven adult autopsy specimens in which both postmortem and antemortem blood cultures were obtained were studied retrospectively. For both studies, positive culture results were scored as either clinically relevant or false positives based on analysis of the autopsy findings and the clinical summary. The rate of false-positive culture results obtained by an iodine-subclavian technique from blood drawn soon after death were statistically significantly lower (13%) than using the classical method of obtaining blood through the atrium after heat searing at the time of the autopsy (34%) in the same set of autopsy subjects. When autopsy results were compared with subjects' antemortem blood culture results, there was no significant difference in the rate of non-clinically relevant culture results in a paired retrospective series of antemortem blood cultures and postmortem blood cultures using the iodine-subclavian postmortem method (11.7% v 13.5%). The results indicate that autopsy blood cultures obtained using the iodine-subclavian technique have reliability equivalent to that of antemortem blood cultures.

Review and classification of variability analysis techniques with clinical applications.

PubMed

Bravi, Andrea; Longtin, André; Seely, Andrew J E

2011-10-10

Analysis of patterns of variation of time-series, termed variability analysis, represents a rapidly evolving discipline with increasing applications in different fields of science. In medicine and in particular critical care, efforts have focussed on evaluating the clinical utility of variability. However, the growth and complexity of techniques applicable to this field have made interpretation and understanding of variability more challenging. Our objective is to provide an updated review of variability analysis techniques suitable for clinical applications. We review more than 70 variability techniques, providing for each technique a brief description of the underlying theory and assumptions, together with a summary of clinical applications. We propose a revised classification for the domains of variability techniques, which include statistical, geometric, energetic, informational, and invariant. We discuss the process of calculation, often necessitating a mathematical transform of the time-series. Our aims are to summarize a broad literature, promote a shared vocabulary that would improve the exchange of ideas, and the analyses of the results between different studies. We conclude with challenges for the evolving science of variability analysis.

Review and classification of variability analysis techniques with clinical applications

PubMed Central

2011-01-01

Analysis of patterns of variation of time-series, termed variability analysis, represents a rapidly evolving discipline with increasing applications in different fields of science. In medicine and in particular critical care, efforts have focussed on evaluating the clinical utility of variability. However, the growth and complexity of techniques applicable to this field have made interpretation and understanding of variability more challenging. Our objective is to provide an updated review of variability analysis techniques suitable for clinical applications. We review more than 70 variability techniques, providing for each technique a brief description of the underlying theory and assumptions, together with a summary of clinical applications. We propose a revised classification for the domains of variability techniques, which include statistical, geometric, energetic, informational, and invariant. We discuss the process of calculation, often necessitating a mathematical transform of the time-series. Our aims are to summarize a broad literature, promote a shared vocabulary that would improve the exchange of ideas, and the analyses of the results between different studies. We conclude with challenges for the evolving science of variability analysis. PMID:21985357

Factors Associated with Intention to Donate Blood: Sociodemographic and Past Experience Variables

PubMed Central

Pule, Pule Ishmael; Rachaba, Boitshwarelo; Magafu, Mgaywa Gilbert Mjungu Damas; Habte, Dereje

2014-01-01

Background and Objectives. This study was conducted to assess the level of intention of the general public towards blood donation and the factors associated with it. Methods. A descriptive cross-sectional study was conducted in South-East Botswana amongst participants aged 21–65 years. An interviewer-administered questionnaire was completed for 384 participants. Results. Of the 384 participants, 104 (27.1%) reported that they had donated blood in the past and 269 (70.1%) stated that they were willing to donate blood in the future. Thirteen out of the 104 past donors (12.5%) reported that they had donated blood in the 12 months preceding the survey and only 10 (9.6%) participants reported that they have been regular donors. In the backward logistic regression analysis, the variables that remained significant predictors of the intention to donate blood were secondary education (adjusted odds ratio (AOR) (95% confidence interval (CI)): 2.92 (1.48, 5.77)), tertiary education (AOR (95% CI): 3.83 (1.52, 9.62)), and knowing a family member who had ever donated blood (AOR (95% CI): 2.84 (1.58, 5.12)). Conclusion. Being informed about blood transfusion and its life-saving benefits through either the education system or the experience made people more likely to intend to donate blood. Evidence-based interventions to retain blood donors as regular donors are recommended. PMID:25431742

Factors associated with intention to donate blood: sociodemographic and past experience variables.

PubMed

Pule, Pule Ishmael; Rachaba, Boitshwarelo; Magafu, Mgaywa Gilbert Mjungu Damas; Habte, Dereje

2014-01-01

Background and Objectives. This study was conducted to assess the level of intention of the general public towards blood donation and the factors associated with it. Methods. A descriptive cross-sectional study was conducted in South-East Botswana amongst participants aged 21-65 years. An interviewer-administered questionnaire was completed for 384 participants. Results. Of the 384 participants, 104 (27.1%) reported that they had donated blood in the past and 269 (70.1%) stated that they were willing to donate blood in the future. Thirteen out of the 104 past donors (12.5%) reported that they had donated blood in the 12 months preceding the survey and only 10 (9.6%) participants reported that they have been regular donors. In the backward logistic regression analysis, the variables that remained significant predictors of the intention to donate blood were secondary education (adjusted odds ratio (AOR) (95% confidence interval (CI)): 2.92 (1.48, 5.77)), tertiary education (AOR (95% CI): 3.83 (1.52, 9.62)), and knowing a family member who had ever donated blood (AOR (95% CI): 2.84 (1.58, 5.12)). Conclusion. Being informed about blood transfusion and its life-saving benefits through either the education system or the experience made people more likely to intend to donate blood. Evidence-based interventions to retain blood donors as regular donors are recommended.

Current concepts in blood glucose monitoring

PubMed Central

Khadilkar, Kranti Shreesh; Bandgar, Tushar; Shivane, Vyankatesh; Lila, Anurag; Shah, Nalini

2013-01-01

Blood glucose monitoring has evolved over the last century. The concept of adequate glycemic control and minimum glycemic variability requires an ideal, accurate and reliable glucose monitoring system. The search for an ideal blood glucose monitoring system still continues. This review explains the various blood glucose monitoring systems with special focus on the monitoring systems like self- monitored blood glucose (SMBG) and continuous glucose monitoring system (CGMS). It also focuses on the newer concepts of blood glucose monitoring and their incorporation in routine clinical management of diabetes mellitus. PMID:24910827

Evaluation of Two New Indices of Blood Pressure Variability Using Postural Change in Older Fallers.

PubMed

Goh, Choon-Hian; Ng, Siew-Cheok; Kamaruzzaman, Shahrul B; Chin, Ai-Vyrn; Poi, Philip J H; Chee, Kok Han; Imran, Z Abidin; Tan, Maw Pin

2016-05-01

To evaluate the utility of blood pressure variability (BPV) calculated using previously published and newly introduced indices using the variables falls and age as comparators.While postural hypotension has long been considered a risk factor for falls, there is currently no documented evidence on the relationship between BPV and falls.A case-controlled study involving 25 fallers and 25 nonfallers was conducted. Systolic (SBPV) and diastolic blood pressure variability (DBPV) were assessed using 5 indices: standard deviation (SD), standard deviation of most stable continuous 120 beats (staSD), average real variability (ARV), root mean square of real variability (RMSRV), and standard deviation of real variability (SDRV). Continuous beat-to-beat blood pressure was recorded during 10 minutes' supine rest and 3 minutes' standing.Standing SBPV was significantly higher than supine SBPV using 4 indices in both groups. The standing-to-supine-BPV ratio (SSR) was then computed for each subject (staSD, ARV, RMSRV, and SDRV). Standing-to-supine ratio for SBPV was significantly higher among fallers compared to nonfallers using RMSRV and SDRV (P = 0.034 and P = 0.025). Using linear discriminant analysis (LDA), 3 indices (ARV, RMSRV, and SDRV) of SSR SBPV provided accuracies of 61.6%, 61.2%, and 60.0% for the prediction of falls which is comparable with timed-up and go (TUG), 64.4%.This study suggests that SSR SBPV using RMSRV and SDRV is a potential predictor for falls among older patients, and deserves further evaluation in larger prospective studies.

Blood pressure variability and risk of cardiovascular events and death in patients with hypertension and different baseline risks.

PubMed

Mehlum, Maria H; Liestøl, Knut; Kjeldsen, Sverre E; Julius, Stevo; Hua, Tsushung A; Rothwell, Peter M; Mancia, Giuseppe; Parati, Gianfranco; Weber, Michael A; Berge, Eivind

2018-01-20

Blood pressure variability is associated with increased risk of cardiovascular events, particularly in high-risk patients. We assessed if variability was associated with increased risk of cardiovascular events and death in hypertensive patients at different risk levels. The Valsartan Antihypertensive Long-term Use Evaluation trial was a randomized controlled trial of valsartan vs. amlodipine in patients with hypertension and different risks of cardiovascular events, followed for a mean of 4.2 years. We calculated standard deviation (SD) of mean systolic blood pressure from visits from 6 months onward in patients with ≥3 visits and no events during the first 6 months. We compared the risk of cardiovascular events in the highest and lowest quintile of visit-to-visit blood pressure variability, using Cox regression. For analysis of death, variability was analysed as a continuous variable. Of 13 803 patients included, 1557 (11.3%) had a cardiovascular event and 1089 (7.9%) died. Patients in the highest quintile of SD had an increased risk of cardiovascular events [hazard ratio (HR) 2.1, 95% confidence interval (95% CI) 1.7-2.4; P < 0.0001], and a 5 mmHg increase in SD of systolic blood pressure was associated with a 10% increase in the risk of death (HR 1.10, 95% CI 1.04-1.17; P = 0.002). Associations were stronger among younger patients and patients with lower systolic blood pressure, and similar between patients with different baseline risks, except for higher risk of death among patients with established cardiovascular disease. Higher visit-to-visit systolic blood pressure variability is associated with increased risk of cardiovascular events in patients with hypertension, irrespective of baseline risk of cardiovascular events. Associations were stronger in younger patients and in those with lower mean systolic blood pressure. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2018. For permissions

Blood-brain barrier dysfunction in brain diseases: clinical experience.

PubMed

Schoknecht, Karl; Shalev, Hadar

2012-11-01

The blood-brain barrier, a unique feature of the cerebral vasculature, is gaining attention as a feature in common neurologic disorders including stroke, traumatic brain injury, epilepsy, and schizophrenia. Although acute blood-brain barrier dysfunction can induce cerebral edema, seizures, or neuropsychiatric symptoms, epileptogenesis and cognitive decline are among the chronic effects. The mechanisms underlying blood-brain barrier dysfunction are diverse and may range from physical endothelial damage in traumatic brain injury to degradation of extracellular matrix proteins via matrix metalloproteinases as part of an inflammatory response. Clinically, blood-brain barrier dysfunction is often detected using contrast-enhanced imaging. However, these techniques do not give any insights into the underlying mechanism. Elucidating the specific pathways of blood-brain barrier dysfunction at different time points and in different brain diseases using novel imaging techniques promises a more accurate blood-brain barrier terminology as well as new treatment options and personalized treatment. Wiley Periodicals, Inc. © 2012 International League Against Epilepsy.

Automated blood-sample handling in the clinical laboratory.

PubMed

Godolphin, W; Bodtker, K; Uyeno, D; Goh, L O

1990-09-01

The only significant advances in blood-taking in 25 years have been the disposable needle and evacuated blood-drawing tube. With the exception of a few isolated barcode experiments, most sample-tracking is performed through handwritten or computer-printed labels. Attempts to reduce the hazards of centrifugation have resulted in air-tight lids or chambers, the use of which is time-consuming and cumbersome. Most commonly used clinical analyzers require serum or plasma, distributed into specialized containers, unique to that analyzer. Aliquots for different tests are prepared by handpouring or pipetting. Moderate to large clinical laboratories perform so many different tests that even multi-analyzers performing multiple analyses on a single sample may account for only a portion of all tests ordered for a patient. Thus several aliquots of each specimen are usually required. We have developed a proprietary serial centrifuge and blood-collection tube suitable for incorporation into an automated or robotic sample-handling system. The system we propose is (a) safe--avoids or prevents biological danger to the many "handlers" of blood; (b) small--minimizes the amount of sample taken and space required to adapt to the needs of satellite and mobile testing, and direct interfacing with analyzers; (c) serial--permits each sample to be treated according to its own "merits," optimizes throughput, and facilitates flexible automation; and (d) smart--ensures quality results through monitoring and intelligent control of patient identification, sample characteristics, and separation process.

Improving power to detect changes in blood miRNA expression by accounting for sources of variability in experimental designs.

PubMed

Daniels, Sarah I; Sillé, Fenna C M; Goldbaum, Audrey; Yee, Brenda; Key, Ellen F; Zhang, Luoping; Smith, Martyn T; Thomas, Reuben

2014-12-01

Blood miRNAs are a new promising area of disease research, but variability in miRNA measurements may limit detection of true-positive findings. Here, we measured sources of miRNA variability and determine whether repeated measures can improve power to detect fold-change differences between comparison groups. Blood from healthy volunteers (N = 12) was collected at three time points. The miRNAs were extracted by a method predetermined to give the highest miRNA yield. Nine different miRNAs were quantified using different qPCR assays and analyzed using mixed models to identify sources of variability. A larger number of miRNAs from a publicly available blood miRNA microarray dataset with repeated measures were used for a bootstrapping procedure to investigate effects of repeated measures on power to detect fold changes in miRNA expression for a theoretical case-control study. Technical variability in qPCR replicates was identified as a significant source of variability (P < 0.05) for all nine miRNAs tested. Variability was larger in the TaqMan qPCR assays (SD = 0.15-0.61) versus the qScript qPCR assays (SD = 0.08-0.14). Inter- and intraindividual and extraction variability also contributed significantly for two miRNAs. The bootstrapping procedure demonstrated that repeated measures (20%-50% of N) increased detection of a 2-fold change for approximately 10% to 45% more miRNAs. Statistical power to detect small fold changes in blood miRNAs can be improved by accounting for sources of variability using repeated measures and choosing appropriate methods to minimize variability in miRNA quantification. This study demonstrates the importance of including repeated measures in experimental designs for blood miRNA research. See all the articles in this CEBP Focus section, "Biomarkers, Biospecimens, and New Technologies in Molecular Epidemiology." ©2014 American Association for Cancer Research.

Assessment of the clinical efficacy of the heart spectrum blood pressure monitor for diagnosis of atrial fibrillation: An unblinded clinical trial.

PubMed

Kao, Wei-Fong; Hou, Sen-Kuang; Huang, Chun-Yao; Chao, Chun-Chieh; Cheng, Chung-Chih; Chen, Yi-Jung

2018-01-01

Atrial fibrillation (AF) is the most common arrhythmia. The most common diagnostic method, 12-lead electrocardiogram (ECG), can record episodes of arrhythmia from which the type and severity can be determined. The Heart Spectrum Blood Pressure Monitor (P2; OSTAR Meditech Corp., New Taipei City, Taiwan) is used to measure cardiovascular pressure change with fast Fourier transform (FFT) analysis to obtain heart rate frequency variability and accurate blood pressure data. We compared the diagnostic efficacy of the Heart Spectrum Blood Pressure Monitor to a 12-lead ECG (gold standard) for patients with AF. Three measurement methods were used in this study to analyze the heart index and compare the results with simultaneous 12-lead ECG: blood pressure; mean arterial pressure, which was calculated from individual blood pressure as a constant pressure; and a constant pressure of 60 mmHg. The physician used a 12-lead ECG and the Heart Spectrum Blood Pressure Monitor simultaneously. The Heart Spectrum Blood Pressure Monitor used FFT analysis to diagnose AF, and the findings were compared to the 12-lead ECG readings. This unblinded clinical trial was conducted in the emergency department of Taipei Medical University Hospital. Twenty-nine subjects with AF and 33 without AF aged 25 to 97 y (mean, 63.5 y) were included. Subjects who were exposed to high-frequency surgical equipment during testing, those with cardiac pacemakers or implantable defibrillators, and pregnant women were excluded. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were 97%, 97%, 97%, and 97%, respectively, for method 1; 90%, 100%, 100%, and 91%, respectively, for method 2; and 100%, 94%, 94%, and 100%, respectively, for method 3. The sensitivity, specificity, PPV, and NPV for both methods ranged between 90% and 100%, indicating that the Heart Spectrum Blood Pressure Monitor can be effectively applied for AF detection.

Assessment of the clinical efficacy of the heart spectrum blood pressure monitor for diagnosis of atrial fibrillation: An unblinded clinical trial

PubMed Central

Kao, Wei-Fong; Hou, Sen-Kuang; Huang, Chun-Yao; Cheng, Chung-Chih; Chen, Yi-Jung

2018-01-01

Atrial fibrillation (AF) is the most common arrhythmia. The most common diagnostic method, 12-lead electrocardiogram (ECG), can record episodes of arrhythmia from which the type and severity can be determined. The Heart Spectrum Blood Pressure Monitor (P2; OSTAR Meditech Corp., New Taipei City, Taiwan) is used to measure cardiovascular pressure change with fast Fourier transform (FFT) analysis to obtain heart rate frequency variability and accurate blood pressure data. We compared the diagnostic efficacy of the Heart Spectrum Blood Pressure Monitor to a 12-lead ECG (gold standard) for patients with AF. Three measurement methods were used in this study to analyze the heart index and compare the results with simultaneous 12-lead ECG: blood pressure; mean arterial pressure, which was calculated from individual blood pressure as a constant pressure; and a constant pressure of 60 mmHg. The physician used a 12-lead ECG and the Heart Spectrum Blood Pressure Monitor simultaneously. The Heart Spectrum Blood Pressure Monitor used FFT analysis to diagnose AF, and the findings were compared to the 12-lead ECG readings. This unblinded clinical trial was conducted in the emergency department of Taipei Medical University Hospital. Twenty-nine subjects with AF and 33 without AF aged 25 to 97 y (mean, 63.5 y) were included. Subjects who were exposed to high-frequency surgical equipment during testing, those with cardiac pacemakers or implantable defibrillators, and pregnant women were excluded. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were 97%, 97%, 97%, and 97%, respectively, for method 1; 90%, 100%, 100%, and 91%, respectively, for method 2; and 100%, 94%, 94%, and 100%, respectively, for method 3. The sensitivity, specificity, PPV, and NPV for both methods ranged between 90% and 100%, indicating that the Heart Spectrum Blood Pressure Monitor can be effectively applied for AF detection. PMID:29902218

Agreement between ambulatory, home, and office blood pressure variability.

PubMed

Juhanoja, Eeva P; Niiranen, Teemu J; Johansson, Jouni K; Puukka, Pauli J; Jula, Antti M

2016-01-01

Ambulatory, home, and office blood pressure (BP) variability are often treated as a single entity. Our aim was to assess the agreement between these three methods for measuring BP variability. Twenty-four-hour ambulatory BP monitoring, 28 home BP measurements, and eight office BP measurements were performed on 461 population-based or hypertensive participants. Five variability indices were calculated for all measurement methods: SD, coefficient of variation, maximum-minimum difference, variability independent of the mean, and average real variability. Pearson's correlation coefficients were calculated for indices measured with different methods. The agreement between different measurement methods on the diagnoses of extreme BP variability (participants in the highest decile of variability) was assessed with kappa (κ) coefficients. SBP/DBP variability was greater in daytime (coefficient of variation: 9.8 ± 2.9/11.9 ± 3.6) and night-time ambulatory measurements (coefficient of variation: 8.6 ± 3.4/12.1 ± 4.5) than in home (coefficient of variation: 4.4 ± 1.8/4.7 ± 1.9) and office (coefficient of variation: 4.6 ± 2.4/5.2 ± 2.6) measurements (P < 0.001/0.001 for all). Pearson's correlation coefficients for systolic/diastolic daytime or night-time ambulatory-home, ambulatory-office, and home-office variability indices ranged between 0.07-0.25/0.12-0.23, 0.13-0.26/0.03-0.22 and 0.13-0.24/0.10-0.19, respectively, indicating, at most, a weak positive (r < 0.3) relationship. The agreement between measurement methods on diagnoses of extreme SBP/DBP variability was only slight (κ < 0.2), with the κ coefficients for daytime and night-time ambulatory-home, ambulatory-office, and home-office agreement varying between-0.014-0.20/0.061-0.15, 0.037-0.18/0.082-0.15, and 0.082-0.13/0.045-0.15, respectively. Shorter-term and longer-term BP variability assessed by different methods of BP measurement seem to correlate only weakly

Visit-to-visit and 24-h blood pressure variability: association with endothelial and smooth muscle function in African Americans.

PubMed

Diaz, K M; Veerabhadrappa, P; Kashem, M A; Thakkar, S R; Feairheller, D L; Sturgeon, K M; Ling, C; Williamson, S T; Kretzschmar, J; Lee, H; Grimm, H; Babbitt, D M; Vin, C; Fan, X; Crabbe, D L; Brown, M D

2013-11-01

The purpose of this study was to investigate the association of visit-to-visit and 24-h blood pressure (BP) variability with markers of endothelial injury and vascular function. We recruited 72 African Americans who were non-diabetic, non-smoking and free of cardiovascular (CV) and renal disease. Office BP was measured at three visits and 24-h ambulatory BP monitoring was conducted to measure visit-to-visit and 24-h BP variability, respectively. The 5-min time-course of brachial artery flow-mediated dilation and nitroglycerin-mediated dilation were assessed as measures of endothelial and smooth muscle function. Fasted blood samples were analyzed for circulating endothelial microparticles (EMPs). Significantly lower CD31+CD42- EMPs were found in participants with high visit-to-visit systolic blood pressure (SBP) variability or high 24-h diastolic blood pressure (DBP) variability. Participants with high visit-to-visit DBP variability had significantly lower flow-mediated dilation and higher nitroglycerin-mediated dilation at multiple time-points. When analyzed as continuous variables, 24-h mean arterial pressure variability was inversely associated with CD62+ EMPs; visit-to-visit DBP variability was inversely associated with flow-mediated dilation normalized by smooth muscle function and was positively associated with nitroglycerin-mediated dilation; and 24-h DBP variability was positively associated with nitroglycerin-mediated dilation. All associations were independent of age, gender, body mass index and mean BP. In conclusion, in this cohort of African Americans visit-to-visit and 24-h BP variability were associated with measures of endothelial injury, endothelial function and smooth muscle function. These results suggest that BP variability may influence the pathogenesis of CV disease, in part, through influences on vascular health.

Impact of clinical input variable uncertainties on ten-year atherosclerotic cardiovascular disease risk using new pooled cohort equations.

PubMed

Gupta, Himanshu; Schiros, Chun G; Sharifov, Oleg F; Jain, Apurva; Denney, Thomas S

2016-08-31

Recently released American College of Cardiology/American Heart Association (ACC/AHA) guideline recommends the Pooled Cohort equations for evaluating atherosclerotic cardiovascular risk of individuals. The impact of the clinical input variable uncertainties on the estimates of ten-year cardiovascular risk based on ACC/AHA guidelines is not known. Using a publicly available the National Health and Nutrition Examination Survey dataset (2005-2010), we computed maximum and minimum ten-year cardiovascular risks by assuming clinically relevant variations/uncertainties in input of age (0-1 year) and ±10 % variation in total-cholesterol, high density lipoprotein- cholesterol, and systolic blood pressure and by assuming uniform distribution of the variance of each variable. We analyzed the changes in risk category compared to the actual inputs at 5 % and 7.5 % risk limits as these limits define the thresholds for consideration of drug therapy in the new guidelines. The new-pooled cohort equations for risk estimation were implemented in a custom software package. Based on our input variances, changes in risk category were possible in up to 24 % of the population cohort at both 5 % and 7.5 % risk boundary limits. This trend was consistently noted across all subgroups except in African American males where most of the cohort had ≥7.5 % baseline risk regardless of the variation in the variables. The uncertainties in the input variables can alter the risk categorization. The impact of these variances on the ten-year risk needs to be incorporated into the patient/clinician discussion and clinical decision making. Incorporating good clinical practices for the measurement of critical clinical variables and robust standardization of laboratory parameters to more stringent reference standards is extremely important for successful implementation of the new guidelines. Furthermore, ability to customize the risk calculator inputs to better represent unique clinical

Heart rate variability, hemostatic and acute inflammatory blood parameters in healthy adults after short-term exposure to welding fume.

PubMed

Scharrer, E; Hessel, H; Kronseder, A; Guth, W; Rolinski, B; Jörres, R A; Radon, K; Schierl, R; Angerer, P; Nowak, D

2007-02-01

The present study aimed to investigate, whether short-term experimental exposure to high levels of welding fumes would be capable of exerting acute effects in healthy subjects. Specifically, we assessed cardiovascular function in terms of heart rate variability (HRV) as well as the concentrations of inflammatory mediators and hemostatic proteins in blood as outcome measures. Twenty subjects without a history of airway and cardiovascular diseases were exposed to either control air or welding fume for 1 h on 2 separate days under standardized conditions. The median concentration of the alveolar particle fraction during welding was 3.5 mg/m(3 )(quartiles: 1.4-6.3 mg/m(3); range 1.0-25.3 mg/m(3)). Five hours later a panel of clinical assessments was performed, including HRV measurement and drawing of blood samples. There were no changes in symptom ratings or lung function after welding fume exposure. Exposures did also not differ regarding effects on time- and frequency-domain parameters of HRV. Similarly, blood leukocyte numbers, cell differentials and the blood levels of fibrinogen, C-reactive protein, antithrombin III, factor VIII, von Willebrand factor, ristocetin cofactor, sICAM-1, tumor necrosis factor alpha, interleukin 6, interleukin 8 and epithelial neutrophil activating peptide 78 were not altered by welding fume inhalation. However, there was a significant fall in the level of endothelin-1 (P < 0.01). In conclusion, the data did not indicate effects of clinical significance of a short-term high-level exposure to welding fumes on HRV or a set of blood hemostatic and acute inflammatory parameters in healthy subjects. The small but statistically significant effect on endothelin levels demonstrated that measurable effects could be elicited even in these individuals. Overall, welding fumes are not likely to exert acute cardiovascular effects in healthy individuals.

Quantifying the Risk of Blood Exposure in Optometric Clinical Education.

ERIC Educational Resources Information Center

Hoppe, Elizabeth

1997-01-01

A study attempted to quantify risk of blood exposure in optometric clinical education by surveying optometric interns in their fourth year at the Southern California College of Optometry concerning their history of exposure or use of a needle. Results indicate blood exposure or needle use ranged from 0.95 to 18.71 per 10,000 patient encounters.…

Assessment of three frequently used blood glucose monitoring devices in clinical routine.

PubMed

Zueger, Thomas; Schuler, Vanessa; Stettler, Christoph; Diem, Peter; Christ, Emanuel R

2012-07-12

Self-monitoring of blood glucose plays an important role in the management of diabetes and has been shown to improve metabolic control. The use of blood glucose meters in clinical practice requires sufficient reliability to allow adequate treatment. Direct comparison of different blood glucose meters in clinical practice, independent of the manufactures is scarce. We, therefore, aimed to evaluate three frequently used blood glucose meters in daily clinical practice. Capillary blood glucose was measured simultaneous using the following glucose meters: Contour® (Bayer Diabetes Care, Zürich, Switzerland), Accu-Chek® aviva (Roche Diagnostics, Rotkreuz, Switzerland), Free-Style® lite (Abbott Diabetes Care, Baar, Switzerland). The reference method consisted of the HemoCue® Glucose 201+ System (HemoCue® AB, Ängelholm, Sweden) with plasma conversion. The devices were assessed by comparison of the Mean Absolute Relative Differences (MARD), the Clarke Error Grid Analysis (EGA) and the compliance with the International Organization of Standardization criteria (ISO 15197:2003). Capillary blood samples were obtained from 150 patients. MARD was 10.1 ± 0.65%, 7.0 ± 0.62% and 7.8 ± 0.48% for Contour®, Accu-Chek® and Free-Style®, respectively. EGA showed 99.3% (Contour®), 98.7% (Accu-Chek®) and 100% (Free-Style®) of all measurements in zone A and B (clinically acceptable). The ISO criteria were fulfilled by Accu-Chek® (95.3%) and Free-Style® (96%), but not by Contour® (92%). In the present study the three glucose meters provided good agreement with the reference and reliable results in daily clinical routine. Overall, the Free-Style® and Accu-Chek® device slightly outperformed the Contour® device.

Influence of transport and time on blood variables commonly measured for the athlete biological passport.

PubMed

Robinson, Neil; Giraud, Sylvain; Schumacher, Yorck Olaf; Saugy, Martial

2016-02-01

Some recent studies have characterized the stability of blood variables commonly measured for the Athlete Biological Passport. The aim of this study was to characterize the impact of different shipments conditions and the quality of the results returned by the haematological analyzer. Twenty-two healthy male subjects provided five EDTA tubes each. Four shipment conditions (24, 36, 48, 72 h) under refrigerated conditions were tested and compared to a set of samples left in the laboratory also under refrigerated conditions (group control). All measurements were conducted using two Sysmex XT-2000i analyzers. Haemoglobin concentration, reticulocytes percentage, and OFF-score numerical data were the same for samples analyzed just after collection and after a shipment under refrigerated conditions up to 72 h. Detailed information reported especially by the differential (DIFF) channel scatterplot of the Sysmex XT-2000i indicated that there were signs of blood deterioration, but were not of relevance for the variables used in the Athlete Biological Passport. As long as the cold chain is guaranteed, the time delay between the collection and the analyses of blood variables can be extended. Copyright © 2015 John Wiley & Sons, Ltd.

Ambulatory and home blood pressure monitoring: gaps between clinical guidelines and clinical practice in Singapore

PubMed Central

Setia, Sajita; Subramaniam, Kannan; Teo, Boon Wee; Tay, Jam Chin

2017-01-01

Purpose Out-of-office blood pressure (BP) measurements (home blood pressure monitoring [HBPM] and ambulatory blood pressure monitoring [ABPM]) provide important additional information for effective hypertension detection and management decisions. Therefore, out-of-office BP measurement is now recommended by several international guidelines. This study evaluated the practice and uptake of HBPM and ABPM among physicians from Singapore. Materials and methods A sample of physicians from Singapore was surveyed between 8 September and 5 October 2016. Those included were in public or private practice had been practicing for ≥3 years, directly cared for patients ≥70% of the time, and treated ≥30 patients for hypertension per month. The questionnaire covered six main categories: general BP management, BP variability (BPV) awareness/diagnosis, HBPM, ABPM, BPV management, and associated training needs. Results Sixty physicians (30 general practitioners, 20 cardiologists, and 10 nephrologists) were included (77% male, 85% aged 31–60 years, and mean 22-year practice). Physicians recommended HBPM and ABPM to 81% and 27% of hypertensive patients, respectively. HBPM was most often used to monitor antihypertensive therapy (88% of physicians) and 97% thought that ABPM was useful for providing information on BPV. HBPM instructions often differed from current guideline recommendations in terms of frequency, number of measurements, and timing. The proportion of consultation time devoted to discussing HBPM and BPV was one-quarter or less for 73% of physicians, and only 55% said that they had the ability to provide education on HBPM and BPV. Patient inertia, poor patient compliance, lack of medical consultation time, and poor patient access to a BP machine were the most common challenges for implementing out-of-office BP monitoring. Conclusion Although physicians from Singapore do recommend out-of-office BP measurement to patients with hypertension, this survey identified several

Ambulatory and home blood pressure monitoring: gaps between clinical guidelines and clinical practice in Singapore.

PubMed

Setia, Sajita; Subramaniam, Kannan; Teo, Boon Wee; Tay, Jam Chin

2017-01-01

Out-of-office blood pressure (BP) measurements (home blood pressure monitoring [HBPM] and ambulatory blood pressure monitoring [ABPM]) provide important additional information for effective hypertension detection and management decisions. Therefore, out-of-office BP measurement is now recommended by several international guidelines. This study evaluated the practice and uptake of HBPM and ABPM among physicians from Singapore. A sample of physicians from Singapore was surveyed between 8 September and 5 October 2016. Those included were in public or private practice had been practicing for ≥3 years, directly cared for patients ≥70% of the time, and treated ≥30 patients for hypertension per month. The questionnaire covered six main categories: general BP management, BP variability (BPV) awareness/diagnosis, HBPM, ABPM, BPV management, and associated training needs. Sixty physicians (30 general practitioners, 20 cardiologists, and 10 nephrologists) were included (77% male, 85% aged 31-60 years, and mean 22-year practice). Physicians recommended HBPM and ABPM to 81% and 27% of hypertensive patients, respectively. HBPM was most often used to monitor antihypertensive therapy (88% of physicians) and 97% thought that ABPM was useful for providing information on BPV. HBPM instructions often differed from current guideline recommendations in terms of frequency, number of measurements, and timing. The proportion of consultation time devoted to discussing HBPM and BPV was one-quarter or less for 73% of physicians, and only 55% said that they had the ability to provide education on HBPM and BPV. Patient inertia, poor patient compliance, lack of medical consultation time, and poor patient access to a BP machine were the most common challenges for implementing out-of-office BP monitoring. Although physicians from Singapore do recommend out-of-office BP measurement to patients with hypertension, this survey identified several important gaps in knowledge and clinical practice.

Clinical impact of reducing routine blood culture incubation time from 7 to 5 days.

PubMed

Marginson, Michael J; Daveson, Kathryn L; Kennedy, Karina J

2014-12-01

The aim of this study was to determine the clinical impact of reducing the blood culture incubation protocol from 7 to 5 days.A laboratory data extraction identified positive blood cultures occurring after 5 or more days of incubation at Canberra Hospital, Australia between 1 January 2001 and 31 August 2011. Isolates were identified as clinically significant using a pre-existing prospective bacteraemia database. Medical records review determined whether the positive result affected clinical management.Positive blood cultures after 5 or more days of incubation accounted for 2.65% (423/15979) of all positive blood cultures, although the majority were false positives or contaminants. Eighty-five were significant/indeterminate, representing an average of eight cases per year or 0.47% (85/15979) of all positive blood cultures sets. Forty-three were isolated for the first time, representing 1.1% of all significant/indeterminate blood culture episodes. Fungi and anaerobic bacteria compromised over 50% of isolates. In 26 cases (2.4 cases per year), the culture result led to a change in patient management.A 7 day incubation protocol is preferable due to late isolation of organisms; however, if space is required to accommodate increasing blood culture numbers, reducing to a 5 or 6 day protocol would miss only a small percentage of clinically significant isolates.

Ambulatory versus home versus clinic blood pressure: the association with subclinical cerebrovascular diseases: the Ohasama Study.

PubMed

Hara, Azusa; Tanaka, Kazushi; Ohkubo, Takayoshi; Kondo, Takeo; Kikuya, Masahiro; Metoki, Hirohito; Hashimoto, Takanao; Satoh, Michihiro; Inoue, Ryusuke; Asayama, Kei; Obara, Taku; Hirose, Takuo; Izumi, Shin-Ichi; Satoh, Hiroshi; Imai, Yutaka

2012-01-01

The usefulness of ambulatory, home, and casual/clinic blood pressure measurements to predict subclinical cerebrovascular diseases (silent cerebrovascular lesions and carotid atherosclerosis) was compared in a general population. Data on ambulatory, home, and casual/clinic blood pressures and brain MRI to detect silent cerebrovascular lesions were obtained in 1007 subjects aged ≥55 years in a general population of Ohasama, Japan. Of the 1007 subjects, 583 underwent evaluation of the extent of carotid atherosclerosis. Twenty-four-hour, daytime, and nighttime ambulatory and home blood pressure levels were closely associated with the risk of silent cerebrovascular lesions and carotid atherosclerosis (all P<0.05). When home and one of the ambulatory blood pressure values were simultaneously included in the same regression model, each of the ambulatory blood pressure values remained a significant predictor of silent cerebrovascular lesions, whereas home blood pressure lost its predictive value. Of the ambulatory blood pressure values, nighttime blood pressure was the strongest predictor of silent cerebrovascular lesions. The home blood pressure value was more closely associated with the risk of carotid atherosclerosis than any of the ambulatory blood pressure values when home and one of the ambulatory blood pressure values were simultaneously included in the same regression model. The casual/clinic blood pressure value had no significant association with the risk of subclinical cerebrovascular diseases. Although the clinical indications for ambulatory blood pressure monitoring and home blood pressure measurements may overlap, the clinical significance of each method for predicting target organ damage may differ for different target organs.

Measurement of Induced Cytokines in AIDS Clinical Trials Using Whole Blood: A Preliminary Report

PubMed Central

Wallis, Robert S.; Lederman, Howard M.; Spritzler, John; Devers, Jennifer L.; Georges, Daniel; Weinberg, Adriana; Stehn, Susan; Lederman, Michael M.; Group, the Actg Inducible Cytokines Focus

1998-01-01

Measures of immune function have become increasingly important as endpoints in AIDS clinical trials, with respect to both modulation and reconstitution of immunity by experimental therapies. Measurement of immune function in this setting requires the development of robust analytic approaches suitable for the clinical laboratory. Experiments were performed to evaluate the suitability of using cultured heparinized (“whole”) blood for induction of tumor necrosis factor alpha (TNF-α) and gamma interferon (IFN-γ), two cytokines critical in AIDS pathogenesis. TNF-α expression ranged from 229 to 769 pg/ml in lipopolysaccharide (LPS)-stimulated cultures and was not detected in unstimulated cultures. IFN-γ expression ranged from 0 to 112,000 pg/ml in phytohemagglutinin A (PHA)-stimulated cultures and from 0 to 789 pg/ml in antigen-stimulated cultures. The mean coefficient of variation observed in three weekly determinations was 0.47 for TNF-α and ranged from 0.12 to 1.73 for IFN-γ. These values indicate that sample sizes of 8, 24, and 29 subjects would be sufficient to detect twofold changes in LPS-induced TNF-α and in PHA- and antigen-induced IFN-γ, respectively, if two baseline and two treatment determinations were obtained, and if the interpatient variability of changes in true levels from baseline to follow-up is negligible compared to the variability in the three weekly measurements. Measurement of LPS-induced TNF-α and mitogen- or antigen-induced IFN-γ can be performed simply and reproducibly in human immunodeficiency virus-infected persons by the whole-blood culture method. Further studies are warranted to determine the effect of overnight shipping on assay reproducibility and to determine the extent to which responses can be reliably detected in subjects with low CD4 cell numbers. PMID:9665966

Optimization of a whole blood phenotyping assay for enumeration of peripheral blood leukocyte populations in multicenter clinical trials.

PubMed

Hensley-McBain, Tiffany; Heit, Antje; De Rosa, Stephen C; McElrath, M Juliana; Andersen-Nissen, Erica

2014-09-01

Vaccination with viral vectors or adjuvants can induce early changes in circulating peripheral blood leukocytes that are predictive of a protective immune response. In this study, we define an 11-color whole blood antibody staining Trucount Panel (TP1) to enumerate and phenotype the major leukocyte populations in a human vaccine experimental medicine trial setting. TP1 can be prepared up to 8weeks prior to use, enabling bulk preparation at a central laboratory and distribution to clinical sites. Cells in whole blood must be stained within 4h of draw to accurately detect the major cell populations. Staining of cells with TP1 followed by storage and shipping at -80°C to a central laboratory has little to no effect on the cell concentrations observed. We also present data from an HIV vaccine multicenter clinical trial obtained using the optimized TP1 assay protocol and show that the data produced accurately correlates with complete blood count (CBC) data. Taken together, these data indicate the optimized TP1 panel assay can be used in a multicenter clinical trial setting to increase our understanding of systemic responses to vaccination or disease. Copyright © 2014 Elsevier B.V. All rights reserved.

Does blood pressure variability affect the summer associated symptoms amongst females?

PubMed

Sinha, Pragya; Singh, N P; Taneja, D K; Sah, Renuka

2010-04-01

Blood pressure usually increases in winter and decreases in summer i.e, shows seasonal variation. In a tropical country like India women often complain off prominent symptoms like dizziness, giddiness, fainting and weakness during summer months. The objective was to study the prevalence of above symptoms which are common during summer and its association with variation in blood pressure among normotensive healthy females aged 18-40 years. The present study was carried out on 132 women as a prospective observational study which included 2 home visits to the participants in the two different seasons in the months of May-June (summer) and December-January (winter) based on the data provided by the meteorological department of Government of India. Blood pressure and pulse rate (hemodynamic variables) was measured in these seasons and information was collected on the occurrence of the symptoms in these seasons. There was mean decrease of 11.07 +/- 10.29 mm of Hg in Systolic blood pressure & 6.79 +/-6.88 mm of Hg in diastolic blood pressure in summer as compared to winter. The symptoms in the form of weakness, dizziness and blackout which are generally perceived by women in this area to be due to low blood pressure were observed in 32.6% of the study subjects in summer compared with 2.3% in winter. The difference was statistically highly significant (p < 0.001). There was no significant difference between the mean value of electrolytes, creatinine and urea in the cases and the controls. Thus the seasonal variation in blood pressure rather than electrolytes abnormality may be responsible for these symptoms.

Ambulatory blood pressure monitoring-derived short-term blood pressure variability is increased in Cushing's syndrome.

PubMed

Rebellato, Andrea; Grillo, Andrea; Dassie, Francesca; Sonino, Nicoletta; Maffei, Pietro; Martini, Chiara; Paoletta, Agostino; Fabris, Bruno; Carretta, Renzo; Fallo, Francesco

2014-11-01

Cushing's syndrome is associated with high cardiovascular morbility and mortality. Blood pressure (BP) variability within a 24-h period is increasingly recognized as an independent predictor of cardiovascular risk. The aim of our study was to investigate the short-term BP variability indices in Cushing's syndrome. Twenty-five patients with Cushing's syndrome (mean age 49 ± 13 years, 4 males; 21 Cushing's disease and 4 adrenal adenoma patients) underwent 24-h ambulatory BP monitoring (ABPM) and evaluation of cardiovascular risk factors. Cushing patients were divided into 8 normotensive (NOR-CUSH) and 17 hypertensive (HYP-CUSH) patients and were compared with 20 normotensive (NOR-CTR) and 20 hypertensive (HYP-CTR) age-, sex-, and BMI-matched control subjects. Short-term BP variability was derived from ABPM and calculated as the following: (1) standard deviation (SD) of 24-h, daytime, and nighttime BP; (2) 24-h weighted SD of BP; and (3) average real variability (ARV), i.e., the average of the absolute differences between consecutive BP measurements over 24 h. In comparison with controls, patients with Cushing's syndrome, either normotensive or hypertensive, had higher 24-h and daytime SD of BP, as well as higher 24-h weighted SD and ARV of BP (P = 0.03 to P < 0.0001). No difference in metabolic parameters was observed between NOR-CTR and NOR-CUSH or between HYP-CTR and HYP-CUSH subgroups. ABPM-derived short-term BP variability is increased in Cushing's syndrome, independent of BP elevation. It may represent an additional cardiovascular risk factor in this disease. The role of excess cortisol in BP variability has to be further clarified.

High-resolution ultrasound imaging and noninvasive optoacoustic monitoring of blood variables in peripheral blood vessels

NASA Astrophysics Data System (ADS)

Petrov, Irene Y.; Petrov, Yuriy; Prough, Donald S.; Esenaliev, Rinat O.

2011-03-01

Ultrasound imaging is being widely used in clinics to obtain diagnostic information non-invasively and in real time. A high-resolution ultrasound imaging platform, Vevo (VisualSonics, Inc.) provides in vivo, real-time images with exceptional resolution (up to 30 microns) using high-frequency transducers (up to 80 MHz). Recently, we built optoacoustic systems for probing radial artery and peripheral veins that can be used for noninvasive monitoring of total hemoglobin concentration, oxyhemoglobin saturation, and concentration of important endogenous and exogenous chromophores (such as ICG). In this work we used the high-resolution ultrasound imaging system Vevo 770 for visualization of the radial artery and peripheral veins and acquired corresponding optoacoustic signals from them using the optoacoustic systems. Analysis of the optoacoustic data with a specially developed algorithm allowed for measurement of blood oxygenation in the blood vessels as well as for continuous, real-time monitoring of arterial and venous blood oxygenation. Our results indicate that: 1) the optoacoustic technique (unlike pure optical approaches and other noninvasive techniques) is capable of accurate peripheral venous oxygenation measurement; and 2) peripheral venous oxygenation is dependent on skin temperature and local hemodynamics. Moreover, we performed for the first time (to the best of our knowledge) a comparative study of optoacoustic arterial oximetry and a standard pulse oximeter in humans and demonstrated superior performance of the optoacoustic arterial oximeter, in particular at low blood flow.

Noncontact blood perfusion mapping in clinical applications

NASA Astrophysics Data System (ADS)

Iakovlev, Dmitry; Dwyer, Vincent; Hu, Sijung; Silberschmidt, Vadim

2016-04-01

Non-contact imaging photoplethysmography (iPPG) to detect pulsatile blood microcirculation in tissue has been selected as a successor to low spatial resolution and slow scanning blood perfusion techniques currently employed by clinicians. The proposed iPPG system employs a novel illumination source constructed of multiple high power LEDs with narrow spectral emission, which are temporally modulated and synchronised with a high performance sCMOS sensor. To ensure spectrum stability and prevent thermal wavelength drift due to junction temperature variations, each LED features a custom-designed thermal management system to effectively dissipate generated heat and auto-adjust current flow. The use of a multi-wavelength approach has resulted in simultaneous microvascular perfusion monitoring at various tissue depths, which is an added benefit for specific clinical applications. A synchronous detection algorithm to extract weak photoplethysmographic pulse-waveforms demonstrated robustness and high efficiency when applied to even small regions of 5 mm2. The experimental results showed evidences that the proposed system could achieve noticeable accuracy in blood perfusion monitoring by creating complex amplitude and phase maps for the tissue under examination.

Diagnostic clinical parasitology: IV. Identification of the blood parasites?

PubMed

Garcia, L S; Voge, M

1981-01-01

This is the fourth article in a series of articles entitled "Diagnostic Clinical Parasitology" and contains information on the recovery and identification of human blood parasites. The organisms covered include those that cause the diseases malaria, babesiosis, leishmaniasis, and trypanosomiasis. Some of the filarial worms, which can be considered "blood parasites," have been discussed in the third article in the series, "Identification of the Helminths." Although some of these organisms may rarely be encountered in the laboratory in clinical specimens, they will probably have to be identified in proficiency testing specimens, some of which may not always be representative of patient clinical material. The differences between potential organism recovery from patients coming from endemic areas and from those individuals who become infected with no prior exposure to the organism will also be emphasized. Often, for a number of different reasons, organism recovery and subsequent identification may be more difficult than the textbook imply. It is very important for the technologist to recognize this fact, particularly when dealing with a possibly fatal infection, ie, Plasmodium falciparum.

Clinical performance of a new blood control peripheral intravenous catheter: A prospective, randomized, controlled study.

PubMed

Seiberlich, Laura E; Keay, Vanessa; Kallos, Stephane; Junghans, Tiffany; Lang, Eddy; McRae, Andrew D

2016-03-01

The performance of a new safety peripheral intravenous catheter (PIVC) that contains a blood control feature in the hub (blood control) was compared against the current hospital standard without blood control (standard). In this prospective, non-blinded trial, patients were randomized 1:1 to receive either device. Insertions were performed and rated by emergency room nurses. Primary endpoints included clinical acceptability, incidence of blood leakage, and risk of blood exposure. Secondary endpoints were digital compression, insertion success, and usability. 15 clinicians performed 152 PIVC insertions (73 blood control, 79 standard). Clinical acceptability of the blood control device (100%) was non-inferior to the standard (98.7%) (p < 0.0001). The blood control device had a lower incidence of blood leakage (14.1% vs 68.4%), was superior in eliminating the risk of blood exposure (93.9% vs 19.1%) and the need for digital compression (95.3% vs 19.1%), while maintaining non-inferior insertion success rates (95.9% vs 93.7%) and usability ratings (p < 0.0001). In comparison with the hospital-standard, the new safety PIVC with integrated blood control valve had similar clinical acceptability ratings yet demonstrated superior advantages to both clinicians and patients to decrease blood leakage and the clinician's risk of blood exposure, during the insertion process. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Identification of low and high frequency ranges for heart rate variability and blood pressure variability analyses using pharmacological autonomic blockade with atropine and propranolol in swine.

USDA-ARS?s Scientific Manuscript database

Understanding autonomic nervous system functioning, which mediates behavioral and physiological responses to stress, offers great potential for evaluation of farm animal stress and welfare. Evaluation of heart rate variability (HRV) and blood pressure variability (BPV), using time and frequency doma...

Combining clinical variables to optimize prediction of antidepressant treatment outcomes.

PubMed

Iniesta, Raquel; Malki, Karim; Maier, Wolfgang; Rietschel, Marcella; Mors, Ole; Hauser, Joanna; Henigsberg, Neven; Dernovsek, Mojca Zvezdana; Souery, Daniel; Stahl, Daniel; Dobson, Richard; Aitchison, Katherine J; Farmer, Anne; Lewis, Cathryn M; McGuffin, Peter; Uher, Rudolf

2016-07-01

The outcome of treatment with antidepressants varies markedly across people with the same diagnosis. A clinically significant prediction of outcomes could spare the frustration of trial and error approach and improve the outcomes of major depressive disorder through individualized treatment selection. It is likely that a combination of multiple predictors is needed to achieve such prediction. We used elastic net regularized regression to optimize prediction of symptom improvement and remission during treatment with escitalopram or nortriptyline and to identify contributing predictors from a range of demographic and clinical variables in 793 adults with major depressive disorder. A combination of demographic and clinical variables, with strong contributions from symptoms of depressed mood, reduced interest, decreased activity, indecisiveness, pessimism and anxiety significantly predicted treatment outcomes, explaining 5-10% of variance in symptom improvement with escitalopram. Similar combinations of variables predicted remission with area under the curve 0.72, explaining approximately 15% of variance (pseudo R(2)) in who achieves remission, with strong contributions from body mass index, appetite, interest-activity symptom dimension and anxious-somatizing depression subtype. Escitalopram-specific outcome prediction was more accurate than generic outcome prediction, and reached effect sizes that were near or above a previously established benchmark for clinical significance. Outcome prediction on the nortriptyline arm did not significantly differ from chance. These results suggest that easily obtained demographic and clinical variables can predict therapeutic response to escitalopram with clinically meaningful accuracy, suggesting a potential for individualized prescription of this antidepressant drug. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

All Clinically-Relevant Blood Components Transmit Prion Disease following a Single Blood Transfusion: A Sheep Model of vCJD

PubMed Central

de Wolf, Christopher; Tan, Boon Chin; Smith, Antony; Groschup, Martin H.; Hunter, Nora; Hornsey, Valerie S.; MacGregor, Ian R.; Prowse, Christopher V.; Turner, Marc; Manson, Jean C.

2011-01-01

Variant CJD (vCJD) is an incurable, infectious human disease, likely arising from the consumption of BSE-contaminated meat products. Whilst the epidemic appears to be waning, there is much concern that vCJD infection may be perpetuated in humans by the transfusion of contaminated blood products. Since 2004, several cases of transfusion-associated vCJD transmission have been reported and linked to blood collected from pre-clinically affected donors. Using an animal model in which the disease manifested resembles that of humans affected with vCJD, we examined which blood components used in human medicine are likely to pose the greatest risk of transmitting vCJD via transfusion. We collected two full units of blood from BSE-infected donor animals during the pre-clinical phase of infection. Using methods employed by transfusion services we prepared red cell concentrates, plasma and platelets units (including leucoreduced equivalents). Following transfusion, we showed that all components contain sufficient levels of infectivity to cause disease following only a single transfusion and also that leucoreduction did not prevent disease transmission. These data suggest that all blood components are vectors for prion disease transmission, and highlight the importance of multiple control measures to minimise the risk of human to human transmission of vCJD by blood transfusion. PMID:21858015

The Association of Posttraumatic Stress Disorder With Clinic and Ambulatory Blood Pressure in Healthy Adults.

PubMed

Edmondson, Donald; Sumner, Jennifer A; Kronish, Ian M; Burg, Matthew M; Oyesiku, Linda; Schwartz, Joseph E

2018-01-01

Posttraumatic stress disorder (PTSD) is associated with incident cardiovascular risk. We tested the association of PTSD with clinic and ambulatory blood pressure (ABP) in a sample of healthy participants and tested ABP reactivity to anxiety as a mechanism by which PTSD may influence blood pressure (BP). Participants were originally enrolled during workplace BP screenings at three sites; approximately 6 years (standard deviation = 1.0) later, they completed nine clinic BP assessments within three visits, 1 week apart. Before the third visit, participants were screened for PTSD (≥33 on the PTSD Checklist-Civilian) and depression (Beck Depression Inventory) and then completed 24-hour ABP monitoring with electronic diary assessment of anxiety (0-100) at each awake reading. Of 440 participants, 92 (21%) screened positive for PTSD. In regression models adjusted for depression and demographic and clinical variables, PTSD was associated with greater mean systolic BP (3.8 mm Hg clinic [95% confidence interval {CI}] = 1.1-6.5, p = .006), 3.0 mm Hg awake ABP [95% CI = 0.1-5.9, p = .04], and a nonsignificant 2.1 mm Hg ABP during sleep [95% CI = -1.0 to 5.1, p = .18]). PTSD was associated with greater 24-hour median anxiety (p < .001), and changes in anxiety were positively associated with concurrent systolic ABP (p < .001). ABP reactivity to anxiety was greater in participants with PTSD, which partially explained the association of PTSD with ABP. PTSD is associated with greater systolic BP, partly because of greater anxiety, and systolic BP reactivity to anxiety throughout the day. Daily anxiety and related BP reactivity may be targets for interventions to reduce the cardiovascular risk associated with PTSD.

Maturation of Heart Rate and Blood Pressure Variability during Sleep in Term-Born Infants

PubMed Central

Yiallourou, Stephanie R.; Sands, Scott A.; Walker, Adrian M.; Horne, Rosemary S.C.

2012-01-01

Study Objectives: Abnormal blood pressure control is implicated in the sudden infant death syndrome (SIDS). However, no data exist on normal development of blood pressure control during infancy. This study assessed maturation of autonomic control of blood pressure and heart rate during sleep within the first 6 months of life. Participants: Term infants (n = 31) were studied longitudinally at 2-4 weeks, 2-3 months, and 5-6 months postnatal age. Interventions: Infants underwent daytime polysomnography at each age studied. Blood pressure and heart rate were recorded during quiet (QS) and active (AS) sleep in undisturbed baseline and head-up tilt conditions. Measurements and Results: Autonomic control was assessed using spectral indices of blood pressure and heart rate variability (BPV and HRV) in ranges of low frequency (LF, reflecting sympathetic + parasympathetic activity) and high frequency (HF, parasympathetic activity), total power (LF+HF), and LF/HF ratio (sympathovagal balance). With increasing postnatal age and predominantly during QS, HRV-LF, HRV-HF, and HRV total power increased, while HRV-LF/HF decreased. BPV-LF/HF also decreased with postnatal age. All changes were evident in both baseline and head-up tilt conditions. BPV-LF and BPV total power during tilts were markedly reduced in QS versus AS at each age. Conclusions: In sleeping infants, sympathetic vascular modulation of the circulation decreases with age, while parasympathetic control of heart rate is strengthened. These normative data will aid in the early identification of conditions where autonomic function is impaired, such as in SIDS. Citation: Yiallourou SR; Sands SA; Walker AM; Horne RSC. Maturation of heart rate and blood pressure variability during sleep in term-born infants. SLEEP 2012;35(2):177-186. PMID:22294807

Use of generalised additive models to categorise continuous variables in clinical prediction

PubMed Central

2013-01-01

Background In medical practice many, essentially continuous, clinical parameters tend to be categorised by physicians for ease of decision-making. Indeed, categorisation is a common practice both in medical research and in the development of clinical prediction rules, particularly where the ensuing models are to be applied in daily clinical practice to support clinicians in the decision-making process. Since the number of categories into which a continuous predictor must be categorised depends partly on the relationship between the predictor and the outcome, the need for more than two categories must be borne in mind. Methods We propose a categorisation methodology for clinical-prediction models, using Generalised Additive Models (GAMs) with P-spline smoothers to determine the relationship between the continuous predictor and the outcome. The proposed method consists of creating at least one average-risk category along with high- and low-risk categories based on the GAM smooth function. We applied this methodology to a prospective cohort of patients with exacerbated chronic obstructive pulmonary disease. The predictors selected were respiratory rate and partial pressure of carbon dioxide in the blood (PCO2), and the response variable was poor evolution. An additive logistic regression model was used to show the relationship between the covariates and the dichotomous response variable. The proposed categorisation was compared to the continuous predictor as the best option, using the AIC and AUC evaluation parameters. The sample was divided into a derivation (60%) and validation (40%) samples. The first was used to obtain the cut points while the second was used to validate the proposed methodology. Results The three-category proposal for the respiratory rate was ≤ 20;(20,24];> 24, for which the following values were obtained: AIC=314.5 and AUC=0.638. The respective values for the continuous predictor were AIC=317.1 and AUC=0.634, with no statistically

In the aftermath of SPRINT: further comparison of unattended automated office blood pressure measurement and 24-hour blood pressure monitoring.

PubMed

Seidlerová, Jitka; Gelžinský, Julius; Mateřánková, Markéta; Ceral, Jiří; König, Petr; Filipovský, Jan

2018-03-22

Several papers reported that unattended automated office blood pressure (uAutoOBP) is closely related to daytime ambulatory blood pressure monitoring (ABPM). In the present study, we aim to study uAutoOBP and its relation to 24-hour ABPM and ABPM variability. Stable treated hypertensive subjects were examined in two Czech academic hypertension centres. uAutoOBP was measured with the BP Tru device; attended BP three times with auscultatory method (AuscOBP) by the physician. ABPM was performed within one week from the clinical visit. Data on 98 subjects aged 67.7 ± 9.3 years with 24-hour ABPM 120.3 ± 10.6/72.7 ± 7.9 mm Hg are reported. uAutoOBP was lower than 24-hour (by -5.2 ± 11.3/-0.5 ± 6.9 mm Hg) and daytime (by -6.7 ± 12.82.4 ± 8.0 mm Hg) ABPM and the individual variability of the difference was very large (up to 30 mm Hg). The correlation coefficients between ABPM and uAutoOBP were similar compared to AuscOBP (p ≥ .17). Variability of uAutoOBP, but not AuscOBP, readings during one clinical visit was related to short-term blood pressure variability of ABPM. The difference between AuscOBP and uAutoOBP was larger in patients with white-coat effect compared to other blood pressure control groups (25.1 ± 7.0 vs. 2.2 ± 10.3 mm Hg; p = .0036). Our study shows that uAutoOBP is not good predictor of ambulatory blood pressure monitoring, not even of the daytime values. It might, however, indicate short-term blood pressure variability and, when compared with AuscOBP, also detect patients with white-coat effect.

75 FR 2549 - Clinical Accuracy Requirements for Point of Care Blood Glucose Meters; Public Meeting; Request...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-01-15

...] Clinical Accuracy Requirements for Point of Care Blood Glucose Meters; Public Meeting; Request for Comments... Requirements for Point of Care Blood Glucose Meters. The purpose of the public meeting is to discuss the clinical accuracy requirements of blood glucose meters and other topics related to their use in point of...

Identifying novel phenotypes of acute heart failure using cluster analysis of clinical variables.

PubMed

Horiuchi, Yu; Tanimoto, Shuzou; Latif, A H M Mahbub; Urayama, Kevin Y; Aoki, Jiro; Yahagi, Kazuyuki; Okuno, Taishi; Sato, Yu; Tanaka, Tetsu; Koseki, Keita; Komiyama, Kota; Nakajima, Hiroyoshi; Hara, Kazuhiro; Tanabe, Kengo

2018-07-01

Acute heart failure (AHF) is a heterogeneous disease caused by various cardiovascular (CV) pathophysiology and multiple non-CV comorbidities. We aimed to identify clinically important subgroups to improve our understanding of the pathophysiology of AHF and inform clinical decision-making. We evaluated detailed clinical data of 345 consecutive AHF patients using non-hierarchical cluster analysis of 77 variables, including age, sex, HF etiology, comorbidities, physical findings, laboratory data, electrocardiogram, echocardiogram and treatment during hospitalization. Cox proportional hazards regression analysis was performed to estimate the association between the clusters and clinical outcomes. Three clusters were identified. Cluster 1 (n=108) represented "vascular failure". This cluster had the highest average systolic blood pressure at admission and lung congestion with type 2 respiratory failure. Cluster 2 (n=89) represented "cardiac and renal failure". They had the lowest ejection fraction (EF) and worst renal function. Cluster 3 (n=148) comprised mostly older patients and had the highest prevalence of atrial fibrillation and preserved EF. Death or HF hospitalization within 12-month occurred in 23% of Cluster 1, 36% of Cluster 2 and 36% of Cluster 3 (p=0.034). Compared with Cluster 1, risk of death or HF hospitalization was 1.74 (95% CI, 1.03-2.95, p=0.037) for Cluster 2 and 1.82 (95% CI, 1.13-2.93, p=0.014) for Cluster 3. Cluster analysis may be effective in producing clinically relevant categories of AHF, and may suggest underlying pathophysiology and potential utility in predicting clinical outcomes. Copyright © 2018 Elsevier B.V. All rights reserved.

[Blood supply of pulmonary metastases and its clinical significance].

PubMed

Jiang, Guo-Min; Zhao, Jin-Wei; Chen, Ya-Xian; Tian, Feng

2006-07-01

Interventional treatment has been widely applied to primary lung carcinoma, but seldom applied to pulmonary metastases because the blood supply of pulmonary metastases has rarely been investigated, and the present understanding is controversial. This study was to explore the correlation of the clinical value of bronchial arterial chemotherapeutic infusion (BAI) combined bronchial arterial embolization (BAE) to the blood supply of pulmonary metastases. Bronchial artery angiography was performed on 33 patients with pulmonary metastases to assess the blood supply and the distribution of pulmonary metastases. BAI was performed on hypovascular nodules, and BAE was performed on hypervascular nodules. Of the 89 metastatic nodules in the lungs of 33 patients, 63 (70.8%) were located in the mid-medial zone, and 26 (29.3%) in the lateral region of the lung; 56 had abundant blood supply, and 33 had poor blood supply. The blood supply of pulmonary metastases was correlated to the location of metastatic nodules. Most nodules in the mid-medial region had abundant blood supply, while most nodules in the lateral region had poor or had no blood supply (P<0.01). The blood supply of bronchial artery had no correlation to the volume of metastatic nodule (P>0.05). The curative efficacy of BAI and BAE was correlated to the blood supply of bronchial artery. The response rate was significantly higher in the hypervascular nodules treated with BAE than in the hypovascular nodules treated with BAI (71.4% vs. 42.4%, P<0.01). Most pulmonary metastases of hepatic cancer were hypervascular and the lipiodol deposited well in the nodules; during the follow-up, the nodules shrunk significantly and kept stable. Bronchial artery is the major feeding artery of pulmonary metastases. BAI and BAE are effective in treating pulmonary metastases with abundant blood supply.

Buffering of blood pressure variability by the renin-angiotensin system in the conscious dog

PubMed Central

Just, Armin; Kirchheim, Hartmut R; Ehmke, Heimo

1998-01-01

The renin-angiotensin system (RAS) participates in the compensation of major blood pressure disturbances such as haemorrhage and is involved in the tonic long-term (> 1 day) maintenance of mean arterial blood pressure (MABP). Since its contribution to the short-term (< 1 h) buffering of normal blood pressure variability is not known, this was investigated in resting conscious dogs.The regulatory efficiency and the response time of the RAS were studied by an acute step reduction of renal artery pressure to 70 mmHg for 1 h using a suprarenal aortic cuff. After a delay of at least 100 s, MABP rose exponentially by 22 ± 5 mmHg in normal dogs (n = 4), by 6 ± 3 mmHg after angiotensin converting enzyme (ACE) inhibition (n = 4), and by 25 ± 5 mmHg after ganglionic blockade (n = 4). MABP returned to control after release of the cuff with similar time courses. The time constants of the MABP responses were in the range of 20 min. Thus, possible feedback oscillations of the RAS would be expected around 0.0025 Hz (1/(4 × 100 s)); a buffering effect would be possible below this frequency.Blood pressure variability was investigated by spectral analysis of MABP from 3.75 h recordings in the frequency ranges of 0.002–0.003 Hz (feedback oscillations) and below 0.002 Hz (buffering effect).ACE inhibition (n = 7) decreased MABP by 11 ± 2 mmHg (P < 0.05), but in both frequency ranges integrated spectral density was not affected. ACE inhibition also failed to significantly change spectral density in either of the two frequency ranges under the following conditions: (1) during ganglionic blockade (n = 7), (2) during a low-sodium diet (except for a very slight elevation below 0.002 Hz) (n = 7), and (3) when the fall of MABP induced by ACE inhibition was compensated by an angiotensin II infusion (n = 7).It is concluded that in spite of its high regulatory efficiency with an adequate response time the RAS does not directly contribute to the short-term buffering of blood pressure

Lifetime shift work exposure: association with anthropometry, body composition, blood pressure, glucose and heart rate variability.

PubMed

Souza, Breno Bernardes; Monteze, Nayara Mussi; de Oliveira, Fernando Luiz Pereira; de Oliveira, José Magalhães; de Freitas Nascimento, Silvia; Marques do Nascimento Neto, Raimundo; Sales, Maria Lilian; Souza, Gabriela Guerra Leal

2015-03-01

To evaluate the association between lifetime exposure to shift work and blood pressure, fasting glucose (FG), anthropometric variables, body composition and heart rate variability (HRV). Male shift workers (N=438) were evaluated using principal component (PC) analysis. The variables used were: weight, body mass index (BMI), waist circumference (WC), neck circumference (NC), hip circumference (HC), waist-to-hip ratio (WHR), waist-to-height ratio (WHtR), body fat mass (BFKg), body fat percentage (BF%), visceral fat area (VFA), FG, systolic (SBP) and diastolic blood pressure (DBP), and HRV variables. ECG was performed, extracting heart rate (HR), root mean square of the successive differences (RMSSD), high frequency (HF), low frequency (LF) and the LF/HF ratio. Using linear regression models, the lifetime shift work exposure was associated with each PC. Five PCs were obtained, which accounted for 79.6% of the total variation of the data. PC1 (weight, BMI, WC, NC, HC, WHR, WHtR, BFKg, BF% and VFA) was designated as body obesity; PC2 (HF, RMSSD and LF) as good cardiac regulation; PC3 (SBP and DBP) as blood pressure; PC4 (LF/HF ratio and HR) as bad cardiac regulation and PC5 (WHR and FG) as insulin resistance. After age adjustment, the regression analysis showed that lifetime shift work was negatively associated with PC2 and positively associated with PC3. The association of lifetime shift work exposure with PC2 and PC3 suggests that shift work promotes unfavourable changes in autonomic cardiac control related to a decrease in parasympathetic modulation and an increase in blood pressure. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Impact of perioperative blood pressure variability on health resource utilization after cardiac surgery: an analysis of the ECLIPSE trials.

PubMed

Aronson, Solomon; Levy, Jerrold H; Lumb, Philip D; Fontes, Manuel; Wang, Yamei; Crothers, Tracy A; Sulham, Katherine A; Navetta, Marco S

2014-06-01

To examine the impact of blood pressure control on hospital health resource utilization using data from the ECLIPSE trials. Post-hoc analysis of data from 3 prospective, open-label, randomized clinical trials (ECLIPSE trials). Sixty-one medical centers in the United States. Patients 18 years or older undergoing cardiac surgery. Clevidipine was compared with nitroglycerin, sodium nitroprusside, and nicardipine. The ECLIPSE trials included 3 individual randomized open-label studies comparing clevidipine to nitroglycerin, sodium nitroprusside, and nicardipine. Blood pressure control was assessed as the integral of the cumulative area under the curve (AUC) outside specified systolic blood pressure ranges, such that lower AUC represents less variability. This analysis examined surgery duration, time to extubation, as well as intensive care unit (ICU) and hospital length of stay (LOS) in patients with AUC≤10 mmHg×min/h compared to patients with AUC>10 mmHg×min/h. One thousand four hundred ten patients were included for analysis; 736 patients (52%) had an AUC≤10 mmHg×min/h, and 674 (48%) had an AUC>10 mmHg×min/h. The duration of surgery and ICU LOS were similar between groups. Time to extubation and postoperative LOS were both significantly shorter (p = 0.05 and p<0.0001, respectively) in patients with AUC≤10. Multivariate analysis demonstrates AUC≤10 was significantly and independently associated with decreased time to extubation (hazard ratio 1.132, p = 0.0261) and postoperative LOS (hazard ratio 1.221, p = 0.0006). Based on data derived from the ECLIPSE studies, increased perioperative BP variability is associated with delayed time to extubation and increased postoperative LOS. Copyright © 2014 Elsevier Inc. All rights reserved.

Relationship of visit-to-visit and ambulatory blood pressure variability to vascular function in African Americans.

PubMed

Diaz, Keith M; Veerabhadrappa, Praveen; Kashem, Mohammed A; Feairheller, Deborah L; Sturgeon, Kathleen M; Williamson, Sheara T; Crabbe, Deborah L; Brown, Michael D

2012-01-01

Visit-to-visit clinic blood pressure variability (BPV) and 24-h BPV have both been identified as independent risk factors for cardiovascular (CV) morbidity and mortality; however, the mechanisms contributing to the increased CV risk as yet are unclear. The purpose of this study was to assess the relationship between BPV and endothelial function in a cohort of putatively healthy African Americans. A total of 36 African Americans who were sedentary, non-diabetic, non-smoking, free of CV and renal disease and not on antihypertensive medication followed an American Heart Association low fat, low salt diet for 6 weeks. Upon completion of the 6-week dietary stabilization period, participants underwent 24-h ambulatory BP monitoring and had their office blood pressure (BP) measured on 3 separate days. Right brachial artery diameter was assessed at rest, during reactive hyperemia (flow-mediated vasodilation: FMD), and after nitroglycerin administration (nitroglycerin-mediated vasodilation: NMD). Participants classified as having decreased endothelial function according to either %FMD or the FMD/NMD ratio had significantly higher 24-h BPV and a trend for higher visit-to-visit BPV when compared with participants with normal endothelial function. Continuous variable analyses revealed a significant positive association between NMD and 24-h diastolic BPV (DBPV). Visit-to-visit systolic BPV (SBPV), 24-h SBPV and 24-h DBPV were all negatively associated with the FMD/NMD ratio. All relationships remained significant after adjustment for age, body mass index and mean BP levels. These results may suggest that BPV is increased in African Americans with decreased endothelial function and is associated with the vascular smooth muscle response to nitric oxide.

Visualizing blood vessel trees in three dimensions: clinical applications

NASA Astrophysics Data System (ADS)

Bullitt, Elizabeth; Aylward, Stephen

2005-04-01

A connected network of blood vessels surrounds and permeates almost every organ of the human body. The ability to define detailed blood vessel trees enables a variety of clinical applications. This paper discusses four such applications and some of the visualization challenges inherent to each. Guidance of endovascular surgery: 3D vessel trees offer important information unavailable by traditional x-ray projection views. How best to combine the 2- and 3D image information is unknown. Planning/guidance of tumor surgery: During tumor resection it is critical to know which blood vessels can be interrupted safely and which cannot. Providing efficient, clear information to the surgeon together with measures of uncertainty in both segmentation and registration can be a complex problem. Vessel-based registration: Vessel-based registration allows pre-and intraoperative images to be registered rapidly. The approach both provides a potential solution to a difficult clinical dilemma and offers a variety of visualization opportunities. Diagnosis/staging of disease: Almost every disease affects blood vessel morphology. The statistical analysis of vessel shape may thus prove to be an important tool in the noninvasive analysis of disease. A plethora of information is available that must be presented meaningfully to the clinician. As medical image analysis methods increase in sophistication, an increasing amount of useful information of varying types will become available to the clinician. New methods must be developed to present a potentially bewildering amount of complex data to individuals who are often accustomed to viewing only tissue slices or flat projection views.

Childhood Depression: Relation to Adaptive, Clinical and Predictor Variables

PubMed Central

Garaigordobil, Maite; Bernarás, Elena; Jaureguizar, Joana; Machimbarrena, Juan M.

2017-01-01

The study had two goals: (1) to explore the relations between self-assessed childhood depression and other adaptive and clinical variables (2) to identify predictor variables of childhood depression. Participants were 420 students aged 7–10 years old (53.3% boys, 46.7% girls). Results revealed: (1) positive correlations between depression and clinical maladjustment, school maladjustment, emotional symptoms, internalizing and externalizing problems, problem behaviors, emotional reactivity, and childhood stress; and (2) negative correlations between depression and personal adaptation, global self-concept, social skills, and resilience (sense of competence and affiliation). Linear regression analysis including the global dimensions revealed 4 predictors of childhood depression that explained 50.6% of the variance: high clinical maladjustment, low global self-concept, high level of stress, and poor social skills. However, upon introducing the sub-dimensions, 9 predictor variables emerged that explained 56.4% of the variance: many internalizing problems, low family self-concept, high anxiety, low responsibility, low personal self-assessment, high social stress, few aggressive behaviors toward peers, many health/psychosomatic problems, and external locus of control. The discussion addresses the importance of implementing prevention programs for childhood depression at early ages. PMID:28572787

Morning pressor surge, blood pressure variability, and arterial stiffness in essential hypertension.

PubMed

Pucci, Giacomo; Battista, Francesca; Anastasio, Fabio; Schillaci, Giuseppe

2017-02-01

An excess morning blood pressure surge (MBPS) may portend an increased cardiovascular risk, but the mechanisms thereof have been little investigated. The link between MBPS, short-term blood pressure (BP) variability, and arterial stiffness has not been entirely defined. In 602 consecutive untreated hypertensive patients (48 ± 12 years, 61% men, office BP 149/93 ± 17/10 mmHg), we measured carotid-femoral pulse wave velocity (cf-PWV, SphygmoCor) and 24-h ambulatory BP. Using self-reported sleep and wake times, MBPS was defined as sleep-trough (ST-MBPS), prewaking, rising. Short-term BP variability was calculated as weighted 24-h SBP SD and average real variability of 24-h SBP (ARV), that is, average of absolute differences between consecutive SBP readings. ST-MBPS (r = 0.16, P < 0.001) and rising MBPS (r = 0.12, P = 0.003) showed a direct correlation with cf-PWV, whereas prewaking MBPS had no such relation (r = 0.06, P = 0.14). Only ST-MBPS was independently associated with cf-PWV (t = 1.96, P = 0.04) after adjustment for age, sex, height, office mean arterial pressure, heart rate, and renal function. This association was lost after further adjustment for weighted 24-h SBP SD (P = 0.13) or ARV (P = 0.24). ARV was a significant mediator of the relationship between ST-MBPS and cf-PWV (P = 0.003). In untreated hypertension, ST-MBPS has a direct relation with aortic stiffness, which is mediated by an increased ARV. The adverse effects of MBPS may be partly explained by its link with arterial stiffness, mediated by short-term SBP variability.

Letter to editor: Blood pressure, hypertension and lead exposure.

PubMed

Yang, Wen-Yi; Staessen, Jan A

2018-02-19

A significant association of office diastolic blood pressure with low-level blood lead exposure was reported in a Brazilian adult population. However, caution should be taken to interpret these results. The multivariable-adjusted association with blood pressure was positive for diastolic blood pressure, but inverse for systolic blood pressure. The association sizes were infinitesimal without clinical relevance. The outcome measures, i.e. blood pressure and the prevalence of hypertension were analysed across categories of the blood lead distribution - not in relation to blood lead as continuous variable. Blood pressure was the average of two oscillometric office readings, whereas ambulatory monitoring is the state-of-the-art.

Blood pressure response to patterns of weather fluctuations and effect on mortality.

PubMed

Aubinière-Robb, Louise; Jeemon, Panniyammakal; Hastie, Claire E; Patel, Rajan K; McCallum, Linsay; Morrison, David; Walters, Matthew; Dawson, Jesse; Sloan, William; Muir, Scott; Dominiczak, Anna F; McInnes, Gordon T; Padmanabhan, Sandosh

2013-07-01

Very few studies have looked at longitudinal intraindividual blood pressure responses to weather conditions. There are no data to suggest that specific response to changes in weather will have an impact on survival. We analyzed >169 000 clinic visits of 16 010 Glasgow Blood Pressure Clinic patients with hypertension. Each clinic visit was mapped to the mean West of Scotland monthly weather (temperature, sunshine, rainfall) data. Percentage change in blood pressure was calculated between pairs of consecutive clinic visits, where the weather alternated between 2 extreme quartiles (Q(1)-Q(4) or Q(4)-Q(1)) or remained in the same quartile (Q(n)-Q(n)) of each weather parameter. Subjects were also categorized into 2 groups depending on whether their blood pressure response in Q(1)-Q(4) or Q(4)-Q(1) were concordant or discordant to Q(n)-Q(n). Generalized estimating equations and Cox proportional hazards model were used to model the effect on longitudinal blood pressure and mortality, respectively. Q(n)-Q(n) showed a mean 2% drop in blood pressure consistently, whereas Q(4)-Q(1) showed a mean 2.1% and 1.6% rise in systolic and diastolic blood pressure, respectively. However, Q(1)-Q(4) did not show significant changes in blood pressure. Temperature-sensitive subjects had significantly higher mortality (1.35 [95% confidence interval, 1.06-1.71]; P=0.01) and higher follow-up systolic blood pressure (1.85 [95% confidence interval, 0.24-3.46]; P=0.02) compared with temperature-nonsensitive subjects. Blood pressure response to temperature may be one of the underlying mechanisms that determine long-term blood pressure variability. Knowing a patient's blood pressure response to weather can help reduce unnecessary antihypertensive treatment modification, which may in turn increase blood pressure variability and, thus, risk.

Definition of variables required for comprehensive description of drug dosage and clinical pharmacokinetics.

PubMed

Medem, Anna V; Seidling, Hanna M; Eichler, Hans-Georg; Kaltschmidt, Jens; Metzner, Michael; Hubert, Carina M; Czock, David; Haefeli, Walter E

2017-05-01

Electronic clinical decision support systems (CDSS) require drug information that can be processed by computers. The goal of this project was to determine and evaluate a compilation of variables that comprehensively capture the information contained in the summary of product characteristic (SmPC) and unequivocally describe the drug, its dosage options, and clinical pharmacokinetics. An expert panel defined and structured a set of variables and drafted a guideline to extract and enter information on dosage and clinical pharmacokinetics from textual SmPCs as published by the European Medicines Agency (EMA). The set of variables was iteratively revised and evaluated by data extraction and variable allocation of roughly 7% of all centrally approved drugs. The information contained in the SmPC was allocated to three information clusters consisting of 260 variables. The cluster "drug characterization" specifies the nature of the drug. The cluster "dosage" provides information on approved drug dosages and defines corresponding specific conditions. The cluster "clinical pharmacokinetics" includes pharmacokinetic parameters of relevance for dosing in clinical practice. A first evaluation demonstrated that, despite the complexity of the current free text SmPCs, dosage and pharmacokinetic information can be reliably extracted from the SmPCs and comprehensively described by a limited set of variables. By proposing a compilation of variables well describing drug dosage and clinical pharmacokinetics, the project represents a step forward towards the development of a comprehensive database system serving as information source for sophisticated CDSS.

Variability of carotid artery measurements on 3-Tesla MRI and its impact on sample size calculation for clinical research.

PubMed

Syed, Mushabbar A; Oshinski, John N; Kitchen, Charles; Ali, Arshad; Charnigo, Richard J; Quyyumi, Arshed A

2009-08-01

Carotid MRI measurements are increasingly being employed in research studies for atherosclerosis imaging. The majority of carotid imaging studies use 1.5 T MRI. Our objective was to investigate intra-observer and inter-observer variability in carotid measurements using high resolution 3 T MRI. We performed 3 T carotid MRI on 10 patients (age 56 +/- 8 years, 7 male) with atherosclerosis risk factors and ultrasound intima-media thickness > or =0.6 mm. A total of 20 transverse images of both right and left carotid arteries were acquired using T2 weighted black-blood sequence. The lumen and outer wall of the common carotid and internal carotid arteries were manually traced; vessel wall area, vessel wall volume, and average wall thickness measurements were then assessed for intra-observer and inter-observer variability. Pearson and intraclass correlations were used in these assessments, along with Bland-Altman plots. For inter-observer variability, Pearson correlations ranged from 0.936 to 0.996 and intraclass correlations from 0.927 to 0.991. For intra-observer variability, Pearson correlations ranged from 0.934 to 0.954 and intraclass correlations from 0.831 to 0.948. Calculations showed that inter-observer variability and other sources of error would inflate sample size requirements for a clinical trial by no more than 7.9%, indicating that 3 T MRI is nearly optimal in this respect. In patients with subclinical atherosclerosis, 3 T carotid MRI measurements are highly reproducible and have important implications for clinical trial design.

Forensic Luminol Blood Test for Preventing Cross-contamination in Dentistry: An Evaluation of a Dental School Clinic.

PubMed

Bortoluzzi, Marcelo Carlos; Cadore, Peterson; Gallon, Andrea; Imanishi, Soraia Almeida Watanabe

2014-10-01

More than 200 different diseases may be transmitted from exposure to blood in the dental setting. The aim of this study is to identify possible faults in the crosscontamination chain control in a dental school clinic searching for traces of blood in the clinical contact surfaces (CCS) through forensic luminol blood test. Traces of invisible blood where randomly searched in CCS of one dental school clinic. Forty eight surfaces areas in the CCS were tested and the presence of invisible and remnant blood was identified in 28 (58.3%) items. We suggest that the luminol method is suitable for identifying contamination with invisible blood traces and this method may be a useful tool to prevent cross-contamination in the dental care setting.

Effect of education and clinical assessment on the accuracy of post partum blood loss estimation

PubMed Central

2014-01-01

Background This research aimed to assess the effect of health care provider education on the accuracy of post partum blood loss estimation. Methods A non-randomized observational study that was conducted at King Abdulaziz Medical City, Riyadh, Saudi Arabia between January 1, 2011 and June 30, 2011. Hundred and twenty three health care providers who are involved in the estimation of post partum blood loss were eligible to participate. The participants were subjected to three research phases and an educational intervention. They have assessed a total of 30 different simulated blood loss stations, with 10 stations in each of the research phases. These phases took place before and after educational sessions on how to visually estimate blood loss and how to best utilize patient data in clinical scenarios. We have assessed the differences between the estimated blood loss and the actual measure. P-values were calculated to assess the differences between the three research phases estimations. Results The participants significantly under-estimated post partum blood loss. The accuracy was improved after training (p-value < 0.0001) and after analysing each patient’s clinical information (p-value = 0.042). The overall results were not affected by the participants’ clinical backgrounds or their years of experience. Under-estimation was more prominent in cases where more than average-excessive blood losses were simulated while over-estimations or accurate estimations were more prominent in less than average blood loss incidents. Conclusion Simple education programmes can improve traditional findings related to under-estimation of blood loss. More sophisticated clinical education programmes may provide additional improvements. PMID:24646156

Challenges of assessing the clinical efficacy of asexual blood-stage Plasmodium falciparum malaria vaccines.

PubMed

Sheehy, Susanne H; Douglas, Alexander D; Draper, Simon J

2013-09-01

In the absence of any highly effective vaccine candidate against Plasmodium falciparum malaria, it remains imperative for the field to pursue all avenues that may lead to the successful development of such a formulation. The development of a subunit vaccine targeting the asexual blood-stage of Plasmodium falciparum malaria infection has proven particularly challenging with only limited success to date in clinical trials. However, only a fraction of potential blood-stage vaccine antigens have been evaluated as targets, and a number of new promising candidate antigen formulations and delivery platforms are approaching clinical development. It is therefore essential that reliable and sensitive methods of detecting, or ruling out, even modest efficacy of blood-stage vaccines in small clinical trials be established. In this article we evaluate the challenges facing blood-stage vaccine developers, assess the appropriateness and limitations of various in vivo approaches for efficacy assessment and suggest future directions for the field.

A Systematic Review and Meta-Analysis of the Clinical Appropriateness of Blood Transfusion in China

PubMed Central

Zhu, Changtai; Gao, Yulu; Li, Zhiqiang; Li, Qinyun; Gao, Zongshuai; Liao, Yanqiu; Deng, Zhifeng

2015-01-01

Abstract The issue of the clinical appropriateness of blood transfusion has become a focus of transfusion medicine worldwide. In China, irrational uses of blood have often been reported in recent years. However, to date there lacks a systematic review of the rational uses of blood. This study aimed to determine the clinical appropriateness of blood transfusion in China. We searched PubMed, Web of Science, the Cochrane Library, China National Knowledge Infrastructure (CNKI), China Science and Technology Journal Database, WanFang Database, and Chinese BioMedical Literature Database, and the retrieval cut-off date was June 31, 2015. SPSS 17.0 and MetaAnalyst 3.13 were employed as the statistics tools in this review. A pooled rate of clinical inappropriateness of transfusion was analyzed by DerSimonian–Laird method. In this study, a total of 39 observational studies were included, which related to 75,132 cases of blood transfusion. According to the meta-analysis results, the overall incidence of clinical inappropriateness of transfusion in China was estimated to be 37.3% (95% confidence interval [CI] [32.1, 42.8]). The subgroup analyses revealed that the pooled rates of clinical inappropriateness of transfusion of plasma, red blood cells (RBCs), cryoprecipitate, and platelets were 56.3% (95% CI [45.8, 66.2]), 30.9% (95% CI [27.1, 35.0]), 25.2% (95% CI [13.2, 42.7]), and 14.1% (95% CI [8.8, 21.9]), respectively. However, the pooled incidence of inappropriateness of transfusion in operative departments was 47.5% (95% CI [36.8, 58.3]), which was significantly higher than that in nonoperative departments, 25.8% (95% CI [18.7, 34.4], P < 0.05). The overall rates of inappropriate use were 36.7% (95% CI [30.2, 43.6]) in major cities and 37.5% (95% CI [31.2, 44.3]) in other cities, respectively; there was no statistically significant difference (P > 0.05). In conclusion, China has suffered from a disadvantage in the clinical appropriateness of blood transfusion

A Systematic Review and Meta-Analysis of the Clinical Appropriateness of Blood Transfusion in China.

PubMed

Zhu, Changtai; Gao, Yulu; Li, Zhiqiang; Li, Qinyun; Gao, Zongshuai; Liao, Yanqiu; Deng, Zhifeng

2015-12-01

The issue of the clinical appropriateness of blood transfusion has become a focus of transfusion medicine worldwide. In China, irrational uses of blood have often been reported in recent years. However, to date there lacks a systematic review of the rational uses of blood. This study aimed to determine the clinical appropriateness of blood transfusion in China. We searched PubMed, Web of Science, the Cochrane Library, China National Knowledge Infrastructure (CNKI), China Science and Technology Journal Database, WanFang Database, and Chinese BioMedical Literature Database, and the retrieval cut-off date was June 31, 2015. SPSS 17.0 and MetaAnalyst 3.13 were employed as the statistics tools in this review. A pooled rate of clinical inappropriateness of transfusion was analyzed by DerSimonian-Laird method. In this study, a total of 39 observational studies were included, which related to 75,132 cases of blood transfusion. According to the meta-analysis results, the overall incidence of clinical inappropriateness of transfusion in China was estimated to be 37.3% (95% confidence interval [CI] [32.1, 42.8]). The subgroup analyses revealed that the pooled rates of clinical inappropriateness of transfusion of plasma, red blood cells (RBCs), cryoprecipitate, and platelets were 56.3% (95% CI [45.8, 66.2]), 30.9% (95% CI [27.1, 35.0]), 25.2% (95% CI [13.2, 42.7]), and 14.1% (95% CI [8.8, 21.9]), respectively. However, the pooled incidence of inappropriateness of transfusion in operative departments was 47.5% (95% CI [36.8, 58.3]), which was significantly higher than that in nonoperative departments, 25.8% (95% CI [18.7, 34.4], P < 0.05). The overall rates of inappropriate use were 36.7% (95% CI [30.2, 43.6]) in major cities and 37.5% (95% CI [31.2, 44.3]) in other cities, respectively; there was no statistically significant difference (P > 0.05). In conclusion, China has suffered from a disadvantage in the clinical appropriateness of blood transfusion, especially in

Blood pressure response to renal denervation is correlated with baseline blood pressure variability: a patient-level meta-analysis.

PubMed

Persu, Alexandre; Gordin, Daniel; Jacobs, Lotte; Thijs, Lutgarde; Bots, Michiel L; Spiering, Wilko; Miroslawska, Atena; Spaak, Jonas; Rosa, Ján; de Jong, Mark R; Berra, Elena; Fadl Elmula, Fadl Elmula M; Wuerzner, Gregoire; Taylor, Alison H M; Olszanecka, Agnieszka; Czarnecka, Danuta; Mark, Patrick B; Burnier, Michel; Renkin, Jean; Kjeldsen, Sverre E; Widimský, Jiří; Elvan, Arif; Kahan, Thomas; Steigen, Terje K; Blankestijn, Peter J; Tikkanen, Ilkka; Staessen, Jan A

2018-02-01

Sympathetic tone is one of the main determinants of blood pressure (BP) variability and treatment-resistant hypertension. The aim of our study was to assess changes in BP variability after renal denervation (RDN). In addition, on an exploratory basis, we investigated whether baseline BP variability predicted the BP changes after RDN. We analyzed 24-h BP recordings obtained at baseline and 6 months after RDN in 167 treatment-resistant hypertension patients (40% women; age, 56.7 years; mean 24-h BP, 152/90 mmHg) recruited at 11 expert centers. BP variability was assessed by weighted SD [SD over time weighted for the time interval between consecutive readings (SDiw)], average real variability (ARV), coefficient of variation, and variability independent of the mean (VIM). Mean office and 24-h BP fell by 15.4/6.6 and 5.5/3.7 mmHg, respectively (P < 0.001). In multivariable-adjusted analyses, systolic/diastolic SDiw and VIM for 24-h SBP/DBP decreased by 1.18/0.63 mmHg (P ≤ 0.01) and 0.86/0.42 mmHg (P ≤ 0.05), respectively, whereas no significant changes in ARV or coefficient of variation occurred. Furthermore, baseline SDiw (P = 0.0006), ARV (P = 0.01), and VIM (P = 0.04) predicted the decrease in 24-h DBP but not 24-h SBP after RDN. RDN was associated with a decrease in BP variability independent of the BP level, suggesting that responders may derive benefits from the reduction in BP variability as well. Furthermore, baseline DBP variability estimates significantly correlated with mean DBP decrease after RDN. If confirmed in younger patients with less arterial damage, in the absence of the confounding effect of drugs and drug adherence, baseline BP variability may prove a good predictor of BP response to RDN.

[Predictive ability of clinical parameters of bacteremia in hemodialysed patients].

PubMed

Egea, Ana L; Vilaró, Mario; De la Fuente, Jorge; Cuestas, Eduardo; Bongiovanni, María E

2012-01-01

No clinical events to differentiate bacteteremia from other pathologies in hemodialysis patients therefore the physicians makes diagnosis and treatment decisions based on clinical evidence an local epidemiology. the aim of this work was to study the frequency of microorganism isolated from blood culture of hemodialysis patients with suspected bacteraemia and evaluate Sensitivity (S) and Specificity (E) of medical diagnostic orientation in this cases of suspected Materials and methods: we performed an observational and prospective study for one year in hemodialysis patient with suspected bacteremia. We evaluated blood pressure, temperature (Tº), altered conscious state (AEC), respiratory frequency (FR), chills (ESC),diarrhea (DIARR), blood culture results and microbiological identification. We work with the mean ± standar desviation for continuous variables and frequencies for categorical variables We analyzed S, E, negative predictive value (VPN), positive predictive value (VPP) RESULTADOS: a total of 87 events with suspected bacteremia 34 (39%) were confirmed with positive blood culture the most common microorganisms were cocci Gram positive (CGP) 65%, Most relevant clinical variables were PCP ≥ 2 (VPN 81%), Tº ≥ 38 (VPN 76%) and AEC (E 98% y VPP 80%). CGP were the most prevalent microorganisms None of the clinical variables shows high S and E indicating low usefulness as a predictive tool of bacteremia Excepting AEC with E98% and VPP 80% but it would be necessary to evaluate this variable with a more number patient. Results justify to routine HC use like diagnostic tool.

Elevated blood pressure in the developing world: a role for clinical pharmacists.

PubMed

Smith, Michael T; Monahan, Megan P; Nelson, Paige; Moruzzi, Matthew; DeLucenay, Alexander J; Birnie, Christine R

2017-09-19

The objective of this study was to evaluate the prevalence and patient knowledge of elevated blood pressure amongst a cross-section of patients in underserved communities in three selected low-income countries worldwide: El Salvador, India and Kenya. Mobile medical clinics were established as part of medical mission trips in El Salvador, India and Kenya. Willing male and female patients, at least 25 years of age, who presented at each clinic were screened for elevated blood pressure, including 332 patients in El Salvador, 847 patients in India and 160 patients in Kenya. Patients were classified into Stage I or II elevated blood pressure based on modified JNCVII guidelines. A questionnaire was completed regarding their knowledge about the existence and management of their disease state. Of the 1339 patients screened, 368 presented with elevated blood pressure (27%). Of these patients, 147 had been previously informed of hypertension or an elevated blood pressure (39.9%), 28 reported receiving antihypertensive medication (7.6%) and 24 reported awareness of non-pharmaceutical treatment options (6.5%). In Kenya, 81 patients were screened in a rural setting and 79 in an urban setting. Patients demonstrating controlled blood pressure were 63 (78%) and 38 (48%), respectively, demonstrating a significant difference between the rural versus urban settings (P = 0.00359). All regions demonstrated similar trends in the prevalence of elevated blood pressure, highlighting the need for increased disease state education in these regions. © 2017 Royal Pharmaceutical Society.

Multicenter Clinical Evaluation of BacT/Alert Virtuo Blood Culture System.

PubMed

Jacobs, Michael R; Mazzulli, Tony; Hazen, Kevin C; Good, Caryn E; Abdelhamed, Ayman M; Lo, Pauline; Shum, Bianche; Roman, Katharine P; Robinson, Danielle C

2017-08-01

BacT/Alert Virtuo is an advanced, automated blood culture system incorporating improved automation and an enhanced detection algorithm to shorten time to detection. A multicenter study of the investigational Virtuo system (bioMérieux, Inc., Durham, NC) compared to BacT/Alert 3D (BTA3D) for detection of bacteremia/fungemia in four bottle types, SA and FA Plus (aerobic) and SN and FN Plus (anaerobic), was performed in a clinical setting with patient samples in a matched system design clinical trial. Blood was added to paired aerobic or anaerobic bottles, with the volume in each bottle in each pair required to be ≤10 ml and with the volumes required to be within 30% of each other. Of 5,709 bottle sets (52.5% aerobic pairs and 47.5% anaerobic pairs), 430 (7.5%) were positive for bacterial or fungal growth, with 342 (6.0%) clinically significant and 83 (1.5%) contaminated. A total of 3,539 sets (62.0%) were volume compliant, with 203 sets (5.7%) clinically significant. The positivity rates for volume-compliant bottle pairs determined by the two systems were comparable, with 68.7% of clinically significant isolates detected by both instruments, 15.7% by Virtuo only, and 15.7% by BTA3D only. Virtuo detected microbial growth nearly 2 h sooner overall than BTA3D (mean, 15.9 h versus 17.7 h). Shorter time to detection by Virtuo was related to organism group, with the time to detection being significantly shorter for enteric Gram-negative bacilli and enterococci (means, 3.6 h and 2.3 h shorter, respectively). This large clinical study demonstrated that the Virtuo blood culture system produced results comparable to those seen with the long-established BTA3D system, with significantly shorter time to detection. Copyright © 2017 Jacobs et al.

Forensic Luminol Blood Test for Preventing Cross-contamination in Dentistry: An Evaluation of a Dental School Clinic

PubMed Central

Bortoluzzi, Marcelo Carlos; Cadore, Peterson; Gallon, Andrea; Imanishi, Soraia Almeida Watanabe

2014-01-01

Background: More than 200 different diseases may be transmitted from exposure to blood in the dental setting. The aim of this study is to identify possible faults in the crosscontamination chain control in a dental school clinic searching for traces of blood in the clinical contact surfaces (CCS) through forensic luminol blood test. Methods: Traces of invisible blood where randomly searched in CCS of one dental school clinic. Results: Forty eight surfaces areas in the CCS were tested and the presence of invisible and remnant blood was identified in 28 (58.3%) items. Conclusions: We suggest that the luminol method is suitable for identifying contamination with invisible blood traces and this method may be a useful tool to prevent cross-contamination in the dental care setting. PMID:25400895

Intra- and Interobserver Variability of Cochlear Length Measurements in Clinical CT.

PubMed

Iyaniwura, John E; Elfarnawany, Mai; Riyahi-Alam, Sadegh; Sharma, Manas; Kassam, Zahra; Bureau, Yves; Parnes, Lorne S; Ladak, Hanif M; Agrawal, Sumit K

2017-07-01

The cochlear A-value measurement exhibits significant inter- and intraobserver variability, and its accuracy is dependent on the visualization method in clinical computed tomography (CT) images of the cochlea. An accurate estimate of the cochlear duct length (CDL) can be used to determine electrode choice, and frequency map the cochlea based on the Greenwood equation. Studies have described estimating the CDL using a single A-value measurement, however the observer variability has not been assessed. Clinical and micro-CT images of 20 cadaveric cochleae were acquired. Four specialists measured A-values on clinical CT images using both standard views and multiplanar reconstructed (MPR) views. Measurements were repeated to assess for intraobserver variability. Observer variabilities were evaluated using intra-class correlation and absolute differences. Accuracy was evaluated by comparison to the gold standard micro-CT images of the same specimens. Interobserver variability was good (average absolute difference: 0.77 ± 0.42 mm) using standard views and fair (average absolute difference: 0.90 ± 0.31 mm) using MPR views. Intraobserver variability had an average absolute difference of 0.31 ± 0.09 mm for the standard views and 0.38 ± 0.17 mm for the MPR views. MPR view measurements were more accurate than standard views, with average relative errors of 9.5 and 14.5%, respectively. There was significant observer variability in A-value measurements using both the standard and MPR views. Creating the MPR views increased variability between experts, however MPR views yielded more accurate results. Automated A-value measurement algorithms may help to reduce variability and increase accuracy in the future.

[Patients' perspective and economic variables as objectives in clinical trials: added value to clinical parameters].

PubMed

Bovaira-García, M J; Soler-Company, E

2012-01-01

Patient-reported outcome (PRO) measures complement traditional biomedical outcome measures. The purpose of this study was to evaluate the use of PRO measures including health-related quality of life (HRQoL) questionnaires as a measurement of efficacy and the frequency of inclusion of economic variables related to direct and indirect costs in the design of clinical trials and phase IV observational studies. Moreover, for the trials quality score were measured, and if there were any relationship between the quality study design score and the PRO inclusion. Retrospective observational study of the clinical trials and phase IV observational studies approved by a Clinical Research Ethics Committee (2008-2010). We gathered data concerning general aspects including medical specialty, pathology, methodological quality based on Jadad scale (0-5), inclusion of PRO and economic variables. For clinical trials including HRQoL measurements, we analysed the type of questionnaire in use. Where there were no HRQoL measurements, we analysed if their inclusion would have been proper or not. A total of 70 protocols (59 CTs and 11 phase IV observational studies) were analysed; 37 (52.8%) included PRO measures, and 3 protocols (4.3%) used them as a primary endpoint. Data analysis by therapeutic area showed that PRO measures were most commonly studied in the fields of endocrinology, neurology, digestive diseases, and cardiology. The average quality score for the trials was 2.8. The trials with more PRO inclusion in their end points had a significantly higher quality score. Only 13 (22%) clinical trials and 2 (18.2%) phase IV observational studies included economic variables. The emergence of economic variables in clinical trials and phase IV observational studies evaluated was low, however, more than half of the revised protocols have included PRO measures, reflecting the importance of these parameters in the assessment of the effectiveness of drug treatments, although its use is still

TOWARD QUANTITATIVE OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY: Visualizing Blood Flow Speeds in Ocular Pathology Using Variable Interscan Time Analysis.

PubMed

Ploner, Stefan B; Moult, Eric M; Choi, WooJhon; Waheed, Nadia K; Lee, ByungKun; Novais, Eduardo A; Cole, Emily D; Potsaid, Benjamin; Husvogt, Lennart; Schottenhamml, Julia; Maier, Andreas; Rosenfeld, Philip J; Duker, Jay S; Hornegger, Joachim; Fujimoto, James G

2016-12-01

Currently available optical coherence tomography angiography systems provide information about blood flux but only limited information about blood flow speed. The authors develop a method for mapping the previously proposed variable interscan time analysis (VISTA) algorithm into a color display that encodes relative blood flow speed. Optical coherence tomography angiography was performed with a 1,050 nm, 400 kHz A-scan rate, swept source optical coherence tomography system using a 5 repeated B-scan protocol. Variable interscan time analysis was used to compute the optical coherence tomography angiography signal from B-scan pairs having 1.5 millisecond and 3.0 milliseconds interscan times. The resulting VISTA data were then mapped to a color space for display. The authors evaluated the VISTA visualization algorithm in normal eyes (n = 2), nonproliferative diabetic retinopathy eyes (n = 6), proliferative diabetic retinopathy eyes (n = 3), geographic atrophy eyes (n = 4), and exudative age-related macular degeneration eyes (n = 2). All eyes showed blood flow speed variations, and all eyes with pathology showed abnormal blood flow speeds compared with controls. The authors developed a novel method for mapping VISTA into a color display, allowing visualization of relative blood flow speeds. The method was found useful, in a small case series, for visualizing blood flow speeds in a variety of ocular diseases and serves as a step toward quantitative optical coherence tomography angiography.

Blood pressure variability in children with primary vs secondary hypertension.

PubMed

Leisman, Daniel; Meyers, Melissa; Schnall, Jeremy; Chorny, Nataliya; Frank, Rachel; Infante, Lulette; Sethna, Christine B

2014-06-01

Increased blood pressure variability (BPV) is correlated with adverse cardiovascular (CV) events in adults. However, there has been limited research on its effect in the pediatric population. Additionally, BPV differences between primary and secondary hypertension (HTN) are not known. Children with primary and secondary HTN underwent 24-hour ambulatory blood pressure monitoring and echocardiography studies. BPV measures of standard deviation (SD), average real variability (ARV), and range were calculated for the 24-hour, daytime, and nighttime periods. Seventy-four patients (median age, 13.5 years; 74% boys) were examined, 40 of whom had primary HTN. Body mass index z score and age were independent predictors of systolic ARV (R(2) =0.14) and SD (R(2) =0.39). There were no statistically significant differences in overall or wake period BPV measures between secondary or primary HTN groups, but sleep period diastolic SD was significantly greater in the secondary HTN group (9.26±3.8 vs 7.1±2.8, P=.039). On multiple regression analysis, secondary HTN was associated with increased sleep period diastolic SD (P=.025). No metrics of BPV in the overall, wake, and sleep periods were found to be significantly associated with left ventricular hypertrophy (LVH). The results of this study do not show a strong relationship between overall or wake BPV with primary vs secondary HTN, but the association of secondary HTN with sleep period diastolic BPV deserves further exploration. Contrary to expectation, the findings of this study failed to indicate a relationship between BPV and LVH for all patients as well for primary hypertensive and secondary hypertensive patients. ©2014 Wiley Periodicals, Inc.

An examination of hospital satisfaction with blood suppliers.

PubMed

Carden, Robert; DelliFraine, Jami L

2004-11-01

The purpose of this study was to identify factors that predict overall hospital satisfaction with blood suppliers. The data for this study came from a 2001 satisfaction survey of hospital blood bank managers conducted by the National Blood Data Resource Center. A total of 1325 blood-utilizing hospitals were included in the final study database. The measurement of hospital satisfaction with its blood supplier encompasses the five composites of the SERVQUAL model. The five composites are 1) tangibles, 2) reliability, 3) responsiveness, 4) assurance, and 5) empathy. Linear regression was performed with overall hospital satisfaction as the dependent variable and the five composites of the SERVQUAL model and control variables as predictors of overall hospital satisfaction with blood suppliers. Significant predictors of hospital satisfaction with blood suppliers are satisfaction with medical and clinical support provided by the blood center, satisfaction with the routine delivery schedule, and price (service fee) of red cells. Prior studies have demonstrated the importance of customer satisfaction to organizations. As organizations, blood centers can benefit from improved satisfaction from their hospital customers. Blood center strategies that focus on improving these three predictors of overall hospital satisfaction with primary blood suppliers will be the most likely to improve and/or maintain hospital customer satisfaction with primary blood suppliers.

Diurnal blood pressure changes.

PubMed

Asayama, Kei; Satoh, Michihiro; Kikuya, Masahiro

2018-05-23

The definition of diurnal blood pressure changes varies widely, which can be confusing. Short-term blood pressure variability during a 24-h period and the dipping status of diurnal blood pressure can be captured by ambulatory blood pressure monitoring, and these metrics are reported to have prognostic significance for cardiovascular complications. Morning blood pressure surge also indicates this risk, but its effect may be limited to populations with specific conditions. Meanwhile, the combined use of conventional office blood pressure and out-of-office blood pressure allows us to identify people with white-coat and masked hypertension. Current home devices can measure nocturnal blood pressure during sleep more conveniently than ambulatory monitoring; however, we should pay attention to blood pressure measurement conditions regardless of whether they are in a home, ambulatory, or office setting. The relatively poor reproducibility of diurnal blood pressure changes, including the nocturnal fall of blood pressure, is another underestimated issue to be addressed. Although information on diurnal blood pressure changes is expected to be used more effectively in the future, we should also keep in mind that blood pressure levels have remained central to the primary and secondary prevention of blood pressure-related cardiovascular diseases in clinical practice.

Whole Body Magnetic Resonance Imaging Features in Diffuse Idiopathic Skeletal Hyperostosis in Conjunction with Clinical Variables to Whole Body MRI and Clinical Variables in Ankylosing Spondylitis.

PubMed

Weiss, Bettina G; Bachmann, Lucas M; Pfirrmann, Christian W A; Kissling, Rudolf O; Zubler, Veronika

2016-02-01

Discrimination of diffuse idiopathic skeletal hyperostosis (DISH) and ankylosing spondylitis (AS) can be challenging. Usefulness of whole-body magnetic resonance imaging (WB-MRI) in diagnosing spondyloarthritis has been recently proved. We assessed the value of clinical variables alone and in combination with WB-MRI to distinguish between DISH and AS. Diagnostic case-control study: 33 patients with AS and 15 patients with DISH were included. All patients underwent 1.5 Tesla WB-MRI scanning. MR scans were read by a blinded radiologist using the Canadian-Danish Working Group's recommendation. Imaging and clinical variables were identified using the bootstrap. The most important variables from MR and clinical history were assessed in a multivariate fashion resulting in 3 diagnostic models (MRI, clinical, and combined). The discriminative capacity was quantified using the area under the receiver-operating characteristic (ROC) curve. The strength of diagnostic variables was quantified with OR. Forty-eight patients provided 1545 positive findings (193 DISH/1352 AS). The final MR model contained upper anterior corner fat infiltration (32 DISH/181 AS), ankylosis on the vertebral endplate (4 DISH/60 AS), facet joint ankylosis (4 DISH/49 AS), sacroiliac joint edema (11 DISH/91 AS), sacroiliac joint fat infiltration (2 DISH/114 AS), sacroiliac joint ankylosis (2 DISH/119 AS); area under the ROC curve was 0.71, 95% CI 0.64-0.78. The final clinical model contained patient's age and body mass index (area under the ROC curve 0.90, 95% CI 0.89-0.91). The full diagnostic model containing clinical and MR information had an area under the ROC curve of 0.93 (95% CI 0.92-0.95). WB-MRI features can contribute to the correct diagnosis after a thorough conventional workup of patients with DISH and AS.

Precision and accuracy of clinical quantification of myocardial blood flow by dynamic PET: A technical perspective.

PubMed

Moody, Jonathan B; Lee, Benjamin C; Corbett, James R; Ficaro, Edward P; Murthy, Venkatesh L

2015-10-01

A number of exciting advances in PET/CT technology and improvements in methodology have recently converged to enhance the feasibility of routine clinical quantification of myocardial blood flow and flow reserve. Recent promising clinical results are pointing toward an important role for myocardial blood flow in the care of patients. Absolute blood flow quantification can be a powerful clinical tool, but its utility will depend on maintaining precision and accuracy in the face of numerous potential sources of methodological errors. Here we review recent data and highlight the impact of PET instrumentation, image reconstruction, and quantification methods, and we emphasize (82)Rb cardiac PET which currently has the widest clinical application. It will be apparent that more data are needed, particularly in relation to newer PET technologies, as well as clinical standardization of PET protocols and methods. We provide recommendations for the methodological factors considered here. At present, myocardial flow reserve appears to be remarkably robust to various methodological errors; however, with greater attention to and more detailed understanding of these sources of error, the clinical benefits of stress-only blood flow measurement may eventually be more fully realized.

[Organization of an anaesthesia preoperative evaluation clinic - The Anaesthesia/Patient Blood Management Clinic: one Model].

PubMed

Schöpper, Christa; Venherm, Stefan; Van Aken, Hugo; Ellermann, Ines; Steinbicker, Andrea

2016-04-01

The anesthesia preoperative evaluation has been developed in recent years in a centralized clinic, that can be visited by the majority of patients, in order to evaluate and obtain patient's consent for anesthesia. In the current article, the organization and structure of such a central anesthesia preoperative evaluation clinic in the Department of Anesthesia, Intensive Care and Pain Medicine at the University Hospital of Muenster, is described. Besides the central preoperative evaluation clinic, 3 clinics are localized in separate buildings and preoperative visits have to be completed in special scenarios on the wards, too. A pharmaceutical evaluation for patient's medication and the patient blood management have been integrated into the anesthesia preoperative evaluation clinic. Processes are explained and current numbers of patients are mentioned. © Georg Thieme Verlag Stuttgart · New York.

Association between different measurements of blood pressure variability by ABP monitoring and ankle-brachial index.

PubMed

Wittke, Estefânia; Fuchs, Sandra C; Fuchs, Flávio D; Moreira, Leila B; Ferlin, Elton; Cichelero, Fábio T; Moreira, Carolina M; Neyeloff, Jeruza; Moreira, Marina B; Gus, Miguel

2010-11-05

Blood pressure (BP) variability has been associated with cardiovascular outcomes, but there is no consensus about the more effective method to measure it by ambulatory blood pressure monitoring (ABPM). We evaluated the association between three different methods to estimate BP variability by ABPM and the ankle brachial index (ABI). In a cross-sectional study of patients with hypertension, BP variability was estimated by the time rate index (the first derivative of SBP over time), standard deviation (SD) of 24-hour SBP; and coefficient of variability of 24-hour SBP. ABI was measured with a doppler probe. The sample included 425 patients with a mean age of 57 ± 12 years, being 69.2% women, 26.1% current smokers and 22.1% diabetics. Abnormal ABI (≤ 0.90 or ≥ 1.40) was present in 58 patients. The time rate index was 0.516 ± 0.146 mmHg/min in patients with abnormal ABI versus 0.476 ± 0.124 mmHg/min in patients with normal ABI (P = 0.007). In a logistic regression model the time rate index was associated with ABI, regardless of age (OR = 6.9, 95% CI = 1.1- 42.1; P = 0.04). In a multiple linear regression model, adjusting for age, SBP and diabetes, the time rate index was strongly associated with ABI (P < 0.01). None of the other indexes of BP variability were associated with ABI in univariate and multivariate analyses. Time rate index is a sensible method to measure BP variability by ABPM. Its performance for risk stratification of patients with hypertension should be explored in longitudinal studies.

The use of biomarkers to describe plasma-, red cell-, and blood volume from a simple blood test.

PubMed

Lobigs, Louisa Margit; Sottas, Pierre-Edouard; Bourdon, Pitre Collier; Nikolovski, Zoran; El-Gingo, Mohamed; Varamenti, Evdokia; Peeling, Peter; Dawson, Brian; Schumacher, Yorck Olaf

2017-01-01

Plasma volume and red cell mass are key health markers used to monitor numerous disease states, such as heart failure, kidney disease, or sepsis. Nevertheless, there is currently no practically applicable method to easily measure absolute plasma or red cell volumes in a clinical setting. Here, a novel marker for plasma volume and red cell mass was developed through analysis of the observed variability caused by plasma volume shifts in common biochemical measures, selected based on their propensity to present with low variations over time. Once a month for 6 months, serum and whole blood samples were collected from 33 active males. Concurrently, the CO-rebreathing method was applied to determine target levels of hemoglobin mass (HbM) and blood volumes. The variability of 18 common chemistry markers and 27 Full Blood Count variables was investigated and matched to the observed plasma volume variation. After the removal of between-subject variations using a Bayesian model, multivariate analysis identified two sets of 8 and 15 biomarkers explaining 68% and 69% of plasma volume variance, respectively. The final multiparametric model contains a weighting function to allow for isolated abnormalities in single biomarkers. This proof-of-concept investigation describes a novel approach to estimate absolute vascular volumes, with a simple blood test. Despite the physiological instability of critically ill patients, it is hypothesized the model, with its multiparametric approach and weighting function, maintains the capacity to describe vascular volumes. This model has potential to transform volume management in clinical settings. Am. J. Hematol. 92:62-67, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

On assessing the quality of physicians' clinical judgment: the search for outcome variables.

PubMed

Wainer, Howard; Mee, Janet

2004-12-01

A primary question that must be resolved in the development of tasks to assess the quality of physicians' clinical judgment is, "What is the outcome variable?" One natural choice would seem to be the correctness of the clinical decision. In this article, we use data on the diagnosis of urinary tract infections among young girls to illustrate why, in many clinical situations, this is not a useful variable. We propose instead a judgment weighted by the relative costs of an error. This variable has the disadvantage of requiring expert judgment for scoring, but the advantage of measuring the construct of interest.

Clinical, operational and economic outcomes of point-of-care blood gas analysis in COPD patients.

PubMed

Oliver, Paloma; Buno, Antonio; Alvarez-Sala, Rodolfo; Fernandez-Calle, Pilar; Alcaide, Maria Jose; Casitas, Raquel; Garcia-Quero, Cristina; Madero, Rosario; Gomez-Rioja, Ruben; Iturzaeta, Jose Manuel

2015-04-01

Arterial blood gas analysis is relevant in chronic obstructive pulmonary disease (COPD) management. The aim of this study was to evaluate whether the use of a blood gas analyzer in pulmonology departments improves the clinical, operational and economic outcomes when compared with clinical laboratory measurements. It is an observational prospective study. 112 patients were selected. After specimen collection, the measurement was performed both in pulmonology office as point-of-care and in laboratory. We evaluated clinical outcomes (modification of the indication of long-term oxygen therapy (LTOT) according to results, changes in blood gas analysis results, relationship of the partial pressure of oxygen (PaO2) obtained in the medical visit and velocity of change of the PaO2, influence of total haemoglobin concentration and the change in PaO2), operational outcomes (turnaround time (TAT) from specimen collection to receiving the blood gas analysis report) and economic outcomes (overall cost per process of patient care). There were discrepancies in the indication of LTOT in 13.4% of patients. All parameters showed changes. PaO2 levels showed changes in 2 ways, though they frequently increase over time. The correlation was not good in the other two clinical outcomes. The median TATs in pulmonology office were 1 min versus 79 in laboratory, with 52 min for specimen preparation and transport and 17 min for TAT intralaboratory. The overall cost for the 112 patients in pulmonology office and laboratory was 16,769.89€ and 22,260.97€ respectively. The use of a blood gas analyzer in a pulmonology office improves clinical, operational and economic outcomes when compared with clinical laboratory. Copyright © 2014 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

High blood pressure in acute ischemic stroke and clinical outcome

PubMed Central

Manabe, Yasuhiro; Kono, Syoichiro; Tanaka, Tomotaka; Narai, Hisashi; Omori, Nobuhiko

2009-01-01

This study aimed to evaluate the prognostic value of acute phase blood pressure in patients with acute ischemic stroke by determining whether or not it contributes to clinical outcome. We studied 515 consecutive patients admitted within the first 48 hours after the onset of ischemic strokes, employing systolic and diastolic blood pressure measurements recorded within 36 hours after admission. High blood pressure was defined when the mean of at least 2 blood pressure measurements was ≥200 mmHg systolic and/or ≥110 mmHg diastolic at 6 to 24 hours after admission or ≥180 mmHg systolic and/or ≥105 mmHg diastolic at 24 to 36 hours after admission. The high blood pressure group was found to include 16% of the patients. Age, sex, diabetes mellitus, hypercholesterolemia, atrial fibrillation, ischemic heart disease, stroke history, carotid artery stenosis, leukoaraiosis, NIH Stroke Scale (NIHSS) on admission and mortality were not significantly correlated with either the high blood pressure or non-high blood pressure group. High blood pressure on admission was significantly associated with a past history of hypertension, kidney disease, the modified Rankin Scale (mRS) on discharge and the length of stay. On logistic regression analysis, with no previous history of hypertension, diabetes mellitus, atrial fibrillation, and kidney disease were independent risk factors associated with the presence of high blood pressure [odds ratio (OR), 1.85 (95% confidence interval (CI): 1.06–3.22), 1.89 (95% CI: 1.11–3.22), and 3.31 (95% CI: 1.36–8.04), respectively]. Multi-organ injury may be presented in acute stroke patients with high blood pressure. Patients with high blood pressure had a poor functional outcome after acute ischemic stroke. PMID:21577346

Systolic blood pressure variability and lower extremity amputation in a non-elderly population with diabetes.

PubMed

Budiman-Mak, Elly; Epstein, Noam; Brennan, Meghan; Stuck, Rodney; Guihan, Marylou; Huo, Zhiping; Emanuele, Nicholas; Sohn, Min-Woong

2016-04-01

Systolic blood pressure (SBP) variability is emerging as a new risk factor for cardiovascular diseases, diabetic nephropathy, and other atherosclerotic conditions. Our objective is to examine whether it has any prognostic value for lower-extremity amputations. This is a nested case-control study of a cohort of patients with diabetes aged<60 years and treated in the US Department of Veterans Healthcare system in 2003. They were followed over five years for any above-ankle (major) amputations. For each case with a major amputation (event), we randomly selected up to five matched controls based on age, sex, race/ethnicity, and calendar time. SBP variability was computed using three or more blood pressure measures taken during the one-year period before the event. Patients were classified into quartiles according to their SBP variability. The study sample included 1038 cases and 2932 controls. Compared to Quartile 1 (lowest variability), Quartile 2 had 1.4 times (OR=1.44, 95% CI=1.00-2.07) and Quartiles 3 and 4 (highest) had 2.5 times (OR for Quartile 3=2.62, 95% CI=1.85-3.72; OR for Quartile 4=2.50, 95% CI=1.74-3.59) higher risk of major amputation (P for trend<0.001). This gradient relationship held in both normotensive and hypertensive groups as well as for individuals without prior peripheral vascular disease. This is the first study to show a significant graded relationship between SBP variability and risk of major amputation among non-elderly persons with diabetes. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Comparison of high glucose concentration blood and crystalloid cardioplegia in paediatric cardiac surgery: a randomized clinical trial

PubMed Central

Mimic, Branko; Ilic, Slobodan; Vulicevic, Irena; Milovanovic, Vladimir; Tomic, Danijela; Mimic, Ana; Stankovic, Sanja; Zecevic, Tatjana; Davies, Ben; Djordjevic, Miroslav

2016-01-01

OBJECTIVES This study investigates the effects of high glucose content on patients undergoing cold crystalloid versus cold blood cardioplegia in terms of early clinical results, functional myocardial recovery and ischaemia–reperfusion injury in patients undergoing repair of acyanotic cardiac lesions. METHODS Patients were randomly assigned to receive either crystalloid (n = 31) or blood cardioplegia (n = 31). Early clinical results were assessed. Changes in left ventricular fractional shortening, arterial blood lactate levels, central venous saturation, cardiac Troponin I release and blood glucose concentration were measured during the first 24 h after ischaemia. RESULTS There was no significant difference in clinical outcomes and postoperative complication rates between groups. The postoperative changes in left ventricular function, lactate levels, central venous saturation and Troponin I were not significantly different between groups. The use of crystalloid cardioplegia was associated with significant increases in serum glucose compared with blood cardioplegia. CONCLUSIONS A high glucose content blood cardioplegia does not show any advantage compared with crystalloid cardioplegia in terms of clinical outcomes, functional recovery and the degree of ischaemic injury in infants and children undergoing repair of acyanotic heart lesions. High glucose concentration of the cardioplegic solution might potentiate ischaemia–reperfusion injury and diminish the beneficial effects of blood cardioplegia. PMID:26831677

Effects of Amlodipine and Valsartan on Blood Pressure Variability and Pulse Wave Velocity in Hypertensive Patients.

PubMed

Shi, Rufeng; Liu, Kai; Shi, Di; Liu, Qi; Chen, Xiaoping

2017-01-01

Antihypertensive therapy is effective to control blood pressure (BP) and to prevent cardiovascular events, but the further treatment strategies for patients who cannot achieve goal BP with low-dose monotherapy is still under dispute. Our study investigates the effects of high-dose amlodipine and valsartan and their low-dose combination on blood pressure variability (BPV) and pulse wave velocity (PWV) to provide references for clinical medication. This study was a prospective, randomized, parallel, case-controlled trial performed in a medical center. A total of 134 outpatients newly diagnosed with essential hypertension or receiving low-dose monotherapy were enrolled and 119 completed the trial. They were randomized into amlodipine 10mg group (n = 40), valsartan 160mg group (n = 38) and amlodipine 5mg + valsartan 80mg (n = 41) in a 1:1:1 allocation ratio for a 10-week treatment. Demographic data and laboratory indicators were collected at the randomization and 10 weeks after the treatment. The 24-hour ambulatory BP and brachial-ankle PWV were also monitored. All therapies reduced systolic and diastolic BP (P < 0.05). The 24-hour systolic BPV was significantly decreased in amlodipine and combination groups (3.55 ± 2.57, 4.11 ± 2.20 versus 2.23 ± 2.54mmHg, P < 0.05). The effects on diastolic BPV differed between different treatments. PWV was lowered by 3 antihypertensive schemes; the degree of which from strongest to weakest were valsartan, combination and amlodipine (228.87 ± 60.41 versus 152.49 ± 49.25 versus 99.35 ± 35.57cm/second, P < 0.01). All further strategies can effectively control BP. The combination treatment reduces both BPV and PWV noticeably, whereas double-dose amlodipine achieves the greatest BPV decrease and valsartan is best in controlling PWV. Copyright © 2017 Southern Society for Clinical Investigation. Published by Elsevier Inc. All rights reserved.

Difference in blood pressure measurements between arms: methodological and clinical implications.

PubMed

Clark, Christopher E

2015-01-01

Differences in blood pressure measurements between arms are commonly encountered in clinical practice. If such differences are not excluded they can delay the diagnosis of hypertension and can lead to poorer control of blood pressure levels. Differences in blood pressure measurements between arms are associated cross sectionally with other signs of vascular disease such as peripheral arterial disease or cerebrovascular disease. Differences are also associated prospectively with increased cardiovascular mortality and morbidity and all cause mortality. Numbers of publications on inter-arm difference are rising year on year, indicating a growing interest in the phenomenon. The prevalence of an inter-arm difference varies widely between reports, and is correlated with the underlying cardiovascular risk of the population studied. Prevalence is also sensitive to the method of measurement used. This review discusses the prevalence of an inter-arm difference in different populations and addresses current best practice for the detection and the measurement of a difference. The evidence for clinical and for vascular associations of an inter-arm difference is presented in considering the emerging role of an inter-arm blood pressure difference as a novel risk factor for increased cardiovascular morbidity and mortality. Competing aetiological explanations for an inter-arm difference are explored, and gaps in our current understanding of this sign, along with areas in need of further research, are considered.

Demographic and Clinical Characteristics of COPD Patients at Different Blood Eosinophil Levels in the UK Clinical Practice Research Datalink.

PubMed

Landis, Sarah; Suruki, Robert; Maskell, Joe; Bonar, Kerina; Hilton, Emma; Compton, Chris

2018-03-20

Blood eosinophil count may be a useful biomarker for predicting response to inhaled corticosteroids and exacerbation risk in chronic obstructive pulmonary disease (COPD) patients. The optimal cut point for categorizing blood eosinophil counts in these contexts remains unclear. We aimed to determine the distribution of blood eosinophil count in COPD patients and matched non-COPD controls, and to describe demographic and clinical characteristics at different cut points. We identified COPD patients within the UK Clinical Practice Research Database aged ≥40 years with a FEV 1 /FVC <0.7, and ≥1 blood eosinophil count recorded during stable disease between January 1, 2010 and December 31, 2012. COPD patients were matched on age, sex, and smoking status to non-COPD controls. Using all blood eosinophil counts recorded during a 12-month period, COPD patients were categorized as "always above," "fluctuating above and below," and "never above" cut points of 100, 150, and 300 cells/μL. The geometric mean blood eosinophil count was statistically significantly higher in COPD patients versus matched controls (196.6 cells/µL vs. 182.1 cells/µL; mean difference 8%, 95% CI: 6.8, 9.2), and in COPD patients with versus without a history of asthma (205.0 cells/µL vs. 192.2 cells/µL; mean difference 6.7%, 95%, CI: 4.9, 8.5). About half of COPD patients had all blood eosinophil counts above 150 cells/μL; this persistent higher eosinophil phenotype was associated with being male, higher body mass index, and history of asthma. In conclusion, COPD patients demonstrated higher blood eosinophil count than non-COPD controls, although there was substantial overlap in the distributions. COPD patients with a history of asthma had significantly higher blood eosinophil count versus those without.

Clinical and hematologic variables in ponies with experimentally induced equine ehrlichial colitis (Potomac horse fever).

PubMed

Ziemer, E L; Whitlock, R H; Palmer, J E; Spencer, P A

1987-01-01

The clinical and hematologic variables of 10 ponies with experimentally induced equine ehrlichial colitis (EEC; syn: Potomac horse fever) were studied for a 30-day period (6 ponies) or until death (4 ponies). The earliest clinical sign indicative of EEC was fever (rectal temperature exceeding 39 C). All ponies became depressed (CNS) at various times during the disease, and 90% of the ponies developed diarrhea between 9 and 15 days after infection was induced. The most significant hematologic change was an increase in plasma protein concentration after the onset of fever (P less than 0.05). The PCV in all ponies became increased above base line during the diarrheic phase of EEC. Forty percent of the ponies developed anemia (PCV less than or equal to 23%) during the study. White blood cell counts were highly variable, with 80% of the ponies developing leukopenia (WBC less than 5,000/microliters) during the illness and 60% of the ponies developing leukocytosis (WBC greater than 14,000/microliters) after leukopenia was observed. Differential WBC changes varied widely and included neutropenia with a left shift, lymphopenia, and eosinopenia. Serial thrombocyte counts, which were done for only 1 pony, identified the development of marked thrombocytopenia. Some hematologic changes in ponies with EEC were similar to those reported in canine monocytic and equine granulocytic ehrlichioses. These data are discussed in the context of the pathogenesis and differential diagnosis of EEC.

Heart Rate and Blood Pressure Variability under Moon, Mars and Zero Gravity Conditions During Parabolic Flights

NASA Astrophysics Data System (ADS)

Aerts, Wouter; Joosen, Pieter; Widjaja, Devy; Varon, Carolina; Vandeput, Steven; Van Huffel, Sabine; Aubert, Andre E.

2013-02-01

Gravity changes during partial-G parabolic flights (0g -0.16g - 0.38g) lead to changes in modulation of the autonomic nervous system (ANS), studied via the heart rate variability (HRV) and blood pressure variability (BPV). HRV and BPV were assessed via classical time and frequency domain measures. Mean systolic and diastolic blood pressure show both increasing trends towards higher gravity levels. The parasympathetic and sympathetic modulation show both an increasing trend with decreasing gravity, although the modulation is sympathetic predominant during reduced gravity. For the mean heart rate, a non-monotonic relation was found, which can be explained by the increased influence of stress on the heart rate. This study shows that there is a relation between changes in gravity and modulations in the ANS. With this in mind, countermeasures can be developed to reduce postflight orthostatic intolerance.

Effects of β-blocker selectivity on blood pressure variability and stroke: a systematic review.

PubMed

Webb, Alastair John Stewart; Fischer, Urs; Rothwell, Peter Malcolm

2011-08-23

β-Blockers increase variability in systolic blood pressure (SBP), which probably explains their lesser effectiveness in preventing stroke vs myocardial infarction compared with other agents. This increase in variability in blood pressure (BP) may be particularly marked on non-cardioselective agents, potentially calling into question the widespread first-line use of propranolol in migraine with aura, elderly patients with essential tremor or anxiety, and other groups at risk of stroke. We determined β-blocker subclass effects on variability in BP and stroke risk in a systematic review of randomized controlled trials (RCTs) comparing different types of β-blocker with placebo or other agents. We determined pooled estimates of the effect of treatment on group variability in BP (ratio of the variances [VR]) and on the risk of stroke vs myocardial infarction during follow-up. Compared with other antihypertensives, variability in SBP was increased more by nonselective β-blockers (VR=1.34, 1.13-1.59, p =0.002, 25 comparisons, 9,992 patients) than by β1-selective agents (VR=1.09, 95% confidence interval 1.00-1.19, p =0.053, 68 comparisons, 40,746 patients; difference-p =0.038). In direct comparisons, variability in SBP was also significantly lower with β1-selective vs nonselective β-blockers (VR=0.81, 0.68-0.97, p =0.03, 18 comparisons, 954 patients). In comparisons with other antihypertensives, the increase in stroke risk with nonselective β-blockers ([OR]=2.29, 1.32-3.96, p =0.002) was more marked than with β1-selective agents (OR=1.24, 1.08-1.42, p =0.003, difference-p =0.03), as was the risk of stroke relative to the risk of myocardial infarction: OR=1.50 (0.93-2.42) vs 0.99 (0.82-1.19). Use of β1-selective rather than nonselective agents may be advisable when β-blockers are indicated for patients at risk of stroke.

Mobile clinic in Massachusetts associated with cost savings from lowering blood pressure and emergency department use.

PubMed

Song, Zirui; Hill, Caterina; Bennet, Jennifer; Vavasis, Anthony; Oriol, Nancy E

2013-01-01

Mobile health clinics are in increasingly wide use, but evidence of their clinical impact or cost-effectiveness is limited. Using a unique data set of 5,900 patients who made a total of 10,509 visits in 2010-12 to the Family Van, an urban mobile health clinic in Massachusetts, we examined the effect of screenings and counseling provided by the clinic on blood pressure. Patients who presented with high blood pressure during their initial visit experienced average reductions of 10.7 mmHg and 6.2 mmHg in systolic and diastolic blood pressure, respectively, during their follow-up visits. These changes were associated with 32.2 percent and 44.6 percent reductions in the relative risk of myocardial infarction and stroke, respectively, which we converted into savings using estimates of the incidence and costs of these conditions over thirty months. The savings from this reduction in blood pressure and patient-reported avoided emergency department visits produced a positive lower bound for the clinic's return on investment of 1.3. All other services of the clinic-those aimed at diabetes, obesity, and maternal health, for example-were excluded from this lower-bound estimate. Policy makers should consider mobile clinics as a delivery model for underserved communities with poor health status and high use of emergency departments.

Transcriptomics in human blood incubation reveals the importance of oxidative stress response in Saccharomyces cerevisiae clinical strains.

PubMed

Llopis, Silvia; Querol, Amparo; Heyken, Antje; Hube, Bernhard; Jespersen, Lene; Fernández-Espinar, M Teresa; Pérez-Torrado, Roberto

2012-08-23

In recent years an increasing number of yeast infections in humans have been related to certain clinical isolates of Saccharomyces cerevisiae. Some clinical strains showed in vivo and in vitro virulence traits and were able to cause death in mice whereas other clinical strains were avirulent. In this work, we studied the transcriptional profiles of two S. cerevisiae clinical strains showing virulent traits and two control non-virulent strains during a blood incubation model and detected a specific transcriptional response of clinical strains. This response involves an mRNA levels increase of amino acid biosynthesis genes and especially oxidative stress related genes. We observed that the clinical strains were more resistant to reactive oxygen species in vitro. In addition, blood survival of clinical isolates was high, reaching similar levels to pathogenic Candida albicans strain. Furthermore, a virulent strain mutant in the transcription factor Yap1p, unable to grow in oxidative stress conditions, presented decreased survival levels in human blood compared with the wild type or YAP1 reconstituted strain. Our data suggest that this enhanced oxidative stress response in virulent clinical isolates, presumably induced in response to oxidative burst from host defense cells, is important to increase survival in human blood and can help to infect and even produce death in mice models.

A blood chemistry profile for lake trout

USGS Publications Warehouse

Edsall, Carol Cotant

1999-01-01

A blood chemistry profile for lake trout Salvelinus namaycush was developed by establishing baseline ranges for several clinical chemistry tests (glucose, total protein, amylase, alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase, creatine kinase, calcium, and magnesium). Measurements were made accurately and rapidly with a Kodak Ektachem DT60 Analyzer and the Ektachem DTSC Module. Blood serum was collected from both laboratory-reared lake trout (1978 and 1986 year-classes) and feral spawning trout from Lake Michigan and then analyzed in the laboratory. No clinically significant differences were found between samples analyzed fresh and those frozen for 1 or 6 weeks. The ranges in chemistry variables for feral lake trout were generally wider than those for laboratory-reared lake trout, and significant differences existed between male and female feral lake trout for several tests. Blood chemistry profiles also varied seasonally on fish sampled repeatedly.

Azilsartan in Patients With Mild to Moderate Hypertension Using Clinic and Ambulatory Blood Pressure Measurements.

PubMed

Perez, Alfonso; Cao, Charlie

2017-01-01

This was a phase 2, multicenter, randomized, parallel-group, double-blind dose-ranging study. Hypertensive adults (n=555) received one of five doses of azilsartan (AZL; 2.5, 5, 10, 20, 40 mg), olmesartan medoxomil (OLM) 20 mg, or placebo once daily. The primary endpoint was change in trough clinic diastolic blood pressure (DBP) at week 8. Compared with placebo, all AZL doses (except 2.5 mg) provided statistically and clinically significant reductions in DBP and systolic blood pressure (SBP) based on both clinic blood pressure (BP) and 24-hour ambulatory BP monitoring (ABPM). AZL 40 mg was statistically superior vs OLM. Clinic BP was associated with a pronounced placebo effect (-6 mm Hg), whereas this was negligible with ABPM (±0.5 mm Hg). Adverse event frequency was similar in the AZL and placebo groups. Based on these and other findings, subsequent trials investigated the commercial AZL medoxomil tablet at doses 20 to 80 mg/d using 24-hour ABPM. ©2016 Wiley Periodicals, Inc.

The Clinical Impact of Rapid, Direct MALDI-ToF Identification of Bacteria from Positive Blood Cultures.

PubMed

French, Kathryn; Evans, Jason; Tanner, Hannah; Gossain, Savita; Hussain, Abid

2016-01-01

Faster identification of bacterial isolates from blood cultures can enable earlier clinical intervention for patients with sepsis. We evaluated the clinical impact of direct identification of micro-organisms from positive blood cultures using MALDI-ToF. Positive blood cultures with organisms seen on Gram stain were included over a four week period. For each patient case, comparison was made between the clinical advice given on day one with only a Gram stain result, and the follow up advice given on day two with the benefit of organism identification. Culture results were then compared with direct MALDI-ToF identification. For 73 of 115 cases (63.5%), direct organism identification was obtained by MALDI-ToF. Of those 73, 70 (95.5%) had a result concordant with that of the plate culture. In 28 of the 115 cases (24.3%) direct MALDI-ToF identification on day one would have had a clear clinical benefit. In 11 cases it would have helped to identify the potential source of bacteraemia. In 11 cases it would have indicated a different antibiotic regimen on day one, with five patients receiving appropriate antibiotics 24 hours earlier. For 14 cases the blood culture isolate could have been designated as unlikely to be clinically significant. We have demonstrated that organism identification on day one of blood culture positivity can have a direct clinical impact. Faster identification using MALDI-ToF assists the clinician in assessing the significance of a blood culture isolate on day one. It can allow earlier appropriate choice of antimicrobial agent, even in the absence of susceptibility testing, and help narrow down the potential source of infection providing a focus for further investigation in a more timely way than conventional techniques alone.

Comparison of ambulatory blood pressure and clinic blood pressure in relation to cardiovascular diseases in diabetic patients.

PubMed

Shen, Jian; Li, Zhi-Ming; He, Li-Zhen; Deng, Ren-Sheng; Liu, Jing-Guang; Shen, Yuan-Sheng

2017-08-01

The aim of this study was to evaluate prognostic values of ambulatory blood pressure (ABP) and clinic blood pressure (CBP) in diabetic patients with hypertension. A total of 450 diabetic hypertensive patients without established cardiovascular diseases were enrolled and 416 patients who had finished 12months' follow-up were included in final analysis. Baseline data were collected and Cox proportional hazards regression analysis was used to evaluate prognostic value of ABP and CBP. Compared to those without study endpoints (n = 370), those experienced study endpoints (n = 46) were more elderly and more likely to be male, and had longer hypertension duration (7.0 ± 3.0 years vs. 6.4 ± 2.1 years, P < .05). No significant between-group differences in CBP indices were observed. However, those with study endpoints had significantly higher 24-hour systolic BP (SBP) (134 ± 10 mmHg vs. 128 ± 7 mmHg), nighttime SBP (130 ± 7 mmHg vs. 120 ± 5 mmHg), night/day SBP ratio (0.97 ± 0.09 vs. 0.94 ± 0.08), higher proportion of non-dipping BP pattern (39.1% vs. 31.4%) and higher 24-hour SBP variability. After extensively adjusted for traditional risk factors, nondipping BP pattern and 24-hourSBP, only 24-hour SBP and nighttime SBP remained independently related with cardiovascular outcomes, with hazard ratios and associated 95% confidence interval as 1.53 (1.28-2.03) and 1.50 (1.26-1.89), respectively. Although no independent relationship between BP pattern and cardiovascular outcomes was observed. In summary, in diabetic hypertensive patients without established cardiovascular diseases, baseline 24-hour SBP and nighttime SBP are useful markers for predicting short-term cardiovascular outcomes.

How novice, skilled and advanced clinical researchers include variables in a case report form for clinical research: a qualitative study

PubMed Central

Chu, Hongling; Zeng, Lin; Fetters, Micheal D; Li, Nan; Tao, Liyuan; Shi, Yanyan; Zhang, Hua; Wang, Xiaoxiao; Li, Fengwei; Zhao, Yiming

2017-01-01

Objectives Despite varying degrees in research training, most academic clinicians are expected to conduct clinical research. The objective of this research was to understand how clinical researchers of different skill levels include variables in a case report form for their clinical research. Setting The setting for this research was a major academic institution in Beijing, China. Participants The target population was clinical researchers with three levels of experience, namely, limited clinical research experience, clinicians with rich clinical research experience and clinical research experts. Methods Using a qualitative approach, we conducted 13 individual interviews (face to face) and one group interview (n=4) with clinical researchers from June to September 2016. Based on maximum variation sampling to identify researchers with three levels of research experience: eight clinicians with limited clinical research experience, five clinicians with rich clinical research experience and four clinical research experts. These 17 researchers had diverse hospital-based medical specialties and or specialisation in clinical research. Results Our analysis yields a typology of three processes developing a case report form that varies according to research experience level. Novice clinician researchers often have an incomplete protocol or none at all, and conduct data collection and publication based on a general framework. Experienced clinician researchers include variables in the case report form based on previous experience with attention to including domains or items at risk for omission and by eliminating unnecessary variables. Expert researchers consider comprehensively in advance data collection and implementation needs and plan accordingly. Conclusion These results illustrate increasing levels of sophistication in research planning that increase sophistication in selection for variables in the case report form. These findings suggest that novice and intermediate

Beat to beat variability in cardiovascular variables: noise or music?

NASA Technical Reports Server (NTRS)

Appel, M. L.; Berger, R. D.; Saul, J. P.; Smith, J. M.; Cohen, R. J.

1989-01-01

Cardiovascular variables such as heart rate, arterial blood pressure, stroke volume and the shape of electrocardiographic complexes all fluctuate on a beat to beat basis. These fluctuations have traditionally been ignored or, at best, treated as noise to be averaged out. The variability in cardiovascular signals reflects the homeodynamic interplay between perturbations to cardiovascular function and the dynamic response of the cardiovascular regulatory systems. Modern signal processing techniques provide a means of analyzing beat to beat fluctuations in cardiovascular signals, so as to permit a quantitative, noninvasive or minimally invasive method of assessing closed loop hemodynamic regulation and cardiac electrical stability. This method promises to provide a new approach to the clinical diagnosis and management of alterations in cardiovascular regulation and stability.

Sentence comprehension in agrammatic aphasia: history and variability to clinical implications.

PubMed

Johnson, Danielle; Cannizzaro, Michael S

2009-01-01

Individuals with Broca's aphasia often present with deficits in their ability to comprehend non-canonical sentences. This has been contrastingly characterized as a systematic loss of specific grammatical abilities or as individual variability in the dynamics between processing load and resource availability. The present study investigated sentence level comprehension in participants with Broca's aphasia in an attempt to integrate these contrasting views into a clinically useful process. Two participants diagnosed with Broca's aphasia were assessed using a sentence-to-picture matching paradigm and a truth-value judgement task, across sentence constructions thought to be problematic for this population. The data demonstrate markedly different patterns of performance between participants, as well as variability within participants (e.g. by sentence type). These findings support the notion of individual performance variability in persons with aphasia. Syntactic theory was instructive for assessing sentence level comprehension, leading to a clinically relevant process of identifying treatment targets considering both performance variability and syntactic complexity for this population.

Patient Blood Management in Europe: surveys on top indications for red blood cell use and Patient Blood Management organization and activities in seven European university hospitals.

PubMed

Bruun, M T; Pendry, K; Georgsen, J; Manzini, P; Lorenzi, M; Wikman, A; Borg-Aquilina, D; van Pampus, E; van Kraaij, M; Fischer, D; Meybohm, P; Zacharowski, K; Geisen, C; Seifried, E; Liumbruno, G M; Folléa, G; Grant-Casey, J; Babra, P; Murphy, M F

2016-11-01

Patient Blood Management (PBM) in Europe is a working group of the European Blood Alliance with the initial objective to identify the starting position of the participating hospitals regarding PBM for benchmarking purposes, and to derive good practices in PBM from the experience and expertise in the participating teams with the further aim of implementing and strengthening these practices in the participating hospitals. We conducted two surveys in seven university hospitals in Europe: Survey on top indications for red blood cell use regarding usage of red blood cells during 1 week and Survey on PBM organization and activities. A total of 3320 units of red blood cells were transfused in 1 week at the seven hospitals. Overall, 61% of red cell units were transfused to medical patients and 36% to surgical patients, although there was much variation between hospitals. The organization and activities of PBM in the seven hospitals were variable, but there was a common focus on optimizing the treatment of bleeding patients, monitoring the use of blood components and treatment of preoperative anaemia. Although the seven hospitals provide a similar range of clinical services, there was variation in transfusion rates between them. Further, there was variable implementation of PBM activities and monitoring of transfusion practice. These findings provide a baseline to develop joint action plans to further implement and strengthen PBM across a number of hospitals in Europe. © 2016 International Society of Blood Transfusion.

Clinical variability of neuroacanthocytosis syndromes-a series of six patients with long follow-up.

PubMed

Dulski, J; Sołtan, W; Schinwelski, M; Rudzińska, M; Wójcik-Pędziwiatr, M; Wictor, L; Schön, F; Puschmann, A; Klempíř, J; Tilley, L; Roth, J; Tacik, P; Fujioka, S; Drozdowski, W; Sitek, E J; Wszolek, Z; Sławek, J

2016-08-01

To provide clinical clues to differential diagnosis in patients with chorea and other movement disorders with blood acanthocytes. We present a long-term video accompanied follow-up of six Caucasian patients with neuroacanthocytosis from several centers, three diagnosed with chorea-acanthocytosis (ChAc): 34-y.o.(no.1), 36-y.o.(no.2), 43-y.o.(no.3), two diagnosed with McLeod Syndrome (MLS): 52-y.o.(no.4), 61-y.o.(no.5) and one 63-y.o.(no.6), a brother of no.5, with clinical suspicion of MLS. Additionally we report pathological findings of the mother of two brothers with MLS reported in our series with acanthocytes on peripheral blood smear The patients had an unremarkable family history and were asymptomatic until adulthood. Patients no. 1,2,4,5,6 developed generalized chorea and patient no. 3 had predominant bradykinesia. Patients no. 1,2,3 had phonic and motor tics, additionally patients no. 1 and 2 exhibited peculiar oromandibular dystonia with tongue thrusting. In patients no. 2 and 3 dystonic supination of feet was observed, patient no. 3 subsequently developed bilateral foot drop. Patients no. 2 and 4 had signs of muscle atrophy. Tendon reflexes were decreased or absent and electroneurography demonstrated sensorimotor neuropathy in patients no. 1,2,3,4,5, except no. 6. Generalized seizures were seen in patients no. 2,3,5,6 and myoclonic jerks in patient no. 1. Cognitive deterioration was reported in patients no. 1,2,3,5,6. Serum creatine kinase levels were elevated in all six patients. We highlight the variability of clinical presentation of neuroacanthocytosis syndromes and the long time from the onset to diagnosis with the need to screen the blood smears in uncertain cases, however, as in one of our cases acanthocytes may even be not found. Based on our observations and data from the literature we propose several red flags that should raise the suspicion of an NA syndrome in a patient with a movement disorder: severe orofacial dyskinesia with tongue and lip

[Clinical utility of home blood pressure monitoring in patients under treatment].

PubMed

Bauk, L; Costa, H A; Caligiuri, S I

2015-01-01

A low number of patients who are treated with antihypertensive drugs achieve therapeutic goals. Home blood pressure monitoring is an excellent tool for studying this population. To determine the prevalence of patients with controlled and uncontrolled hypertension, as well as white-coat-effect and masked hypertension, and to evaluate the relationship with target organ damage in different groups. Blood pressure readings were performed simultaneously in the clinic and in the home using the same validated oscillometric equipment on 83 hypertensive patients on treatment with 2 or more antihypertensive drugs. They were then classified into 4 groups according to the cut-off values of the clinic and home blood pressure measurements. Left ventricular mass index, carotid intima media thickness, and microalbuminuria as markers of target organ damage, were also evaluated. Controlled blood pressure was present in 32.5%, 30.2% had sustained hypertension. The white coat effect was seen in 26.5%, while 10.8% were masked uncontrolled hypertension. Left ventricular mass index was higher in patients with no ambulatory control compared to controlled patients, and carotid IMT was also higher too in uncontrolled and white coat effect groups than controlled patients. More than one third of our patients who were treated with 2 or more drugs were not properly controlled, and they had significantly greater target organ damage than controlled patients. Copyright © 2014 SEHLELHA. Published by Elsevier Espana. All rights reserved.

Gene expression profiling of immunomagnetically separated cells directly from stabilized whole blood for multicenter clinical trials

PubMed Central

2014-01-01

Background Clinically useful biomarkers for patient stratification and monitoring of disease progression and drug response are in big demand in drug development and for addressing potential safety concerns. Many diseases influence the frequency and phenotype of cells found in the peripheral blood and the transcriptome of blood cells. Changes in cell type composition influence whole blood gene expression analysis results and thus the discovery of true transcript level changes remains a challenge. We propose a robust and reproducible procedure, which includes whole transcriptome gene expression profiling of major subsets of immune cell cells directly sorted from whole blood. Methods Target cells were enriched using magnetic microbeads and an autoMACS® Pro Separator (Miltenyi Biotec). Flow cytometric analysis for purity was performed before and after magnetic cell sorting. Total RNA was hybridized on HGU133 Plus 2.0 expression microarrays (Affymetrix, USA). CEL files signal intensity values were condensed using RMA and a custom CDF file (EntrezGene-based). Results Positive selection by use of MACS® Technology coupled to transcriptomics was assessed for eight different peripheral blood cell types, CD14+ monocytes, CD3+, CD4+, or CD8+ T cells, CD15+ granulocytes, CD19+ B cells, CD56+ NK cells, and CD45+ pan leukocytes. RNA quality from enriched cells was above a RIN of eight. GeneChip analysis confirmed cell type specific transcriptome profiles. Storing whole blood collected in an EDTA Vacutainer® tube at 4°C followed by MACS does not activate sorted cells. Gene expression analysis supports cell enrichment measurements by MACS. Conclusions The proposed workflow generates reproducible cell-type specific transcriptome data which can be translated to clinical settings and used to identify clinically relevant gene expression biomarkers from whole blood samples. This procedure enables the integration of transcriptomics of relevant immune cell subsets sorted directly from

Arm position during ambulatory blood pressure monitoring: a review of the evidence and clinical guidelines.

PubMed

Byrd, James B; Brook, Robert D

2014-03-01

Ambulatory blood pressure monitoring (ABPM) offers advantages over clinic blood pressure measurement. Supporting the arm at the level of the right atrium has long been standard in clinic blood pressure measurement. In contrast, there is no consensus regarding arm position in the guidelines addressing ABPM. Research studies have used a variety of arm positions during ABPM. Discussed in this review are the merits of ABPM and a review of the several arm positions recommended in ABPM guidelines, suggested by cuff manufacturers, and used in research studies. To address this lack of standardization, a rationale for a clinically reasonable arm position during ABPM is offered. Specifically, the authors recommend advising the patient to keep the arm still and relaxed straight down at the side of the body when the cuff is going to inflate, when safe to do so. ©2014 Wiley Periodicals, Inc.

When to trust our learners? Clinical teachers' perceptions of decision variables in the entrustment process.

PubMed

Duijn, Chantal C M A; Welink, Lisanne S; Bok, Harold G J; Ten Cate, Olle T J

2018-06-01

Clinical training programs increasingly use entrustable professional activities (EPAs) as focus of assessment. However, questions remain about which information should ground decisions to trust learners. This qualitative study aimed to identify decision variables in the workplace that clinical teachers find relevant in the elaboration of the entrustment decision processes. The findings can substantiate entrustment decision-making in the clinical workplace. Focus groups were conducted with medical and veterinary clinical teachers, using the structured consensus method of the Nominal Group Technique to generate decision variables. A ranking was made based on a relevance score assigned by the clinical teachers to the different decision variables. Field notes, audio recordings and flip chart lists were analyzed and subsequently translated and, as a form of axial coding, merged into one list, combining the decision variables that were similar in their meaning. A list of 11 and 17 decision variables were acknowledged as relevant by the medical and veterinary teacher groups, respectively. The focus groups yielded 21 unique decision variables that were considered relevant to inform readiness to perform a clinical task on a designated level of supervision. The decision variables consisted of skills, generic qualities, characteristics, previous performance or other information. We were able to group the decision variables into five categories: ability, humility, integrity, reliability and adequate exposure. To entrust a learner to perform a task at a specific level of supervision, a supervisor needs information to support such a judgement. This trust cannot be credited on a single case at a single moment of assessment, but requires different variables and multiple sources of information. This study provides an overview of decision variables giving evidence to justify the multifactorial process of making an entrustment decision.

Transcriptomics in human blood incubation reveals the importance of oxidative stress response in Saccharomyces cerevisiae clinical strains

PubMed Central

2012-01-01

Background In recent years an increasing number of yeast infections in humans have been related to certain clinical isolates of Saccharomyces cerevisiae. Some clinical strains showed in vivo and in vitro virulence traits and were able to cause death in mice whereas other clinical strains were avirulent. Results In this work, we studied the transcriptional profiles of two S. cerevisiae clinical strains showing virulent traits and two control non-virulent strains during a blood incubation model and detected a specific transcriptional response of clinical strains. This response involves an mRNA levels increase of amino acid biosynthesis genes and especially oxidative stress related genes. We observed that the clinical strains were more resistant to reactive oxygen species in vitro. In addition, blood survival of clinical isolates was high, reaching similar levels to pathogenic Candida albicans strain. Furthermore, a virulent strain mutant in the transcription factor Yap1p, unable to grow in oxidative stress conditions, presented decreased survival levels in human blood compared with the wild type or YAP1 reconstituted strain. Conclusions Our data suggest that this enhanced oxidative stress response in virulent clinical isolates, presumably induced in response to oxidative burst from host defense cells, is important to increase survival in human blood and can help to infect and even produce death in mice models. PMID:22916735

Using performance indicators to monitor attendance at the Broken Hill blood lead screening clinic.

PubMed

Boreland, Frances; Lyle, David

2009-04-01

Although the average blood lead level of 1-4-year-old children in Broken Hill has halved since 1991, about 1 in 5 still have blood lead levels higher than the national target (<10 microg/dL). The estimated proportion of children attending the Lead Clinic has declined, to approximately 42% in 2006, raising concern that some children with elevated blood lead levels may not be presenting, thus missing out on appropriate treatment and advice. The aim of this study was to describe patterns of attendance at the clinic as a first step to understanding what factors contribute to clinic attendance and non-attendance. Routinely collected data from the Lead Clinic database were used to describe the impact of factors such as child age, the lead-risk area in which they live, seasonal influences and specific promotional activities on clinic attendance rates from 1999 to June 2007. Estimates of the number of children living in each of the five lead-risk areas were derived from 2001 and 2006 census data and estimates of the number of children born to mothers resident in Broken Hill were derived from the Midwives Data Collection. Attendance rates declined by approximately one-third during the study period. Younger children, and those living closer to the central mining area, were more likely to attend for blood lead screening. Cohort analysis indicated cumulative attendance has declined, with children born in 2005 having a cumulative incidence at 18 months of age 5-10% lower than that for previous birth cohorts. The majority (54%) of children who developed a notifiable blood lead level (15 microg/dL) were first detected at 2 years of age or older, a number of whom (40%) had no recorded tests before the age of 2 years. The analysis has demonstrated the benefits of using an expanded set of performance indicators to monitor the blood lead screening programme. It provides valuable additional information about the reach of the programme. Next steps include seeking additional feedback

Prediction of remission of depression with clinical variables, neuropsychological performance, and serotonergic/dopaminergic gene polymorphisms.

PubMed

Gudayol-Ferré, Esteve; Herrera-Guzmán, Ixchel; Camarena, Beatriz; Cortés-Penagos, Carlos; Herrera-Abarca, Jorge E; Martínez-Medina, Patricia; Asbun-Bojalil, Juan; Lira-Islas, Yuridia; Reyes-Ponce, Celia; Guàrdia-Olmos, Joan

2012-11-01

The aim of our work is to study the possible role of clinical variables, neuropsychological performance, and the 5HTTLPR, rs25531, and val108/58Met COMT polymorphisms on the prediction of depression remission after 12 weeks' treatment with fluoxetine. These variables have been studied as potential predictors of depression remission, but they present poor prognostic sensitivity and specificity by themselves. Seventy-two depressed patients were genotyped according to the aforementioned polymorphisms and were clinically and neuropsychologically assessed before a 12-week fluxetine treatment. Only the La allele of rs25531 polymorphism and the GG and AA forms of the val 108/158 Met polymorphism predict major depressive disorder remission after 12 weeks' treatment with fluoxetine. None of the clinical and neuropsychological variables studied predicted remission. Our results suggest that clinical and neuropsychological variables can initially predict early response to fluoxetine and mask the predictive role of genetic variables; but in remission, where clinical and neuropsychological symptoms associated with depression tend to disappear thanks to the treatment administered, the polymorphisms studied are the only variables in our model capable of predicting remission. However, placebo effects that are difficult to control require cautious interpretation of the results.

Short-term variability and nocturnal decline in ambulatory blood pressure in normotension, white-coat hypertension, masked hypertension and sustained hypertension: a population-based study of older individuals in Spain.

PubMed

Gijón-Conde, Teresa; Graciani, Auxiliadora; López-García, Esther; Guallar-Castillón, Pilar; García-Esquinas, Esther; Rodríguez-Artalejo, Fernando; Banegas, José R

2017-06-01

Blood pressure (BP) variability and nocturnal decline in blood pressure are associated with cardiovascular outcomes. However, little is known about whether these indexes are associated with white-coat and masked hypertension. We performed a cross-sectional analysis of 1047 community-dwelling individuals aged ⩾60 years in Spain in 2012. Three observer-measured home BPs and 24-h ambulatory blood pressure monitoring (ABPM) were performed under standardized conditions. BP variability was defined as BP s.d. and coefficient of variation. Differences in BP variability and nocturnal BP decrease between groups were adjusted for sociodemographic and clinical covariates using generalized linear models. Of the cohort, 21.7% had white-coat hypertension, 7.0% had masked hypertension, 21.4% had sustained hypertension, and 49.9% were normotensive. Twenty-four hour, daytime and night-time systolic BP s.d. and coefficients of variation were significantly higher in subjects with white-coat hypertension than those with normotension (P<0.05) and were similar to subjects with sustained hypertension. In untreated subjects, 24-h but not daytime or night-time BP variability indexes were significantly higher in subjects with white-coat hypertension than in those with normotension (P<0.05). Percentage decrease in nocturnal systolic and diastolic BP was greatest in the white-coat hypertension group and lowest in the masked hypertension group in all patients and untreated patients (P<0.05). Lack of nocturnal decline in systolic blood pressure was observed in 70.2% of subjects with normotension, 57.8% of subjects with white-coat hypertension, 78.1% of subjects with masked hypertension, and 72.2% of subjects with sustained hypertension (P<0.001). In conclusion, 24-h BP variability was higher in subjects with white-coat hypertension and blunted nocturnal BP decrease was observed more frequently in subjects with masked hypertension. These findings may help to explain the reports of increased

Assessment of clinical significance of positive blood cultures of relatively low-virulence isolates.

PubMed

Hirakata, Y; Furuya, N; Iwata, M; Kashitani, F; Ishikawa, M; Yumoto, S; Yasui, K; Endoh, H; Marui, A; Kaku, M; Tateda, K; Yamaguchi, K

1996-03-01

In Omori Hospital, Toho University School of Medicine, relatively low-virulence blood isolates, including coagulase-negative staphylococci (CNS), enterococci and nonfermentative gram-negative rods other than Pseudomonas aeruginosa comprised c. 60% of total blood isolates. A retrospective study was conducted to assess their clinical significance by reviewing a total of 91 hospital charts. The physicians' assessments of these positive blood cultures as recorded in the charts were classified into four categories--sepsis, possible sepsis, contamination and no comment. The episodes classified as sepsis accounted for 5.0-19.6%. These episodes were also evaluated by a graded clinical significance score based on multiple factors, including number of positive cultures and clinical signs. The scores for the 91 episodes covered a wide range from 1 to 9, indicating that both contaminants and causative organisms may have been involved. The episodes judged as sepsis or possible sepsis tended to have higher scores. The scores for the episodes associated with enterococci were also higher than those involving CNS or non-fermentative gram-negative rods. The scores for episodes associated with intravenous hyperalimentation catheters were higher than those not associated with the catheters.

24-hour aortic blood pressure variability showed a stronger association with carotid damage than 24-hour brachial blood pressure variability: The SAFAR study.

PubMed

Yu, Shikai; Chi, Chen; Protogerou, Athanase D; Safar, Michel E; Blacher, Jacques; Argyris, Antonis A; Nasothimiou, Efthimia G; Sfikakis, Petros P; Papaioannou, Theodore G; Xu, Henry; Zhang, Yi; Xu, Yawei

2018-03-01

We aim to compare 24-hour aortic blood pressure variability (BPV) with brachial BPV in relation to carotid damage as estimated by carotid intima-media thickness (CIMT) and cross-sectional area (CCSA). Four hundred and forty five individuals received brachial and aortic 24-hour ambulatory BP monitoring with a validated device (Mobil-O-Graph). Systolic BPV was estimated by average real variability (ARV) and time-weighted standard deviation (wSD). In multiple logistic regression analysis, CIMT > 900 μm was significantly and independently associated with aortic ARV (OR = 1.38; 95% CI: 1.04-1.84), aortic wSD (OR = 1.65; 95% CI: 1.19-2.29) and brachial ARV (OR = 1.53; 95% CI: 1.07-2.18), but not with brachial wSD. CCSA > 90th percentile was significantly and independently associated with aortic ARV (OR = 1.50; 95% CI: 1.07-2.10) and wSD (OR = 1.70; 95% CI: 1.12-2.56), but not with brachial BPVs. In receiver operator characteristics curve analysis, aortic wSD identified CCSA > 90th percentile better than brachial wSD (AUC: 0.73 vs 0.68, P < .01). In conclusion, aortic 24-hour systolic BPV showed a slightly stronger association with carotid damage than brachial BPV. ©2018 Wiley Periodicals, Inc.

Relationship between blood calcium level and ST peak interval of electrocardiographic variables in peripartum Holstein cows

PubMed Central

ITOH, Megumi; SAKURAI, Yoshie; NAKAJIMA, Yasuhiro; KAWAMOTO, Satoshi

2015-01-01

The association between blood calcium levels and electrocardiographic variables was compared in 137 normal parturient and 36 peripartum recumbent Holstein cows to determine whether hypocalcemia in peripartum dairy cows can be rapidly diagnosed using electrocardiograph. Inverse of STc (ST peak interval/SS interval0.5) and blood ionized calcium or serum calcium concentrations were strongly correlated, and both correlation coefficients were 0.81 (P<0.001). The 95% prediction interval indicated that cows with STc >0.385 ± 0.001 sec are very likely to be hypocalcemic (blood ionized or serum calcium concentrations of <0.9 mmol/l or <7.5 mg/dl, respectively). These findings indicate that hypocalcemia in parturient cows can be non-invasively estimated using the STc. PMID:26118411

Blood collection tubes as medical devices: The potential to affect assays and proposed verification and validation processes for the clinical laboratory.

PubMed

Bowen, Raffick A R; Adcock, Dorothy M

2016-12-01

Blood collection tubes (BCTs) are an often under-recognized variable in the preanalytical phase of clinical laboratory testing. Unfortunately, even the best-designed and manufactured BCTs may not work well in all clinical settings. Clinical laboratories, in collaboration with healthcare providers, should carefully evaluate BCTs prior to putting them into clinical use to determine their limitations and ensure that patients are not placed at risk because of inaccuracies due to poor tube performance. Selection of the best BCTs can be achieved through comparing advertising materials, reviewing the literature, observing the device at a scientific meeting, receiving a demonstration, evaluating the device under simulated conditions, or testing the device with patient samples. Although many publications have discussed method validations, few detail how to perform experiments for tube verification and validation. This article highlights the most common and impactful variables related to BCTs and discusses the validation studies that a typical clinical laboratory should perform when selecting BCTs. We also present a brief review of how in vitro diagnostic devices, particularly BCTs, are regulated in the United States, the European Union, and Canada. The verification and validation of BCTs will help to avoid the economic and human costs associated with incorrect test results, including poor patient care, unnecessary testing, and delays in test results. We urge laboratorians, tube manufacturers, diagnostic companies, and other researchers to take all the necessary steps to protect against the adverse effects of BCT components and their additives on clinical assays. Copyright © 2016 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

Prediction of hypertensive crisis based on average, variability and approximate entropy of 24-h ambulatory blood pressure monitoring.

PubMed

Schoenenberger, A W; Erne, P; Ammann, S; Perrig, M; Bürgi, U; Stuck, A E

2008-01-01

Approximate entropy (ApEn) of blood pressure (BP) can be easily measured based on software analysing 24-h ambulatory BP monitoring (ABPM), but the clinical value of this measure is unknown. In a prospective study we investigated whether ApEn of BP predicts, in addition to average and variability of BP, the risk of hypertensive crisis. In 57 patients with known hypertension we measured ApEn, average and variability of systolic and diastolic BP based on 24-h ABPM. Eight of these fifty-seven patients developed hypertensive crisis during follow-up (mean follow-up duration 726 days). In bivariate regression analysis, ApEn of systolic BP (P<0.01), average of systolic BP (P=0.02) and average of diastolic BP (P=0.03) were significant predictors of hypertensive crisis. The incidence rate ratio of hypertensive crisis was 14.0 (95% confidence interval (CI) 1.8, 631.5; P<0.01) for high ApEn of systolic BP as compared to low values. In multivariable regression analysis, ApEn of systolic (P=0.01) and average of diastolic BP (P<0.01) were independent predictors of hypertensive crisis. A combination of these two measures had a positive predictive value of 75%, and a negative predictive value of 91%, respectively. ApEn, combined with other measures of 24-h ABPM, is a potentially powerful predictor of hypertensive crisis. If confirmed in independent samples, these findings have major clinical implications since measures predicting the risk of hypertensive crisis define patients requiring intensive follow-up and intensified therapy.

Comparisons of measured and self-reported anthropometric variables and blood pressure in a sample of Hong Kong female nurses.

PubMed

Xie, Yao Jie; Ho, Suzanne C; Liu, Zhao Min; Hui, Stanley Sai-Chuen

2014-01-01

To assess the validity of self-reported weight, height, body mass index (BMI), waist circumference and blood pressure compared with standardized clinical measurements and to determine the classification accuracy in overweight/obesity and central adiposity. This pilot study was integrated into a life-course study entitled "Hong Kong Women's Health Study" among 1,253 female nurses in Hong Kong who were aged 35 years to 65 years. Data were collected from self-administered questionnaires that were mailed to the respondents. Of these participants, we obtained the standard body measurements of 144 (11.5%) at our research center. We then compared the self-reported anthropometric variables and blood pressure with the measured data to assess validity based on the level of misreporting, percentage of agreement, consistency, sensitivity and specificity. The self-reported and measured values were highly correlated in terms of anthropometry and blood pressure (correlation coefficients ranged from 0.72 to 0.96). Height was overestimated at an average of 0.42 cm, and waist circumference was underestimated at 2.33 cm (both P<0.05), while no significant differences were observed from weight, blood pressure and BMI (all P>0.05). The proportions of overweight, obesity, and central adiposity by self-reported data did not vary greatly from the measured data (all P>0.05). The self-reporting resulted in correct classifications of BMI, waist circumference, and systolic blood pressure in 85%, 78%, and 87% of women, with corresponding Kappa index values of 0.79, 0.55, and 0.82, respectively. Sensitivity and specificity were 84.6% and 95.7%, respectively, with respect to overweight/obesity detection, whereas those for central adiposity detection were 70.6% and 83.8%, respectively. In a sample of female Hong Kong nurses, the self-reported measures of height, weight, BMI, waist circumference and blood pressure were generally valid. Furthermore, the classification accuracies of overweight

Blood DNA methylation biomarkers predict clinical reactivity in food-sensitized infants.

PubMed

Martino, David; Dang, Thanh; Sexton-Oates, Alexandra; Prescott, Susan; Tang, Mimi L K; Dharmage, Shyamali; Gurrin, Lyle; Koplin, Jennifer; Ponsonby, Anne-Louise; Allen, Katrina J; Saffery, Richard

2015-05-01

The diagnosis of food allergy (FA) can be challenging because approximately half of food-sensitized patients are asymptomatic. Current diagnostic tests are excellent makers of sensitization but poor predictors of clinical reactivity. Thus oral food challenges (OFCs) are required to determine a patient's risk of reactivity. We sought to discover genomic biomarkers of clinical FA with utility for predicting food challenge outcomes. Genome-wide DNA methylation (DNAm) profiling was performed on blood mononuclear cells from volunteers who had undergone objective OFCs, concurrent skin prick tests, and specific IgE tests. Fifty-eight food-sensitized patients (aged 11-15 months) were assessed, half of whom were clinically reactive. Thirteen nonallergic control subjects were also assessed. Reproducibility was assessed in an additional 48 samples by using methylation data from an independent population of patients with clinical FA. Using a supervised learning approach, we discovered a DNAm signature of 96 CpG sites that predict clinical outcomes. Diagnostic scores were derived from these 96 methylation sites, and cutoffs were determined in a sensitivity analysis. Methylation biomarkers outperformed allergen-specific IgE and skin prick tests for predicting OFC outcomes. FA status was correctly predicted in the replication cohort with an accuracy of 79.2%. DNAm biomarkers with clinical utility for predicting food challenge outcomes are readily detectable in blood. The development of this technology in detailed follow-up studies will yield highly innovative diagnostic assays. Copyright © 2015 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

Clinical assessment of the accuracy of blood glucose measurement devices.

PubMed

Pfützner, Andreas; Mitri, Michael; Musholt, Petra B; Sachsenheimer, Daniela; Borchert, Marcus; Yap, Andrew; Forst, Thomas

2012-04-01

Blood glucose meters for patient self-measurement need to comply with the accuracy standards of the ISO 15197 guideline. We investigated the accuracy of the two new blood glucose meters BG*Star and iBG*Star (Sanofi-Aventis) in comparison to four other competitive devices (Accu-Chek Aviva, Roche Diagnostics; FreeStyle Freedom Lite, Abbott Medisense; Contour, Bayer; OneTouch Ultra 2, Lifescan) at different blood glucose ranges in a clinical setting with healthy subjects and patients with type 1 and type 2 diabetes. BGStar and iBGStar are employ dynamic electrochemistry, which is supposed to result in highly accurate results. The study was performed on 106 participants (53 female, 53 male, age (mean ± SD): 46 ± 16 years, type 1: 32 patients, type 2: 34 patients, and 40 healthy subjects). Two devices from each type and strips from two different production lots were used for glucose assessment (∼200 readings/meter). Spontaneous glucose assessments and glucose or insulin interventions under medical supervision were applied to perform measurements in the different glucose ranges in accordance with the ISO 15197 requirements. Sample values <50 mg/dL and >400 mg/dL were prepared by laboratory manipulations. The YSI glucose analyzer (glucose oxidase method) served as the standard reference method which may be considered to be a limitation in light of glucose hexokinase-based meters. For all devices, there was a very close correlation between the glucose results compared to the YSI reference method results. The correlation coefficients were r = 0.995 for BGStar and r = 0.992 for iBGStar (Aviva: 0.995, Freedom Lite: 0.990, Contour: 0.993, Ultra 2: 0.990). Error-grid analysis according to Parkes and Clarke revealed both 100% of the readings to be within the clinically acceptable areas (Clarke: A + B with BG*Star (100 + 0), Aviva (97 + 3), and Contour (97 + 3); and 99.5% with iBG*Star (97.5 + 2), Freedom Lite (98 + 1.5), and Ultra

Exaggerated blood pressure variability is associated with memory impairment in very elderly patients.

PubMed

Fujiwara, Takeshi; Hoshide, Satoshi; Kanegae, Hiroshi; Eguchi, Kazuo; Kario, Kazuomi

2018-04-01

We investigated the association between working memory (WM) impairment and blood pressure variability (BPV) in very elderly patients. Japanese outpatients ≥80 years who engaged in normal activities of daily living were the study cohort. WM function was evaluated by a simple visual WM test consisting of 3 figures. We considered the number of figures recalled by the patient his/her test score. We defined the patients with a score of 0 or 1 as those with WM impairment and those with scores of 2 or 3 as those without. To investigate the relative risk of WM impairment, we evaluated each patient's 24 hour ambulatory systolic blood pressure (SBP) and its weighted standard deviation (SD SBP ), office SBP, and the visit-to-visit SD SBP during the 1 year period from the patient's enrollment. A total of 66 patients (mean 84 ± 3.6 years) showed WM impairment, and 431 patients (mean 83 ± 3.1 years) showed no WM impairment. There were no significant differences in 24 hour ambulatory SBP or office SBP between these two groups. However, the WM impairment patients showed significantly higher weighted SD SBP and visit-to-visit SD SBP values compared to the no-impairment group even after adjusting for age. Among these ≥80-year-old patients, those with the highest quartile of both weighted SD SBP (≥21.4 mm Hg) and visit-to-visit SD SBP (≥14.5 mm Hg) showed the highest relative risk (odds ratio 3.52, 95% confidence interval 1.42-8.72) for WM impairment. Exaggerated blood pressure variability parameters were significantly associated with working memory impairment in very elderly individuals. ©2018 Wiley Periodicals, Inc.

Effects of carvedilol or amlodipine on target organ damage in L-NAME hypertensive rats: their relationship with blood pressure variability.

PubMed

Del Mauro, Julieta S; Prince, Paula D; Donato, Martín; Fernandez Machulsky, Nahuel; Morettón, Marcela A; González, Germán E; Bertera, Facundo M; Carranza, Andrea; Gorzalczany, Susana B; Chiappetta, Diego A; Berg, Gabriela; Morales, Celina; Gelpi, Ricardo J; Taira, Carlos A; Höcht, Christian

2017-04-01

The aim of the study was to compare the effects of chronic oral treatment with carvedilol or amlodipine on blood pressure, blood pressure variability and target organ damage in N-nitro-l-arginine methyl ester (L-NAME) hypertensive rats. Wistar rats were treated with L-NAME administered in the drinking water for 8 weeks together with oral administration of carvedilol 30 mg/kg (n = 6), amlodipine 10 mg/kg (n = 6), or vehicle (n = 6). At the end of the treatment, echocardiographic evaluation, blood pressure, and short-term variability measurements were performed. Left ventricular and thoracic aortas were removed to assess activity of metalloproteinase 2 and 9 and expression levels of transforming growth factor β, tumor necrosis factor α, and interleukin 6. Histological samples were prepared from both tissues. Carvedilol and amlodipine induced a comparable reduction of systolic and mean arterial pressure and its short-term variability in L-NAME rats. The expression of transforming growth factor β, tumor necrosis factor α, and interleukin 6 decreased in both organs after carvedilol or amlodipine treatment and the activity of metalloproteinase was reduced in aortic tissue. Treatment with carvedilol or amlodipine completely prevented left ventricular collagen deposition and morphometric alterations in aorta. Oral chronic treatment with carvedilol or amlodipine significantly attenuates blood pressure variability and reduces target organ damage and biomarkers of tissue fibrosis and inflammation in L-NAME hypertensive rats. Copyright © 2017 American Society of Hypertension. Published by Elsevier Inc. All rights reserved.

School burnout: increased sympathetic vasomotor tone and attenuated ambulatory diurnal blood pressure variability in young adult women.

PubMed

May, Ross W; Sanchez-Gonzalez, Marcos A; Fincham, Frank D

2015-01-01

Two studies examined autonomic and cardiovascular functioning that may link school burnout to cardiovascular risk factors in young healthy adult females. Study 1 (N = 136) investigated whether school burnout was related to resting values of blood pressure (BP) and blood pressure variability (BPV) through laboratory beat-to-beat BP assessment. Study 2 (N = 94) examined the link between school burnout and diurnal BPV through ambulatory BP monitoring. Controlling for anxiety and depressive symptomatology, school burnout demonstrated strong positive relationships with indices of cardiac sympathovagal tone, sympathetic vasomotor tone, inefficient myocardial oxygen consumption, increased 24-h ambulatory heart rate and BP, blunted BP diurnal variability, and increased arterial stiffness. These studies establish cardiovascular biomarkers of school burnout and suggest that even in a seemingly healthy sample school burnout may predispose females to increased cardiovascular risk. Several future lines of research are outlined.

How novice, skilled and advanced clinical researchers include variables in a case report form for clinical research: a qualitative study.

PubMed

Chu, Hongling; Zeng, Lin; Fetters, Micheal D; Li, Nan; Tao, Liyuan; Shi, Yanyan; Zhang, Hua; Wang, Xiaoxiao; Li, Fengwei; Zhao, Yiming

2017-09-18

Despite varying degrees in research training, most academic clinicians are expected to conduct clinical research. The objective of this research was to understand how clinical researchers of different skill levels include variables in a case report form for their clinical research. The setting for this research was a major academic institution in Beijing, China. The target population was clinical researchers with three levels of experience, namely, limited clinical research experience, clinicians with rich clinical research experience and clinical research experts. Using a qualitative approach, we conducted 13 individual interviews (face to face) and one group interview (n=4) with clinical researchers from June to September 2016. Based on maximum variation sampling to identify researchers with three levels of research experience: eight clinicians with limited clinical research experience, five clinicians with rich clinical research experience and four clinical research experts. These 17 researchers had diverse hospital-based medical specialties and or specialisation in clinical research. Our analysis yields a typology of three processes developing a case report form that varies according to research experience level. Novice clinician researchers often have an incomplete protocol or none at all, and conduct data collection and publication based on a general framework. Experienced clinician researchers include variables in the case report form based on previous experience with attention to including domains or items at risk for omission and by eliminating unnecessary variables. Expert researchers consider comprehensively in advance data collection and implementation needs and plan accordingly. These results illustrate increasing levels of sophistication in research planning that increase sophistication in selection for variables in the case report form. These findings suggest that novice and intermediate-level researchers could benefit by emulating the comprehensive

Cerebral blood flow and oxygenation in infants after birth asphyxia. Clinically useful information?

PubMed

Greisen, Gorm

2014-10-01

The term 'luxury perfusion' was coined nearly 50 years ago after observation of bright-red blood in the cerebral veins of adults with various brain pathologies. The bright-red blood represents decreased oxygen extraction and hence the perfusion is 'luxurious' compared to oxygen needs. Gradual loss of cellular energy charge during the hours following severe birth asphyxia was observed twenty years later by sequential cranial magnetic resonance spectroscopy. This led to the concept of delayed energy failure that is linked to mitochondrial dysfunction and apoptotic cell death. Abnormally increased perfusion and lack of normal cerebral blood flow regulation are also typically present, but whether the perfusion abnormalities at this secondary stage are detrimental, beneficial, or a mere epiphenomenon remains elusive. In contrast, incomplete reoxygenation of the brain during and following resuscitation is likely to compromise outcome. The clinical value of cerebral oximetry in this context can only be examined in a randomised clinical trial. Copyright © 2014 Elsevier Ltd. All rights reserved.

Heart Rate Variability Moderates the Association Between Separation-Related Psychological Distress and Blood Pressure Reactivity Over Time.

PubMed

Bourassa, Kyle J; Hasselmo, Karen; Sbarra, David A

2016-08-01

Divorce is a stressor associated with long-term health risk, though the mechanisms of this effect are poorly understood. Cardiovascular reactivity is one biological pathway implicated as a predictor of poor long-term health after divorce. A sample of recently separated and divorced adults (N = 138) was assessed over an average of 7.5 months to explore whether individual differences in heart rate variability-assessed by respiratory sinus arrhythmia-operate in combination with subjective reports of separation-related distress to predict prospective changes in cardiovascular reactivity, as indexed by blood pressure reactivity. Participants with low resting respiratory sinus arrhythmia at baseline showed no association between divorce-related distress and later blood pressure reactivity, whereas participants with high respiratory sinus arrhythmia showed a positive association. In addition, within-person variation in respiratory sinus arrhythmia and between-persons variation in separation-related distress interacted to predict blood pressure reactivity at each laboratory visit. Individual differences in heart rate variability and subjective distress operate together to predict cardiovascular reactivity and may explain some of the long-term health risk associated with divorce. © The Author(s) 2016.

Cocaine and metabolite concentrations in DBS and venous blood after controlled intravenous cocaine administration

PubMed Central

Ellefsen, Kayla N; da Costa, Jose Luiz; Concheiro, Marta; Anizan, Sebastien; Barnes, Allan J; Pirard, Sandrine; Gorelick, David A; Huestis, Marilyn A

2015-01-01

Background: DBS are an increasingly common clinical matrix. Methods & results: Sensitive and specific methods for DBS and venous blood cocaine and metabolite detection by LC–HRMS and 2D GC–MS, respectively, were validated to examine correlation between concentrations following controlled intravenous cocaine administration. Linear ranges from 1 to 200 µg/l were achieved, with acceptable bias and imprecision. Authentic matched specimens’ (392 DBS, 97 venous blood) cocaine and benzoylecgonine concentrations were qualitatively similar, but DBS had much greater variability (21.4–105.9 %CV) and were lower than in blood. Conclusion: DBS offer advantages for monitoring cocaine intake; however, differences between capillary and venous blood and DBS concentration variability must be addressed. PMID:26327184

The next chapter in patient blood management: real-time clinical decision support.

PubMed

Goodnough, Lawrence Tim; Shah, Neil

2014-12-01

Blood transfusion was identified by the American Medical Association as one of the top five most frequently overused therapies. Utilization review has been required by accreditation agencies, but retrospective review has been ineffective due to labor-intense resources applied to only a sampling of transfusion events. Electronic medical records have allowed clinical decision support (CDS) to occur via a best practices alert at the critical decision point concurrently with physician order entry. We review emerging strategies for improving blood utilization. Implementation of CDS at our institution decreased the percentage of transfusions in patients with a hemoglobin level of more than 8 g/dL from 60% to less than 30%. Annual RBC transfusions were reduced by 24%, despite concurrent increases in patient discharge volumes and case mix complexity. This resulted in acquisition costs savings (direct blood product purchase costs) of $6.4 million over 4 years. We have been able to significantly reduce inappropriate blood transfusions and related costs through an educational initiative coupled with real-time CDS. In deriving increased value out of health care, CDS can be applied to a number of overuse measures in laboratory testing, radiology, and therapy such as antibiotics, as outlined by the American Board of Internal Medicine's Choosing Wisely campaign. Copyright© by the American Society for Clinical Pathology.

Clinical Trials With Large Numbers of Variables: Important Advantages of Canonical Analysis.

PubMed

Cleophas, Ton J

2016-01-01

Canonical analysis assesses the combined effects of a set of predictor variables on a set of outcome variables, but it is little used in clinical trials despite the omnipresence of multiple variables. The aim of this study was to assess the performance of canonical analysis as compared with traditional multivariate methods using multivariate analysis of covariance (MANCOVA). As an example, a simulated data file with 12 gene expression levels and 4 drug efficacy scores was used. The correlation coefficient between the 12 predictor and 4 outcome variables was 0.87 (P = 0.0001) meaning that 76% of the variability in the outcome variables was explained by the 12 covariates. Repeated testing after the removal of 5 unimportant predictor and 1 outcome variable produced virtually the same overall result. The MANCOVA identified identical unimportant variables, but it was unable to provide overall statistics. (1) Canonical analysis is remarkable, because it can handle many more variables than traditional multivariate methods such as MANCOVA can. (2) At the same time, it accounts for the relative importance of the separate variables, their interactions and differences in units. (3) Canonical analysis provides overall statistics of the effects of sets of variables, whereas traditional multivariate methods only provide the statistics of the separate variables. (4) Unlike other methods for combining the effects of multiple variables such as factor analysis/partial least squares, canonical analysis is scientifically entirely rigorous. (5) Limitations include that it is less flexible than factor analysis/partial least squares, because only 2 sets of variables are used and because multiple solutions instead of one is offered. We do hope that this article will stimulate clinical investigators to start using this remarkable method.

The Paradox of Pelvic Exenteration: The Interaction of Clinical and Psychological Variables.

PubMed

Arnaboldi, Paola; Santoro, Luigi; Mazzocco, Ketti; Oliveri, Serena; Maggioni, Angelo; Pravettoni, Gabriella

2015-10-01

To text the feasibility of a psychological intervention package administered to 49 pelvic exenteration candidates, aimed at evaluating the preoperative prevalence of psychological distress and assessing the presence of any correlation between preoperative psychological distress and clinical variables such as pain and hospitalization length. Patients were referred to the psychology unit from the very beginning of their clinical pathway and were administered the Psychological Distress Inventory (PDI) and the Mini-Mental Adjustment to Cancer (Mini-MAC) questionnaire at prehospital admission. Patients presenting with a significant level of distress received nonstandardized psychological support. Statistical analyses were performed to detect the presence of any correlation between psychological variables at prehospital admission and clinical outcomes. The 40% of patients had significant levels of distress at prehospital admission (PDI ≥ 30). As regards Mini-MAC, the mean value of fighting spirit attitude and fatalism was higher in our sample than in the normative sample of the Mini-MAC validation study in the Italian cancer population. Their anxious preoccupation attitude was lower. There were no correlations between clinical and psychological variables: level of postsurgery pain was higher (3.7) in the subgroup of patients with presurgery PDI < 30 compared with those with PDI ≥ 30 (3.5). However, this difference was not statistically significant (P = 1.00). Considering hospitalization length, the above described trend was similar. Although highly distressed, pelvic exenteration candidates show an adaptive range of coping mechanisms. This calls for a greater effort in studying the complexity of their psychoemotional status to provide them with the best multidisciplinary care. Extensive study of the real effectiveness of psychological intervention is warranted: randomized clinical trials could help in detecting the presence of any correlation between clinical and

Mobile Clinic In Massachusetts Associated With Cost Savings From Lowering Blood Pressure And Emergency Department Use

PubMed Central

Hill, Caterina; Bennet, Jennifer; Vavasis, Anthony; Oriol, Nancy E.

2014-01-01

Mobile health clinics are in increasingly wide use, but evidence of their clinical impact or cost-effectiveness is limited. Using a unique data set of 5,900 patients who made a total of 10,509 visits in 2010–12 to the Family Van, an urban mobile health clinic in Massachusetts, we examined the effect of screenings and counseling provided by the clinic on blood pressure. Patients who presented with high blood pressure during their initial visit experienced average reductions of 10.7 mmHg and 6.2 mmHg in systolic and diastolic blood pressure, respectively, during their follow-up visits. These changes were associated with 32.2 percent and 44.6 percent reductions in the relative risk of myocardial infarction and stroke, respectively, which we converted into savings using estimates of the incidence and costs of these conditions over thirty months. The savings from this reduction in blood pressure and patient-reported avoided emergency department visits produced a positive lower bound for the clinic’s return on investment of 1.3. All other services of the clinic—those aimed at diabetes, obesity, and maternal health, for example—were excluded from this lower-bound estimate. Policy makers should consider mobile clinics as a delivery model for underserved communities with poor health status and high use of emergency departments. PMID:23297269

Evaluation of Blood Glucose Meter Efficacy in an Antenatal Diabetes Clinic.

PubMed

McGrath, Rachel T; Donnelly, Vanessa C; Glastras, Sarah J; Preda, Veronica A; Sheriff, Nisa; Ward, Peter; Hocking, Samantha L; Fulcher, Gregory R

2016-02-01

The optimal treatment of diabetes in pregnancy requires accurate measurement of blood glucose levels, in order to minimize adverse outcomes for both mother and neonate. Self-monitoring of blood glucose is routinely used to measure glycemic control and to assess whether treatment targets are being met; however, the accuracy of blood glucose meters in pregnancy is unclear. Pregnant women with gestational, type 1, or type 2 diabetes mellitus were eligible to participate. Nonfasting capillary blood glucose levels were measured in duplicate using the BGStar(®) (Sanofi, Sydney, Australia) and FreeStyle Lite(®) (Abbott, Sydney) blood glucose meters. Venous blood samples were collected and analyzed for plasma glucose, hematocrit, and glycated hemoglobin. Capillary blood glucose was compared with plasma glucose and further assessed according to International Organization for Standardization (ISO) 15197:2013 standards. One hundred ten women were recruited, providing 96 samples suitable for analysis. The mean ± SD laboratory plasma glucose level was 4.6 ± 1.4 mmol/L; the BGStar and FreeStyle Lite capillary blood glucose values were 5.3 ± 1.4 mmol/L and 5.0 ± 1.3 mmol/L, respectively. Both meters showed a positive bias (0.42 mmol/L for the FreeStyle Lite and 0.65 mmol/L for the BGStar). Furthermore, neither meter fulfilled the ISO 15197:2013 standards, and there was a nonsignificant improvement in meter performance at blood glucose levels of ≤4.2 mmol/L. Hematocrit did not affect the results of either blood glucose meter. Clarke Error Grid analysis demonstrated that approximately 70% of the results of both meters would lead to appropriate clinical action. The BGStar and FreeStyle Lite blood glucose meters did not meet ISO 15197:2013 recommendations for blood glucose monitoring systems when assessed in a population of women with diabetes in pregnancy. Clinicians should consider this difference in blood glucose readings when making diabetes

Very poor agreement between routine outpatient clinic office and ambulatory blood pressure: time to improve an old hospital outpatient clinic routine?

PubMed

Reinhard, Mark; Poulsen, Per L; Christensen, Kent L

2016-12-01

We investigated the agreement between elevated outpatient clinic office blood pressure (OC-OBP) as measured in the daily routine in our University Hospital Cardiology Outpatient Clinic and subsequent awake ambulatory blood pressure (AABP). In all patients referred for ambulatory blood pressure monitoring from our Cardiology Outpatient Clinic, we identified OC-OBP and changes in medication in the period from 1 January 2014 to 15 September 2015. The AABP was used as a reference measurement for the OC-OBP. A total of 183 patients were included in the study. Their mean age was 62.1±14.0 years and 49% were women. The mean systolic OC-OBP was 166.8±17.9 mmHg and the difference between the mean systolic OC-OBP and AABP was 28.0±19.5 mmHg (P<0.001) with 95% limits of agreement from -10.2 to +66.3 mmHg. The difference in mean systolic OC-OBP and AABP was 18.6±14.7 mmHg in patients less than 45 years (n=21), 24.8±18.2 mmHg in patients 45-74 years (n=121) and 42.3±18.5 mmHg in patients more than or equal to 75 years (n=41). In 32 (17%) of the patients, the antihypertensive treatment was intensified before the AABP, but in nine (28%) of these patients, the antihypertensive treatment was reduced again after the AABP because of low blood pressure. Routine OC-OBP in a busy cardiology clinic agrees poorly with AABP and may lead to unnecessary treatment and pharmacologically induced symptomatic hypotension, particularly in elderly patients. The results of this study urgently call for alternative solutions to routine OC-OBP in hospital outpatient clinics.

Beat-to-beat, reading-to-reading, and day-to-day blood pressure variability in relation to organ damage in untreated Chinese.

PubMed

Wei, Fang-Fei; Li, Yan; Zhang, Lu; Xu, Ting-Yan; Ding, Feng-Hua; Wang, Ji-Guang; Staessen, Jan A

2014-04-01

Whether target organ damage is associated with blood pressure (BP) variability independent of level remains debated. We assessed these associations from 10-minute beat-to-beat, 24-hour ambulatory, and 7-day home BP recordings in 256 untreated subjects referred to a hypertension clinic. BP variability indices were variability independent of the mean, maximum-minimum difference, and average real variability. Effect sizes (standardized β) were computed using multivariable regression models. In beat-to-beat recordings, left ventricular mass index (n=128) was not (P≥0.18) associated with systolic BP but increased with all 3 systolic variability indices (+2.97-3.53 g/m(2); P<0.04); the urinary albumin-to-creatinine ratio increased (P≤0.03) with systolic BP (+1.14-1.17 mg/mmol) and maximum-minimum difference (+1.18 mg/mmol); and pulse wave velocity increased with systolic BP (+0.69 m/s; P<0.001). In 24-hour recordings, all 3 indices of organ damage increased (P<0.03) with systolic BP, whereas the associations with BP variability were nonsignificant (P≥0.15) except for increases in pulse wave velocity (P<0.05) with variability independent of the mean (+0.16 m/s) and maximum-minimum difference (+0.17 m/s). In home recordings, the urinary albumin-to-creatinine ratio (+1.27-1.30 mg/mmol) and pulse wave velocity (+0.36-0.40 m/s) increased (P<0.05) with systolic BP, whereas all associations of target organ damage with the variability indices were nonsignificant (P≥0.07). In conclusion, while accounting for BP level, associations of target organ damage with BP variability were readily detectable in beat-to-beat recordings, least noticeable in home recordings, with 24-hour ambulatory monitoring being informative only for pulse wave velocity.

Intravenous cannulation of adolescents does not affect the modulation of autonomic tone assessed by heart rate and blood pressure variability.

PubMed

Stewart, J M

2000-02-01

Invasive arterial monitoring alters autonomic tone. The effects of intravenous (i.v.) insertion are less clear. The author assessed the effects of i.v. insertion on autonomic activity in patients aged 11 to 19 years prior to head-up tilt by measuring heart rate, blood pressure, heart rate variability, blood pressure variability, and baroreceptor gain before and after i.v. insertion with continuous electrocardiography and arterial tonometry in patients with orthostatic tachycardia syndrome (OTS, N = 21), in patients who experienced simple fainting (N = 14), and in normal control subjects (N = 6). Five-minute samples were collected after 30 minutes supine. Fifteen minutes after i.v. insertion, data were collected again. These 5-minute samples were also collected in a separate control population without i.v. insertion after 30 minutes supine and again 30 minutes later. This population included 12 patients with OTS, 13 patients who experienced simple fainting, and 6 normal control subjects. Heart rate variability included the mean RR, the standard deviation of the RR interval (SDNN), and the root mean square of successive RR differences (RMSSD). Autoregressive spectral modeling was used. Low-frequency power (LFP, 0.04-0.15 Hz), high-frequency power (HFP, 0.15-0.40 Hz), and total power (TP, 0.01-0.40 Hz) were compared. Blood pressure variability included standard deviation of systolic blood pressure, LFP, and HFP. Baroreceptor gain at low frequency and high frequency was calculated from cross-spectral transfer function magnitudes when coherence was greater than 0.5. In patients with OTS, RR (790 +/- 50 msec), SDNN (54 +/- 6 msec), RMSSD (55 +/- 5 msec), LFP (422 +/- 200 ms2/Hz), HFP (846 +/- 400 ms2/Hz), and TP (1550 +/- 320 ms2/Hz) were less than in patients who experienced simple fainting (RR, 940 +/- 50 msec; SDNN, 84 +/- 10 msec; RMSSD, 91 +/- 7 msec; LFP, 880 +/- 342 ms2/Hz; HFP, 1720 +/- 210 ms2/Hz; and TP, 3228 +/- 490 ms2/Hz) or normal control subjects (RR, 920

Impact of flexible insulin therapy on blood glucose variability, oxidative stress and inflammation in type 1 diabetic patients: the VARIAFIT study.

PubMed

Benhamou, P Y; Somers, F; Lablanche, S; Debaty, I; Borel, A L; Nasse, L; Stanke-Labesque, F; Faure, P; Boizel, R; Halimi, S

2014-09-01

HbA1c only partially predicts vascular risk in patients with type 1 diabetes (T1D), and a role for blood glucose variability (BGV) is a matter of debate. For this reason, this study investigated the impact of an educational programme of flexible insulin therapy (FIT) on BGV and oxidative stress. Tests were conducted on 30 adult T1D patients in a prospective, single-centre trial at baseline (M0), and at 3 and 6 months (M3 and M6, respectively) of the FIT programme to determine BGV, as reflected by mean amplitude of glycaemic excursions (MAGE), low blood glucose index (LBGI), lability index (LI), average daily risk range (ADRR), glycaemic lability (scored by two diabetologists), urinary leukotriene E4 (LTE4), 11-dehydro-thromboxane B2 (TXB2) and 8-iso-prostaglandin F2α (PGF2). HbA1c (7.7 ± 0.9%), ADRR, MAGE, LBGI and LI did not change from M0 to M3 and M6, although ADRR and LBGI significantly improved at M3 and M6 in patients with the highest baseline indices (≥ 40 and ≥ 5, respectively). TXB2 declined at M6 (832 ± 625 vs. 633 ± 972 pg/mg; P=0.048), whereas LTE4 and PGF2 remained stable. ADRR showed the strongest correlation with glycaemic lability scores at all visits (r≥0.84, P<0.0001). A FIT educational programme improved BGV only in patients with the highest baseline variability, and led to no changes in HbA1c, while ADRR closely correlated with glycaemic lability score. Our data do not support a relationship between BGV and oxidative stress in T1D patients, although the impact of variability on TXB2 deserves further investigation (ClinicalTrials.gov NCT00973492). Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Impact of advanced monitoring variables on intraoperative clinical decision-making: an international survey.

PubMed

Joosten, Alexandre; Desebbe, Olivier; Suehiro, Koichi; Essiet, Mfonobong; Alexander, Brenton; Ricks, Cameron; Rinehart, Joseph; Faraoni, David; Cecconi, Maurizio; Van der Linden, Philippe; Cannesson, Maxime

2017-02-01

To assess the relationship between the addition of advanced monitoring variables and changes in clinical decision-making. A 15-questions survey was anonymously emailed to international experts and physician members of five anesthesia societies which focused on assessing treatment decisions of clinicians during three realistic clinical scenarios measured at two distinct time points. The first is when typical case information and basic monitoring (T1) were provided, and then once again after the addition of advanced monitoring variables (T2). We hypothesized that the addition of advanced variables would increase the incidence of an optimal therapeutic decision (a priori defined as the answer with the highest percentage of expert agreement) and decrease the variability among the physician's suggested treatments. The survey was completed by 18 experts and 839 physicians. Overall, adding advanced monitoring did not significantly increase physician response accuracy, with the least substantial changes noted on questions related to volume expansion or vasopressor administration. Moreover, advanced monitoring data did not significantly decrease the high level of initial practice variability in physician suggested treatments (P = 0.13), in contrast to the low variability observed within the expert group (P = 0.039). Additionally, 5-10 years of practice (P < 0.0001) and a cardiovascular subspecialty (P = 0.048) were both physician characteristics associated with a higher rate of optimal therapeutic decisions. The addition of advanced variables was of limited benefit for most physicians, further indicating the need for more in depth education on the clinical value and technical understanding of such variables.

Maturation of heart rate and blood pressure variability during sleep in term-born infants.

PubMed

Yiallourou, Stephanie R; Sands, Scott A; Walker, Adrian M; Horne, Rosemary S C

2012-02-01

Abnormal blood pressure control is implicated in the sudden infant death syndrome (SIDS). However, no data exist on normal development of blood pressure control during infancy. This study assessed maturation of autonomic control of blood pressure and heart rate during sleep within the first 6 months of life. Term infants (n = 31) were studied longitudinally at 2-4 weeks, 2-3 months, and 5-6 months postnatal age. Infants underwent daytime polysomnography at each age studied. Blood pressure and heart rate were recorded during quiet (QS) and active (AS) sleep in undisturbed baseline and head-up tilt conditions. Autonomic control was assessed using spectral indices of blood pressure and heart rate variability (BPV and HRV) in ranges of low frequency (LF, reflecting sympathetic + parasympathetic activity) and high frequency (HF, parasympathetic activity), total power (LF+HF), and LF/HF ratio (sympathovagal balance). With increasing postnatal age and predominantly during QS, HRV-LF, HRV-HF, and HRV total power increased, while HRV-LF/HF decreased. BPV-LF/HF also decreased with postnatal age. All changes were evident in both baseline and head-up tilt conditions. BPV-LF and BPV total power during tilts were markedly reduced in QS versus AS at each age. In sleeping infants, sympathetic vascular modulation of the circulation decreases with age, while parasympathetic control of heart rate is strengthened. These normative data will aid in the early identification of conditions where autonomic function is impaired, such as in SIDS.

Characterizing biological variability in livestock blood cholinesterase activity for biomonitoring organophosphate nerve agent exposure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Halbrook, R.S.; Shugart, L.R.; Watson, A.P.

1992-09-01

A biomonitoring protocol, using blood cholinesterase (ChE) activity in livestock as a monitor of potential organophosphate nerve agent exposure during the planned destruction of US unitary chemical warfare agent stockpiles, is described. The experimental design included analysis of blood ChE activity in individual healthy sheep, horses, and dairy and beef cattle during a 10- to 12-month period. Castrated and sexually intact males, pregnant and lactating females, and adult and immature animals were examined through at least one reproductive cycle. The same animals were used throughout the period of observation and were not exposed to ChE-inhibiting organophosphate or carbamate compounds. Amore » framework for an effective biomonitoring protocol within a monitoring area includes establishing individual baseline blood ChE activity for a sentinel group of 6 animals on the bases of blood samples collected over a 6-month period, monthly collection of blood samples for ChE-activity determination during monitoring, and selection of adult animals as sentinels. Exposure to ChE-inhibiting compounds would be suspected when all blood ChE activity of all animals within the sentinel group are decreased greater than 20% from their own baseline value. Sentinel species selection is primarily a logistical and operational concern; however, sheep appear to be the species of choice because within-individual baseline ChE activity and among age and gender group ChE activity in sheep had the least variability, compared with data from other species. This protocol provides an effective and efficient means for detecting abnormal depressions in blood ChE activity in livestock and can serve as a valuable indicator of the extent of actual plume movement and/or deposition in the event of organophosphate nerve agent release.« less

Biomarkers of Traumatic Injury Are Transported from Brain to Blood via the Glymphatic System

PubMed Central

Plog, Benjamin A.; Dashnaw, Matthew L.; Hitomi, Emi; Peng, Weiguo; Liao, Yonghong; Lou, Nanhong; Deane, Rashid

2015-01-01

The nonspecific and variable presentation of traumatic brain injury (TBI) has motivated an intense search for blood-based biomarkers that can objectively predict the severity of injury. However, it is not known how cytosolic proteins released from traumatized brain tissue reach the peripheral blood. Here we show in a murine TBI model that CSF movement through the recently characterized glymphatic pathway transports biomarkers to blood via the cervical lymphatics. Clinically relevant manipulation of glymphatic activity, including sleep deprivation and cisternotomy, suppressed or eliminated TBI-induced increases in serum S100β, GFAP, and neuron specific enolase. We conclude that routine TBI patient management may limit the clinical utility of blood-based biomarkers because their brain-to-blood transport depends on glymphatic activity. PMID:25589747

Clinical Practice Guidelines From the AABB: Red Blood Cell Transfusion Thresholds and Storage.

PubMed

Carson, Jeffrey L; Guyatt, Gordon; Heddle, Nancy M; Grossman, Brenda J; Cohn, Claudia S; Fung, Mark K; Gernsheimer, Terry; Holcomb, John B; Kaplan, Lewis J; Katz, Louis M; Peterson, Nikki; Ramsey, Glenn; Rao, Sunil V; Roback, John D; Shander, Aryeh; Tobian, Aaron A R

2016-11-15

More than 100 million units of blood are collected worldwide each year, yet the indication for red blood cell (RBC) transfusion and the optimal length of RBC storage prior to transfusion are uncertain. To provide recommendations for the target hemoglobin level for RBC transfusion among hospitalized adult patients who are hemodynamically stable and the length of time RBCs should be stored prior to transfusion. Reference librarians conducted a literature search for randomized clinical trials (RCTs) evaluating hemoglobin thresholds for RBC transfusion (1950-May 2016) and RBC storage duration (1948-May 2016) without language restrictions. The results were summarized using the Grading of Recommendations Assessment, Development and Evaluation method. For RBC transfusion thresholds, 31 RCTs included 12 587 participants and compared restrictive thresholds (transfusion not indicated until the hemoglobin level is 7-8 g/dL) with liberal thresholds (transfusion not indicated until the hemoglobin level is 9-10 g/dL). The summary estimates across trials demonstrated that restrictive RBC transfusion thresholds were not associated with higher rates of adverse clinical outcomes, including 30-day mortality, myocardial infarction, cerebrovascular accident, rebleeding, pneumonia, or thromboembolism. For RBC storage duration, 13 RCTs included 5515 participants randomly allocated to receive fresher blood or standard-issue blood. These RCTs demonstrated that fresher blood did not improve clinical outcomes. It is good practice to consider the hemoglobin level, the overall clinical context, patient preferences, and alternative therapies when making transfusion decisions regarding an individual patient. Recommendation 1: a restrictive RBC transfusion threshold in which the transfusion is not indicated until the hemoglobin level is 7 g/dL is recommended for hospitalized adult patients who are hemodynamically stable, including critically ill patients, rather than when the hemoglobin level

The clinical utility of tricyclic antidepressant blood levels: a review of the literature.

PubMed

Van Brunt, N

1983-01-01

An effort has been made to summarize clinical selection criteria for therapeutic drug monitoring for the tricyclic antidepressants (TCAs). A clear understanding of this would increase the number of patients who benefit from TCA blood-level determinations. Depression has been defined in terms of the old and new nomenclature in an attempt to clarify the ambiguities that necessarily exist in such an all-encompassing classification of disease. The biogenic amine hypothesis of depression is briefly reviewed, followed by the effect of pharmacokinetic parameters on the establishment of steady-state blood levels. The protein binding of the TCAs and the resulting effect on free versus total drug levels is discussed. Pharmaceuticals and other factors known to affect TCA blood levels are mentioned. Following a discussion of anticholinergic side effects and cardiotoxicity, therapeutic ranges for various TCAs are reviewed as to our current level of understanding. The remainder of the paper explores patient selection criteria for future clinical studies attempting to establish a drug level-effect relationship. Recent case histories are supplied throughout the text to illustrate the various subjects addressed. They also instruct the clinician and the laboratory scientist as to the potential use of TCA blood-level monitoring in the treatment of depression.

[Ambulatory blood pressure monitoring is a useful tool for all patients].

PubMed

de la Sierra, A

Clinical blood pressure measurement (BP) is an occasional and imperfect way of estimating this biological variable. Ambulatory blood pressure monitoring (ABPM) is by far the best clinical tool for measuring an individual's blood pressure. Mean values over 24h, through the daytime and at night all make it more possible to predict organic damage and the future development of the disorder. ABPM enables the detection of white-coat hypertension and masked hypertension in both the diagnosis and follow-up of treated patients. Although some of the advantages of ABPM can be reproduced by more automated measurement without the presence of an observer in the clinic or self-measurement at home, there are some other elements of great interest that are unique to ABPM, such as seeing what happens to a patient's BP at night, the night time dipping pattern and short-term variability, all of which relate equally to the patient's prognosis. There is no scientific or clinical justification for denying these advantages, and ABPM should form part of the evaluation and follow-up of practically all hypertensive patients. Rather than continuing unhelpful discussions as to its availability and acceptability, we should concentrate our efforts on ensuring its universal availability and clearly explaining its advantages to both doctors and patients. Copyright © 2016 SEH-LELHA. Publicado por Elsevier España, S.L.U. All rights reserved.

Effect of Azilsartan on Day-to-Day Variability in Home Blood Pressure: A Prospective Multicenter Clinical Trial.

PubMed

Miyoshi, Toru; Suetsuna, Ryoji; Tokunaga, Naoto; Kusaka, Masayasu; Tsuzaki, Ryuichiro; Koten, Kazuya; Kunihisa, Kohno; Ito, Hiroshi

2017-07-01

The blood pressure variability (BPV) such as visit-to-visit, day-by-day, and ambulatory BPV has been also shown to be a risk of future cardiovascular events. However, the effects of antihypertensive therapy on BPV remain unclear. The purpose of this study was to evaluate the effect of azilsartan after switching from another angiotensin II receptor blocker (ARB) on day-to-day BPV in home BP monitoring. This prospective, multicenter, open-labeled, single-arm study included 28 patients undergoing treatment with an ARB, which was switched to azilsartan after enrollment. The primary outcome was the change in the mean of the standard deviation and the coefficient of variation of morning home BP for 5 consecutive days from baseline to the 24-week follow-up. The secondary outcome was the change in arterial stiffness measured by the cardio-ankle vascular index. The mean BPs in the morning and evening for 5 days did not statistically differ between baseline and 24 weeks. For the morning BP, the means of the standard deviations and coefficient of variation of the systolic BP were significantly decreased from 7.4 ± 3.6 mm Hg to 6.1 ± 3.2 mm Hg and from 5.4±2.7% to 4.6±2.3% (mean ± standard deviation, P = 0.04 and P = 0.04, respectively). For the evening BP, no significant change was observed in the systolic or diastolic BPV. The cardio-ankle vascular index significantly decreased from 8.3 ± 0.8 to 8.1 ± 0.8 (P = 0.03). Switching from another ARB to azilsartan reduced day-to-day BPV in the morning and improved arterial stiffness.

Development of a PCR Assay to Detect Low Level Trypanosoma cruzi in Blood Specimens Collected with PAXgene Blood DNA Tubes for Clinical Trials Treating Chagas Disease.

PubMed

Wei, Bo; Chen, Lei; Kibukawa, Miho; Kang, John; Waskin, Hetty; Marton, Matthew

2016-12-01

Chagas disease is caused by the parasitic infection of Trypanosoma cruzi (T. cruzi). The STOP CHAGAS clinical trial was initiated in 2011 to evaluate posaconazole in treating Chagas disease, with treatment success defined as negative qualitative PCR results of detecting the parasites in blood specimens collected post-treatment. PAXgene Blood DNA tubes were utilized as a simple procedure to collect and process blood specimens. However, the PAXgene blood specimens challenged published T. cruzi PCR methods, resulting in poor sensitivity and reproducibility. To accurately evaluate the treatment efficacy of the clinical study, we developed and validated a robust PCR assay for detecting low level T. cruzi in PAXgene blood specimens. The assay combines a new DNA extraction method with a custom designed qPCR assay, resulting in limit of detection of 0.005 and 0.01 fg/μl for K98 and CL Brener, two representative strains of two of T. cruzi's discrete typing units. Reliable qPCR standard curves were established for both strains to measure parasite loads, with amplification efficiency ≥ 90% and the lower limit of linearity ≥ 0.05 fg/μl. The assay successfully analyzed the samples collected from the STOP CHAGAS study and may prove useful for future global clinical trials evaluating new therapies for asymptomatic chronic Chagas disease.

Formant Frequencies and Bandwidths in Relation to Clinical Variables in an Obstructive Sleep Apnea Population.

PubMed

Montero Benavides, Ana; Blanco Murillo, José Luis; Fernández Pozo, Rubén; Espinoza Cuadros, Fernando; Torre Toledano, Doroteo; Alcázar-Ramírez, José D; Hernández Gómez, Luis A

2016-01-01

We investigated whether differences in formants and their bandwidths, previously reported comparing small sample population of healthy individuals and patients with obstructive sleep apnea (OSA), are detected on a larger population representative of a clinical practice scenario. We examine possible indirect or mediated effects of clinical variables, which may shed some light on the connection between speech and OSA. In a retrospective study, 241 male subjects suspected to suffer from OSA were examined. The apnea-hypopnea index (AHI) was obtained for every subject using overnight polysomnography. Furthermore, the clinical variables usually reported as predictors of OSA, body mass index (BMI), cervical perimeter, height, weight, and age, were collected. Voice samples of sustained phonations of the vowels /a/, /e/, /i/, /o/, and /u/ were recorded. Formant frequencies F1, F2, and F3 and bandwidths BW1, BW2, and BW3 of the sustained vowels were determined using spectrographic analysis. Correlations among AHI, clinical parameters, and formants and bandwidths were determined. Correlations between AHI and clinical variables were stronger than those between AHI and voice features. AHI only correlates poorly with BW2 of /a/ and BW3 of /e/. A number of further weak but significant correlations have been detected between voice and clinical variables. Most of them were for height and age, with two higher values for age and F2 of /o/ and F2 of /u/. Only few very weak correlations were detected between voice and BMI, weight and cervical perimeter, wich are the clinical variables more correlated with AHI. No significant correlations were detected between AHI and formant frequencies and bandwidths. Correlations between voice and other clinical factors characterizing OSA are weak but highlight the importance of considering indirect or mediated effects of such clinical variables in any research on speech and OSA. Copyright © 2016 The Voice Foundation. Published by Elsevier Inc. All

HIV-1 Genetic Variability in Cuba and Implications for Transmission and Clinical Progression.

PubMed

Blanco, Madeline; Machado, Liuber Y; Díaz, Héctor; Ruiz, Nancy; Romay, Dania; Silva, Eladio

2015-10-01

INTRODUCTION Serological and molecular HIV-1 studies in Cuba have shown very low prevalence of seropositivity, but an increasing genetic diversity attributable to introduction of many HIV-1 variants from different areas, exchange of such variants among HIV-positive people with several coinciding routes of infection and other epidemiologic risk factors in the seropositive population. The high HIV-1 genetic variability observed in Cuba has possible implications for transmission and clinical progression. OBJECTIVE Study genetic variability for the HIV-1 env, gag and pol structural genes in Cuba; determine the prevalence of B and non-B subtypes according to epidemiologic and behavioral variables and determine whether a relationship exists between genetic variability and transmissibility, and between genetic variability and clinical disease progression in people living with HIV/AIDS. METHODS Using two molecular assays (heteroduplex mobility assay and nucleic acid sequencing), structural genes were characterized in 590 people with HIV-1 (480 men and 110 women), accounting for 3.4% of seropositive individuals in Cuba as of December 31, 2013. Nonrandom sampling, proportional to HIV prevalence by province, was conducted. Relationships between molecular results and viral factors, host characteristics, and patients' clinical, epidemiologic and behavioral variables were studied for molecular epidemiology, transmission, and progression analyses. RESULTS Molecular analysis of the three HIV-1 structural genes classified 297 samples as subtype B (50.3%), 269 as non-B subtypes (45.6%) and 24 were not typeable. Subtype B prevailed overall and in men, mainly in those who have sex with men. Non-B subtypes were prevalent in women and heterosexual men, showing multiple circulating variants and recombinant forms. Sexual transmission was the predominant form of infection for all. B and non-B subtypes were encountered throughout Cuba. No association was found between subtypes and

Predicting out-of-office blood pressure level using repeated measurements in the clinic: an observational cohort study

PubMed Central

Sheppard, James P.; Holder, Roger; Nichols, Linda; Bray, Emma; Hobbs, F.D. Richard; Mant, Jonathan; Little, Paul; Williams, Bryan; Greenfield, Sheila; McManus, Richard J.

2014-01-01

Objectives: Identification of people with lower (white-coat effect) or higher (masked effect) blood pressure at home compared to the clinic usually requires ambulatory or home monitoring. This study assessed whether changes in SBP with repeated measurement at a single clinic predict subsequent differences between clinic and home measurements. Methods: This study used an observational cohort design and included 220 individuals aged 35–84 years, receiving treatment for hypertension, but whose SBP was not controlled. The characteristics of change in SBP over six clinic readings were defined as the SBP drop, the slope and the quadratic coefficient using polynomial regression modelling. The predictive abilities of these characteristics for lower or higher home SBP readings were investigated with logistic regression and repeated operating characteristic analysis. Results: The single clinic SBP drop was predictive of the white-coat effect with a sensitivity of 90%, specificity of 50%, positive predictive value of 56% and negative predictive value of 88%. Predictive values for the masked effect and those of the slope and quadratic coefficient were slightly lower, but when the slope and quadratic variables were combined, the sensitivity, specificity, positive and negative predictive values for the masked effect were improved to 91, 48, 24 and 97%, respectively. Conclusion: Characteristics obtainable from multiple SBP measurements in a single clinic in patients with treated hypertension appear to reasonably predict those unlikely to have a large white-coat or masked effect, potentially allowing better targeting of out-of-office monitoring in routine clinical practice. PMID:25144295

Collaborating to Compete: Blood Profiling Atlas in Cancer (BloodPAC) Consortium.

PubMed

Grossman, R L; Abel, B; Angiuoli, S; Barrett, J C; Bassett, D; Bramlett, K; Blumenthal, G M; Carlsson, A; Cortese, R; DiGiovanna, J; Davis-Dusenbery, B; Dittamore, R; Eberhard, D A; Febbo, P; Fitzsimons, M; Flamig, Z; Godsey, J; Goswami, J; Gruen, A; Ortuño, F; Han, J; Hayes, D; Hicks, J; Holloway, D; Hovelson, D; Johnson, J; Juhl, H; Kalamegham, R; Kamal, R; Kang, Q; Kelloff, G J; Klozenbuecher, M; Kolatkar, A; Kuhn, P; Langone, K; Leary, R; Loverso, P; Manmathan, H; Martin, A-M; Martini, J; Miller, D; Mitchell, M; Morgan, T; Mulpuri, R; Nguyen, T; Otto, G; Pathak, A; Peters, E; Philip, R; Posadas, E; Reese, D; Reese, M G; Robinson, D; Dei Rossi, A; Sakul, H; Schageman, J; Singh, S; Scher, H I; Schmitt, K; Silvestro, A; Simmons, J; Simmons, T; Sislow, J; Talasaz, A; Tang, P; Tewari, M; Tomlins, S; Toukhy, H; Tseng, H R; Tuck, M; Tzou, A; Vinson, J; Wang, Y; Wells, W; Welsh, A; Wilbanks, J; Wolf, J; Young, L; Lee, Jsh; Leiman, L C

2017-05-01

The cancer community understands the value of blood profiling measurements in assessing and monitoring cancer. We describe an effort among academic, government, biotechnology, diagnostic, and pharmaceutical companies called the Blood Profiling Atlas in Cancer (BloodPAC) Project. BloodPAC will aggregate, make freely available, and harmonize for further analyses, raw datasets, relevant associated clinical data (e.g., clinical diagnosis, treatment history, and outcomes), and sample preparation and handling protocols to accelerate the development of blood profiling assays. © 2017 Authors Clinical Pharmacology & Therapeutics published by Wiley Periodicals, Inc. on behalf of American Society for Clinical Pharmacology and Therapeutics.

Visit-to-visit cholesterol variability correlates with coronary atheroma progression and clinical outcomes.

PubMed

Clark, Donald; Nicholls, Stephen J; St John, Julie; Elshazly, Mohamed B; Kapadia, Samir R; Tuzcu, E Murat; Nissen, Steven E; Puri, Rishi

2018-04-21

Utilizing serial intravascular ultrasonography (IVUS), we aimed to exam the association of intra-individual lipid variability, coronary atheroma progression, and clinical outcomes. We performed a post hoc patient-level analysis of nine clinical trials involving 4976 patients with coronary artery disease who underwent serial coronary IVUS in the setting of a range of medical therapies. We assessed the associations between progression in percent atheroma volume (ΔPAV), clinical outcomes, and visit-to-visit lipid variability including low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), non-HDL-C, total cholesterol (TC)/HDL-C, and apolipoprotein B (ApoB). Variability of lipid parameters was measured using intra-individual standard deviation over 3, 6, 12, 18, and 24 months. Atherogenic lipoprotein variability significantly associated with ΔPAV [odds ratio (95% confidence interval; P-value), LDL-C: 1.09 (1.02, 1.17, P = 0.01); non-HDL-C: 1.10 (1.02, 1.18, P = 0.01); TC/HDL-C: 1.14 (1.06, 1.24, P = 0.001); ApoB: 1.13 (1.03, 1.24, P = 0.01)]. Survival curves revealed significant stepwise relationships between cumulative major adverse cardiovascular events and increasing quartiles of atherogenic lipoprotein variability at 24-months follow-up (log-rank P < 0.01 for all lipoproteins except HDL-C). Stronger associations were noted between achieved lipoprotein levels and ΔPAV [LDL-C: 1.27 (1.17, 1.39; P < 0.001); non-HDL-C: 1.32 (1.21, 1.45; P < 0.001); TC/HDL-C: 1.31 (1.19, 1.45; P < 0.001); ApoB: 1.20 (1.07, 1.35; P = 0.003)]. Greater visit-to-visit variability in atherogenic lipoprotein levels significantly associates with coronary atheroma progression and clinical outcomes, although the association between achieved atherogenic lipoproteins and atheroma progression appears stronger. These data highlight the importance of achieving low and consistent atherogenic lipoprotein levels to promote

Point-of-care blood gases, electrolytes, chemistries, hemoglobin, and hematocrit measurement in venous samples from pet rabbits.

PubMed

Selleri, Paolo; Di Girolamo, Nicola

2014-01-01

Point-of-care testing is an attractive option in rabbit medicine, because it permits rapid analysis of a panel of electrolytes, chemistries, blood gases, hemoglobin, and hematocrit, requiring only 65 μL of blood. The purpose of this study was to evaluate the performance of a portable clinical analyzer for measurement of pH, partial pressure of CO2, Na, chloride, potassium, blood urea nitrogen, glucose, hematocrit, and hemoglobin in healthy and diseased rabbits. Blood samples obtained from 30 pet rabbits were analyzed immediately after collection by the portable clinical analyzer (PCA) and immediately thereafter (time <20 sec) by a reference analyzer. Bland-Altman plots and Passing-Bablok regression analysis were used to compare the results. Limits of agreement were wide for all the variables studied, with the exception of pH. Most variables presented significant proportional and/or constant bias. The current study provides sufficient evidence that the PCA presents reliability for pH, although its low agreement with a reference analyzer for the other variables does not support their interchangeability. Limits of agreement provided for each variable allow researchers to evaluate if the PCA is reliable enough for their scope. To the authors' knowledge, the present is the first report evaluating a PCA in the rabbit.

A Systematic Evaluation of Blood Serum and Plasma Pre-Analytics for Metabolomics Cohort Studies

PubMed Central

Jobard, Elodie; Trédan, Olivier; Postoly, Déborah; André, Fabrice; Martin, Anne-Laure; Elena-Herrmann, Bénédicte; Boyault, Sandrine

2016-01-01

The recent thriving development of biobanks and associated high-throughput phenotyping studies requires the elaboration of large-scale approaches for monitoring biological sample quality and compliance with standard protocols. We present a metabolomic investigation of human blood samples that delineates pitfalls and guidelines for the collection, storage and handling procedures for serum and plasma. A series of eight pre-processing technical parameters is systematically investigated along variable ranges commonly encountered across clinical studies. While metabolic fingerprints, as assessed by nuclear magnetic resonance, are not significantly affected by altered centrifugation parameters or delays between sample pre-processing (blood centrifugation) and storage, our metabolomic investigation highlights that both the delay and storage temperature between blood draw and centrifugation are the primary parameters impacting serum and plasma metabolic profiles. Storing the blood drawn at 4 °C is shown to be a reliable routine to confine variability associated with idle time prior to sample pre-processing. Based on their fine sensitivity to pre-analytical parameters and protocol variations, metabolic fingerprints could be exploited as valuable ways to determine compliance with standard procedures and quality assessment of blood samples within large multi-omic clinical and translational cohort studies. PMID:27929400

Achieving blood pressure control among renal transplant recipients by integrating electronic health technology and clinical pharmacy services.

PubMed

Migliozzi, Daniel R; Zullo, Andrew R; Collins, Christine; Elsaid, Khaled A

2015-11-15

The implementation and outcomes of a program combining electronic home blood pressure monitoring (HBPM) and pharmacist-provided medication therapy management (MTM) services in a renal transplantation clinic are described. Patients enrolled in the program were provided with a computer-enabled blood pressure monitor. A dedicated renal transplantation pharmacist was integrated into the renal transplantation team under a collaborative care practice agreement. The collaborative care agreement allowed the pharmacist to authorize medication additions, deletions, and dosage changes. Comprehensive disease and blood pressure education was provided by a clinical pharmacist. In the pretransplantation setting, the pharmacist interviewed the renal transplant candidate and documents allergies, verified the patient's medication profile, and identified and assessed barriers to medication adherence. A total of 50 renal transplant recipients with at least one recorded home blood pressure reading and at least one year of follow-up were included in our analysis. A significant reduction in mean systolic and diastolic blood pressure values were observed at 30, 90, 180, and 360 days after enrollment in the program (p < 0.05). Pharmacist interventions were documented for 37 patients. Medication-related problems accounted for 46% of these interventions and included dosage modifications, regimen changes, and mitigation of barriers to medication access and adherence. Implementation of electronic HBPM and pharmacist-provided MTM services implemented in a renal transplant clinic was associated with sustained improvements in blood pressure control. Incorporation of a pharmacist in the renal transplant clinic resulted in the detection and resolution of medication-related problems. Copyright © 2015 by the American Society of Health-System Pharmacists, Inc. All rights reserved.

Blood pressure reactivity to psychological stress is associated with clinical outcomes in patients with heart failure.

PubMed

Sherwood, Andrew; Hill, LaBarron K; Blumenthal, James A; Adams, Kirkwood F; Paine, Nicola J; Koch, Gary G; O'Connor, Christopher M; Johnson, Kristy S; Hinderliter, Alan L

2017-09-01

Cardiovascular (CV) reactivity to psychological stress has been implicated in the development and exacerbation of cardiovascular disease (CVD). Although high CV reactivity traditionally is thought to convey greater risk of CVD, the relationship between reactivity and clinical outcomes is inconsistent and may depend on the patient population under investigation. The present study examined CV reactivity in patients with heart failure (HF) and its potential association with long-term clinical outcomes. One hundred ninety-nine outpatients diagnosed with HF, with ejection fraction ≤40%, underwent an evaluation of blood pressure (BP) and heart rate reactivity to a laboratory-based simulated public-speaking stressor. Cox proportional hazards regression models were used to examine the prospective association between BP and heart rate reactivity on a combined end point of death or CV hospitalization over a 5-year median follow-up period. Both systolic blood pressure (SBP) and diastolic blood pressure (DBP) reactivity, quantified as continuous variables, were inversely related to risk of death or CV hospitalization (Ps < .01) after controlling for established risk factors, including HF disease severity and etiology. In similar models, heart rate reactivity was unrelated to outcome (P = .12). In models with tertiles of reactivity, high SBP reactivity, compared with intermediate SBP reactivity, was associated with lower risk (hazard ratio [HR] = .498, 95% CI .335-.742, P =.001), whereas low SBP reactivity did not differ from intermediate reactivity. For DBP, high reactivity was marginally associated with lower risk compared with intermediate DBP reactivity (HR = .767, 95% CI .515-1.14, P =.193), whereas low DBP reactivity was associated with greater risk (HR = 1.49, 95% CI 1.027-2.155, P =.0359). No relationship of heart rate reactivity to outcome was identified. For HF patients with reduced ejection fraction, a robust increase in BP evoked by a laboratory

T-wave alternans and beat-to-beat variability of repolarization: pathophysiological backgrounds and clinical relevance.

PubMed

Floré, Vincent; Willems, Rik

2012-12-01

In this review, we focus on temporal variability of cardiac repolarization. This phenomenon has been related to a higher risk for ventricular arrhythmia and is therefore interesting as a marker of sudden cardiac death risk. We review two non-invasive clinical techniques quantifying repolarization variability: T-wave alternans (TWA) and beat-to-beat variability of repolarization (BVR). We discuss their pathophysiological link with ventricular arrhythmia and the current clinical relevance of these techniques.

Ambient particulate air pollution, heart rate variability, and blood markers of inflammation in a panel of elderly subjects.

PubMed Central

Pope, C Arden; Hansen, Matthew L; Long, Russell W; Nielsen, Karen R; Eatough, Norman L; Wilson, William E; Eatough, Delbert J

2004-01-01

Epidemiologic studies report associations between particulate air pollution and cardiopulmonary morbidity and mortality. Although the underlying pathophysiologic mechanisms remain unclear, it has been hypothesized that altered autonomic function and pulmonary/systemic inflammation may play a role. In this study we explored the effects of air pollution on autonomic function measured by changes in heart rate variability (HRV) and blood markers of inflammation in a panel of 88 elderly subjects from three communities along the Wasatch Front in Utah. Subjects participated in multiple sessions of 24-hr ambulatory electrocardiographic monitoring and blood tests. Regression analysis was used to evaluate associations between fine particulate matter [aerodynamic diameter less than or equal to 2.5 microm (PM2.5)] and HRV, C-reactive protein (CRP), blood cell counts, and whole blood viscosity. A 100- microg/m3 increase in PM2.5 was associated with approximately a 35 (SE = 8)-msec decline in standard deviation of all normal R-R intervals (SDNN, a measure of overall HRV); a 42 (SE = 11)-msec decline in square root of the mean of the squared differences between adjacent normal R-R intervals (r-MSSD, an estimate of short-term components of HRV); and a 0.81 (SE = 0.17)-mg/dL increase in CRP. The PM2.5-HRV associations were reasonably consistent and statistically robust, but the CRP association dropped to 0.19 (SE = 0.10) after excluding the most influential subject. PM2.5 was not significantly associated with white or red blood cell counts, platelets, or whole-blood viscosity. Most short-term variability in temporal deviations of HRV and CRP was not explained by PM2.5; however, the small statistically significant associations that were observed suggest that exposure to PM2.5 may be one of multiple factors that influence HRV and CRP. PMID:14998750

Biomarkers of traumatic injury are transported from brain to blood via the glymphatic system.

PubMed

Plog, Benjamin A; Dashnaw, Matthew L; Hitomi, Emi; Peng, Weiguo; Liao, Yonghong; Lou, Nanhong; Deane, Rashid; Nedergaard, Maiken

2015-01-14

The nonspecific and variable presentation of traumatic brain injury (TBI) has motivated an intense search for blood-based biomarkers that can objectively predict the severity of injury. However, it is not known how cytosolic proteins released from traumatized brain tissue reach the peripheral blood. Here we show in a murine TBI model that CSF movement through the recently characterized glymphatic pathway transports biomarkers to blood via the cervical lymphatics. Clinically relevant manipulation of glymphatic activity, including sleep deprivation and cisternotomy, suppressed or eliminated TBI-induced increases in serum S100β, GFAP, and neuron specific enolase. We conclude that routine TBI patient management may limit the clinical utility of blood-based biomarkers because their brain-to-blood transport depends on glymphatic activity. Copyright © 2015 the authors 0270-6474/15/350518-09$15.00/0.

Investigation of clinical pharmacokinetic variability of an opioid antagonist through physiologically based absorption modeling.

PubMed

Ding, Xuan; He, Minxia; Kulkarni, Rajesh; Patel, Nita; Zhang, Xiaoyu

2013-08-01

Identifying the source of inter- and/or intrasubject variability in pharmacokinetics (PK) provides fundamental information in understanding the pharmacokinetics-pharmacodynamics relationship of a drug and project its efficacy and safety in clinical populations. This identification process can be challenging given that a large number of potential causes could lead to PK variability. Here we present an integrated approach of physiologically based absorption modeling to investigate the root cause of unexpectedly high PK variability of a Phase I clinical trial drug. LY2196044 exhibited high intersubject variability in the absorption phase of plasma concentration-time profiles in humans. This could not be explained by in vitro measurements of drug properties and excellent bioavailability with low variability observed in preclinical species. GastroPlus™ modeling suggested that the compound's optimal solubility and permeability characteristics would enable rapid and complete absorption in preclinical species and in humans. However, simulations of human plasma concentration-time profiles indicated that despite sufficient solubility and rapid dissolution of LY2196044 in humans, permeability and/or transit in the gastrointestinal (GI) tract may have been negatively affected. It was concluded that clinical PK variability was potentially due to the drug's antagonism on opioid receptors that affected its transit and absorption in the GI tract. Copyright © 2013 Wiley Periodicals, Inc.

Reconstituted fresh whole blood improves clinical outcomes compared with stored component blood therapy for neonates undergoing cardiopulmonary bypass for cardiac surgery: a randomized controlled trial.

PubMed

Gruenwald, Colleen E; McCrindle, Brian W; Crawford-Lean, Lynn; Holtby, Helen; Parshuram, Christopher; Massicotte, Patricia; Van Arsdell, Glen

2008-12-01

This study compared the effects of reconstituted fresh whole blood against standard blood component therapy in neonates undergoing cardiac surgery. Patients less than 1 month of age were randomized to receive either reconstituted fresh whole blood (n = 31) or standard blood component therapy (n = 33) to prime the bypass circuit and for transfusion during the 24 hours after cardiopulmonary bypass. Primary outcome was chest tube drainage; secondary outcomes included transfusion needs, inotrope score, ventilation time, and hospital length of stay. Patients who received reconstituted fresh whole blood had significantly less postoperative chest tube volume loss per kilogram of body weight (7.7 mL/kg vs 11.8 mL/kg; P = .03). Standard blood component therapy was associated with higher inotropic score (6.6 vs 3.3; P = .002), longer ventilation times (164 hours vs 119 hours; P = .04), as well as longer hospital stays (18 days vs 12 days; P = .006) than patients receiving reconstituted fresh whole blood. Of the different factors associated with the use of reconstituted fresh whole blood, lower platelet counts at 10 minutes and at the end of cardiopulmonary bypass, older age of cells used in the prime and throughout bypass, and exposures to higher number of allogeneic donors were found to be independent predictors of poor clinical outcomes. Reconstituted fresh whole blood used for the prime, throughout cardiopulmonary bypass, and for all transfusion requirements within the first 24 hours postoperatively results in reduced chest tube volume loss and improved clinical outcomes in neonatal patients undergoing cardiac surgery.

Central blood pressure variability is increased in hypertensive patients with target organ damage.

PubMed

de la Sierra, Alejandro; Pareja, Julia; Yun, Sergi; Acosta, Eva; Aiello, Francesco; Oliveras, Anna; Vázquez, Susana; Armario, Pedro; Blanch, Pedro; Sierra, Cristina; Calero, Francesca; Fernández-Llama, Patricia

2018-02-01

We aimed to evaluate the association of aortic and brachial short-term blood pressure variability (BPV) with the presence of target organ damage (TOD) in hypertensive patients. One-hundred seventy-eight patients, aged 57 ± 12 years, 33% women were studied. TOD was defined by the presence of left ventricular hypertrophy on echocardiogram, microalbuminuria, reduced glomerular filtration rate, or increased aortic pulse wave velocity. Aortic and brachial BPV was assessed by 24-hour ambulatory BP monitoring (Mobil-O-Graph). TOD was present in 92 patients (51.7%). Compared to those without evidence of TOD, they had increased night-to-day ratios of systolic and diastolic BP (both aortic and brachial) and heart rate. They also had significant increased systolic BPV, as measured by both aortic and brachial daytime and 24-hours standard deviations and coefficients of variation, as well as for average real variability. Circadian patterns and short-term variability measures were very similar for aortic and brachial BP. We conclude that BPV is increased in hypertensive-related TOD. Aortic BPV does not add relevant information in comparison to brachial BPV. ©2018 Wiley Periodicals, Inc.

White blood cell and platelet count as adjuncts to standard clinical evaluation for risk assessment in patients at low probability of acute aortic syndrome.

PubMed

Morello, Fulvio; Cavalot, Giulia; Giachino, Francesca; Tizzani, Maria; Nazerian, Peiman; Carbone, Federica; Pivetta, Emanuele; Mengozzi, Giulio; Moiraghi, Corrado; Lupia, Enrico

2017-08-01

Pre-test probability assessment is key in the approach to suspected acute aortic syndromes (AASs). However, most patients with AAS-compatible symptoms are classified at low probability, warranting further evaluation for decision on aortic imaging. White blood cell count, platelet count and fibrinogen explore pathophysiological pathways mobilized in AASs and are routinely assayed in the workup of AASs. However, the diagnostic performance of these variables for AASs, alone and as a bundle, is unknown. We tested the hypothesis that white blood cell count, platelet count and/or fibrinogen at presentation may be applied as additional tools to standard clinical evaluation for pre-test risk assessment in patients at low probability of AAS. This was a retrospective observational study conducted on consecutive patients managed in our Emergency Department from 2009 to 2014 for suspected AAS. White blood cell count, platelet count and fibrinogen were assayed during evaluation in the Emergency Department. The final diagnosis was obtained by computed tomography angiography. The pre-test probability of AAS was defined according to guidelines. Of 1210 patients with suspected AAS, 1006 (83.1%) were classified at low probability, and 271 (22.4%) were diagnosed with AAS. Within patients at low probability, presence of at least one alteration among white blood cell count >9*10 3 /µl, platelet count <200*10 3 /µl and fibrinogen <350 mg/dl was associated with a sensitivity of 95.5% (89.7-98.5%) and a specificity of 18.3% (15.6-21.2%). In patients at low probability, white blood cell count >9*10 3 /µl and platelet count <200*10 3 /µl were found as independent predictors of AAS beyond established clinical risk markers. Within patients at low probability, the estimated risk of AAS based on the number of alterations amongst white blood cell count >9*10 3 /µl and platelet count <200*10 3 /µl was 2.7% (1.2-5.7%) with zero alterations, 11.3% (8.8-14.3%) with one alteration and 31.9% (24

Clinical implications and economic impact of accuracy differences among commercially available blood glucose monitoring systems.

PubMed

Budiman, Erwin S; Samant, Navendu; Resch, Ansgar

2013-03-01

Despite accuracy standards, there are performance differences among commercially available blood glucose monitoring (BGM) systems. The objective of this analysis was to assess the potential clinical and economic impact of accuracy differences of various BGM systems using a modeling approach. We simulated additional risk of hypoglycemia due to blood glucose (BG) measurement errors of five different BGM systems based on results of a real-world accuracy study, while retaining other sources of glycemic variability. Using data from published literature, we estimated an annual additional number of required medical interventions as a result of hypoglycemia. We based our calculations on patients with type 1 diabetes mellitus (T1DM) and T2DM requiring multiple daily injections (MDIs) of insulin in a U.S. health care system. We estimated additional costs attributable to treatment of severe hypoglycemic episodes resulting from BG measurement errors. Results from our model predict an annual difference of approximately 296,000 severe hypoglycemic episodes from BG measurement errors for T1DM (105,000 for T2DM MDI) patients for the estimated U.S. population of 958,800 T1DM and 1,353,600 T2DM MDI patients, using the least accurate BGM system versus patients using the most accurate system in a U.S. health care system. This resulted in additional direct costs of approximately $339 million for T1DM and approximately $121 million for T2DM MDI patients per year. Our analysis shows that error patterns over the operating range of BGM meter may lead to relevant clinical and economic outcome differences that may not be reflected in a common accuracy metric or standard. Further research is necessary to validate the findings of this model-based approach. © 2013 Diabetes Technology Society.

Clinical Implications and Economic Impact of Accuracy Differences among Commercially Available Blood Glucose Monitoring Systems

PubMed Central

Budiman, Erwin S.; Samant, Navendu; Resch, Ansgar

2013-01-01

Background Despite accuracy standards, there are performance differences among commercially available blood glucose monitoring (BGM) systems. The objective of this analysis was to assess the potential clinical and economic impact of accuracy differences of various BGM systems using a modeling approach. Methods We simulated additional risk of hypoglycemia due to blood glucose (BG) measurement errors of five different BGM systems based on results of a real-world accuracy study, while retaining other sources of glycemic variability. Using data from published literature, we estimated an annual additional number of required medical interventions as a result of hypoglycemia. We based our calculations on patients with type 1 diabetes mellitus (T1DM) and T2DM requiring multiple daily injections (MDIs) of insulin in a U.S. health care system. We estimated additional costs attributable to treatment of severe hypoglycemic episodes resulting from BG measurement errors.. Results Results from our model predict an annual difference of approximately 296,000 severe hypoglycemic episodes from BG measurement errors for T1DM (105,000 for T2DM MDI) patients for the estimated U.S. population of 958,800 T1DM and 1,353,600 T2DM MDI patients, using the least accurate BGM system versus patients using the most accurate system in a U.S. health care system. This resulted in additional direct costs of approximately $339 million for T1DM and approximately $121 million for T2DM MDI patients per year. Conclusions Our analysis shows that error patterns over the operating range of BGM meter may lead to relevant clinical and economic outcome differences that may not be reflected in a common accuracy metric or standard. PMID:23566995

Effect of Azilsartan on Day-to-Day Variability in Home Blood Pressure: A Prospective Multicenter Clinical Trial

PubMed Central

Miyoshi, Toru; Suetsuna, Ryoji; Tokunaga, Naoto; Kusaka, Masayasu; Tsuzaki, Ryuichiro; Koten, Kazuya; Kunihisa, Kohno; Ito, Hiroshi

2017-01-01

Background The blood pressure variability (BPV) such as visit-to-visit, day-by-day, and ambulatory BPV has been also shown to be a risk of future cardiovascular events. However, the effects of antihypertensive therapy on BPV remain unclear. The purpose of this study was to evaluate the effect of azilsartan after switching from another angiotensin II receptor blocker (ARB) on day-to-day BPV in home BP monitoring. Methods This prospective, multicenter, open-labeled, single-arm study included 28 patients undergoing treatment with an ARB, which was switched to azilsartan after enrollment. The primary outcome was the change in the mean of the standard deviation and the coefficient of variation of morning home BP for 5 consecutive days from baseline to the 24-week follow-up. The secondary outcome was the change in arterial stiffness measured by the cardio-ankle vascular index. Results The mean BPs in the morning and evening for 5 days did not statistically differ between baseline and 24 weeks. For the morning BP, the means of the standard deviations and coefficient of variation of the systolic BP were significantly decreased from 7.4 ± 3.6 mm Hg to 6.1 ± 3.2 mm Hg and from 5.4±2.7% to 4.6±2.3% (mean ± standard deviation, P = 0.04 and P = 0.04, respectively). For the evening BP, no significant change was observed in the systolic or diastolic BPV. The cardio-ankle vascular index significantly decreased from 8.3 ± 0.8 to 8.1 ± 0.8 (P = 0.03). Conclusions Switching from another ARB to azilsartan reduced day-to-day BPV in the morning and improved arterial stiffness. PMID:28611863

Single-cell measurement of red blood cell oxygen affinity.

PubMed

Di Caprio, Giuseppe; Stokes, Chris; Higgins, John M; Schonbrun, Ethan

2015-08-11

Oxygen is transported throughout the body by hemoglobin (Hb) in red blood cells (RBCs). Although the oxygen affinity of blood is well-understood and routinely assessed in patients by pulse oximetry, variability at the single-cell level has not been previously measured. In contrast, single-cell measurements of RBC volume and Hb concentration are taken millions of times per day by clinical hematology analyzers, and they are important factors in determining the health of the hematologic system. To better understand the variability and determinants of oxygen affinity on a cellular level, we have developed a system that quantifies the oxygen saturation, cell volume, and Hb concentration for individual RBCs in high throughput. We find that the variability in single-cell saturation peaks at an oxygen partial pressure of 2.9%, which corresponds to the maximum slope of the oxygen-Hb dissociation curve. In addition, single-cell oxygen affinity is positively correlated with Hb concentration but independent of osmolarity, which suggests variation in the Hb to 2,3-diphosphoglycerate (2-3 DPG) ratio on a cellular level. By quantifying the functional behavior of a cellular population, our system adds a dimension to blood cell analysis and other measurements of single-cell variability.

Single-cell measurement of red blood cell oxygen affinity

PubMed Central

Di Caprio, Giuseppe; Stokes, Chris; Higgins, John M.; Schonbrun, Ethan

2015-01-01

Oxygen is transported throughout the body by hemoglobin (Hb) in red blood cells (RBCs). Although the oxygen affinity of blood is well-understood and routinely assessed in patients by pulse oximetry, variability at the single-cell level has not been previously measured. In contrast, single-cell measurements of RBC volume and Hb concentration are taken millions of times per day by clinical hematology analyzers, and they are important factors in determining the health of the hematologic system. To better understand the variability and determinants of oxygen affinity on a cellular level, we have developed a system that quantifies the oxygen saturation, cell volume, and Hb concentration for individual RBCs in high throughput. We find that the variability in single-cell saturation peaks at an oxygen partial pressure of 2.9%, which corresponds to the maximum slope of the oxygen–Hb dissociation curve. In addition, single-cell oxygen affinity is positively correlated with Hb concentration but independent of osmolarity, which suggests variation in the Hb to 2,3-diphosphoglycerate (2–3 DPG) ratio on a cellular level. By quantifying the functional behavior of a cellular population, our system adds a dimension to blood cell analysis and other measurements of single-cell variability. PMID:26216973

Relevancy of Serum Calcium in Predicting Blood Product Transfusion in Trauma

DTIC Science & Technology

2017-08-10

reduction. Most pre-hospital or field medical criteria used to predict blood product needs in trauma patients rely on a combination of physiological ...This effect was age specific for the subject group aged 40 years and below. Patients with normal blood pressure could give medical teams a false...transfusion, as well as transfusion of more than four units within 4 hours, even after controlling for other clinical variables. This effect was age

Mechanism of blood pressure and R-R variability: insights from ganglion blockade in humans

NASA Technical Reports Server (NTRS)

Zhang, Rong; Iwasaki, Kenichi; Zuckerman, Julie H.; Behbehani, Khosrow; Crandall, Craig G.; Levine, Benjamin D.; Blomqvist, C. G. (Principal Investigator)

2002-01-01

Spontaneous blood pressure (BP) and R-R variability are used frequently as 'windows' into cardiovascular control mechanisms. However, the origin of these rhythmic fluctuations is not completely understood. In this study, with ganglion blockade, we evaluated the role of autonomic neural activity versus other 'non-neural' factors in the origin of BP and R-R variability in humans. Beat-to-beat BP, R-R interval and respiratory excursions were recorded in ten healthy subjects (aged 30 +/- 6 years) before and after ganglion blockade with trimethaphan. The spectral power of these variables was calculated in the very low (0.0078-0.05 Hz), low (0.05-0.15 Hz) and high (0.15-0.35 Hz) frequency ranges. The relationship between systolic BP and R-R variability was examined by cross-spectral analysis. After blockade, R-R variability was virtually abolished at all frequencies; however, respiration and high frequency BP variability remained unchanged. Very low and low frequency BP variability was reduced substantially by 84 and 69 %, respectively, but still persisted. Transfer function gain between systolic BP and R-R interval variability decreased by 92 and 88 % at low and high frequencies, respectively, while the phase changed from negative to positive values at the high frequencies. These data suggest that under supine resting conditions with spontaneous breathing: (1) R-R variability at all measured frequencies is predominantly controlled by autonomic neural activity; (2) BP variability at high frequencies (> 0.15 Hz) is mediated largely, if not exclusively, by mechanical effects of respiration on intrathoracic pressure and/or cardiac filling; (3) BP variability at very low and low frequencies (< 0.15 Hz) is probably mediated by both sympathetic nerve activity and intrinsic vasomotor rhythmicity; and (4) the dynamic relationship between BP and R-R variability as quantified by transfer function analysis is determined predominantly by autonomic neural activity rather than other

Variability sensitivity of dynamic texture based recognition in clinical CT data

NASA Astrophysics Data System (ADS)

Kwitt, Roland; Razzaque, Sharif; Lowell, Jeffrey; Aylward, Stephen

2014-03-01

Dynamic texture recognition using a database of template models has recently shown promising results for the task of localizing anatomical structures in Ultrasound video. In order to understand its clinical value, it is imperative to study the sensitivity with respect to inter-patient variability as well as sensitivity to acquisition parameters such as Ultrasound probe angle. Fully addressing patient and acquisition variability issues, however, would require a large database of clinical Ultrasound from many patients, acquired in a multitude of controlled conditions, e.g., using a tracked transducer. Since such data is not readily attainable, we advocate an alternative evaluation strategy using abdominal CT data as a surrogate. In this paper, we describe how to replicate Ultrasound variabilities by extracting subvolumes from CT and interpreting the image material as an ordered sequence of video frames. Utilizing this technique, and based on a database of abdominal CT from 45 patients, we report recognition results on an organ (kidney) recognition task, where we try to discriminate kidney subvolumes/videos from a collection of randomly sampled negative instances. We demonstrate that (1) dynamic texture recognition is relatively insensitive to inter-patient variation while (2) viewing angle variability needs to be accounted for in the template database. Since naively extending the template database to counteract variability issues can lead to impractical database sizes, we propose an alternative strategy based on automated identification of a small set of representative models.

An Evaluation of a Clinical Pharmacy-Directed Intervention on Blood Pressure Control

PubMed Central

Kicklighter, Caroline E.; Nelson, Kent M.; Humphries, Tammy L.; Delate, Thomas

Objective To compare short and long term blood pressure control with clinical pharmacy specialist involvement to traditional physician management. Setting A non-profit health maintenance organization in the United States covering approximately 385,000 lives. Methods This analysis utilized a prospective parallel design. Adult patients with a baseline Blood pressure>140/90 mmHg and receiving at least one antihypertensive medication were eligible for the study. Eligible hypertension management patients at one medical office were referred to the office’s clinical pharmacy specialist (intervention cohort) while at another comparable medical office they received usual physician-directed care (control cohort). The primary outcome measure was achievement of a goal BP (<140/90 mmHg) during a six month follow-up. Medical records were also reviewed approximately 1.5 years post enrollment to assess long-term BP control after clinical pharmacy-managed patients returned to usual care. Multivariate analyses were performed to adjust for baseline cohort differences. Results One hundred-thirteen and 111 subjects in the intervention and control cohorts completed the study, respectively. At the end of the follow-up period, clinical pharmacy-managed subjects were more likely to have achieved goal BP (64.6%) and received a thiazide diuretic (68.1%) compared to control subjects (40.7% and 33.3%, respectively) (adjusted p=0.002 and p<0.001, respectively). The proportion of clinical pharmacy-managed subjects with controlled BP decreased to 22.2% after returning to usual care (p<0.001). Conclusion Clinical pharmacy involvement in hypertension management resulted in increased BP control. Loss of long-term control after discontinuation of clinical pharmacy management supports a change in care processes that prevent patients from being lost to follow-up. PMID:25214896

Long-term Prognosis in COPD Exacerbation: Role of Biomarkers, Clinical Variables and Exacerbation Type.

PubMed

Grolimund, Eva; Kutz, Alexander; Marlowe, Robert J; Vögeli, Alaadin; Alan, Murat; Christ-Crain, Mirjam; Thomann, Robert; Falconnier, Claudine; Hoess, Claus; Henzen, Christoph; Zimmerli, Werner; Mueller, Beat; Schuetz, Philipp

2015-06-01

Long-term outcome prediction in COPD is challenging. We conducted a prospective 5-7-year follow-up study in patients with COPD to determine the association of exacerbation type, discharge levels of inflammatory biomarkers including procalctionin (PCT), C-reactive protein (CRP), white blood cell count (WBC) and plasma proadrenomedullin (ProADM), alone or combined with demographic/clinical characteristics, with long-term all-cause mortality in the COPD setting. The analyzed cohort comprised 469 patients with index hospitalization for pneumonic (n = 252) or non-pneumonic (n = 217) COPD exacerbation. Five-to-seven-year vital status was ascertained via structured phone interviews with patients or their household members/primary care physicians. We investigated predictive accuracy using univariate and multivariate Cox regression models and area under the receiver operating characteristic curve (AUC). After a median [25th-75th percentile] 6.1 [5.6-6.5] years, mortality was 55% (95%CI 50%-59%). Discharge ProADM concentration was strongly associated with 5-7-year non-survival: adjusted hazard ratio (HR)/10-fold increase (95%CI) 10.4 (6.2-17.7). Weaker associations were found for PCT and no significant associations were found for CRP or WBC. Combining ProADM with demographic/clinical variables including age, smoking status, BMI, New York Heart Association dyspnea class, exacerbation type, and comorbidities significantly improved long-term predictive accuracy over that of the demographic/clinical model alone: AUC (95%CI) 0.745 (0.701-0.789) versus 0.727 (0.681-0.772), (p) = .043. In patients hospitalized for COPD exacerbation, discharge ProADM levels appeared to accurately predict 5-7-year all-cause mortality and to improve long-term prognostic accuracy of multidimensional demographic/clinical mortality risk assessment.

Effects of a contraceptive containing drospirenone and ethinyl estradiol on blood pressure and autonomic tone: a prospective controlled clinical trial.

PubMed

Nisenbaum, Marcelo Gil; de Melo, Nilson Roberto; Giribela, Cassiana Rosa Galvão; de Morais, Tércio Lemos; Guerra, Grazia Maria; de Angelis, Katia; Mostarda, Cristiano; Baracat, Edmund Chada; Consolim-Colombo, Fernanda Marciano

2014-04-01

The use of combined oral contraceptives has been associated with an increased risk of adverse cardiovascular events. Whether these drugs alter cardiac autonomic nervous system control is not completely determined. To evaluate the effect of a contraceptive containing 20mcg of ethinyl estradiol and 3mg of drospirenone on the heart rate variability, baroreflex sensitivity and blood pressure of healthy women. Prospective controlled trial with 69 healthy women allocated in two groups: 36 volunteers under oral combined contraceptive use and 33 volunteers using of non-hormonal contraceptive methods. Subjects were tested before the introduction of the contraceptive method and 6 months after its use. For data acquisition, we used continuous non-invasive beat-to-beat blood pressure curve recordings. Multiple ANOVA was used to determine differences between groups and moments and p< 0.05 was considered statistically significant. At baseline, there were no differences in demographic and autonomic parameters between groups. Comparing cardiac sympatho-vagal modulation, baroreceptor sensitivity and blood pressure measurements between baseline and after 6 months, no significant difference was detected in each group or between groups. A contraceptive containing 20mcg of ethinyl estradiol and 3mg of drospirenone causes no significant changes in clinical, hemodynamic and autonomic parameters of normal women. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

IDENTIFYING GENETIC ASSOCIATIONS WITH VARIABILITY IN METABOLIC HEALTH AND BLOOD COUNT LABORATORY VALUES: DIVING INTO THE QUANTITATIVE TRAITS BY LEVERAGING LONGITUDINAL DATA FROM AN EHR.

PubMed

Verma, Shefali S; Lucas, Anastasia M; Lavage, Daniel R; Leader, Joseph B; Metpally, Raghu; Krishnamurthy, Sarathbabu; Dewey, Frederick; Borecki, Ingrid; Lopez, Alexander; Overton, John; Penn, John; Reid, Jeffrey; Pendergrass, Sarah A; Breitwieser, Gerda; Ritchie, Marylyn D

2017-01-01

A wide range of patient health data is recorded in Electronic Health Records (EHR). This data includes diagnosis, surgical procedures, clinical laboratory measurements, and medication information. Together this information reflects the patient's medical history. Many studies have efficiently used this data from the EHR to find associations that are clinically relevant, either by utilizing International Classification of Diseases, version 9 (ICD-9) codes or laboratory measurements, or by designing phenotype algorithms to extract case and control status with accuracy from the EHR. Here we developed a strategy to utilize longitudinal quantitative trait data from the EHR at Geisinger Health System focusing on outpatient metabolic and complete blood panel data as a starting point. Comprehensive Metabolic Panel (CMP) as well as Complete Blood Counts (CBC) are parts of routine care and provide a comprehensive picture from high level screening of patients' overall health and disease. We randomly split our data into two datasets to allow for discovery and replication. We first conducted a genome-wide association study (GWAS) with median values of 25 different clinical laboratory measurements to identify variants from Human Omni Express Exome beadchip data that are associated with these measurements. We identified 687 variants that associated and replicated with the tested clinical measurements at p<5×10-08. Since longitudinal data from the EHR provides a record of a patient's medical history, we utilized this information to further investigate the ICD-9 codes that might be associated with differences in variability of the measurements in the longitudinal dataset. We identified low and high variance patients by looking at changes within their individual longitudinal EHR laboratory results for each of the 25 clinical lab values (thus creating 50 groups - a high variance and a low variance for each lab variable). We then performed a PheWAS analysis with ICD-9 diagnosis codes

Factors associated with poor functional outcome in bipolar disorder: sociodemographic, clinical, and neurocognitive variables.

PubMed

Sanchez-Moreno, J; Bonnin, C M; González-Pinto, A; Amann, B L; Solé, B; Balanzá-Martinez, V; Arango, C; Jiménez, E; Tabarés-Seisdedos, R; Garcia-Portilla, M P; Ibáñez, A; Crespo, J M; Ayuso-Mateos, J L; Martinez-Aran, A; Torrent, C; Vieta, E

2018-05-03

The current investigation aimed at studying the sociodemographic, clinical, and neuropsychological variables related to functional outcome in a sample of euthymic patients with bipolar disorder(BD) presenting moderate-severe levels of functional impairment. Two-hundred and thirty-nine participants with BD disorders and with Functioning Assessment Short Test(FAST) scores equal or above 18 were administered a clinical and diagnostic interview, and the administration of mood measure scales and a comprehensive neuropsychological battery. Analyses involved preliminary Pearson bivariate correlations to identify sociodemographic and clinical variables associated with the FAST total score. Regarding neuropsychological variables, a principal component analysis (PCA) was performed to group the variables in orthogonal factors. Finally, a hierarchical multiple regression was run. The best fitting model for the variables associated with functioning was a linear combination of gender, age, estimated IQ, Hamilton Depression Rating Scale (HAM-D), number of previous manic episodes, Factor 1 and Factor 2 extracted from the PCA. The model, including all these previous variables, explained up to 29.4% of the observed variance. Male gender, older age, lower premorbid IQ, subdepressive symptoms, higher number of manic episodes, and lower performance in verbal memory, working memory, verbal fluency, and processing speed were associated with lower functioning in patients with BD. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Effects of color temperatures (kelvin) of led bulbs on blood physiological variables of broilers grown to heavy weights

USDA-ARS?s Scientific Manuscript database

Light-emitting diode (LED) lighting is being used in the poultry industry to reduce energy usage in broiler production facilities. However, limited data are available comparing efficacy of different spectral distribution of LED bulbs on blood physiological variables of broilers grown to heavy weight...

Excess Vitamin Intake before Starvation does not Affect Body Mass, Organ Mass, or Blood Variables but Affects Urinary Excretion of Riboflavin in Starving Rats.

PubMed

Moriya, Aya; Fukuwatari, Tsutomu; Shibata, Katsumi

2013-01-01

B-vitamins are important for producing energy from amino acids, fatty acids, and glucose. The aim of this study was to elucidate the effects of excess vitamin intake before starvation on body mass, organ mass, blood, and biological variables as well as on urinary excretion of riboflavin in rats. Adult rats were fed two types of diets, one with a low vitamin content (minimum vitamin diet for optimum growth) and one with a sufficient amount of vitamins (excess vitamin diet). Body mass, organ mass, and blood variables were not affected by excess vitamin intake before starvation. Interestingly, urinary riboflavin excretion showed a different pattern. Urine riboflavin in the excess vitamin intake group declined gradually during starvation, whereas it increased in the low vitamin intake group. Excess vitamin intake before starvation does not affect body mass, organ mass, or blood variables but does affect the urinary excretion of riboflavin in starving rats.

Ambulatory Blood Pressure Variability Increases Over a 10-Year Follow-Up in Community-Dwelling Older People

PubMed Central

Pearce, Mark S.; Wincenciak, Joanna; Kerr, Simon R.J.; Newton, Julia L.

2016-01-01

Abstract BACKGROUND Greater ambulatory blood pressure variability (ABPV) is associated with end-organ damage and increased mortality. Age-related changes in the cardiovascular and autonomic nervous systems make age-associated increases in ABPV likely. Cross-sectional studies support this hypothesis, showing greater ABPV among older compared to younger adults. The only longitudinal study to examine changes in ABPV, however, found ABPV decreased over 5 years follow-up. This unexpected observation probably reflected the highly selected nature of the study participants. METHODS In this longitudinal study, we assessed changes in ABPV over 10 years in a community-cohort of older people. In addition, we examined the extent to which ABPV was predicted by demographics, cardiovascular risk factors, and medication. Clinical examination and 24-hour ambulatory blood pressure monitoring were carried out at baseline and at 10 years follow-up in 83 people, median age 70 years. ABPV was calculated using SD and coefficient of variation (Cv). Three time periods were examined: daytime, nighttime, and 24 hours. RESULTS Daytime and 24-hour, systolic and diastolic, SD, and Cv were significantly greater at follow-up than at baseline ( P < 0.001 in all cases). Mean BP did not change. CONCLUSIONS Multilevel modeling showed follow-up interval had a significant, positive effect on SD and Cv ( P < 0.004), independent of age, sex, and medication. ABPV increased over a 10-year follow-up despite stable mean BP. ABPV may therefore be an additional target for treatment in older people. Future studies should examine what degree of ABPV is harmful and if control of ABPV reduces adverse outcome. PMID:26310662

Morning blood pressure surge: pathophysiology, clinical relevance and therapeutic aspects

PubMed Central

Bilo, Grzegorz; Grillo, Andrea; Guida, Valentina; Parati, Gianfranco

2018-01-01

Morning hours are the period of the day characterized by the highest incidence of major cardiovascular events including myocardial infarction, sudden death or stroke. They are also characterized by important neurohormonal changes, in particular, the activation of sympathetic nervous system which usually leads to a rapid increase in blood pressure (BP), known as morning blood pressure surge (MBPS). It was hypothesized that excessive MBPS may be causally involved in the pathogenesis of cardiovascular events occurring in the morning by inducing hemodynamic stress. A number of studies support an independent relationship of MBPS with organ damage, cerebrovascular complications and mortality, although some heterogeneity exists in the available evidence. This may be due to ethnic differences, methodological issues and the confounding relationship of MBPS with other features of 24-hour BP profile, such as nocturnal dipping or BP variability. Several studies are also available dealing with treatment effects on MBPS and indicating the importance of long-acting antihypertensive drugs in this regard. This paper provides an overview of pathophysiologic, methodological, prognostic and therapeutic aspects related to MBPS. PMID:29872338

Long-Term Blood Pressure Variability, New-Onset Diabetes Mellitus, and New-Onset Chronic Kidney Disease in the Japanese General Population.

PubMed

Yano, Yuichiro; Fujimoto, Shouichi; Kramer, Holly; Sato, Yuji; Konta, Tsuneo; Iseki, Kunitoshi; Iseki, Chiho; Moriyama, Toshiki; Yamagata, Kunihiro; Tsuruya, Kazuhiko; Narita, Ichiei; Kondo, Masahide; Kimura, Kenjiro; Asahi, Koichi; Kurahashi, Issei; Ohashi, Yasuo; Watanabe, Tsuyoshi

2015-07-01

Whether long-term blood pressure (BP) variability among individuals without diabetes mellitus is associated with new-onset chronic kidney disease (CKD) risk, independently of other BP parameters (eg, mean BP, cumulative exposure to BP) and metabolic profile changes during follow-up, remains uncertain. We used data from a nationwide study of 48 587 Japanese adults aged 40 to 74 years (mean age, 61.7 years; 39% men) without diabetes mellitus or CKD (estimated glomerular filtration rate <60 mL/min per 1.73 m2 or proteinuria by dipstick). BP was measured at baseline and during 3 annual follow-up visits (4 visits). BP variability was defined as standard deviation (SD) and average real variability during the 4 visits. At the year 3 follow-up visit, 6.3% of the population had developed CKD. In multivariable-adjusted logistic regression models, 1 SD increases in SDSBP (per 5 mmHg), SDDBP (per 3 mmHg), average real variabilitySBP (per 6 mmHg), and average real variabilityDBP (per 4 mmHg) were associated with new-onset CKD (odds ratios [ORs] and 95% confidence intervals, 1.15 [1.11-1.20], 1.08 [1.04-1.12], 1.13 [1.09-1.17], 1.06 [1.02-1.10], respectively; all P<0.01) after adjustment for clinical characteristics, and with mean BP from year 0 to year 3. The associations of SDBP and average real variabilityBP with CKD remained significant after additional adjustments for metabolic parameter changes during follow-up (ORs, 1.06-1.15; all P<0.01). Sensitivity analyses by sex, antihypertensive medication use, and the presence of hypertension showed similar conclusions. Among those in the middle-aged and elderly general population without diabetes mellitus, long-term BP variability during 3 years was associated with new-onset CKD risk, independently of mean or cumulative exposure to BP and metabolic profile changes during follow-up. © 2015 American Heart Association, Inc.

Audit of clinical-laboratory practices in haematology and blood transfusion at Muhimbili National Hospital in Tanzania.

PubMed

Makubi, Abel N; Meda, Collins; Magesa, Alex; Minja, Peter; Mlalasi, Juliana; Salum, Zubeda; Kweka, Rumisha E; Rwehabura, James; Quaresh, Amrana; Magesa, Pius M; Robert, David; Makani, Julie; Kaaya, Ephata

2012-10-01

In Tanzania, there is paucity of data for monitoring laboratory medicine including haematology. This therefore calls for audits of practices in haematology and blood transfusion in order to provide appraise practice and devise strategies that would result in improved quality of health care services. This descriptive cross-sectional study which audited laboratory practice in haematology and blood transfusion at Muhimbili National Hospital (MNH) aimed at assessing the pre-analytical stage of laboratory investigations including laboratory request forms and handling specimen processing in the haematology laboratory and assessing the chain from donor selection, blood component processing to administration of blood during transfusion. A national standard checklist was used to audit the laboratory request forms (LRF), phlebotomists' practices on handling and assessing the from donor selection to administration 6f blood during transfusion. Both interview and observations were used. A total of 195 LRF were audited and 100% of had incomplete information such as patients' identification numbers, time sample ordered, reason for request, summary of clinical assessment and differential diagnoses. The labelling of specimens was poorly done by phlebotomists/clinicians in 82% of the specimens. Also 65% (132/202) of the blood samples delivered in the haematology laboratory did not contain the recommended volume of blood. There was no laboratory request form specific for ordering blood and there were no guidelines for indication of blood transfusion in the wards/ clinics. The blood transfusion laboratory section was not participating in external quality assessment and the hospital transfusion committee was not in operation. It is recommended that a referral hospital like MNH should have a transfusion committee to provide an active forum to facilitate communication between those involved with transfusion, monitor, coordinate and audit blood transfusion practices as per national

Evolving Identification of Blood Cells Associated with Clinically Isolated Syndrome: Importance of Time since Clinical Presentation and Diagnostic MRI

PubMed Central

Trend, Stephanie; Jones, Anderson P.; Geldenhuys, Sian; Byrne, Scott N.; Fabis-Pedrini, Marzena J.; Nolan, David; Booth, David R.; Carroll, William M.; Lucas, Robyn M.; Kermode, Allan G.; Hart, Prue H.

2017-01-01

It is not clear how the profile of immune cells in peripheral blood differs between patients with clinically isolated syndrome (CIS) and healthy controls (HC). This study aimed to identify a CIS peripheral blood signature that may provide clues for potential immunomodulatory approaches early in disease. Peripheral blood mononuclear cells (PBMCs) were collected from 18 people with CIS, 19 HC and 13 individuals with other demyelinating conditions (ODC) including multiple sclerosis (MS). Individuals with CIS separated into two groups, namely those with early (≤14 days post-diagnostic magnetic resonance imaging (MRI); n = 6) and late (≥27 days; n = 12) blood sampling. Transitional B cells were increased in the blood of CIS patients independently of when blood was taken. However, there were two time-dependent effects found in the late CIS group relative to HC, including decreased CD56bright NK cells, which correlated significantly with time since MRI, and increased CD141+ myeloid dendritic cell (mDC2) frequencies. Higher CD1c+ B cells and lower non-classical monocyte frequencies were characteristic of more recent demyelinating disease activity (ODC and early CIS). Analysing cell populations by time since symptoms (subjective) and diagnostic MRI (objective) may contribute to understanding CIS. PMID:28617321

Evolving Identification of Blood Cells Associated with Clinically Isolated Syndrome: Importance of Time since Clinical Presentation and Diagnostic MRI.

PubMed

Trend, Stephanie; Jones, Anderson P; Geldenhuys, Sian; Byrne, Scott N; Fabis-Pedrini, Marzena J; Nolan, David; Booth, David R; Carroll, William M; Lucas, Robyn M; Kermode, Allan G; Hart, Prue H

2017-06-15

It is not clear how the profile of immune cells in peripheral blood differs between patients with clinically isolated syndrome (CIS) and healthy controls (HC). This study aimed to identify a CIS peripheral blood signature that may provide clues for potential immunomodulatory approaches early in disease. Peripheral blood mononuclear cells (PBMCs) were collected from 18 people with CIS, 19 HC and 13 individuals with other demyelinating conditions (ODC) including multiple sclerosis (MS). Individuals with CIS separated into two groups, namely those with early (≤14 days post-diagnostic magnetic resonance imaging (MRI); n = 6) and late (≥27 days; n = 12) blood sampling. Transitional B cells were increased in the blood of CIS patients independently of when blood was taken. However, there were two time-dependent effects found in the late CIS group relative to HC, including decreased CD56bright NK cells, which correlated significantly with time since MRI, and increased CD141+ myeloid dendritic cell (mDC2) frequencies. Higher CD1c+ B cells and lower non-classical monocyte frequencies were characteristic of more recent demyelinating disease activity (ODC and early CIS). Analysing cell populations by time since symptoms (subjective) and diagnostic MRI (objective) may contribute to understanding CIS.

Implementation of patient blood management remains extremely variable in Europe and Canada: the NATA benchmark project: An observational study.

PubMed

Van der Linden, Philippe; Hardy, Jean-François

2016-12-01

Preoperative anaemia is associated with increased postoperative morbidity and mortality. Patient blood management (PBM) is advocated to improve patient outcomes. NATA, the 'Network for the advancement of patient blood management, haemostasis and thrombosis', initiated a benchmark project with the aim of providing the basis for educational strategies to implement optimal PBM in participating centres. Prospective, observational study with online data collection in 11 secondary and tertiary care institutions interested in developing PBM. Ten European centres (Austria, Spain, England, Denmark, Belgium, Netherlands, Romania, Greece, France, and Germany) and one Canadian centre participated between January 2010 and June 2011. A total of 2470 patients undergoing total hip (THR) or knee replacement, or coronary artery bypass grafting (CABG), were registered in the study. Data from 2431 records were included in the final analysis. Primary outcome measures were the incidence and volume of red blood cells (RBC) transfused. Logistic regression analysis identified variables independently associated with RBC transfusions. The incidence of transfusion was significantly different between centres for THR (range 7 to 95%), total knee replacement (range 3 to 100%) and CABG (range 20 to 95%). The volume of RBC transfused was significantly different between centres for THR and CABG. The incidence of preoperative anaemia ranged between 3 and 40% and its treatment between 0 and 40%, the latter not being related to the former. Patient characteristics, evolution of haemoglobin concentrations and blood losses were also different between centres. Variables independently associated with RBC transfusion were preoperative haemoglobin concentration, lost volume of RBC and female sex. Implementation of PBM remains extremely variable across centres. The relative importance of factors explaining RBC transfusion differs across institutions, some being patient related whereas others are related to

Influence of euthanasia method on blood and gill variables in normoxic and hypoxic Gulf killifish Fundulus grandis.

PubMed

Larter, K F; Rees, B B

2017-06-01

In many experiments, euthanasia, or humane killing, of animals is necessary. Some methods of euthanasia cause death through cessation of respiratory or cardiovascular systems, causing oxygen levels of blood and tissues to drop. For experiments where the goal is to measure the effects of environmental low oxygen (hypoxia), the choice of euthanasia technique, therefore, may confound the results. This study examined the effects of four euthanasia methods commonly used in fish biology (overdose of MS-222, overdose of clove oil, rapid cooling and blunt trauma to the head) on variables known to be altered during hypoxia (haematocrit, plasma cortisol, blood lactate and blood glucose) or reflecting gill damage (trypan blue exclusion) and energetic status (ATP, ADP and ATP:ADP) in Gulf killifish Fundulus grandis after 24 h exposure to well-aerated conditions (normoxia, 7·93 mg O 2  l -1 , c. 150 mm Hg or c. 20 kPa) or reduced oxygen levels (0·86 mg O 2  l -1 , c. 17 mm Hg or c. 2·2 kPa). Regardless of oxygen treatment, fish euthanized by an overdose of MS-222 had higher haematocrit and lower gill ATP:ADP than fish euthanized by other methods. The effects of 24 h hypoxic exposure on these and other variables, however, were equivalent among methods of euthanasia (i.e. there were no significant interactions between euthanasia method and oxygen treatment). The choice of an appropriate euthanasia method, therefore, will depend upon the magnitude of the treatment effects (e.g. hypoxia) relative to potential artefacts caused by euthanasia on the variables of interest. © 2017 The Fisheries Society of the British Isles.

Switch from aprotinin to ε-aminocaproic acid: impact on blood loss, transfusion, and clinical outcome in neonates undergoing cardiac surgery.

PubMed

Martin, K; Gertler, R; Liermann, H; Mayr, N P; MacGuill, M; Schreiber, C; Vogt, M; Tassani, P; Wiesner, G

2011-12-01

With the withdrawal of aprotinin from worldwide marketing in November 2007, many institutions treating patients at high risk for hyperfibrinolysis had to update their therapeutic protocols. At our institution, the standard was switched from aprotinin to ε-aminocaproic acid (EACA) in all patients undergoing cardiac surgery with extracorporeal circulation including neonates. Although both antifibrinolytic medications have been used widely for many years, there are few data directly comparing their blood-sparing effect and their side-effects especially in neonates. Perioperative data from 235 neonates aged up to 30 days undergoing primary cardiac surgery were analysed. Between July 1, 2006 and November 5, 2007, all patients (n=95) received aprotinin. Starting November 6, 2007 until December 31, 2009, all patients (n=140) were treated with EACA. The primary outcome criterion was blood loss; secondary outcome criteria were transfusion requirements, renal, vascular, and neurological complications and also in-hospital mortality. All descriptive and intraoperative data variable were similar. Blood loss was significantly higher in the EACA group (P=0.001), but there was no difference in the rate of re-operation for bleeding (P=0.218) nor the number of transfusions. There were no differences in the incidences of postoperative renal, neurological, and vascular events or in-hospital mortality. In neonatal patients undergoing cardiac surgery, the switch to EACA treatment led to a higher postoperative blood loss. However, there were no differences in transfusion requirements or major clinical outcomes.

[The impact of long- and short-time blood pressure variability on glomerular filtration rate in elderly population].

PubMed

Wang, Yang; Zheng, Xiaoming; An, Shasha; Li, Zhifang; Zhang, Wenyan; Li, Chunhui; Zhao, Hualing; Song, Lu; Chen, Shuohua; Zheng, Yao; Ruan, Chunyu; Wu, Shouling

2016-01-01

To investigate the impact of long-time and short-time blood pressure variability (BPV) on glomerular filtration rate (eGFR) in elderly population. A total of 2 464 participants aged of ≥60 years old without history of stroke and coronary heart disease were selected with random sampling method from the individuals underwent health check up in Tangshan Kailuan Hospital, Kailuan Linxi Hospital, Kailuan Zhaogezhuang Hospital between 2006 and 2013. The study participants were asked to join a face-to-face interview every two years. Long-time BPV was defined as the standard deviation of all SBP values at the baseline visit and following visits, short-time BPV was defined as the standard deviation of day time blood pressure and night time blood pressure which was derived from 24 hours ambulatory blood pressure monitoring. Multivariate linear regression models were used to test the impact of long- and short-time BPV on eGFR. The study included 3 participants groups including the long-time SBPV group (2 279 participants), the short-time SBPV group (1 636 participants) and the long- plus short-time SBPV group (1 632 participants). Participants were further sub grouped by median value (NO.1median value). eGFR in the long-time SBPV NO.1 and NO.2 group was 83.19 and 81.49 ml·min(-1)·1.73 m(-2) respectively, in the short time SBPV NO.1 and NO.2 group was 83.53 and 80.81ml·min(-1)·1.73 m(-2) of the day time, and was 83.20 and 81.14 ml·min(-1)·1.73 m(-2) of the night time, respectively. eGFR in the long- plus short-time SBPV NO.1 and NO.2 group was 83.21 and 81.08 ml·min(-1)·1.73 m(-2) of the long-time SBPV, and was 83.53 and 80.75 ml·min(-1)·1.73 m(-2) of the day time, and was 83.18 and 81.11 ml·min(-1)·1.73 m(-2) of the night time. Significant linear relationship was found between higher day time SBPV and lower eGFR (P<0.05). After adjusting for confounding parameters including age, sex, body mass index, 1 mmHg(1 mmHg=0.133 kPa) of day time SBPV

The Effect of Anthocyanins on Blood Pressure: A PRISMA-Compliant Meta-Analysis of Randomized Clinical Trials.

PubMed

Zhu, Yongjian; Bo, Yacong; Wang, Xi; Lu, Wenjie; Wang, Xule; Han, Zhanying; Qiu, Chunguang

2016-04-01

The findings of clinical studies concerning the association between anthocyanins supplementation and blood pressure (BP) are inconsistent. In order to provide a more precise estimate of the overall effect of anthocyanins on systolic blood pressure (SBP) and diastolic blood pressure (DBP), we conducted a meta-analysis of clinical trials about anthocyanins supplementation and BP. PubMed, Web of Science, Wanfang Database, and China National Knowledge Infrastructure (CNKI) (until October 2015) were searched to identify potential studies with information on anthocyanins extract supplementation and arterial BP. The weighted mean difference (WMD) and 95% confidence interval (CI) were used as a summary statistic. Net changes in SBP and DBP between anthocyanins supplementation and placebo groups were calculated by subtracting the values at end of follow-up from those at baseline. Meta regression was used to explore the potential moderators of effect size. The publication bias was assessed using Begger's Funnel plots and Egger's tests; P < 0.05 was considered to be statistically significant. Finally, 6 clinical studies with 472 participants for the effect of anthocyanins consumption on BP were included in the present meta-analysis. There is no significant effect on either SBP (WMD: 1.15 mm Hg, 95% CI: -3.17 to 5.47, I2 = 56%) or DBP (WMD: 1.06 mm Hg, 95% CI: -0.71 to 2.83, I2 = 0%) following supplementation with anthocyanins. In summary, results from this meta-analysis do not favor any clinical efficacy of supplementation with anthocyanins in improving blood pressure. Further well-designed large randomized controlled trials (RCTs) with long follow-up period are needed to verify the association of anthocyanins supplementation and blood pressure.

Effects of 16-week spinning and bicycle exercise on body composition, physical fitness and blood variables of middle school students

PubMed Central

Yoon, Jang-Gun; Kim, Seok-Hee; Rhyu, Hyun-Seung

2017-01-01

The purpose of this study was to investigate the effects of 16 weeks of spinning and bicycling exercises on body composition, physical fitness and blood variables in female adolescents. Subjects participated in this study were 24 female middle school students (12 spinning cycles, 12 general bicycles) attending to Seoul Yeoksam middle school. Each group was trained for 16 weeks, 3 times a week, and 1 hr per day after school. Body composition, physical fitness (1,200 running, sit-ups, back strength, sit and reach, side-steps) and blood variables (low-density lipoprotein cholesterol, glucose, reactive oxygen species, and malondialdehyde) were examined before and after 16 weeks of training. As the results, body weight did not show any significant difference; however, body mass index, and % body fat were significantly difference in spinning group. The enhancement in physical fitness factors were recognized in both groups, which was greater in spinning group in sit-ups, back strength, and side steps. Blood parameters were significantly difference between groups, but between group and time interactions were significantly difference in glucose and reactive oxygen species. In conclusion, this study suggests that 16 weeks of bicycle exercises were positive changes in body composition, physical fitness and blood constituents, indicating that spinning cycle is more beneficial as compared to ordinary bicycle. PMID:29114504

Lack of association between systolic blood pressure and blood viscosity in normotensive healthy subjects.

PubMed

Irace, Concetta; Carallo, Claudio; Scavelli, Faustina; Loprete, Antonio; Merante, Valentina; Gnasso, Agostino

2012-01-01

A direct relationship between blood pressure and viscosity has frequently been reported, although clear data are not available. To better understand the relationship between these two variables, we evaluated blood viscosity and blood pressure in a group of healthy subjects without cardiovascular risk factors. Healthy subjects were selected from participants in a campaign of prevention of cardiovascular disease (n = 103). They underwent blood sampling for measurement of plasma and blood viscosity, haematocrit, blood lipids and glucose. The quantity and distribution of body fat was assessed by body mass index and waist/hip ratio, respectively. Systolic blood pressure (SBP) correlated significantly with age (r = 0.222) and waist/hip ratio (r = 0.374). Diastolic blood pressure (DBP) correlated significantly with waist/hip ratio (r = 0.216), haematocrit (r = 0.333) and blood viscosity (r = 0.258). Multiple linear regression analyses demonstrated that the only variable significantly associated with SBP was age, while haematocrit was the only variable significantly associated with DBP. Blood viscosity was closely related to waist/hip ratio. These findings show that SBP, in healthy subjects, is not influenced by haematocrit and blood viscosity. In contrast, DBP is related to the values of haematocrit. Among classical cardiovascular risk factors, waist/hip ratio is closely related to blood viscosity.

Hepcidin as a new biomarker for detecting autologous blood transfusion.

PubMed

Leuenberger, Nicolas; Barras, Laura; Nicoli, Raul; Robinson, Neil; Baume, Norbert; Lion, Niels; Barelli, Stefano; Tissot, Jean-Daniel; Saugy, Martial

2016-05-01

Autologous blood transfusion (ABT) is an efficient way to increase sport performance. It is also the most challenging doping method to detect. At present, individual follow-up of haematological variables via the athlete biological passport (ABP) is used to detect it. Quantification of a novel hepatic peptide called hepcidin may be a new alternative to detect ABT. In this prospective clinical trial, healthy subjects received a saline injection for the control phase, after which they donated blood that was stored and then transfused 36 days later. The impact of ABT on hepcidin as well as haematological parameters, iron metabolism, and inflammation markers was investigated. Blood transfusion had a particularly marked effect on hepcidin concentrations compared to the other biomarkers, which included haematological variables. Hepcidin concentrations increased significantly: 12 hr and 1 day after blood reinfusion, these concentrations rose by seven- and fourfold, respectively. No significant change was observed in the control phase. Hepcidin quantification is a cost-effective strategy that could be used in an "ironomics" strategy to improve the detection of ABT. © 2016 Wiley Periodicals, Inc.

Effects of color temperatures (Kelvin) of LED bulbs on blood physiological variables of broilers grown to heavy weights.

PubMed

Olanrewaju, H A; Purswell, J L; Collier, S D; Branton, S L

2015-08-01

Light-emitting diode (LED) lighting is being used in the poultry industry to reduce energy usage in broiler production facilities. However, limited data are available comparing efficacy of different spectral distribution of LED bulbs on blood physiological variables of broilers grown to heavy weights (>3 kg). The present study evaluated the effects of color temperature (Kelvin) of LED bulbs on blood physiological variables of heavy broilers in 2 trials with 4 replicates/trial. The study was a randomized complete block design. Four light treatments consisted of 3 LED light bulbs [2,700 K, (Warm-LED); 5,000 K, (Cool-LED-#1); 5,000 K, (Cool-LED-#2)] and incandescent light (ICD, standard) from 1 to 56 d age. A total of 960 1-day-old Ross × Ross 708 chicks (30 males/room 30 females/room) were equally and randomly distributed among 16 environmentally controlled rooms at 50% RH. Each of the 4 treatments was represented by 4 rooms. Feed and water were provided ad libitum. All treatment groups were provided the same diet. Venous blood samples were collected on d 21, 28, 42, and 56 for immediate analysis of selected physiological variables and plasma collection. In comparison with ICD, Cool-LED-#1 had greater (P < 0.05) effects on pH, partial pressure of CO₂(pCO₂), partial pressure of O₂(pO₂), saturated O₂(sO₂), and K⁺. However, all these acid-base changes remained within the normal venous acid-base homeostasis and physiological ranges. In addition, no effect of treatments was observed on HCO(3)(-), hematocrit (Hct), hemoglobin (Hb), Na⁺, Ca²⁺, Cl⁻, mean corpuscular hemoglobin concentration (McHc), osmolality, and anion gap. Moreover, blood glucose concentrations were not affected by treatments. This study shows that the 3 LED light bulbs evaluated in this study may be suitable for replacement of ICD light sources in commercial poultry facilities to reduce energy cost and optimize production efficiency without inducing physiological stress on

The contribution of carotid rete variability to brain temperature variability in sheep in a thermoneutral environment.

PubMed

Maloney, Shane K; Mitchell, Duncan; Blache, Dominique

2007-03-01

The degree of variability in the temperature difference between the brain and carotid arterial blood is greater than expected from the presumed tight coupling between brain heat production and brain blood flow. In animals with a carotid rete, some of that variability arises in the rete. Using thermometric data loggers in five sheep, we have measured the temperature of arterial blood before it enters the carotid rete and after it has perfused the carotid rete, as well as hypothalamic temperature, every 2 min for between 6 and 12 days. The sheep were conscious, unrestrained, and maintained at an ambient temperature of 20-22 degrees C. On average, carotid arterial blood and brain temperatures were the same, with a decrease in blood temperature of 0.35 degrees C across the rete and then an increase in temperature of the same magnitude between blood leaving the rete and the brain. Rete cooling of arterial blood took place at temperatures below the threshold for selective brain cooling. All of the variability in the temperature difference between carotid artery and brain was attributable statistically to variability in the temperature difference across the rete. The temperature difference between arterial blood leaving the rete and the brain varied from -0.1 to 0.9 degrees C. Some of this variability was related to a thermal inertia of the brain, but the majority we attribute to instability in the relationship between brain blood flow and brain heat production.

Clinico-pathological and biological prognostic variables in squamous cell carcinoma of the vulva.

PubMed

Gadducci, Angiolo; Tana, Roberta; Barsotti, Cecilia; Guerrieri, Maria Elena; Genazzani, Andrea Riccardo

2012-07-01

Several clinical-pathological parameters have been related to survival of patients with invasive squamous cell carcinoma of the vulva, whereas few studies have investigated the ability of biological variables to predict the clinical outcome of these patients. The present paper reviews the literature data on the prognostic relevance of lymph node-related parameters, primary tumor-related parameters, FIGO stage, blood variables, and tissue biological variables. Regarding these latter, the paper takes into account the analysis of DNA content, cell cycle-regulatory proteins, apoptosis-related proteins, epidermal growth factor receptor [EGFR], and proteins that are involved in tumor invasiveness, metastasis and angiogenesis. At present, the lymph node status and FIGO stage according to the new 2009 classification system are the main predictors for vulvar squamous cell carcinoma, whereas biological variables do not have yet a clinical relevance and their role is still investigational. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Variability in CKD stage in outpatients followed in two large renal clinics.

PubMed

Sikaneta, Tabo; Abdolell, Mohamed; Taskapan, Hulya; Roscoe, Janet; Fung, Jason; Nagai, Gordon; Ting, Robert H; Ng, Paul; Wu, George; Oreopoulos, Dimitrios; Tam, Paul Y

2012-10-01

Chronic kidney disease (CKD) is staged by glomerular filtration rate (GFR). CKD stages sometimes vary between routine office visits, and it is unknown if this impacts renal and patient survival separately from a cross-sectional CKD stage value. We quantified and categorized CKD stage variability in a large group of outpatients and correlated this with clinical and demographic features and with renal and patient survival. All estimated GFRs were staged in the first observation period. CKD stages were then categorized as static, improving, worsening, or fluctuating. Logistic regression analysis was performed to identify clinical variables associated with CKD stage variability. Death and dialysis progression rates were then collected and analyzed using Cox proportional regression. During a 1.1-year observation period, 1,262 patients (mean age 71.25 years) had a mean 5 eGFR's. CKD stages were static in 60.4%, worsened in 14.4%, improved in 7.4%, and fluctuated in 17.2% of patients. Secondary analysis revealed heavy proteinuria and East Asian ethnicity to be negatively, and diabetes mellitus and previous acute kidney injury to be positively associated with improving CKD stages. Cox proportional regression of 902 patients analyzed 2.3 years later revealed a negative association with improving CKD stage and subsequent need for dialysis. CKD stage changed in 40% of 1,262 elderly patients when determined 5 times in just over 1 year. Improving CKD stage was the only variability pattern significantly associated with any of the clinical outcomes when assessed 2.3 years later, being unlikely to be linked with subsequent need for dialysis.

Increased numbers of total nucleated and CD34+ cells in blood group O cord blood: an analysis of neonatal innate factors in the Korean population.

PubMed

Lee, Hye Ryun; Park, Jeong Su; Shin, Sue; Roh, Eun Youn; Yoon, Jong Hyun; Han, Kyou Sup; Kim, Byung Jae; Storms, Robert W; Chao, Nelson J

2012-01-01

We analyzed neonatal factors that could affect hematopoietic variables of cord blood (CB) donated from Korean neonates. The numbers of total nucleated cells (TNCs), CD34+ cells, and CD34+ cells/TNCs of CB in neonates were compared according to sex, gestational age, birth weight, birth weight centile for gestational age, and ABO blood group. With 11,098 CB units analyzed, blood group O CB showed an increased number of TNCs, CD34+ cells, and CD34+ cells/TNCs compared with other blood groups. Although TNC counts were lower in males, no difference in the number of CD34+ cells was demonstrated because the number of CD34+ cells/TNCs was higher in males. An increase in the gestational age resulted in an increase in the number of TNCs and decreases in the number of CD34+ cells and CD34+ cells/TNCs. The numbers of TNCs, CD34+ cells, and CD34+ cells/TNCs increased according to increased birth weight centile as well as birth weight. CB with blood group O has unique hematologic variables in this large-scale analysis of Korean neonates, although the impact on the storage policies of CB banks or the clinical outcome of transplantation remains to be determined. © 2011 American Association of Blood Banks.

[Blood pressure measurement].

PubMed

Bang, Lia Evi; Wiinberg, Niels

2009-06-08

Blood pressure measurement should follow recommended procedures, otherwise incorrect diagnoses will follow resulting in incorrect treatment and cardiovascular events. The standard for clinical blood pressure measurement is the auscultatory method, but mercury sphygmomanometers can still be used. Blood pressure measurement at home using 24-hour or home blood pressure has documented a better reproducibility and predicts cardiovascular event more precisely than clinic blood pressure. 24-hour measurement or home blood pressure measurement should be performed in patients with suspected hypertension without hypertensive organ damage to reveal white-coat hypertension.

Genome-Level Determination of Plasmodium falciparum Blood-Stage Targets of Malarial Clinical Immunity in the Peruvian Amazon

PubMed Central

Torres, Katherine J.; Castrillon, Carlos E.; Moss, Eli L.; Saito, Mayuko; Tenorio, Roy; Molina, Douglas M.; Davies, Huw; Neafsey, Daniel E.; Felgner, Philip; Vinetz, Joseph M.; Gamboa, Dionicia

2015-01-01

Background. Persons with blood-stage Plasmodium falciparum parasitemia in the absence of symptoms are considered to be clinically immune. We hypothesized that asymptomatic subjects with P. falciparum parasitemia would differentially recognize a subset of P. falciparum proteins on a genomic scale. Methods and Findings. Compared with symptomatic subjects, sera from clinically immune, asymptomatically infected individuals differentially recognized 51 P. falciparum proteins, including the established vaccine candidate PfMSP1. Novel, hitherto unstudied hypothetical proteins and other proteins not previously recognized as potential vaccine candidates were also differentially recognized. Genes encoding the proteins differentially recognized by the Peruvian clinically immune individuals exhibited a significant enrichment of nonsynonymous nucleotide variation, an observation consistent with these genes undergoing immune selection. Conclusions. A limited set of P. falciparum protein antigens was associated with the development of naturally acquired clinical immunity in the low-transmission setting of the Peruvian Amazon. These results imply that, even in a low-transmission setting, an asexual blood-stage vaccine designed to reduce clinical malaria symptoms will likely need to contain large numbers of often-polymorphic proteins, a finding at odds with many current efforts in the design of vaccines against asexual blood-stage P. falciparum. PMID:25381370

IDENTIFICATION OF BACTERIA IN BLOOD CULTURES FROM CLINICALLY ILL CAPTIVE ANTILLEAN MANATEES (TRICHECHUS MANATUS MANATUS).

PubMed

Silva, Mariana C O; Attademo, Fernanda F L; Freire, Augusto C B; Sousa, Glaucia P; Luna, Fábia O; Lima, Débora C V; Mota, Rinaldo A; Mendes, Emiko S; Silva, Jean C R

2017-03-01

Between September 2001 and March 2013, 62 bacterial cultures (37 aerobic and 25 anaerobic) were performed on 37 blood samples from 23 Antillean manatees ( Trichechus manatus manatus) that were kept in captivity at the Brazilian National Center for Research and Conservation of Aquatic Mammals (CMA) in Pernambuco (CMA-PE) and Alagoas (CMA-AL), Brazil. All of the animals sampled exhibited clinical signs at the time of sampling including abscesses (n = 8), debilitation and anorexia (n = 22), and profound lethargy-moribundity (n = 7). The 4 animals with profound lethargy-moribundity died shortly after sampling of unknown causes. Bacteria were isolated from 15/37 (40.5%) and aerobic blood cultures from 13/23 animals (56.5%). None of the anaerobic cultures were positive. Aeromonas caviae , Aeromonas hydrophila , Aeromonas sp., Escherichia coli , Leclercia adecarboxylata , Pantoea agglomerans , Pseudomonas aeruginosa , Pseudomonas stutzeri , Pseudomonas sp., Sphingomonas paucimobilis , coagulase-negative Staphylococcus, and Staphylococcus epidermidis were each found in only one animal; Staphylococcus spp. was found in two; and Vibrio fluvialis in four. Thirteen samples had only one bacteria isolated, one sample had two bacteria, and one sample had three bacteria isolated. Regarding sex, age group, and origin among the manatees examined, 54.5% (6/11) of the females, 58.3% (7/12) of the males, 40% (2/5) of the calves, 66.7% (8/12) of the juveniles, 50% (3/6) of the adults, 55.5% (10/18) at CMA-PE, and 60% (3/5) at CMA-AL were found to be positive for bacterial growth during at least one sampling time. All Antillean manatees were clinically ill. Regarding clinical signs, bacteria were found in 50% (11/22) of blood samples of the animals showing debilitation and anorexia, 1 of 8 (12.5%) of blood samples of the animals showing abscesses, and 3 of 7 (42.9%) of blood samples of the animals showing profound lethargy-moribundity.

The effect of intermittent fasting on blood pressure variability in patients with newly diagnosed hypertension or prehypertension.

PubMed

Erdem, Yunus; Özkan, Gülsüm; Ulusoy, Şükrü; Arıcı, Mustafa; Derici, Ülver; Şengül, Şule; Sindel, Şükrü; Ertürk, Şehsuvar

2018-01-01

Intermittent fasting is a phenomenon which can be observed in most humans. The effect of intermittent fasting on blood pressure variability (BPV) has not previously been investigated. The purpose of this study was to assess the effect of fasting on blood pressure (BP) (with office, home, central, and ambulatory blood pressure monitoring [ABPM]) and on BPV. Sixty individuals were included in the study. Office, home, ABPM, and central BP measurements were performed before and during intermittent fasting. Standard deviation and coefficient variation were used for office and home BPV measurement, while the smoothness index was used to calculate ABPM variability. Patients' BP and BPV values before and during intermittent fasting were then compared. Intermittent fasting resulted in a significant decrease in office BP values and ABPM measurements but caused no significant change in home and central BP measurements. Twenty-four hour urinary sodium excretion decreased. Smoothness values obtained from ABPM measurements were low; in other words, BPV was greater. BPV was higher in patients who woke up to eat before sunrise, but BPV was low in patients with high body mass index. Intermittent fasting produced a significant decrease in BP values in terms of office and ABPM measurements in this study but caused no significant change in central BP and home measurements. We also identified an increase in BPV during intermittent fasting, particularly in patients who rose before sunrise. Copyright © 2017 American Society of Hypertension. Published by Elsevier Inc. All rights reserved.

Clinical Utility of Blood Cell Histogram Interpretation.

PubMed

Thomas, E T Arun; Bhagya, S; Majeed, Abdul

2017-09-01

An automated haematology analyser provides blood cell histograms by plotting the sizes of different blood cells on X-axis and their relative number on Y-axis. Histogram interpretation needs careful analysis of Red Blood Cell (RBC), White Blood Cell (WBC) and platelet distribution curves. Histogram analysis is often a neglected part of the automated haemogram which if interpreted well, has significant potential to provide diagnostically relevant information even before higher level investigations are ordered.

Blood stem cells and non-hematological clinical practice: pragmatics before therapeutics.

PubMed

Parker, Graham C

2007-02-01

There is considerable interest in biological sources for replacement, repair, as well as vascularization of tissue. The remarkable properties of blood stem cells encourage interest in their therapeutic potential. But what are these properties, and how do they influence their clinical potential and the advisability of stem cell use as a therapeutic resource? Rational assessment of the significance of in vitro and animal in vivo data should precede the rush from the bench to the bedside. Basic stem cell research is rife with examples where the truth of the subsequently demonstrated mechanism is stranger than the initial interpretation proved fiction. This review will assess tissue contribution by different blood related stem cells, differing possible mechanisms underlying observed repair phenomena, and consider the potency and pitfalls of stem cell therapeutics.

A novel approach for prediction of tacrolimus blood concentration in liver transplantation patients in the intensive care unit through support vector regression.

PubMed

Van Looy, Stijn; Verplancke, Thierry; Benoit, Dominique; Hoste, Eric; Van Maele, Georges; De Turck, Filip; Decruyenaere, Johan

2007-01-01

Tacrolimus is an important immunosuppressive drug for organ transplantation patients. It has a narrow therapeutic range, toxic side effects, and a blood concentration with wide intra- and interindividual variability. Hence, it is of the utmost importance to monitor tacrolimus blood concentration, thereby ensuring clinical effect and avoiding toxic side effects. Prediction models for tacrolimus blood concentration can improve clinical care by optimizing monitoring of these concentrations, especially in the initial phase after transplantation during intensive care unit (ICU) stay. This is the first study in the ICU in which support vector machines, as a new data modeling technique, are investigated and tested in their prediction capabilities of tacrolimus blood concentration. Linear support vector regression (SVR) and nonlinear radial basis function (RBF) SVR are compared with multiple linear regression (MLR). Tacrolimus blood concentrations, together with 35 other relevant variables from 50 liver transplantation patients, were extracted from our ICU database. This resulted in a dataset of 457 blood samples, on average between 9 and 10 samples per patient, finally resulting in a database of more than 16,000 data values. Nonlinear RBF SVR, linear SVR, and MLR were performed after selection of clinically relevant input variables and model parameters. Differences between observed and predicted tacrolimus blood concentrations were calculated. Prediction accuracy of the three methods was compared after fivefold cross-validation (Friedman test and Wilcoxon signed rank analysis). Linear SVR and nonlinear RBF SVR had mean absolute differences between observed and predicted tacrolimus blood concentrations of 2.31 ng/ml (standard deviation [SD] 2.47) and 2.38 ng/ml (SD 2.49), respectively. MLR had a mean absolute difference of 2.73 ng/ml (SD 3.79). The difference between linear SVR and MLR was statistically significant (p < 0.001). RBF SVR had the advantage of requiring only 2

Preanalytical variables in measurement of free (ionized) calcium in lithium heparin-containing blood collection tubes.

PubMed

Haverstick, Doris M; Brill, Louis B; Scott, Mitchell G; Bruns, David E

2009-05-01

Measurements of free (ionized) calcium (iCa) are increasingly requested in patient care locations where immediate analysis is unavailable. Evacuated blood collection tubes containing lithium heparin and gel separator material are widely used in clinical laboratories, but little information is available on the effects of these tubes or of delay prior to analysis on the concentration or stability of iCa. We collected blood from volunteers into lithium-heparin tubes (PST, Vacutainer PST, BD Pre-Analytic Systems) of multiple lots and into electrolyte-balanced heparin syringes (Portex Dry Heparin, Smiths Medical). iCa was measured (Siemens 1265 blood gas analyzers) immediately and, in PST, at 0-7 h with or without transportation of the tubes from remote sites. The mean difference of free calcium results in the PST tubes and electrolyte-balanced syringes was -0.08 (95% confidence interval -0.17 to 0.012) mmol/l, and the SD of the residuals (Sy, x) of the regression was 0.03 mmol/l. There was no detectable lot-to-lot variation in results. Free calcium was stable in tubes at room temperature and at 4 degrees C for at least 7 h with or without transportation. iCa measured in the examined blood collection tubes is stable and unaffected by lot-to-lot variation of tubes, but results are slightly lower than with special blood gas syringes.

Clinical Utility of Blood Cell Histogram Interpretation

PubMed Central

Bhagya, S.; Majeed, Abdul

2017-01-01

An automated haematology analyser provides blood cell histograms by plotting the sizes of different blood cells on X-axis and their relative number on Y-axis. Histogram interpretation needs careful analysis of Red Blood Cell (RBC), White Blood Cell (WBC) and platelet distribution curves. Histogram analysis is often a neglected part of the automated haemogram which if interpreted well, has significant potential to provide diagnostically relevant information even before higher level investigations are ordered. PMID:29207767

Clinical periodontal variables in patients with and without dementia-a systematic review and meta-analysis.

PubMed

Maldonado, Alejandra; Laugisch, Oliver; Bürgin, Walter; Sculean, Anton; Eick, Sigrun

2018-06-22

Considering the increasing number of elderly people, dementia has gained an important role in today's society. Although the contributing factors for dementia have not been fully understood, chronic periodontitis (CP) seems to have a possible link to dementia. To conduct a systematic review including meta-analysis in order to assess potential differences in clinical periodontal variables between patients with dementia and non-demented individuals. The following focused question was evaluated: is periodontitis associated with dementia? Electronic searches in two databases, MEDLINE and EMBASE, were conducted. Meta-analysis was performed with the collected data in order to find a statistically significant difference in clinical periodontal variables between the group of dementia and the cognitive normal controls. Forty-two articles remained for full text reading. Finally, seven articles met the inclusion criteria and only five studies provided data suitable for meta-analysis. Periodontal probing depth (PPD), bleeding on probing (BOP), gingival bleeding index (GBI), clinical attachment level (CAL), and plaque index (PI) were included as periodontal variables in the meta-analysis. Each variable revealed a statistically significant difference between the groups. In an attempt to reveal an overall difference between the periodontal variables in dementia patients and non-demented individuals, the chosen variables were transformed into units that resulted in a statistically significant overall difference (p < 0.00001). The current findings indicate that compared to systemically healthy individuals, demented patients show significantly worse clinical periodontal variables. However, further epidemiological studies including a high numbers of participants, the use of exact definitions both for dementia and chronic periodontitis and adjusted for cofounders is warranted. These findings appear to support the putative link between CP and dementia. Consequently, the need for

Efficacy of Dragon's blood cream on wound healing: A randomized, double-blind, placebo-controlled clinical trial

PubMed Central

Namjoyan, Foroogh; Kiashi, Fatemeh; Moosavi, Zahra Beigom; Saffari, Fatemeh; Makhmalzadeh, Behzad Sharif

2015-01-01

The blood-red sap of Dragon's blood has been used in folk medicine for fractures, wounds, inflammation, gastrointestinal disorders, rheumatism, blood circulation dysfunctions, and cancer. Existing in vitro and in vivo bioactivity of this herb on different mechanisms of healing shows strong potential of this sap in wound healing. This clinical trial study was designated to evaluate the wound healing effect of Dragon's blood on human wounds. Sixty patients, between the ages of 14–65 years, who were referred to remove their skin tag, were assigned to this double-blind, placebo-controlled, randomized clinical trial and received either Dragon's blood or a placebo cream. They were visited on the 3rd, 5th, 7th, 10th, 14th, and 20th day of the trial to check the process of healing and to measure the wound's surface. At the end of trial, there was a significant difference in the mean duration of wound healing between the two groups (p = 0.0001). The phenolic compounds and the alkaloid taspine, which exist in Dragon's-blood resin, are probably the main reasons for the wound healing property of this plant. Being natural accessible, safe, and affordable makes Dragon's blood cream, a good choice for addition to the wound healing armamentarium. Further studies on wounds with different causes and among larger populations are suggested to ensure the effectiveness and safety of Dragon's blood. PMID:26870678

Efficacy of Dragon's blood cream on wound healing: A randomized, double-blind, placebo-controlled clinical trial.

PubMed

Namjoyan, Foroogh; Kiashi, Fatemeh; Moosavi, Zahra Beigom; Saffari, Fatemeh; Makhmalzadeh, Behzad Sharif

2016-01-01

The blood-red sap of Dragon's blood has been used in folk medicine for fractures, wounds, inflammation, gastrointestinal disorders, rheumatism, blood circulation dysfunctions, and cancer. Existing in vitro and in vivo bioactivity of this herb on different mechanisms of healing shows strong potential of this sap in wound healing. This clinical trial study was designated to evaluate the wound healing effect of Dragon's blood on human wounds. Sixty patients, between the ages of 14-65 years, who were referred to remove their skin tag, were assigned to this double-blind, placebo-controlled, randomized clinical trial and received either Dragon's blood or a placebo cream. They were visited on the 3rd, 5th, 7th, 10th, 14th, and 20th day of the trial to check the process of healing and to measure the wound's surface. At the end of trial, there was a significant difference in the mean duration of wound healing between the two groups (p = 0.0001). The phenolic compounds and the alkaloid taspine, which exist in Dragon's-blood resin, are probably the main reasons for the wound healing property of this plant. Being natural accessible, safe, and affordable makes Dragon's blood cream, a good choice for addition to the wound healing armamentarium. Further studies on wounds with different causes and among larger populations are suggested to ensure the effectiveness and safety of Dragon's blood.

Evidence-based blood pressure reducing actions of electroacupuncture: mechanisms and clinical application.

PubMed

Longhurst, John C; Tjen-A-Looi, Stephanie C

2017-10-25

Hypertension is a serious world-wide health problem as it increases cardiovascular atherosclerotic risk, stroke and attending morbidity and mortality. Both systolic and diastolic blood pressures and particularly systolic pressure increase with aging. The downsides from pharmacological therapy have led to consideration of additional treatments, including acupuncture, which evokes endogenous neural-hormonal systems to lower blood pressure. Using basic science studies to guide clinical approaches to research, it is apparent that low frequency, low intensity electroacupuncture reduces sympathetic outflow in approximately 70% of patients with mild to moderate hypertension who are off antihypertensive drugs. Systolic and, to a lesser extent, diastolic arterial blood pressures can be lowered over two to four weeks for prolonged periods, lasting as long as one month, after cessation of an eight weeks of once weekly stimulation. Many questions about long-term therapy, treatment of resistant patients and efficacy in patients on medication remain to be studied. Current data, however, suggest that there may be a role of acupuncture in treatment of hypertension.

Twelve hour reproducibility of choroidal blood flow parameters in healthy subjects.

PubMed

Polska, E; Polak, K; Luksch, A; Fuchsjager-Mayrl, G; Petternel, V; Findl, O; Schmetterer, L

2004-04-01

To investigate the reproducibility and potential diurnal variation of choroidal blood flow parameters in healthy subjects over a period of 12 hours. The choroidal blood flow parameters of 16 healthy non-smoking subjects were measured at five time points during the day (8:00, 11:00, 14:00, 17:00, and 20:00). Outcome parameters were pulsatile ocular blood flow as assessed by pneumotonometry, fundus pulsation amplitude as assessed by laser interferometry, blood velocities in the opthalmic and posterior ciliary arteries as assessed by colour Doppler imaging, and choroidal blood flow, volume, and velocity as assessed by fundus camera based laser Doppler flowmetry. The coefficient of variation and the maximum change from baseline in an individual were calculated for each outcome parameter. None of the techniques used found a diurnal variation in choroidal blood flow. Coefficients of variation were within 2.9% and 13.6% for all outcome parameters. The maximum change from baseline in an individual was much higher, ranging from 11.2% to 58.8%. These data indicate that in healthy subjects the selected techniques provide adequate reproducibility to be used in clinical studies. Variability may, however, be considerably higher in older subjects or subjects with ocular disease. The higher individual differences in flow parameter readings limit the use of the techniques in clinical practice. To overcome problems with measurement validity, a clinical trial should include as many choroidal blood flow outcome parameters as possible to check for consistency.

Day to Day Variability and Reliability of Blood Oxidative Stress Markers within a Four-Week Period in Healthy Young Men.

PubMed

Goldfarb, A H; Garten, R S; Waller, J; Labban, J D

2014-01-01

The present study aimed to determine the day to day variability and reliability of several blood oxidative stress markers at rest in a healthy young cohort over a four-week period. Twelve apparently healthy resistance trained males (24.6 ± 3.0 yrs) were tested over 7 visits within 4 weeks with at least 72 hrs between visits at the same time of day. Subjects rested 30 minutes prior to blood being obtained by vacutainer. Results. The highest IntraClass correlations (ICC's) were obtained for protein carbonyls (PC) and oxygen radical absorbance capacity (ORAC) (PC = 0.785 and ORAC = 0.780). Cronbach's α reliability score for PC was 0.967 and for ORAC was 0.961. The ICC's for GSH, GSSG, and the GSSG/TGH ratio ICC were 0.600, 0.573, and 0.570, respectively, with Cronbach's α being 0.913, 0.904, and 0.903, respectively. Xanthine oxidase ICC was 0.163 and Cronbach's α was 0.538. Conclusions. PC and ORAC demonstrated good to excellent reliability while glutathione factors had poor to excellent reliability. Xanthine oxidase showed poor reliability and high variability. These results suggest that the PC and ORAC markers were the most stable and reliable oxidative stress markers in blood and that daily changes across visits should be considered when interpreting resting blood oxidative stress markers.

Episiotomy and its relationship to various clinical variables that influence its performance

PubMed Central

Ballesteros-Meseguer, Carmen; Carrillo-García, César; Meseguer-de-Pedro, Mariano; Canteras-Jordana, Manuel; Martínez-Roche, Mª Emilia

2016-01-01

Objective: to understand the episiotomy rate and its relationship with various clinical variables. Method: a descriptive, cross-sectional, analytic study of 12,093 births in a tertiary hospital. Variables: Parity, gestational age, start of labor, use of epidural analgesia, oxytocin usage, position during fetal explusion, weight of neonate, and completion of birth. The analysis was performed with SPSS 19.0. Results: the global percentage of episiotomies was 50%. The clinical variables that presented a significant association were primiparity (RR=2.98), gestational age >41 weeks (RR=1.2), augmented or induced labor (RR=1.33), epidural analgesia use (RR=1,95), oxytocin use (RR=1.58), lithotomy position during fetal expulsion (RR=6.4), and instrumentation (RR=1.84). Furthermore, maternal age ≥35 years (RR=0.85) and neonatal weight <2500 g (RR=0.8) were associated with a lower incidence of episiotomy. Conclusions: episiotomy is dependent on obstetric interventions performed during labor. If we wish to reduce the episiotomy rate, it will be necessary to bear in mind these risk factors when establishing policies for reducing this procedure. PMID:27224064

Comparison of the clinical and microbiological characteristics of Campylobacter and Helicobacter bacteremia: the importance of time to blood culture positivity using the BACTEC blood culture systems.

PubMed

Yamamoto, Kei; Hayakawa, Kayoko; Nagashima, Maki; Shimada, Kayo; Kutsuna, Satoshi; Takeshita, Nozomi; Kato, Yasuyuki; Kanagawa, Shuzo; Yamada, Koji; Mezaki, Kazuhisa; Kirikae, Teruo; Ohmagari, Norio

2017-11-28

Campylobacter spp. and Helicobacter spp. are rare but important causes of bacteremia in humans. Distinguishing these bacteria is complicated because of their similar phenotypic profiles. We conducted clinical and microbiological investigations of Campylobacter spp. or Helicobacter spp. bacteremia. Patients diagnosed with bacteremia from 2008 to 2014 were included. The clinical and microbiological characteristics of Campylobacter spp. and Helicobacter spp. bacteremia were compared. The BACTEC system was used in blood cultures. A receiver operating characteristic curve was plotted based on the time to blood culture positivity. Sixteen cases of Helicobacter spp. bacteremia (patient age: 61 ± 18 years) and 14 cases of Campylobacter spp. bacteremia (patient age: 49 ± 21 years) were identified. Median time to blood culture positivity was longer for the Helicobacter spp. cases than the Campylobacter spp. cases (91.4 h vs 55.3 h, p < 0.01). A time to blood culture positivity > 75 h predicted Helicobacter spp. bacteremia with a sensitivity of 0.88 and a specificity of 0.93 (area under the receiver operating characteristic curve of 0.90). In conclusion, a time to blood culture positivity was useful in distinguishing Helicobacter spp. bacteremia from Campylobacter spp. bacteremia.

Therapeutics incorporating blood constituents.

PubMed

Charoenphol, Phapanin; Oswalt, Katie; Bishop, Corey J

2018-04-05

Blood deficiency and dysfunctionality can result in adverse events, which can primarily be treated by transfusion of blood or the re-introduction of properly functioning sub-components. Blood constituents can be engineered on the sub-cellular (i.e., DNA recombinant technology) and cellular level (i.e., cellular hitchhiking for drug delivery) for supplementing and enhancing therapeutic efficacy, in addition to rectifying dysfunctioning mechanisms (i.e., clotting). Herein, we report the progress of blood-based therapeutics, with an emphasis on recent applications of blood transfusion, blood cell-based therapies and biomimetic carriers. Clinically translated technologies and commercial products of blood-based therapeutics are subsequently highlighted and perspectives on challenges and future prospects are discussed. Blood-based therapeutics is a burgeoning field and has advanced considerably in recent years. Blood and its constituents, with and without modification (i.e., combinatorial), have been utilized in a broad spectrum of pre-clinical and clinically-translated treatments. This review article summarizes the most up-to-date progress of blood-based therapeutics in the following contexts: synthetic blood substitutes, acellular/non-recombinant therapies, cell-based therapies, and therapeutic sub-components. The article subsequently discusses clinically-translated technologies and future prospects thereof. Copyright © 2018 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Effect of static and dynamic exercise on heart rate and blood pressure variabilities.

PubMed

González-Camarena, R; Carrasco-Sosa, S; Román-Ramos, R; Gaitán-González, M J; Medina-Bañuelos, V; Azpiroz-Leehan, J

2000-10-01

This study examines the effect of static and dynamic leg exercises on heart rate variability (HRV) and blood pressure variability (BPV) in humans. 10 healthy male subjects were studied at rest, during static exercise performed at 30% of maximal voluntary contraction (SX30), and during dynamic cycling exercises done at 30% of VO2max (DX30) and at 60% of VO2max (DX60). Respiration, heart rate, and blood pressure signals were digitized to analyze temporal and spectral parameters involving short and overall indexes (SD, deltaRANGE, RMSSD, Total power), power of the low (LF), middle (MF), and high (HF) frequency components, and the baroreceptor sensitivity by the alphaMF index. During SX30, indexes of HRV as SD, deltaRANGE, Total power, and MF in absolute units increased in relation with rest values and were significantly higher (P < 0.001) than during DX30 and DX60; HF during SX30, in normalized and absolute units, was not different of the rest condition but was higher (P < 0.001) than HF during DX30 and DX60. Parameters of BPV as SD and deltaRANGE increased (P < 0.001) during both type of exercises, and significant (P < 0.01) increments were observed on MF during SX30 and DX30; systolic HF was attenuated during DX30 (P < 0.05), whereas diastolic HF was augmented during DX60 (P < 0.001). Compared with rest condition, the alphaMF index decreased (P < 0.01) only during dynamic exercises. Because HRV and BPV response is different when induced by static or dynamic exercise, differences in the autonomic activity can be advised. Instead of the vagal withdrawal and sympathetic augmentation observed during dynamic exercise, the increase in the overall HRV and the MF component during static exercise suggest an increased activity of both autonomic branches.

Effect of Intensive Versus Standard Clinic-Based Hypertension Management on Ambulatory Blood Pressure: Results From the SPRINT (Systolic Blood Pressure Intervention Trial) Ambulatory Blood Pressure Study.

PubMed

Drawz, Paul E; Pajewski, Nicholas M; Bates, Jeffrey T; Bello, Natalie A; Cushman, William C; Dwyer, Jamie P; Fine, Lawrence J; Goff, David C; Haley, William E; Krousel-Wood, Marie; McWilliams, Andrew; Rifkin, Dena E; Slinin, Yelena; Taylor, Addison; Townsend, Raymond; Wall, Barry; Wright, Jackson T; Rahman, Mahboob

2017-01-01

The effect of clinic-based intensive hypertension treatment on ambulatory blood pressure (BP) is unknown. The goal of the SPRINT (Systolic Blood Pressure Intervention Trial) ambulatory BP ancillary study was to evaluate the effect of intensive versus standard clinic-based BP targets on ambulatory BP. Ambulatory BP was obtained within 3 weeks of the 27-month study visit in 897 SPRINT participants. Intensive treatment resulted in lower clinic systolic BP (mean difference between groups=16.0 mm Hg; 95% confidence interval, 14.1-17.8 mm Hg), nighttime systolic BP (mean difference=9.6 mm Hg; 95% confidence interval, 7.7-11.5 mm Hg), daytime systolic BP (mean difference=12.3 mm Hg; 95% confidence interval, 10.6-13.9 mm Hg), and 24-hour systolic BP (mean difference=11.2 mm Hg; 95% confidence interval, 9.7-12.8 mm Hg). The night/day systolic BP ratio was similar between the intensive (0.92±0.09) and standard-treatment groups (0.91±0.09). There was considerable lack of agreement within participants between clinic systolic BP and daytime ambulatory systolic BP with wide limits of agreement on Bland-Altman plots. In conclusion, targeting a systolic BP of <120 mm Hg, when compared with <140 mm Hg, resulted in lower nighttime, daytime, and 24-hour systolic BP, but did not change the night/day systolic BP ratio. Ambulatory BP monitoring may be required to assess the effect of targeted hypertension therapy on out of office BP. Further studies are needed to assess whether targeting hypertension therapy based on ambulatory BP improves clinical outcomes. URL: http://www.clinicaltrials.gov. Unique identifier: NCT01835249. © 2016 American Heart Association, Inc.

Genome-level determination of Plasmodium falciparum blood-stage targets of malarial clinical immunity in the Peruvian Amazon.

PubMed

Torres, Katherine J; Castrillon, Carlos E; Moss, Eli L; Saito, Mayuko; Tenorio, Roy; Molina, Douglas M; Davies, Huw; Neafsey, Daniel E; Felgner, Philip; Vinetz, Joseph M; Gamboa, Dionicia

2015-04-15

Persons with blood-stage Plasmodium falciparum parasitemia in the absence of symptoms are considered to be clinically immune. We hypothesized that asymptomatic subjects with P. falciparum parasitemia would differentially recognize a subset of P. falciparum proteins on a genomic scale. Compared with symptomatic subjects, sera from clinically immune, asymptomatically infected individuals differentially recognized 51 P. falciparum proteins, including the established vaccine candidate PfMSP1. Novel, hitherto unstudied hypothetical proteins and other proteins not previously recognized as potential vaccine candidates were also differentially recognized. Genes encoding the proteins differentially recognized by the Peruvian clinically immune individuals exhibited a significant enrichment of nonsynonymous nucleotide variation, an observation consistent with these genes undergoing immune selection. A limited set of P. falciparum protein antigens was associated with the development of naturally acquired clinical immunity in the low-transmission setting of the Peruvian Amazon. These results imply that, even in a low-transmission setting, an asexual blood-stage vaccine designed to reduce clinical malaria symptoms will likely need to contain large numbers of often-polymorphic proteins, a finding at odds with many current efforts in the design of vaccines against asexual blood-stage P. falciparum. © The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Superior Diagnostic Performance of Malaria Rapid Diagnostic Tests as compared to Blood Smears in U.S. Clinical Practice

PubMed Central

Stauffer, William M.; Cartwright, Charles P.; Olson, Douglas; Juni, Billie Anne; Taylor, Charlotte M; Bowers, Susan H.; Hanson, Kevan L.; Rosenblatt, Jon E.; Boulware, David R.

2010-01-01

Background Approximately 4 million U.S. travelers to developing countries are ill enough to seek healthcare with 1,500 malaria cases reported in the U.S. annually. The diagnosis of malaria is frequently delayed due to the time to prepare malaria blood films and lack of technical expertise. An easy, reliable rapid diagnostic test (RDT) with high sensitivity and negative predictive value (NPV), particularly for Plasmodium falciparum, would be clinically useful. The study objective was to determine the diagnostic performance of the FDA-approved NOW® Malaria Test in comparison to traditional thick and thin blood smears for malaria diagnosis. Methods This prospective study tested 852 consecutive blood samples sent for thick and thin smears with blinded, malaria rapid tests at three hospital laboratories during 2003–2006. Polymerase chain reaction (PCR) verified positive tests and discordant results. Results Malaria occurred in 11% (95/852). The rapid test had superior performance than the standard Giemsa thick blood smear (P=.003). The rapid test’s sensitivity for all malaria was 97% (92/95) vs. 85% (81/95) by blood smear, and the RDT had superior NPV of 99.6% vs. 98.2% (P=.001). The P. falciparum performance was excellent with 100% rapid test sensitivity versus only 88% (65/74) by blood smear (P=.003). Conclusions This operational study demonstrates the FDA-approved rapid malaria test is superior to a single set of blood smears performed under routine U.S. clinical laboratory conditions. The most valuable clinical role of the RDT is in the rapid diagnosis or the exclusion of P. falciparum malaria, which is particularly useful in outpatient settings when evaluating febrile travelers. PMID:19686072

Utility of blood cultures in children admitted to hospital with community-acquired pneumonia.

PubMed

Davis, Tessa R; Evans, Hannah R; Murtas, Jennifer; Weisman, Aimee; Francis, J Lynn; Khan, Ahmed

2017-03-01

The aim of the study was to assess the utility of blood cultures in children admitted to hospital with community-acquired pneumonia. The primary outcome was the number of positive blood culture results, and secondary outcomes included the effect of positive blood culture results on management, and the identification of other clinical/biochemical variables that could predict blood culture results or the course of illness. A retrospective data analysis was carried out on all children admitted to Gosford Hospital during the 2-year period from July 2013 to June 2015. Included were patients under 16 years old who had a diagnosis-related group code of pneumonia. A review of blood culture results, chest X-ray, serology, C-reactive protein and white cell count and clinical outcomes were analysed. There were 215 paediatric admissions with a diagnosis of pneumonia during the 2-year study period. A blood culture was collected in 82.3% (177/215). Although seven had a positive blood culture, only two of these were finally reported as true positives and both were Streptococcus pneumoniae. Both patients were treated with a cephalosporin and demonstrated clinical improvement. No changes were made to their treatment based on the blood culture results. Blood cultures have a low yield and do not appear to be helpful when collected in all patients admitted to hospital with community-acquired pneumonia. © 2016 Paediatrics and Child Health Division (The Royal Australasian College of Physicians).

Consensus Report of the Coalition for Clinical Research—Self-Monitoring of Blood Glucose

PubMed Central

Klonoff, David C.; Bergenstal, Richard; Blonde, Lawrence; Boren, Suzanne Austin; Church, Timothy S.; Gaffaney, Jenifer; Jovanovič, Lois; Kendall, David M.; Kollman, Craig; Kovatchev, Boris P.; Leippert, Claudia; DDG, Diabetesberaterin; Owens, David R.; Polonsky, William H.; Reach, Gérard; Renard, Eric; Riddell, Michael C.; Rubin, Richard R.; Schnell, Oliver; Siminiero, Linda M.; Vigersky, Robert A.; Wilson, Darrell M.; Wollitzer, Alison Okada

2008-01-01

The Coalition for Clinical Research—Self-Monitoring of Blood Glucose Scientific Board, a group of nine academic clinicians and scientists from the United States and Europe, convened in San Francisco, California, on June 11–12, 2008, to discuss the appropriate uses of self-monitoring of blood glucose (SMBG) and the measures necessary to accurately assess the potential benefit of this practice in noninsulin-treated type 2 diabetes mellitus (T2DM). Thirteen consultants from the United States, Europe, and Canada from academia, practice, and government also participated and contributed based on their fields of expertise. These experts represent a range of disciplines that include adult endocrinology, pediatric endocrinology, health education, mathematics, statistics, psychology, nutrition, exercise physiology, and nursing. This coalition was organized by Diabetes Technology Management, Inc. Among the participants, there was consensus that: protocols assessing the performance of SMBG in noninsulin treated T2DM must provide the SMBG intervention subjects with blood glucose (BG) goals and instructions on how to respond to BG data in randomized controlled trials (RCTs);intervention subjects in clinical trials of SMBG-driven interventions must aggressively titrate their therapeutic responses or lifestyle changes in response to hyperglycemia;control subjects in clinical trials of SMBG must be isolated from SMBG-driven interventions and not be contaminated by physician experience with study subjects receiving a SMBG intervention;the best endpoints to measure in a clinical trial of SMBG in T2DM include delta Hemoglobin A1c levels, hyperglycemic events, hypoglycemic events, time to titrate noninsulin therapy to a maximum necessary dosage, and quality of life indices;either individual randomization or cluster randomization may be appropriate methods for separating control subjects from SMBG intervention subjects, provided that precautions are taken to avoid bias and that the

Preliminary experience with a hospital blood pressure follow up clinic with nurse practitioner assessment and microprocessor based data retrieval.

PubMed Central

Rubin, P C; Curzio, J L; Kelman, A; Elliott, H L; Reid, J L

1984-01-01

Experience over two years with 376 hypertensive patients managed at a clinic where the primary observations are made by a trained nurse, clinical information is held on a microprocessor, and treatment follows a standard stepped care approach has been assessed. Blood pressure control after both one and two years was appreciably improved, with over 70% of patients having diastolic pressure below 90 mm Hg compared with 22% of patients when they first attended the new clinic. The non-attendance rate was half that of the conventional hospital outpatient clinic. A computer based record system with a nurse run hypertension clinic is acceptable to patients and offers the possibility of more effective long term control of blood pressure in large numbers of patients. PMID:6432180

The effect of music on the level of cortisol, blood glucose and physiological variables in patients undergoing spinal anesthesia.

PubMed

Mottahedian Tabrizi, Elaheh; Sahraei, Hedayat; Movahhedi Rad, Saeid; Hajizadeh, Ebrahim; Lak, Marziyeh

2012-01-01

Surgical procedures performed using spinal anesthetic techniques present a special challenge to anesthesiologists, because patients are awake and are exposed to multiple anxiety provoking visual and auditory stimuli. Therefore, this study was carried out to define the effect of music on the level of cortisol, blood glucose and physiological variables in patients under spinal anesthesia. In this semi-experimental research, 90 men aging from 18-48 years with ASA (acetylsalicylic acid) class I, who underwent urological and abdominal surgery, were investigated. Patients were divided randomly into three groups of thirty subjects. Music group (headphone with music), Silence group (headphone without music) and the control group (without interference). The level of cortisol and blood sugar was measured half an hour before and after the operation. Moreover, the physiological indicators in each of these three groups were monitored and recorded from ten minutes before getting spinal anesthesia to ten minutes after the operation. The level of blood cortisol didn't have any increase in the music group after operation compared to the time before that. However, in the groups of silence and control this level had risen (p< 0.05). The level of blood glucose in music group had declined and in the other two groups it had increased. Our data showed that listening to music during surgery under regional anesthesia has effects on cortisol levels and some of the physiological variables. Therefore the researcher offers to be used music therapy as a complementary method in patients on the reduce anxiety.

[Application of variable magnetic fields in medicine--15 years experience].

PubMed

Sieroń, Aleksander; Cieślar, Grzegorz

2003-01-01

The results of 15-year own experimental and clinical research on application of variable magnetic fields in medicine were presented. In experimental studies analgesic effect (related to endogenous opioid system and nitrogen oxide activity) and regenerative effect of variable magnetic fields with therapeutical parameters was observed. The influence of this fields on enzymatic and hormonal activity, free oxygen radicals, carbohydrates, protein and lipid metabolism, dielectric and rheological properties of blood as well as behavioural reactions and activity of central dopamine receptor in experimental animals was proved. In clinical studies high therapeutic efficacy of magnetotherapy and magnetostimulation in the treatment of osteoarthrosis, abnormal ossification, osteoporosis, nasosinusitis, multiple sclerosis, Parkinson's disease, spastic paresis, diabetic polyneuropathy and retinopathy, vegetative neurosis, peptic ulcers, colon irritable and trophic ulcers was confirmed.

Assessing national provision of care: variability in bariatric clinical care pathways.

PubMed

Telem, Dana A; Majid, Saniea F; Powers, Kinga; DeMaria, Eric; Morton, John; Jones, Daniel B

2017-02-01

The American Society for Metabolic and Bariatric Surgery (ASMBS) Quality Improvement and Patient Safety (QIPS) Committee hypothesized that collecting and sharing clinical pathways could provide a valuable resource to new and existing bariatric programs. To shed light on the variability in practice patterns across the country by analyzing pathways. United States Centers of Excellence METHODS: From June 2014 to April 2015, clinical pathways pertaining to preoperative, intraoperative, and postoperative management of bariatric patients were solicited from the ASMBS executive council (EC), QIPS committee members, and state chapter presidents. Pathways were de-identified and then analyzed based on predetermined metrics pertaining to preoperative, intraoperative, and postoperative care. Concordance and discordance were then analyzed. In total, 31 pathways were collected; response rate was 80% from the EC, 77% from the QIPS committee, and 21% from state chapter presidents. The number of pathways sent in ranged from 1 to 10 with a median of 3 pathways per individual or institution. The majority of pathways centered on perioperative care (80%). Binary assessment (presence or absence) of variables found a high concordance (defined by greater than 65% of pathways accounting for that parameter) in only 6 variables: nutritional evaluation, psychological evaluation, intraoperative venous thromboembolism (VTE) prophylaxis, utilization of antiemetics in the postoperative period, a dedicated pain pathway, and postoperative laboratory evaluation. There is considerable national variation in clinical pathways among practicing bariatric surgeons. Most pathways center on Metabolic and Bariatric Surgery Accredited Quality Improvement Program (MBSAQIP) accreditation parameters, patient satisfaction, or Surgical Care Improvement Protocol (SCIP) measures. These pathways provide a path toward standardization of improved care. Copyright © 2016. Published by Elsevier Inc.

Variability of mammary blood flow in lactating Holstein-Friesian cows during the first twelve weeks of lactation.

PubMed

Götze, A; Honnens, A; Flachowsky, G; Bollwein, H

2010-01-01

The goals of the present study were to measure mammary blood flow volume (BFV) during the first 12 wk of lactation in dairy cows by using color Doppler sonography and to determine what affects the mammary blood flow. Forty cows were examined via color Doppler sonography on d 1, 7, 14, 28, 56, and 84 after parturition (d 0). The total BFV (BFV(total)) to the 4 mammary glands was calculated by measuring time-averaged maximum velocities (TAMV) and cross-sectional areas (A) of the left and right pudendoepigastric trunks via transrectal color Doppler sonography. Because there were no significant differences in A, TAMV, and BFV between the right and left pudendoepigastric trunks, the means of A and TAMV, and the BFV(total) of both trunks were used for calculations. The intraindividual and interindividual variability of repeated BFV measures quantified by intraclass correlation coefficients were 96 and 98%, respectively. The BFV(total) ranged from 19.9 to 27.9 L/min, with a mean of 22.3+/-4.9 L/min. Interindividual differences in BFV values were attributable to variations in A and TAMV. The interindividual variability of the BFV(total), which was determined using the coefficients of variation of the BFV(total) on individual days, ranged from 16 to 28%. All the cows had similar changes in the BFV(total) during the study. Changes in BFV(total) were not correlated with changes in the mean of A, but there was a good correlation between changes in BFV(total) and in the mean of TAMV (r=0.94). The BFV(total) was highest on d 1 of lactation, decreased 28% by d 7, and remained at this level until d 28. By d 56, the BFV(total) had increased by 15% compared with d 14 and by 10% compared with d 28. The BFV(total) on d 84 was significantly different from all other days except d 56. There were moderate correlations between daily milk yield and BFV on individual days (0.24blood flow in the pudendoepigastric

Practices for Identifying and Rejecting Hemolyzed Specimens Are Highly Variable in Clinical Laboratories.

PubMed

Howanitz, Peter J; Lehman, Christopher M; Jones, Bruce A; Meier, Frederick A; Horowitz, Gary L

2015-08-01

Hemolysis is an important clinical laboratory quality attribute that influences result reliability. To determine hemolysis identification and rejection practices occurring in clinical laboratories. We used the College of American Pathologists Survey program to distribute a Q-Probes-type questionnaire about hemolysis practices to Chemistry Survey participants. Of 3495 participants sent the questionnaire, 846 (24%) responded. In 71% of 772 laboratories, the hemolysis rate was less than 3.0%, whereas in 5%, it was 6.0% or greater. A visual scale, an instrument scale, and combination of visual and instrument scales were used to identify hemolysis in 48%, 11%, and 41% of laboratories, respectively. A picture of the hemolysis level was used as an aid to technologists' visual interpretation of hemolysis levels in 40% of laboratories. In 7.0% of laboratories, all hemolyzed specimens were rejected; in 4% of laboratories, no hemolyzed specimens were rejected; and in 88% of laboratories, some specimens were rejected depending on hemolysis levels. Participants used 69 different terms to describe hemolysis scales, with 21 terms used in more than 10 laboratories. Slight and moderate were the terms used most commonly. Of 16 different cutoffs used to reject hemolyzed specimens, moderate was the most common, occurring in 30% of laboratories. For whole blood electrolyte measurements performed in 86 laboratories, 57% did not evaluate the presence of hemolysis, but for those that did, the most common practice in 21 laboratories (24%) was centrifuging and visually determining the presence of hemolysis in all specimens. Hemolysis practices vary widely. Standard assessment and consistent reporting are the first steps in reducing interlaboratory variability among results.

Improving blood pressure control in diabetes: limitations of a clinical reminder in influencing physician behavior.

PubMed

Sanders, Karen M; Satyvavolu, Anuradha

2002-01-01

Hypertension should be aggressively treated, especially in diabetic patients. But studies of physician prescribing habits reveal that physicians often delay making medication changes or initiating antihypertensive therapy. A chart-based reminder was designed to improve physician medication prescribing in this clinical situation. A randomized controlled trial was conducted at the Veterans Affairs Medical Center in Richmond, Virginia. Patients with diabetes and hypertension were selected. A highly visible chart reminder was applied to the front of outpatient charts in the intervention group practice. A chart review was conducted to assess physician-directed medication changes. A successful outcome was defined as any antihypertensive medication increase or addition at that same visit. Physicians were more likely to intensify antihypertensive medication as the blood pressure increased regardless of the reminder. Overall, only 33% of visits resulted in a medication change, even though 93% of patients had elevations over target blood pressure at the follow-up visit. Physicians in the intervention and control groups made changes to medication at similar rates (chi 2 = 0.621, p = .511). In this study, a chart reminder failed to improve physician compliance with the clinical guideline for hypertension management in diabetics, Sixth Report of the Joint National Committee on the Detection, Evaluation, Prevention and Treatment of High Blood Pressure. To inform the design of effective intervention strategies, further research should explore specific barriers to guideline adherence in this clinical situation.

A simple set for ıntrauterine fetal blood transfusion constructed by readily available materials in every clinic.

PubMed

Keskin, Uğur; Karasahin, Kazim Emre; Ulubay, Mustafa; Fidan, Ulaş; Gungor, Sadettin; Ergun, Ali

2015-11-01

Intrauterine fetal transfusion needs extensive experience and requires excellent eye-hand coordination, good equipment and experienced team workers to achieve success. While the needle is in the umbilical vein, an assistant withdraws and/or transfuses blood. The needle point should be kept still to prevent lacerations and dislodging. We propose a simple set for Intrauterine Fetal blood transfusion is constructed by readily available materials in every clinic to minimize needle tip movement and movements during syringe attachments and withdrawals during the intrauterine fetal transfusion. This makes possible to withdraw fetal blood sample, and to transfuse blood with minimal intervention.

Protocol for a prospective collaborative systematic review and meta-analysis of individual patient data from randomized controlled trials of vasoactive drugs in acute stroke: The Blood pressure in Acute Stroke Collaboration, stage-3.

PubMed

Sandset, Else Charlotte; Sanossian, Nerses; Woodhouse, Lisa J; Anderson, Craig; Berge, Eivind; Lees, Kennedy R; Potter, John F; Robinson, Thompson G; Sprigg, Nikola; Wardlaw, Joanna M; Bath, Philip M

2018-01-01

Rationale Despite several large clinical trials assessing blood pressure lowering in acute stroke, equipoise remains particularly for ischemic stroke. The "Blood pressure in Acute Stroke Collaboration" commenced in the mid-1990s focussing on systematic reviews and meta-analysis of blood pressure lowering in acute stroke. From the start, Blood pressure in Acute Stroke Collaboration planned to assess safety and efficacy of blood pressure lowering in acute stroke using individual patient data. Aims To determine the optimal management of blood pressure in patients with acute stroke, including both intracerebral hemorrhage and ischemic stroke. Secondary aims are to assess which clinical and therapeutic factors may alter the optimal management of high blood pressure in patients with acute stroke and to assess the effect of vasoactive treatments on hemodynamic variables. Methods and design Individual patient data from randomized controlled trials of blood pressure management in participants with ischemic stroke and/or intracerebral hemorrhage enrolled during the ultra-acute (pre-hospital), hyper-acute (<6 h), acute (<48 h), and sub-acute (<168 h) phases of stroke. Study outcomes The primary effect variable will be functional outcome defined by the ordinal distribution of the modified Rankin Scale; analyses will also be carried out in pre-specified subgroups to assess the modifying effects of stroke-related and pre-stroke patient characteristics. Key secondary variables will include clinical, hemodynamic and neuroradiological variables; safety variables will comprise death and serious adverse events. Discussion Study questions will be addressed in stages, according to the protocol, before integrating these into a final overreaching analysis. We invite eligible trials to join the collaboration.

[Analysis of 24-hour blood pressure profile, heart rate variability and carotid atherosclerosis in hypertensive patients among native and nonnative population living in Yamalo-Nenets autonomous district].

PubMed

Gapon, L I; Sereda, T V; Leont'eva, A V

2014-01-01

To study special characteristics of the course of arterial hypertension (AH) among native and nonnative population of Yamalo-Nenets autonomous district. We examined 100 residents of Far North with AH (men and women aged 21-55, mean age 44.08 ± 1.15 years). All patients were divided into 2 equal groups by 50 subjects: group I consisted of representatives of native and group II--nonnative population. Examination was carried out in outpatient clinic in Salekhard and included 24-hour ambulatory blood pressure monitoring (ABPM), registration of heart rate variability, duplex scanning of brachiocephalic arteries, and assessment of blood lipid profile. The groups were matched by age, gender and disease duration. Analysis of heart rate variability detected significant degree of strain of regulatory systems in most patients of both groups. According to results of ABPM "non-dipper" patients prevailed in group I compared to group II (p = 0.01). Common carotid artery intima-media complex was significantly greater compared to normal value in all patients; it was thicker in group I (p < 0.03), but number of carotid artery stenoses was similar in both groups. No dyslipoproteinemia was detected. Compared with group of representatives of nonnative (adopted) population group of native subjects with AH was characterized by greater carotid intima media thickness and prevalence of "non-dipper" patients.

Low heart rate variability in patients with clinical burnout.

PubMed

Lennartsson, Anna-Karin; Jonsdottir, Ingibjörg; Sjörs, Anna

2016-12-01

Several studies have shown that acute psychosocial stress and chronic psychosocial stress reduce heart rate variability (HRV). It is likely that individuals suffering from burnout have reduced HRV, as a consequence of the long-term stress exposure. This study investigated HRV in 54 patients with clinical burnout (40 women and 14 men) and in 55 individuals reporting low burnout scores (healthy; 24 women and 31 men) and 52 individuals reporting high burnout scores (non-clinical burnout; 33 women and 19 men). The participants underwent a 300s ECG recording in the supine position. Standard deviation of normal R-R intervals (SDNN) and the root mean square of successive normal interval differences (RMSSD) were derived from time domain HRV analysis. Frequency domain HRV measures; total power (TP), low frequency power (LF), high frequency power (HF), and LF/HF ratio were calculated. All HRV measures, except LF/HF ratio, were lower in the clinical burnout patients compared to both the non-clinical burnout group and the healthy group. The difference was larger between the patients and the healthy group than between the patients and the non-clinical burnout group. HRV did not differ significantly between the non-clinical burnout group and the healthy group. Low HRV in burnout patients may constitute one of the links to associated adverse health, since low HRV reflects low parasympathetic activity - and accordingly low anabolic/regenerative activity. Copyright © 2016 Elsevier B.V. All rights reserved.

[The blood glucose value not necessarily indicates correctly the cellular metabolic state].

PubMed

Simon, Kornél; Wittmann, István

2017-03-01

In clinical recommendations the normalized blood glucose level is declared as the main target in therapy of diabetes mellitus, i.e. the achievement of euglycemia is the main therapeutic goal. This approach suggests, that the normal blood glucose value is the marker of the normal carbohydrate metabolism (eumetabolism), and vice versa: hyperglycemia is associated with abnormal metabolism (dysmetabolism). However the question arises, whether identical blood glucose values do reflect the same intracellular biochemical mechanisms? On the basis of data published in the literature authors try to answer these questions by studying the relations between the short/longterm blood glucose level and the cellular metabolism in different clinical settings characterized by divergent pathophysiological parameters. The correlations between blood glucose level and cellular metabolism in development of micro-, and macroangiopathy, in the breakthrough phenomenon, as well as during administration of metabolic promoters, the discrepancies of relation between blood glucose values and cellular metabolism in type 1, and type 2 diabetes mellitus, furthermore association between blood glucose value and myocardial metabolism in acute and chronic stress were analyzed. Authors conclude, that the actual blood glucose values reveal the actual cellular metabolism in a very variable manner: neither euglycemia does mandatorily indicate eumetabolism (balance of cellular energy production), nor hyperglycemia is necessarily a marker of abnormal metabolic state (dept of cellular energy production). Moreover, at the same actual blood glucose level both the metabolic efficacy of the same organ may sharply vary, and the intracellular biochemical machinery could also be very different. In case of the very same longterm blood glucose level the metabolic state of the different organs could be very variable: some organs show an energetically balanced metabolism, while others produce a significant deficit. These

The National Blood Service. Supporting better blood transfusion.

PubMed

Gerrard, Rebecca

2004-05-01

The National Blood Service (NBS) is an integral part of the National Health Service that provides blood, blood components, blood products and tissues from fifteen blood centres to England and North Wales. Each year, the NBS collects tests, processes, stores and issues approximately 2.3 million blood donations. The service also undertakes research into blood safety, provides clinical advice to hospital staff and supports hospital transfusion practitioners. Rebecca Gerrard describes some of the initiatives to improve blood transfusion practices, including monitoring of the serious hazards of transfusion, bench marking schemes and the roles of blood transfusion liaison (BTL) nurses.

Variations from morning to afternoon of middle cerebral and umbilical artery blood flow, and fetal heart rate variability, and fetal characteristics in the normally developing fetus.

PubMed

Avitan, Tehila; Sanders, Ari; Brain, Ursula; Rurak, Dan; Oberlander, Tim F; Lim, Ken

2018-05-01

To determine if there are changes in maternal uterine blood flow, fetal brain blood flow, fetal heart rate variability, and umbilical blood flow between morning (AM) and afternoon (PM) in healthy, uncomplicated pregnancies. In this prospective study, 68 uncomplicated singleton pregnancies (mean 35 + 0.7 weeks gestation) underwent a standard observational protocol at both 08:00 (AM) and 13:30 (PM) of the same day. This protocol included Doppler measurements of uterine, umbilical, and fetal middle cerebral artery (MCA) volume flow parameters (flow, HR, peak systolic velocity [PSV], PI, and RI) followed by computerized cardiotocography. Standard descriptive statistics, χ 2 and t tests were used where appropriate. P < .05 was considered significant. A significant increase in MCA flow and MCA PSV was observed in the PM compared to the AM. This was accompanied by a fall in MCA resistance. Higher umbilical artery resistance indices were also observed in the PM compared to AM. In contrast, fetal heart rate characteristics, maternal uterine artery Doppler flow and resistance indices did not vary significantly between the AM and PM. In normal pregnancies, variations in fetal cerebral and umbilical blood flow parameters were observed between AM and PM independent of other fetal movements or baseline fetal heart rate. In contrast, uterine flow parameters remained stable across the day. These findings may have implications for the use of serial Doppler parameters used to guide clinical management in high-risk pregnancies. © 2017 Wiley Periodicals, Inc.

Muscle pH, rigor mortis and blood variables in Atlantic salmon transported in two types of well-boat.

PubMed

Gatica, M C; Monti, G E; Knowles, T G; Gallo, C B

2010-01-09

Two systems for transporting live salmon (Salmo salar) were compared in terms of their effects on blood variables, muscle pH and rigor index: an 'open system' well-boat with recirculated sea water at 13.5 degrees C and a stocking density of 107 kg/m3 during an eight-hour journey, and a 'closed system' well-boat with water chilled from 16.7 to 2.1 degrees C and a stocking density of 243.7 kg/m3 during a seven-hour journey. Groups of 10 fish were sampled at each of four stages: in cages at the farm, in the well-boat after loading, in the well-boat after the journey and before unloading, and in the processing plant after they were pumped from the resting cages. At each sampling, the fish were stunned and bled by gill cutting. Blood samples were taken to measure lactate, osmolality, chloride, sodium, cortisol and glucose, and their muscle pH and rigor index were measured at death and three hours later. In the open system well-boat, the initial muscle pH of the fish decreased at each successive stage, and at the final stage they had a significantly lower initial muscle pH and more rapid onset of rigor than the fish transported on the closed system well-boat. At the final stage all the blood variables except glucose were significantly affected in the fish transported on both types of well-boat.

Heart Rate and Systolic Blood Pressure Variability in the Time Domain in Patients with Recent and Long-Standing Diabetes Mellitus

PubMed Central

Rivera, Ana Leonor; Estañol, Bruno; Sentíes-Madrid, Horacio; Fossion, Ruben; Toledo-Roy, Juan C.; Mendoza-Temis, Joel; Morales, Irving O.; Landa, Emmanuel; Robles-Cabrera, Adriana; Moreno, Rene; Frank, Alejandro

2016-01-01

Diabetes Mellitus (DM) affects the cardiovascular response of patients. To study this effect, interbeat intervals (IBI) and beat-to-beat systolic blood pressure (SBP) variability of patients during supine, standing and controlled breathing tests were analyzed in the time domain. Simultaneous noninvasive measurements of IBI and SBP for 30 recently diagnosed and 15 long-standing DM patients were compared with the results for 30 rigorously screened healthy subjects (control). A statistically significant distinction between control and diabetic subjects was provided by the standard deviation and the higher moments of the distributions (skewness, and kurtosis) with respect to the median. To compare IBI and SBP for different populations, we define a parameter, α, that combines the variability of the heart rate and the blood pressure, as the ratio of the radius of the moments for IBI and the same radius for SBP. As diabetes evolves, α decreases, standard deviation of the IBI detrended signal diminishes (heart rate signal becomes more “rigid”), skewness with respect to the median approaches zero (signal fluctuations gain symmetry), and kurtosis increases (fluctuations concentrate around the median). Diabetes produces not only a rigid heart rate, but also increases symmetry and has leptokurtic distributions. SBP time series exhibit the most variable behavior for recently diagnosed DM with platykurtic distributions. Under controlled breathing, SBP has symmetric distributions for DM patients, while control subjects have non-zero skewness. This may be due to a progressive decrease of parasympathetic and sympathetic activity to the heart and blood vessels as diabetes evolves. PMID:26849653

Heart Rate and Systolic Blood Pressure Variability in the Time Domain in Patients with Recent and Long-Standing Diabetes Mellitus.

PubMed

Rivera, Ana Leonor; Estañol, Bruno; Sentíes-Madrid, Horacio; Fossion, Ruben; Toledo-Roy, Juan C; Mendoza-Temis, Joel; Morales, Irving O; Landa, Emmanuel; Robles-Cabrera, Adriana; Moreno, Rene; Frank, Alejandro

2016-01-01

Diabetes Mellitus (DM) affects the cardiovascular response of patients. To study this effect, interbeat intervals (IBI) and beat-to-beat systolic blood pressure (SBP) variability of patients during supine, standing and controlled breathing tests were analyzed in the time domain. Simultaneous noninvasive measurements of IBI and SBP for 30 recently diagnosed and 15 long-standing DM patients were compared with the results for 30 rigorously screened healthy subjects (control). A statistically significant distinction between control and diabetic subjects was provided by the standard deviation and the higher moments of the distributions (skewness, and kurtosis) with respect to the median. To compare IBI and SBP for different populations, we define a parameter, α, that combines the variability of the heart rate and the blood pressure, as the ratio of the radius of the moments for IBI and the same radius for SBP. As diabetes evolves, α decreases, standard deviation of the IBI detrended signal diminishes (heart rate signal becomes more "rigid"), skewness with respect to the median approaches zero (signal fluctuations gain symmetry), and kurtosis increases (fluctuations concentrate around the median). Diabetes produces not only a rigid heart rate, but also increases symmetry and has leptokurtic distributions. SBP time series exhibit the most variable behavior for recently diagnosed DM with platykurtic distributions. Under controlled breathing, SBP has symmetric distributions for DM patients, while control subjects have non-zero skewness. This may be due to a progressive decrease of parasympathetic and sympathetic activity to the heart and blood vessels as diabetes evolves.

[Infective endocarditis in intensive cardiac care unit - clinical and biochemical differences of blood-culture negative infective endocarditis].

PubMed

Kaziród-Wolski, Karol; Sielski, Janusz; Ciuraszkiewicz, Katarzyna

2017-01-23

Diagnosis and treatment of infective endocarditis (IE) is still a challenge for physicians. Group of patients with the worst prognosis is treated in Intensive Cardiac Care Unit (ICCU). Etiologic agent can not be identified in a substantial number of patients. The aim of study is to find differences between patients with blood culture negative infective endocarditis (BCNIE) and blood culture positive infective endocarditis (BCPIE) treated in ICCU by comparing their clinical course and laboratory parameters. Retrospective analysis of 30 patients with IE hospitalized in ICCU Swietokrzyskie Cardiac Centre between 2010 and 2016. This group consist of 26 men (86,67%) and 4 women (13,3%). Mean age was 58 years ±13. Most of the cases were new disease, recurrence of the disease was observed in 2 cases (6,7%). 8 patients (26,7%) required artificial ventilation, 11 (36,7%) received inotropes and 6 (20%) vasopresors. In 14 (46,7%) cases blood cultures was negative (BCNIE), the rest of patients (16, 53,3%) was blood cultures - positive infective endocarditis (BCIE). Both of the groups were clinically similar. There were no statistically significant differences in incidence of cardiac implants, localization of bacterial vegetations, administered catecholamines, antibiotic therapy, artificial ventilation, surgical treatment, complication and in-hospital mortality. Incidence of cardiac complications in all of BCNIE cases and in 81,3% cases of BCPIE draws attention, but it is not statistically significant difference (p=0,08). There was statistically significant difference in mean BNP blood concentration (3005,17 ng/ml ±2045,2 vs 1013,42 ng/ml ±1087,6; p=0,01), but there were no statistically significant differences in rest of laboratory parameters. BCNIE group has got higher mean BNP blood concentration than BCPIE group. There were no statistically significant differences between these groups in others laboratory parameters, clinical course and administered antibiotic therapy

Return behavior of occasional and multigallon blood donors: the role of theory of planned behavior, self-identity, and organizational variables.

PubMed

Wevers, Anne; Wigboldus, Daniël H J; van Baaren, Rick; Veldhuizen, Ingrid J T

2014-03-01

For blood establishments it is important that blood donors return for a donation. Past research has stressed the importance of theory of planned behavior (TPB) on return behavior, but self-identity (SI) and organizational variables (OVs) might play a role as well. This study added SI and OVs to the TPB to identify the determinants for return behavior. Whole blood donors (n = 2005) completed a questionnaire assessing TPB, SI, and OVs. OVs contained "perceived satisfaction with the blood bank" and "feeling pressure from the blood bank to donate blood." Return behavior over the past 2 years was dichotomized as low return (0%-50%) versus high return (51%-100%). Logistic regression analyses assessed the effects of TPB, SI, and OVs on high return, separately for occasional donors (two to 10 lifetime donations) and multigallon donors (>10 lifetime donations). Results showed that, for all donors, affective attitude was positively associated with return behavior, whereas pressure to donate blood was negatively associated with return behavior. The point estimates of self-efficacy, SI, and perceived satisfaction are high for multigallon donors, but do not reach significance. For all donors, positive feelings about donating blood stimulate return behavior, while experiencing a pressure to donate blood emanating from the blood bank was not beneficial. Results suggest that multigallon donors are more stimulated to return when they score higher on self-efficacy, SI, and perceived satisfaction. Interventions aiming at donor retention need to be carefully formulated to avoid negative effects of feeling pressure to donate blood. © 2013 American Association of Blood Banks.

Assessment of published models and prognostic variables in epithelial ovarian cancer at Mayo Clinic

PubMed Central

Hendrickson, Andrea Wahner; Hawthorne, Kieran M.; Goode, Ellen L.; Kalli, Kimberly R.; Goergen, Krista M.; Bakkum-Gamez, Jamie N.; Cliby, William A.; Keeney, Gary L.; Visscher, Dan W.; Tarabishy, Yaman; Oberg, Ann L.; Hartmann, Lynn C.; Maurer, Matthew J.

2015-01-01

Objectives Epithelial ovarian cancer (EOC) is an aggressive disease in which first line therapy consists of a surgical staging/debulking procedure and platinum based chemotherapy. There is significant interest in clinically applicable, easy to use prognostic tools to estimate risk of recurrence and overall survival. In this study we used a large prospectively collected cohort of women with EOC to validate currently published models and assess prognostic variables. Methods Women with invasive ovarian, peritoneal, or fallopian tube cancer diagnosed between 2000-2011 and prospectively enrolled into the Mayo Clinic Ovarian Cancer registry were identified. Demographics and known prognostic markers as well as epidemiologic exposure variables were abstracted from the medical record and collected via questionnaire. Six previously published models of overall and recurrence-free survival were assessed for external validity. In addition, predictors of outcome were assessed in our dataset. Results Previously published models validated with a range of c-statistics (0.587-0.827), though application of models containing variables not part of routine practice were somewhat limited by missing data; utilization of all applicable models and comparison of results is suggested. Examination of prognostic variables identified only the presence of ascites and ASA score to be independent predictors of prognosis in our dataset, albeit with marginal gain in prognostic information, after accounting for stage and debulking. Conclusions Existing prognostic models for newly diagnosed EOC showed acceptable calibration in our cohort for clinical application. However, modeling of prospective variables in our dataset reiterates that stage and debulking remain the most important predictors of prognosis in this setting. PMID:25620544

Twelve hour reproducibility of choroidal blood flow parameters in healthy subjects

PubMed Central

Polska, E; Polak, K; Luksch, A; Fuchsjager-Mayrl, G; Petternel, V; Findl, O; Schmetterer, L

2004-01-01

Aims/background: To investigate the reproducibility and potential diurnal variation of choroidal blood flow parameters in healthy subjects over a period of 12 hours. Methods: The choroidal blood flow parameters of 16 healthy non-smoking subjects were measured at five time points during the day (8:00, 11:00, 14:00, 17:00, and 20:00). Outcome parameters were pulsatile ocular blood flow as assessed by pneumotonometry, fundus pulsation amplitude as assessed by laser interferometry, blood velocities in the opthalmic and posterior ciliary arteries as assessed by colour Doppler imaging, and choroidal blood flow, volume, and velocity as assessed by fundus camera based laser Doppler flowmetry. The coefficient of variation and the maximum change from baseline in an individual were calculated for each outcome parameter. Results: None of the techniques used found a diurnal variation in choroidal blood flow. Coefficients of variation were within 2.9% and 13.6% for all outcome parameters. The maximum change from baseline in an individual was much higher, ranging from 11.2% to 58.8%. Conclusions: These data indicate that in healthy subjects the selected techniques provide adequate reproducibility to be used in clinical studies. Variability may, however, be considerably higher in older subjects or subjects with ocular disease. The higher individual differences in flow parameter readings limit the use of the techniques in clinical practice. To overcome problems with measurement validity, a clinical trial should include as many choroidal blood flow outcome parameters as possible to check for consistency. PMID:15031172

[Abnormality of blood coagulation indexes in patients with de novo acute leukemia and its clinical significance].

PubMed

Xiao, Fang-Fang; Hu, Kai-Xun; Guo, Mei; Qiao, Jian-Hui; Sun, Qi-Yun; Ai, Hui-Sheng; Yu, Chang-Lin

2013-04-01

To explore hemorrhage risk and the clinical significance of abnormal change of prothrombin time (PT), activated partial thromboplastin time (APTT), plasma fibrinogen (FIB), plasma thrombin time (TT) and d-dimer (D-D) in de novo acute leukemia (except for APL), the different bleeding manifestations of 114 cases of de novo acute leukemia with different coagulation indexes were analyzed retrospectively. The correlation between these blood coagulation indexes and the possible correlative clinical characteristics were analysed, including age, sex, type of acute leukemia, initial white blood cell(WBC) and platelet(Plt) count, the proportion of blast cells in bone marrow and cytogenetic abnormality of patients at diagnosis. The results indicated that the incidence of abnormal blood coagulation was as high as 78.1% for de novo AL patients. These patients with 5 normal blood coagulation indexes may have mild bleeding manifestation, but the more abnormal indexes, the more severe bleeding. Both PT and D-D were sensitive indexes for diagnosis of level II bleeding. Incidence of abnormal blood coagulation significantly correlates with the proportion of blast cells in bone marrow (χ(2) = 4.184, OR = 1.021, P < 0.05) and more with D-D (P < 0.01), while age, sex, type of AL, WBC count, Plt count and abnormality of cytogenetics did not correlate with abnormal blood coagulation. It is concluded that the coagulation and fibrinolysis are abnormal in most patients with de novo acute leukemia. More abnormal indexes indicate more severe bleeding, and both PT and D-D are sensitive indexes for diagnosis of level II bleeding. Higher proportion of blast cells in bone marrow predicts higher incidence of abnormal blood clotting. Acute leukemia with elderly age, high white blood cell count and adverse cytogenetics do not predict severer abnormal blood clotting. Detection of PT, APTT, TT, FIB, and D-D may help to judge whether the patients are in a state of hypercoagulability or disseminated

Effect of physical variables on capture of magnetic nanoparticles in simulated blood vessels

NASA Astrophysics Data System (ADS)

Zhang, Minghui; Brazel, Christopher

2011-11-01

This study investigated how the percent capture of magnetic nanoparticles in a simulated vessel varies with physical variables. Magnetic nanoparticles (MNPs) can used as part of therapeutic or diagnostic materials for cancer patients. By capturing these devices with a magnetic field, the particles can be concentrated in an area of diseased tissue. In this study, flow of nanoparticles in simulated blood vessels was used to determine the affect of applying an external magnetic field. This study used maghemite nanoparticles as the MNPs and either water or Fetal Bovine Serum as the carrier fluid. A UV-Vis collected capture data. The percent capture of MNPs was positively influenced by five physical variables: larger vessel diameters, lower linear flow velocity, higher magnetic field strength, better dispersion, lower MNP concentration, and lower protein content in fluid. Free MNPs were also compared to micelles, with the free particles having more successful magnetic capture. Four factors contributed to these trends: the strength of the magnetic field's influence on the MNPs, the MNPs' interactions with other particles and the fluid, the momentum of the nanoparticles, and magnetic mass to total mass ratio of the flowing particles. Funded by NSF REU Site #1062611.

Reciprocal Interaction of 24-Hour Blood Pressure Variability and Systolic Blood Pressure on Outcome in Stroke Thrombolysis.

PubMed

Kellert, Lars; Hametner, Christian; Ahmed, Niaz; Rauch, Geraldine; MacLeod, Mary J; Perini, Francesco; Lees, Kennedy R; Ringleb, Peter A

2017-07-01

Significance and management of blood pressure (BP) changes in acute stroke care are unclear. Here, we aimed to investigate the impact of 24-hour BP variability (BPV) on outcome in patients with acute ischemic stroke treated with intravenous thrombolysis. From the Safe Implementation of Treatment in Stroke International Stroke Thrombolysis registry, 28 976 patients with documented pre-treatment systolic BP at 2 and 24 hours were analyzed. The primary measure of BP variability was successive variability. Data were preprocessed using coarsened exact matching. We assessed early neurological improvement, symptomatic intracerebral hemorrhage (SICH), and long-term functional outcome (modified Rankin Scale [mRS] at 90 days) by binary and ordinal regression analyses. Attempts to explain successive variation for analysis of BPV with patients characteristics at admission found systolic BP (5.5% variance) to be most influential, yet 92% of BPV variance remained unexplained. Independently from systolic BP, successive variation for analysis of BPV was associated with poor functional outcome mRS score of 0 to 2 (odds ratio [OR], 0.94; 95% confidence interval [CI], 0.90-0.98), disadvantage across the shift of mRS (OR, 1.04; 95% CI, 1.01-1.08), mortality (OR, 1.10; 95% CI, 1.01-1.08), SICH SITS (OR, 1.14; 95% CI, 1.06-1.23), and SICH ECASS (OR, 1.24; 95% CI, 1.10-1.40; ECASS [European Cooperative Acute Stroke Study 2]). Analyzing successive variation for analysis of BPV as a function of pre-treatment, systolic BP significantly improved the prediction of functional outcome (mRS score of 0-1, mRS score of 0-2, neurological improvement, mRS-shift: all P interaction <0.01). Excluding patients with atrial fibrillation in a sensitivity analysis gave consistent results overall. This study suggests the need for a more individual BP management accounting for pre-treatment BP and the acute BP course (ie, BPV) to achieve best possible outcome for the patient. © 2017 American Heart

Harmonization of blood-based indicators of iron status: making the hard work matter.

PubMed

Hoofnagle, Andrew N

2017-12-01

Blood-based indicators that are used in the assessment of iron status are assumed to be accurate. In practice, inaccuracies in these measurements exist and stem from bias and variability. For example, the analytic variability of serum ferritin measurements across laboratories is very high (>15%), which increases the rate of misclassification in clinical and epidemiologic studies. The procedures that are used in laboratory medicine to minimize bias and variability could be used effectively in clinical research studies, particularly in the evaluation of iron deficiency and its associated anemia in pregnancy and early childhood and in characterizing states of iron repletion and excess. The harmonization and standardization of traditional and novel bioindicators of iron status will allow results from clinical studies to be more meaningfully translated into clinical practice by providing a firm foundation for clinical laboratories to set appropriate cutoffs. In addition, proficiency testing monitors the performance of the methods over time. It is important that measures of iron status be evaluated, validated, and performed in a manner that is consistent with standard procedures in laboratory medicine. © 2017 American Society for Nutrition.

Comparison of the clinical information provided by the FreeStyle Navigator continuous interstitial glucose monitor versus traditional blood glucose readings.

PubMed

McGarraugh, Geoffrey V; Clarke, William L; Kovatchev, Boris P

2010-05-01

The purpose of the analysis was to compare the clinical utility of data from traditional self-monitoring of blood glucose (SMBG) to that of continuous glucose monitoring (CGM). A clinical study of the clinical accuracy of the FreeStyle Navigator CGM System (Abbott Diabetes Care, Alameda, CA), which includes SMBG capabilities, was conducted by comparison to the YSI blood glucose analyzer (YSI Inc., Yellow Springs, OH) using 58 subjects with type 1 diabetes. The Continuous Glucose-Error Grid Analysis (CG-EGA) was used as the analytical tool. Using CG-EGA, the "clinically accurate," "benign errors," and "clinical errors" were 86.8%, 8.7%, and 4.5% for SMBG and 92.7%, 3.7%, and 3.6% for CGM, respectively. If blood glucose is viewed as a process in time, SMBG would provide accurate information about this process 86.8% of the time, whereas CGM would provide accurate information about this process 92.7% of the time (P < 0.0001). In the hypoglycemic range, however, SMBG is more accurate as the "clinically accurate," "benign errors," and "clinical errors" were 83.5%, 6.4%, and 10.1% for SMBG and 57.1%, 8.4%, and 34.5% (P < 0.0001) for CGM, respectively. While SMBG produces more accurate instantaneous glucose values than CGM, control of blood glucose involves a system in flux, and CGM provides more detailed insight into the dynamics of that system. In the normal and elevated glucose ranges, the additional information about the direction and rate of glucose change provided by the FreeStyle Navigator CGM System increases the ability to make correct clinical decisions when compared to episodic SMBG tests.

The prognostic blood biomarker proadrenomedullin for outcome prediction in patients with chronic obstructive pulmonary disease (COPD): a qualitative clinical review.

PubMed

Schuetz, Philipp; Marlowe, Robert J; Mueller, Beat

2015-03-01

Plasma proadrenomedullin (ProADM) is a blood biomarker that may aid in multidimensional risk assessment of patients with chronic obstructive pulmonary disease (COPD). Co-secreted 1:1 with adrenomedullin (ADM), ProADM is a less biologically active, more chemically stable surrogate for this pluripotent regulatory peptide, which due to biological and ex vivo physical characteristics is difficult to reliably directly quantify. Upregulated by hypoxia, inflammatory cytokines, bacterial products, and shear stress and expressed widely in pulmonary cells and ubiquitously throughout the body, ADM exerts or mediates vasodilatory, natriuretic, diuretic, antioxidative, anti-inflammatory, antimicrobial, and metabolic effects. Observational data from four separate studies totaling 1366 patients suggest that as a single factor, ProADM is a significant independent, and accurate, long-term all-cause mortality predictor in COPD. This body of work also suggests that combined with different groups of demographic/clinical variables, ProADM provides significant incremental long-term mortality prediction power relative to the groups of variables alone. Additionally, the literature contains indications that ProADM may be a global cardiopulmonary stress marker, potentially supplying prognostic information when cardiopulmonary exercise testing results such as 6-min walk distance are unavailable due to time or other resource constraints or to a patient's advanced disease. Prospective, randomized, controlled interventional studies are needed to demonstrate whether ProADM use in risk-based guidance of site-of-care, monitoring, and treatment decisions improves clinical, quality-of-life, or pharmacoeconomic outcomes in patients with COPD.

Morphological analysis of red blood cells by polychromatic interference microscopy of thin films

NASA Astrophysics Data System (ADS)

Dyachenko, A. A.; Malinova, L. I.; Ryabukho, V. P.

2016-11-01

Red blood cells (RBC) distribution width (RDW) is a promising hematological parameter with broadapplications in clinical practice; in various studies RDWhas been shown to be associated with increased risk of heart failure (HF) in general population. It predicts mortality and other major adverse events in HF patients. In this report new method of RDWmeasurement is presented. It's based on interference color analysis of red blood cells in blood smear and further measurement of its optical thickness. Descriptive statistics of the of the RBC optical thickness distribution in a blood smear were used for RDW estimation in every studied sample. Proposed method is considered to be avoiding type II errors and minimizing the variability of measured RDW.

Platelet-rich plasma differs according to preparation method and human variability.

PubMed

Mazzocca, Augustus D; McCarthy, Mary Beth R; Chowaniec, David M; Cote, Mark P; Romeo, Anthony A; Bradley, James P; Arciero, Robert A; Beitzel, Knut

2012-02-15

Varying concentrations of blood components in platelet-rich plasma preparations may contribute to the variable results seen in recently published clinical studies. The purposes of this investigation were (1) to quantify the level of platelets, growth factors, red blood cells, and white blood cells in so-called one-step (clinically used commercial devices) and two-step separation systems and (2) to determine the influence of three separate blood draws on the resulting components of platelet-rich plasma. Three different platelet-rich plasma (PRP) separation methods (on blood samples from eight subjects with a mean age [and standard deviation] of 31.6 ± 10.9 years) were used: two single-spin processes (PRPLP and PRPHP) and a double-spin process (PRPDS) were evaluated for concentrations of platelets, red and white blood cells, and growth factors. Additionally, the effect of three repetitive blood draws on platelet-rich plasma components was evaluated. The content and concentrations of platelets, white blood cells, and growth factors for each method of separation differed significantly. All separation techniques resulted in a significant increase in platelet concentration compared with native blood. Platelet and white blood-cell concentrations of the PRPHP procedure were significantly higher than platelet and white blood-cell concentrations produced by the so-called single-step PRPLP and the so-called two-step PRPDS procedures, although significant differences between PRPLP and PRPDS were not observed. Comparing the results of the three blood draws with regard to the reliability of platelet number and cell counts, wide variations of intra-individual numbers were observed. Single-step procedures are capable of producing sufficient amounts of platelets for clinical usage. Within the evaluated procedures, platelet numbers and numbers of white blood cells differ significantly. The intra-individual results of platelet-rich plasma separations showed wide variations in

Variable clinical presentations of secondary delusional infestation: an experience of six cases from a psychodermatology clinic.

PubMed

Altunay, Ilknur K; Ates, Bilge; Mercan, Sibel; Demirci, Gulsen Tukenmez; Kayaoglu, Semra

2012-01-01

Delusional Infestation (DI) is a relatively rare condition with a fixed belief of being infested with living organisms, despite a lack of medical evidence of such infestation. Although it seems to be a psychiatric disease, patients commonly are admitted to dermatology clinics because of skin findings. Psychiatrists can underestimate its prevalance, whereas dermatologists can miss the diagnosis. It should be managed as a psychodermatological disease. Our aim in the study was to evaluate six patients with different clinical presentations of DI and to emphasize some clinical features. All patients were internalized in the psychodermatology clinic for this study. Medical history and clinical data from dermatologic and psychiatric examinations were noted; Mini International Neuropsychiatric Interview (MINI-Plus) and laboratory investigations including blood and urine analyses, microscopic analysis of so-called pathogens, and skin biopsy if needed, were performed. The diagnosis was made based on detailed history, dermatologic and psychiatric examinations, and laboratory investigations. All patients had symptoms of itching, burning, or crawling sensations dermatologically and thus were admitted to dermatology clinic. They were all considered secondary DI to another medical condition or to psychiatric illness. Vitamin B12 deficiency, diabetes, and hypothyroidism were the underlying medical conditions. Related psychiatric illnesses were trichotillomania and schizoaffective disorder, schizophrenia, shared pychotic disorder, and brief psychotic disorder. Two patients had delusions of inanimate materials; four patients had partial and complete remissions; and two patients have dropped out. Each patient had different clinical characteristics creating diagnostic challenges. All complaints were related to the infestation of the skin. The presence of different psychiatric comorbidities is remarkable. It seems that both psychiatrists and dermatologists can face diagnostic and

Comparison of haematology, coagulation and clinical chemistry parameters in blood samples from the sublingual vein and vena cava in Sprague-Dawley rats.

PubMed

Seibel, J; Bodié, K; Weber, S; Bury, D; Kron, M; Blaich, G

2010-10-01

The investigation of clinical pathology parameters (haematology, clinical chemistry and coagulation) is an important part of the preclinical evaluation of drug safety. However, the blood sampling method employed should avoid or minimize stress and injury in laboratory animals. In the present study, we compared the clinical pathology results from blood samples collected terminally from the vena cava (VC) immediately before necropsy with samples taken from the sublingual vein (VS) also prior to necropsy in order to determine whether the sampling method has an influence on clinical pathology parameters. Forty-six 12-week-old male Sprague-Dawley rats were assigned to two groups (VC or VS; n = 23 each). All rats were anaesthetized with isoflurane prior to sampling. In the VC group, blood was withdrawn from the inferior VC. For VS sampling, the tongue was gently pulled out and the VS was punctured. The haematology, coagulation and clinical chemistry parameters were compared. Equivalence was established for 13 parameters, such as mean corpuscular volume, white blood cells and calcium. No equivalence was found for the remaining 26 parameters, although they were considered to be similar when compared with the historical data and normal ranges. The most conspicuous finding was that activated prothrombin time was 30.3% less in blood taken from the VC (16.6 ± 0.89 s) than that in the VS samples (23.8 ± 1.58 s). Summing up, blood sampling from the inferior VC prior to necropsy appears to be a suitable and reliable method for terminal blood sampling that reduces stress and injury to laboratory rats in preclinical drug safety studies.

Clinical variables related to antidepressant-induced mania in bipolar disorder.

PubMed

Mundo, Emanuela; Cattaneo, Elisabetta; Russo, Michela; Altamura, A Carlo

2006-06-01

The development of mania or hypomania during antidepressant treatment is a serious complication of the clinical management of bipolar disorder (BP). The primary aim of this study was to evaluate the clinical variables related to antidepressant-induced mania or hypomania (AIM) in patients with BP. DSM-IV BP-I or BP-II patients who had had at least one depressive episode treated with antidepressants were considered. Patients were subdivided into two groups according to the presence (n = 30) or absence (n = 106) of manic or hypomanic episodes occurring during antidepressant treatment. Possible predictive clinical variables of AIM were considered: gender, diagnostic subtype, age at onset, duration of illness, duration of untreated illness, type of antidepressant administered, number of previous spontaneous hypomanic or manic episodes, number of previous depressive episodes, presence of lifetime suicide attempts, presence of mood stabilizer treatments, presence of psychotic symptoms during spontaneous episodes, family history for psychiatric disorders in first degree relatives. Data were compared between the two groups, with (AIM+) and without (AIM-) antidepressant-induced mania, using Student's t tests and chi-square tests. The lack of mood stabilizer treatments during antidepressant therapy (chi-square = 37.602, df = 1, p < 0.001) and the exposure to tricyclic antidepressants (chi-square = 4.901, df = 1, p < 0.05) resulted significantly associated to the development of AIM. This study was not done under controlled conditions and the relatively small sample studied warrants further replications. These results point out the risk of mania induction associated to the use of tricyclic antidepressants in BP patients, mainly in absence of adequate mood stabilizers.

Clinical Applications of Near-infrared Diffuse Correlation Spectroscopy and Tomography for Tissue Blood Flow Monitoring and Imaging

PubMed Central

Shang, Yu; Li, Ting; Yu, Guoqiang

2017-01-01

Blood flow is one such available observable promoting a wealth of physiological insight both individually and in combination with other metrics. Near-infrared diffuse correlation spectroscopy (DCS) and, to a lesser extent, diffuse correlation tomography (DCT), have increasingly received interest over the past decade as noninvasive methods for tissue blood flow measurements and imaging. DCS/DCT offers several attractive features for tissue blood flow measurements/imaging such as noninvasiveness, portability, high temporal resolution, and relatively large penetration depth (up to several centimeters). This review first introduces the basic principle and instrumentation of DCS/DCT, followed by presenting clinical application examples of DCS/DCT for the diagnosis and therapeutic monitoring of diseases in a variety of organs/tissues including brain, skeletal muscle, and tumor. Clinical study results demonstrate technical versatility of DCS/DCT in providing important information for disease diagnosis and intervention monitoring. PMID:28199219

[Arterial hypertension, antihypertensive therapy, and visit-to-visit blood pressure variability of elderly nursing home residents].

PubMed

Könner, F; Kuhnert, R; Budnick, A; Kolloch, R; Scholze, J; Dräger, D; Kreutz, R

2014-11-01

Arterial hypertension is a common health problem in older nursing home residents (NHR). The aim of this study was to prospectively analyze blood pressure (BP) patterns, antihypertensive therapy, and visit-to-visit BP variability in NHR. BP, visit-to-visit variability (estimated by standard deviation of means) of systolic BP (SBP) were analyzed in 12 nursing homes in Germany. NHR who were at least 65 years old and had no moderate or severe dementia were studied at baseline (T0), after 3 and 6 months, respectively. BP data were available for 177 NHR (mean age 83.8, 69.5% female) at T0.  A total of 90.4% NHR was affected by hypertension. Mean systolic/diastolic blood pressure was 130,1/75,5 mmHg. BP values of ≥ 140/90 mmHg were found in 29.9%, while 33.9% of NHR exhibited SBP values < 120 mmHg. At least one antihypertensive drug was used in 84.2%, and 40.7% of NHR were treated with at least three different drugs. The median of the visit-to-visit SBP variability was 9.05 (Min. 0, Max. 35.78); an influence of age, sex, and type of antihypertensive medication was not found. Elderly German NHR showed a high prevalence of hypertension and BP was controlled in 80%. However, a large proportion received intensive BP lowering pharmacotherapy and exhibited SBP values clearly lower than recommend target values between 140 and 150 mmHg particularly for elderly patients over 80 years. Thus, to avoid overtreatment BP should be monitored closely to adapt antihypertensive therapy in this population. © Georg Thieme Verlag KG Stuttgart · New York.

[Descriptive study of ambulatory blood pressure monitoring in the Primary Care Nursing clinic].

PubMed

Garzón-Quiñones, Marina; Gallardo-Gonzalo, Cristina; Padín-Minaya, Cristina; López-Pisa, Rosa M; Rodríguez-Latre, Luisa M

2013-01-01

To analyze the clinical characteristics and the circadian patterns of patients who received ambulatory blood pressure monitoring (ABPM) by a Primary Care Team. A descriptive, observational, cross-sectional study at community level. People older than 18 years on ABPM (2007-2011). demographic, cardiovascular disease, diabetes mellitus, cardiovascular risk factors, any type of arterial hypertension and circadian pattern. Intruments of measurement: 2 validated instruments with comparable results were used. The instruments for ABPM were placed during the nursing visit. The instruments were then removed after 24h, and the data was retrieved and recorded in the computerized clinical history. A total of 326 people were studied, with a mean age of 60.53±12.96 years, of whom 56.7% were male. According to ABPM the patient results showed that: 38.5% had «white coat» arterial hypertension, 36.2% were classified as poorly controlled arterial hypertension, 17.2% had masked hypertension, and 8% with isolated hypertension. Dipper circadian patterns were present in 39.6% of patients and non- dipper in 60.4%. ABPM allows to Primary Health Care professionals to check the actual situation of the blood pressure over 24h and analyze the circadian pattern. In clinical practice this involves having a comprehensive care strategy on life style, as well as adherence to treatment. Copyright © 2013 Elsevier España, S.L. All rights reserved.

Performance of the Colson MAM BP 3AA1-2 automatic blood pressure monitor according to the European Society of Hypertension validation protocol.

PubMed

Pereira, Telmo; Maldonado, João

2005-11-01

To evaluate the performance of the Colson MAM BP 3AA1-2 oscillometric automatic blood pressure monitor according to the validation protocol of the European Society of Hypertension, testing its suitability for self-measurement of blood pressure. The performance of the device was assessed in relation to various clinical variables, including age, gender, body mass index, arm circumference and arterial stiffness. 33 subjects (15 men and 18 women), with a mean age of 47 +/- 10 years, were studied according to the procedures laid down in the European Society of Hypertension validation protocol. Sequential same-arm blood pressure measurements were made, alternating between a mercury standard and the automatic device. The differences among the test-control measurements were assessed and divided into categorization zones of 5, 10 and 15 mmHg discrepancy. Aortic pulse wave velocity was assessed in all subjects with a Complior device (Colson, Paris). The Colson MAM BP 3AA1-2 passed all three phases of the protocol for both systolic and diastolic blood pressure. The mean differences between the test and control measurements were -1.0 +/- 5.0 mmHg for systolic blood pressure and -1.1 +/- 4.1 mmHg for diastolic blood pressure. Both standard deviations are well below the 8 mmHg limit proposed by the Association for the Advancement of Medical Instrumentation. The predictive value of various clinical variables for the discrepancies was assessed by a regression model analysis, with no variable being found that independently undermined the performance of the monitor. In another regression analysis, we found a similar relation between test and control blood pressures and aortic pulse wave velocity, a widely recognized and validated index of target organ damage. These data show that the Colson MAM BP 3AA1-2 satisfies the quality requirements proposed by the European Society of Hypertension, demonstrating its suitability for inclusion in integrated programs of clinical surveillance

Undergraduate Nurse Variables that Predict Academic Achievement and Clinical Competence in Nursing

ERIC Educational Resources Information Center

Blackman, Ian; Hall, Margaret; Darmawan, I Gusti Ngurah.

2007-01-01

A hypothetical model was formulated to explore factors that influenced academic and clinical achievement for undergraduate nursing students. Sixteen latent variables were considered including the students' background, gender, type of first language, age, their previous successes with their undergraduate nursing studies and status given for…

Positron-emitting myocardial blood flow tracers and clinical potential.

PubMed

Schindler, Thomas H

2015-01-01

Positron-emitting myocardial flow radiotracers such as (15)O-water, (13)N-ammonia and (82)Rubidium in conjunction with positron-emission-tomography (PET) are increasingly applied in clinical routine for coronary artery disease (CAD) detection, yielding high diagnostic accuracy, while providing valuable information on cardiovascular (CV) outcome. Owing to a cyclotron dependency of (15)O-water and (13)N-ammonia, their clinical use for PET myocardial perfusion imaging is limited to a few centers. This limitation could be overcome by the increasing use of (82)Rubidium as it can be eluted from a commercially available (82)Strontium generator and, thus, is independent of a nearby cyclotron. Another novel F-18-labeled myocardial flow radiotracer is flurpiridaz which has attracted increasing interest due to its excellent radiotracer characteristics for perfusion and flow imaging with PET. In particular, the relatively long half-life of 109 minutes of flurpiridaz may afford a general application of this radiotracer for PET perfusion imaging comparable to technetium-99m-labeled single-photon emission computed tomography (SPECT). The ability of PET in conjunction with several radiotracers to assess myocardial blood flow (MBF) in ml/g/min at rest and during vasomotor stress has contributed to unravel pathophysiological mechanisms underlying coronary artery disease (CAD), to improve the detection and characterization of CAD burden in multivessel disease, and to provide incremental prognostic information in individuals with subclinical and clinically-manifest CAD. The concurrent evaluation of myocardial perfusion and MBF may lead to a new era of a personalized, image-guided therapy approach that may offer potential to further improve clinical outcome in CV disease patients but needing validation in large-scale clinical trials. Copyright © 2015 Elsevier Inc. All rights reserved.

Arterial blood pressure estimation using ultrasound: Clinical results on healthy volunteers and a medicated hypertensive volunteer.

PubMed

Zakrzewski, Aaron M; Anthony, Brian W

2017-07-01

This study presents a non-occlusive and non-invasive ultrasound-based technique to measure blood pressure. Most popular clinically-used arterial blood pressure measurement techniques suffer from important weaknesses including being inaccurate, invasive, or occlusive. In the proposed technique, an ultrasound probe is placed on the patient's carotid artery and the contact force between the probe and the tissue is slowly increased while ultrasound images and contact force data are recorded. From this data, the artery is segmented and the segmentation data is sent into an optimization procedure; after post-processing, blood pressure is displayed to the user. This technique was applied to 24 healthy single-visit volunteers, one multi-visit healthy volunteer, and one multi-visit medicated hypertensive volunteer. Compared to the oscillometric cuff, the accuracy and precision of the algorithm-reported systolic pressure is -2.4 ± 10.2 mmHg, and for diastolic pressure is -0.3 ± 8.2 mmHg. This method has the potential to occupy a clinical middle-ground between the arterial catheter and the oscillometric cuff.

Incidence of postoperative hypothermia and the relationship to clinical variables.

PubMed

Burns, Shari M; Piotrowski, Kathy; Caraffa, Guy; Wojnakowski, Mary

2010-10-01

A prospective, quantitative, correlational study was conducted to determine the incidence of postoperative hypothermia and the relationship of hypothermia to numerous clinical variables previously studied. The study reflects the researchers' interest in updating previous data regarding the incidence of hypothermia. Although hypothermia remains a significant clinical concern, interventions aimed at minimizing hypothermia have evolved over the past 20 years, thus prompting new interest in determining the extent to which hypothermia exists in today's PACU patients. A convenience sample of 287 adult, nonemergency patients scheduled for surgery were included in the study. Hypothermia (temperature <36°C) was demonstrated in only 4% of the sample (N = 287). Because of the low incidence of hypothermia, correlation statistics were not performed. The study provides a foundation for future research regarding this important clinical phenomenon while offering evidence supporting efforts to avoid hypothermia in today's surgical patients. Copyright © 2010 American Society of PeriAnesthesia Nurses. Published by Elsevier Inc. All rights reserved.

Effect of intensive versus standard clinic-based hypertension management on ambulatory blood pressure – results from the SPRINT ambulatory blood pressure study

PubMed Central

Drawz, Paul; Pajewski, Nicholas M.; Bates, Jeffrey T.; Bello, Natalie A.; Cushman, William C.; Dwyer, Jamie P.; Fine, Lawrence J.; Goff, David C.; Haley, William E.; Krousel-Wood, Marie; McWilliams, Andrew; Rifkin, Dena E.; Slinin, Yelena; Taylor, Addison; Townsend, Raymond; Wall, Barry; Wright, Jackson T.; Rahman, Mahboob

2016-01-01

The effect of clinic-based intensive hypertension treatment on ambulatory blood pressure (BP) is unknown. The goal of the Systolic Blood Pressure Intervention Trial (SPRINT) Ambulatory BP Ancillary Study was to evaluate the effect of intensive versus standard clinic-based BP targets on ambulatory BP. Ambulatory BP was obtained within 3 weeks of the 27 month study visit in 897 SPRINT participants. Intensive treatment resulted in lower clinic systolic BP (mean difference between groups = 16.0 mmHg (95% CI: 14.1 to 17.8 mmHg)), nighttime systolic BP (mean difference = 9.6 mmHg (95% CI: 7.7 to 11.5 mmHg)), daytime systolic BP (mean difference = 12.3 mmHg (95% CI: 10.6 to 13.9 mmHg)), and 24 hour systolic BP (mean difference = 11.2 mmHg (95% CI: 9.7 to 12.8 mmHg)). The night/day systolic BP ratio was similar between the intensive (0.92 ± 0.09) and standard treatment groups (0.91 ± 0.09). There was considerable lack of agreement within participants between clinic systolic BP and daytime ambulatory systolic BP with wide limits of agreement on Bland-Altman plots. In conclusion, targeting a systolic BP of less than 120 mmHg, as compared with less than 140 mmHg, resulted in lower nighttime, daytime, and 24 hour systolic BP, but did not change the night/day systolic BP ratio. Ambulatory BP monitoring may be required to assess the effect of targeted hypertension therapy on out of office BP. Further studies are needed to assess whether targeting hypertension therapy based on ambulatory BP improves clinical outcomes. PMID:27849563

Reliability of blood color and blood gases in discriminating arterial from venous puncture during cardiopulmonary resuscitation.

PubMed

Park, Je Sung; Lee, Byung Kook; Jeung, Kyung Woon; Choi, Sung Soo; Park, Sang Wook; Song, Kyung Hwan; Lee, Sung Min; Heo, Tag; Min, Yong Il

2015-04-01

We investigated the use of blood color brightness and blood gas variables for discriminating arterial from venous puncture during cardiopulmonary resuscitation (CPR). The study's aims were to determine if discrimination using Po2 is superior to using blood color brightness, and if blood color brightness, Po2, and acid-base variables derived from blood gas analysis accurately discriminate arterial from venous blood during CPR. Fifteen pigs underwent ventricular fibrillation followed by CPR. During CPR, paired femoral arterial and venous blood samples were obtained, and 2 blinded observers were asked to identify the blood's origin. Blood color brightness was measured using a blood brightness scale (BBS). The discriminatory performances of the BBS and blood gas variables were evaluated by calculating the area under receiver operating characteristic curves (AUC). The observers accurately discriminated arterial from venous blood with a sensitivity of 97.0% (84.7%-99.5%) and specificity of 84.9% (69.1%-93.4%). The BBS (AUC = 0.983) and Po2 (AUC = 0.981) methods both showed comparable and excellent discriminatory performances. pH, Pco2, and HCO3(-) all discriminated arterial from venous blood (AUC = 0.831, 0.971, and 0.652, respectively). The AUC for Pco2 was comparable to that for Po2 but significantly larger than that for pH (P = .002) or HCO3(-) (P < .001). The BBS and Po2 methods showed comparable and excellent discrimination performances. Using pH, Pco2, and HCO3(-) levels also discriminated arterial from venous blood during CPR with statistical significance. Copyright © 2015 Elsevier Inc. All rights reserved.

Large-scale clinical comparison of the lysis-centrifugation and radiometric systems for blood culture

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brannon, P.; Kiehn, T.E.

1985-12-01

The Isolator 10 lysis-centrifugation blood culture system (E. I. du Pont de Nemours and Co., Inc., Wilmington, Del.) was compared with the BACTEC radiometric method (Johnston Laboratories, Inc., Towson, Md.) with 6B and 7D broth media for the recovery of bacteria and yeasts. From 11,000 blood cultures, 1,174 clinically significant organisms were isolated. The Isolator system recovered significantly more total organisms, members of the family Enterobacteriaceae, Staphylococcus spp., and yeasts. The BACTEC system recovered significantly more Pseudomonas spp., Streptococcus spp., and anaerobes. Of the Isolator colony counts, 87% measured less than 11 CFU/ml of blood. Organisms, on an average, weremore » detected the same day from each of the two culture systems. Only 13 of the 975 BACTEC isolates (0.01%) were recovered by subculture of growth-index-negative bottles, and 12 of the 13 were detected in another broth blood culture taken within 24 h. Contaminants were recovered from 4.8% of the Isolator 10 and 2.3% of the BACTEC cultures.« less

Integrated Blood Barcode Chips

PubMed Central

Fan, Rong; Vermesh, Ophir; Srivastava, Alok; Yen, Brian K.H.; Qin, Lidong; Ahmad, Habib; Kwong, Gabriel A.; Liu, Chao-Chao; Gould, Juliane; Hood, Leroy; Heath, James R.

2008-01-01

Blood comprises the largest version of the human proteome1. Changes of plasma protein profiles can reflect physiological or pathological conditions associated with many human diseases, making blood the most important fluid for clinical diagnostics2-4. Nevertheless, only a handful of plasma proteins are utilized in routine clinical tests. This is due to a host of reasons, including the intrinsic complexity of the plasma proteome1, the heterogeneity of human diseases and the fast kinetics associated with protein degradation in sampled blood5. Simple technologies that can sensitively sample large numbers of proteins over broad concentration ranges, from small amounts of blood, and within minutes of sample collection, would assist in solving these problems. Herein, we report on an integrated microfluidic system, called the Integrated Blood Barcode Chip (IBBC). It enables on-chip blood separation and the rapid measurement of a panel of plasma proteins from small quantities of blood samples including a fingerprick of whole blood. This platform holds potential for inexpensive, non-invasive, and informative clinical diagnoses, particularly, for point-of-care. PMID:19029914

[Population characteristics and impact on heart rate variability, heart rate and blood pressure of passive smoking].

PubMed

Zhao, Jing; He, Fei; Hu, Da-yi; Ding, Rong-jing; Yu, Xiao-jun; Wang, Long; Zhang, Ping; Li, Xue-bin; Guo, Ji-hong; Liu, Wen-ling; Li, Cui-lan; Li, Lei; Gao, Chuan-yu; Zhao, Luo-sha; Chu, Ying-jie; Huang, Zhen-wen; Wei, Jing-han; Hua, Shao-hua; Liu, Rui-yun; Zhuang, Xiao-feng

2013-05-01

To investigate the basic characteristics of passive smoking population, and the impact of passive smoking on heart rate variability, heart rate and blood pressure. Eighty-six passive smokers [mean age: (52.4 ± 7.6) years] were recruited from patients and their relatives who visited cardiovascular outpatient department and excluded structural heart disease between June 2010 and June 2012, 80 normal subjects who were not exposed to smoking served as controls. Questionnaire survey, 24 hours ambulatory electrocardiogram examination and blood pressure measurement were performed in all recruited subjects. (1) Non-marriage rate [18.60% (16/86) vs. 3.75% (3/80), P < 0.01] was significantly higher while education level were significantly lower in passive smoking group than in control group. Passive smokers were more likely service industry workers [29.07% (25/86) vs. 15.00% (12/80), P < 0.05] and had longer daily working time [(7.56 ± 1.24) h vs. (6.02 ± 0.96) h, P < 0.01], and were less likely to be professional technology industry employers [20.93% (18/86) vs. 36.25% (29/80), P < 0.05] and managers [13.95% (12/86) vs. 38.75% (31/80), P < 0.01] compared to controls. The main place of passive smoking was workplace (67.44%, 58/86), entertainment venues (63.95%,55/86), restaurants (48.84%, 42/86). (2) Standard of the normal sinus RR intervals (SDNN), the normal consecutive sinus RR interval difference between the root-mean-square (rMSSD) and adjacent the difference between the RR interval>50 ms the number of share the percentage (PNN50) were significantly lower in passive smoking group than in the control group (all P < 0.05). Every 5 min average of the standard deviation of sinus RR cycle (SDNN index) and 24 h every 5 min sinus RR interval mean standard deviation (SDANN) were similar between the 2 groups (all P > 0.05). Ultra-low-frequency power (VLF), low frequency power (LF), high frequency power (HF) and LF/HF were significantly lower in passive smoking group than in

Umbilical Arterial Blood Sampling Alters Cerebral Tissue Oxygenation in Very Low Birth Weight Neonates.

PubMed

Mintzer, Jonathan P; Parvez, Boriana; La Gamma, Edmund F

2015-11-01

To evaluate the magnitude, consistency, and natural history of reductions in cerebral regional tissue oxygenation (CrSO2) during umbilical arterial (UA) blood sampling in very low birth weight neonates. Data were collected during a prospective observational near-infrared spectroscopy survey conducted on a convenience sample of 500-1250 g neonates during the first 10 postnatal days. A before-after analysis of UA blood sampling effects on CrSO2 absolute values and variability was performed. The present analysis was not designed a priori and was conducted following the bedside observation of CrSO2 decrements contiguous with UA blood draws. Fifteen very low birth weight neonates had 201 UA blood draws. Baseline CrSO2 (mean ± SEM) decreased following UA blood sampling, from 70 ± 1% to a nadir of 63 ± 1% (P < .001) occurring 4 ± 3 (range 2-24) minutes following blood draws. CrSO2 subsequently increased to 70 ± 1% (P < .001 compared with nadir) at 10 ± 4 (range 4-28) minutes following UA blood sampling. Coefficients of variation (mean ± SEM) increased from 0.02 ± 0.001 at baseline to 0.05 ± 0.004 (P < .001), followed by a decrease to 0.03 ± 0.003 (P < .001 for all comparisons), thus denoting increased CrSO2 variability following UA blood sampling. UA blood sampling is associated with significant CrSO2 decrements with increased variability over clinically significant intervals. Whether these changes impact complications of prematurity, including intraventricular hemorrhage and periventricular leukomalacia, remain unknown. Copyright © 2015 Elsevier Inc. All rights reserved.

Quality assurance of clinical transfusion practice by implementation of the privilege of blood prescription and computerized prospective audit of blood requests.

PubMed

Marconi, M; Almini, D; Pizzi, M N; Riccardi, D; Bergamaschi, W; Giovanetti, A M; Rebulla, P; Sirchia, G

1996-03-01

Guidelines, algorithms and recommendations have been issued in the attempt to ensure appropriateness of transfusion practice, but the results are less than satisfactory, mainly due to the difficulty to turn paper procedures into actual practice. In our hospital we have tried to overcome this difficulty through the implementation of a quality assurance programme which includes giving the privilege of nonurgent blood prescription to a limited number of physicians and a computerized prospective audit of blood requests. The latter is performed through verification of the compliance of blood requests, which are designed to include a patient's laboratory and clinical data, with hospital guidelines for the proper use of blood. In the 12 months since implementation of the computerized prospective audit the transfusion service has evaluated 7884 requests. Of these, 63.4% (n = 4998) were for red blood cells, 21.1% (n = 1664) for platelets and 15.5% (n = 1222) for fresh frozen plasma. The prospective audit showed that 96.8% and 98.1% of requests for red units and platelets were appropriate, respectively. Conversely, approximately 27% of plasma requests did not comply with guidelines, mainly because the evidence of coagulopathy was missing. However, inappropriateness of plasma requests for elective general surgery decreased from 39% at the onset of the programme to 14% in the last trimester considered. Moreover, the evaluation by retrospective audit of the proportion of patients transfused with both red blood cells and plasma in the perioperative period out of those transfused with red blood cells only, as an indicator of unwanted reconstitution of whole blood, showed that this proportion decreased from 47.6% (320/672) in the 12 months before implementation of computerized audit to 37.8% (244/646) in the following 12 months (difference = -9.8%, 95% confidence interval of the difference from -4.5% to -15.1%; P < 0.005 by chi 2 test). Our initial experience, together with the

Diagnostic accuracy of routine blood examinations and CSF lactate level for post-neurosurgical bacterial meningitis.

PubMed

Zhang, Yang; Xiao, Xiong; Zhang, Junting; Gao, Zhixian; Ji, Nan; Zhang, Liwei

2017-06-01

To evaluate the diagnostic accuracy of routine blood examinations and Cerebrospinal Fluid (CSF) lactate level for Post-neurosurgical Bacterial Meningitis (PBM) at a large sample-size of post-neurosurgical patients. The diagnostic accuracies of routine blood examinations and CSF lactate level to distinguish between PAM and PBM were evaluated with the values of the Area Under the Curve of the Receiver Operating Characteristic (AUC -ROC ) by retrospectively analyzing the datasets of post-neurosurgical patients in the clinical information databases. The diagnostic accuracy of routine blood examinations was relatively low (AUC -ROC <0.7). The CSF lactate level achieved rather high diagnostic accuracy (AUC -ROC =0.891; CI 95%, 0.852-0.922). The variables of patient age, operation duration, surgical diagnosis and postoperative days (the interval days between the neurosurgery and examinations) were shown to affect the diagnostic accuracy of these examinations. The variables were integrated with routine blood examinations and CSF lactate level by Fisher discriminant analysis to improve their diagnostic accuracy. As a result, the diagnostic accuracy of blood examinations and CSF lactate level was significantly improved with an AUC -ROC value=0.760 (CI 95%, 0.737-0.782) and 0.921 (CI 95%, 0.887-0.948) respectively. The PBM diagnostic accuracy of routine blood examinations was relatively low, whereas the accuracy of CSF lactate level was high. Some variables that are involved in the incidence of PBM can also affect the diagnostic accuracy for PBM. Taking into account the effects of these variables significantly improves the diagnostic accuracies of routine blood examinations and CSF lactate level. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Contribution of the autonomic nervous system to blood pressure and heart rate variability changes in early experimental hyperthyroidism.

PubMed

Safa-Tisseront, V; Ponchon, P; Laude, D; Elghozi, J L

1998-07-10

A great deal of uncertainty persists regarding the exact nature of the interaction between autonomic nervous system activity and thyroid hormones in the control of heart rate and blood pressure. We now report on thyrotoxicosis produced by daily intraperitoneal (i.p.) injection of L-thyroxine (0.5 mg/kg body wt. in 1 ml of 5 mM NaOH for 5 days). Control rats received i.p. daily injections of the thyroxine solvent. In order to estimate the degree of autonomic activation in hyperthyroidism, specific blockers were administered intravenously: atropine (0.5 mg/kg), prazosin (1 mg/kg), atenolol (1 mg/kg) or the combination of atenolol and atropine. A jet of air was administered in other animals to induce sympathoactivation. Eight animals were studied in each group. The dose and duration of L-thyroxine treatment was sufficient to induce a significant degree of hyperthyroidism with accompanying tachycardia, systolic blood pressure elevation, increased pulse pressure, cardiac hypertrophy, weight loss, tachypnea and hyperthermia. In addition, the intrinsic heart period observed after double blockade (atenolol + atropine) was markedly decreased after treatment with L-thyroxine (121.5+/-3.6 ms vs. 141.2+/-3.7 ms, P < 0.01). Of the autonomic indices, vagal tone (difference between heart period obtained after atenolol and intrinsic heart period) was negatively linearly related to intrinsic heart period (r = 0.71, P < 0.05). Atenolol modified neither the heart period nor blood pressure variability in rats with hyperthyroidism and in these rats the jet of air did not significantly affect the heart period level. The thyrotoxicosis was associated with a reduction of the 0.4 Hz component of blood pressure variability (analyses on 102.4 s segments, modulus 1.10+/-0.07 vs. 1.41+/-0.06 mm Hg, P < 0.01) and prazosin was without effect on this 0.4 Hz component in these animals. These data show a functional diminution of the vascular and cardiac sympathetic tone in early experimental

A Comparison and Calibration of a Wrist-Worn Blood Pressure Monitor for Patient Management: Assessing the Reliability of Innovative Blood Pressure Devices

PubMed Central

Melville, Sarah; Teskey, Robert; Philip, Shona; Simpson, Jeremy A; Lutchmedial, Sohrab

2018-01-01

Background Clinical guidelines recommend monitoring of blood pressure at home using an automatic blood pressure device for the management of hypertension. Devices are not often calibrated against direct blood pressure measures, leaving health care providers and patients with less reliable information than is possible with current technology. Rigorous assessments of medical devices are necessary for establishing clinical utility. Objective The purpose of our study was 2-fold: (1) to assess the validity and perform iterative calibration of indirect blood pressure measurements by a noninvasive wrist cuff blood pressure device in direct comparison with simultaneously recorded peripheral and central intra-arterial blood pressure measurements and (2) to assess the validity of the measurements thereafter of the noninvasive wrist cuff blood pressure device in comparison with measurements by a noninvasive upper arm blood pressure device to the Canadian hypertension guidelines. Methods The cloud-based blood pressure algorithms for an oscillometric wrist cuff device were iteratively calibrated to direct pressure measures in 20 consented patient participants. We then assessed measurement validity of the device, using Bland-Altman analysis during routine cardiovascular catheterization. Results The precalibrated absolute mean difference between direct intra-arterial to wrist cuff pressure measurements were 10.8 (SD 9.7) for systolic and 16.1 (SD 6.3) for diastolic. The postcalibrated absolute mean difference was 7.2 (SD 5.1) for systolic and 4.3 (SD 3.3) for diastolic pressures. This is an improvement in accuracy of 33% systolic and 73% diastolic with a 48% reduction in the variability for both measures. Furthermore, the wrist cuff device demonstrated similar sensitivity in measuring high blood pressure compared with the direct intra-arterial method. The device, when calibrated to direct aortic pressures, demonstrated the potential to reduce a treatment gap in high blood

Quantifying temporal glucose variability in diabetes via continuous glucose monitoring: mathematical methods and clinical application.

PubMed

Kovatchev, Boris P; Clarke, William L; Breton, Marc; Brayman, Kenneth; McCall, Anthony

2005-12-01

Continuous glucose monitors (CGMs) collect detailed blood glucose (BG) time series, which carry significant information about the dynamics of BG fluctuations. In contrast, the methods for analysis of CGM data remain those developed for infrequent BG self-monitoring. As a result, important information about the temporal structure of the data is lost during the translation of raw sensor readings into clinically interpretable statistics and images. The following mathematical methods are introduced into the field of CGM data interpretation: (1) analysis of BG rate of change; (2) risk analysis using previously reported Low/High BG Indices and Poincare (lag) plot of risk associated with temporal BG variability; and (3) spatial aggregation of the process of BG fluctuations and its Markov chain visualization. The clinical application of these methods is illustrated by analysis of data of a patient with Type 1 diabetes mellitus who underwent islet transplantation and with data from clinical trials. Normative data [12,025 reference (YSI device, Yellow Springs Instruments, Yellow Springs, OH) BG determinations] in patients with Type 1 diabetes mellitus who underwent insulin and glucose challenges suggest that the 90%, 95%, and 99% confidence intervals of BG rate of change that could be maximally sustained over 15-30 min are [-2,2], [-3,3], and [-4,4] mg/dL/min, respectively. BG dynamics and risk parameters clearly differentiated the stages of transplantation and the effects of medication. Aspects of treatment were clearly visualized by graphs of BG rate of change and Low/High BG Indices, by a Poincare plot of risk for rapid BG fluctuations, and by a plot of the aggregated Markov process. Advanced analysis and visualization of CGM data allow for evaluation of dynamical characteristics of diabetes and reveal clinical information that is inaccessible via standard statistics, which do not take into account the temporal structure of the data. The use of such methods improves the

Phosphoglucomutase-1 deficiency: Intrafamilial clinical variability and common secondary adrenal insufficiency.

PubMed

Loewenthal, Neta; Haim, Alon; Parvari, Ruti; Hershkovitz, Eli

2015-12-01

Phosphoglucomutase 1 (PGM1, EC 5.4.2.2) plays a critical role in glucose homeostasis and is also essential for protein N-glycosylation. The main clinical manifestations of PGM1 deficiency (MIM 614921) reported in 19 patients from different ethnic backgrounds include the following: cleft uvula/palate, Pierre Robin sequence, muscle weakness, dilated cardiomyopathy, growth retardation, elevated serum transaminases, hypoglycemia, and various endocrine abnormalities. We report the variable clinical picture of seven patients with PGM1 deficiency from a consanguineous family. Medical records of the patients were reviewed for clinical details and endocrine evaluation. Whole exome sequencing (WES) was performed. Seven patients aged 2-29 years were included, one patient died at 13 years old when getting off the school bus. All patients have an abnormal palatine structure (cleft palate, bifid uvula) and elevated serum transaminases, 4/7 have short stature (<-2 SDS) and one was diagnosed with growth hormone deficiency. Recurrent episodes of ketotic hypoglycemia were present in 6/7 patients. In two patients, hypoglycemic episodes have spontaneously resolved later on. Four out of seven patients have deteriorating adrenal function with abnormally low cortisol and ACTH levels during hypoglycemia and subnormal response of cortisol to low dose ACTH test . Serum electrolytes were within normal range. Hydrocortisone replacement therapy improved, but not entirely eliminated hypoglycemic episodes. WES revealed a previously described homozygous mutation c.112A>T, p.Asn38Tyr in the PGM1 gene. The clinical picture of PGM1 deficiency is variable among patients with the same mutation and genetic background. ACTH deficiency should be considered in any PGM1 deficient patient with hypoglycemia. © 2015 Wiley Periodicals, Inc.

Does this adult patient with suspected bacteremia require blood cultures?

PubMed

Coburn, Bryan; Morris, Andrew M; Tomlinson, George; Detsky, Allan S

2012-08-01

Clinicians order blood cultures liberally among patients in whom bacteremia is suspected, though a small proportion of blood cultures yield true-positive results. Ordering blood cultures inappropriately may be both wasteful and harmful. To review the accuracy of easily obtained clinical and laboratory findings to inform the decision to obtain blood cultures in suspected bacteremia. A MEDLINE and EMBASE search (inception to April 2012) yielded 35 studies that met inclusion criteria for evaluating the accuracy of clinical variables for bacteremia in adult immunocompetent patients, representing 4566 bacteremia and 25,946 negative blood culture episodes. Data were extracted to determine the prevalence and likelihood ratios (LRs) of findings for bacteremia. The pretest probability of bacteremia varies depending on the clinical context, from low (eg, cellulitis: 2%) to high (eg, septic shock: 69%). Elevated temperatures alone do not accurately predict bacteremia (for ≥38°C [>100.3°F], LR, 1.9 [95% CI, 1.4-2.4]; for ≥38.5°C [>101.2°F], LR, 1.4 [95% CI, 1.1-2.0]), nor does isolated leukocytosis (LR, <1.7). The severity of chills graded on an ordinal scale (shaking chills, LR, 4.7; 95% CI, 3.0-7.2) may be more useful. Both the systemic inflammatory response syndrome (SIRS) and a multivariable decision rule with major and minor criteria are sensitive (but not specific) predictors of bacteremia (SIRS, negative LR, 0.09 [95% CI, 0.03-0.26]; decision rule, negative LR, 0.08 [95% CI, 0.04-0.17]). Blood cultures should not be ordered for adult patients with isolated fever or leukocytosis without considering the pretest probability. SIRS and the decision rule may be helpful in identifying patients who do not need blood cultures. These conclusions do not apply to immunocompromised patients or when endocarditis is suspected.

Variability in objective and subjective measures affects baseline values in studies of patients with COPD

PubMed Central

Ha, Jae Wook; Couper, David J.; O’Neal, Wanda K.; Barr, R. Graham; Bleecker, Eugene R.; Carretta, Elizabeth E.; Cooper, Christopher B.; Doerschuk, Claire M.; Drummond, M Bradley; Han, MeiLan K.; Hansel, Nadia N.; Kim, Victor; Kleerup, Eric C.; Martinez, Fernando J.; Rennard, Stephen I.; Tashkin, Donald; Woodruff, Prescott G.; Paine, Robert; Curtis, Jeffrey L.; Kanner, Richard E.

2017-01-01

Rationale Understanding the reliability and repeatability of clinical measurements used in the diagnosis, treatment and monitoring of disease progression is of critical importance across all disciplines of clinical practice and in clinical trials to assess therapeutic efficacy and safety. Objectives Our goal is to understand normal variability for assessing true changes in health status and to more accurately utilize this data to differentiate disease characteristics and outcomes. Methods Our study is the first study designed entirely to establish the repeatability of a large number of instruments utilized for the clinical assessment of COPD in the same subjects over the same period. We utilized SPIROMICS participants (n = 98) that returned to their clinical center within 6 weeks of their baseline visit to repeat complete baseline assessments. Demographics, spirometry, questionnaires, complete blood cell counts (CBC), medical history, and emphysema status by computerized tomography (CT) imaging were obtained. Results Pulmonary function tests (PFTs) were highly repeatable (ICC’s >0.9) but the 6 minute walk (6MW) was less so (ICC = 0.79). Among questionnaires, the Saint George’s Respiratory Questionnaire (SGRQ) was most repeatable. Self-reported clinical features, such as exacerbation history, and features of chronic bronchitis, often produced kappa values <0.6. Reported age at starting smoking and average number of cigarettes smoked were modestly repeatable (kappa = 0.76 and 0.79). Complete blood counts (CBC) variables produced intraclass correlation coefficients (ICC) values between 0.6 and 0.8. Conclusions PFTs were highly repeatable, while subjective measures and subject recall were more variable. Analyses using features with poor repeatability could lead to misclassification and outcome errors. Hence, care should be taken when interpreting change in clinical features based on measures with low repeatability. Efforts to improve repeatability of key clinical