The relationship between self-efficacy and resting blood pressure in spousal Alzheimer's caregivers

Objective. To examine whether high levels of self-efficacy for problem-focused coping were significantly related to several resting BP measures in spousal Alzheimer's disease caregivers. Design. Cross-sectional. Methods. Participants included 100 older caregivers (mean age = 73.8 ± 8.14 years) providing in home care for a spouse with Alzheimer's disease. All participants completed a 13-item short form of the Coping Self-Efficacy Scale and underwent an in-home assessment where a visiting nurse took the average of three serial BP readings. Multiple regression was used to examine the relationship between self-efficacy and mean arterial pressure (MAP), systolic BP (SBP), diastolic BP (DBP), and pulse pressure (PP) after controlling for age, gender, smoking history, body mass index, the care recipient's clinical dementia rating, diabetes, alcohol use, and the use of antihypertensive medications. Results. Overall, high levels of self-efficacy for problem-focused coping were associated with lower MAP, SBP, and PP. Self-efficacy for problem-focused coping was marginally associated with resting DBP, but not significant. In addition, we conducted secondary analyses of the other two self-efficacy scales to explore the relationship between each dimension and MAP. We found that there were no significant relationships found between MAP and self-efficacy for stopping unpleasant thoughts/emotions or self-efficacy for getting social support. Conclusions. The present study adds to the current body of literature by illustrating the possibility that higher self-efficacy can have physiological advantages, perhaps by buffering chronic stress's impact on resting BP. Another contribution of the current study is its attempt to understand the role of each individual component of self-efficacy. These findings invite future research to investigate whether caregivers might experience cardiovascular benefits from interventions aimed at enhancing self-efficacy.

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

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.

Cerebral oxygenation in patients after severe head injury: monitoring and effects of arterial hyperoxia on cerebral blood flow, metabolism and intracranial pressure

Early impaired cerebral blood flow (CBF) after severe head injury (SHI) leads to poor brain tissue oxygen delivery and lactate accumulation. The purpose of this investigation was to elucidate the relationship between CBF, local dialysate lactate (lact(md)) and dialysate glucose (gluc(md)), and brain tissue oxygen levels (PtiO2) under arterial normoxia. The effect of increased brain tissue oxygenation due to high fractions of inspired oxygen (FiO2) on lact(md) and CBF was explored. A total of 47 patients with SHI were enrolled in this studies (Glasgow Coma Score [GCS] < 8). CBF was first assessed in 40 patients at one time point in the first 96 hours (27 +/- 28 hours) after SHI using stable xenon computed tomography (Xe-CT) (30% inspired xenon [FiXe] and 35% FiO2). In a second study, sequential double CBF measurements were performed in 7 patients with 35% FiO2 and 60% FiO2, respectively, with an interval of 30 minutes. In a subsequent study, 14 patients underwent normobaric hyperoxia by increasing FiO2 from 35 +/- 5% to 60% and then 100% over a period of 6 hours. This was done to test the effect of normobaric hyperoxia on lact(md) and brain gluc(md), as measured by local microdialysis. Changes in PtiO2 in response to changes in FiO2 were analyzed by calculating the oxygen reactivity. Oxygen reactivity was then related to the 3-month outcome data. The levels of lact(md) and gluc(md) under hyperoxia were compared with the baseline levels, measured at 35% FiO2. Under normoxic conditions, there was a significant correlation between CBF and PtiO2 (R = 0.7; P < .001). In the sequential double CBF study, however, FiO2 was inversely correlated with CBF (P < .05). In the 14 patients undergoing the 6-hour 100% FiO2 challenge, the mean PtiO2 levels increased to 353 (87% compared with baseline), although the mean lact(md) levels decreased by 38 +/- 16% (P < .05). The PtiO2 response to 100% FiO2 (oxygen reactivity) was inversely correlated with outcome (P < .01). Monitoring PtiO2 after SHI provides valuable information about cerebral oxygenation and substrate delivery. Increasing arterial oxygen tension (PaO2) effectively increased PtiO2, and brain lact(md) was reduced by the same maneuver.

Bloodstream infections in pediatric ECLS: usefulness of daily blood culture monitoring and predictive value of biological markers. The British Columbia experience

INTRODUCTION: The incidence of bloodstream infection (BSI) in extracorporeal life support (ECLS) is reported between 0.9 and 19.5%. In January 2006, the Extracorporeal Life Support Organization (ELSO) reported an overall incidence of 8.78% distributed as follows: respiratory: 6.5% (neonatal), 20.8% (pediatric); cardiac: 8.2% (neonatal) and 12.6% (pediatric). METHOD: At BC Children's Hospital (BCCH) daily surveillance blood cultures (BC) are performed and antibiotic prophylaxis is not routinely recommended. Positive BC (BC+) were reviewed, including resistance profiles, collection time of BC+, time to positivity and mortality. White blood cell count, absolute neutrophile count, immature/total ratio, platelet count, fibrinogen and lactate were analyzed 48, 24 and 0 h prior to BSI. A univariate linear regression analysis was performed. RESULTS: From 1999 to 2005, 89 patients underwent ECLS. After exclusion, 84 patients were reviewed. The attack rate was 22.6% (19 BSI) and 13.1% after exclusion of coagulase-negative staphylococci (n = 8). BSI patients were significantly longer on ECLS (157 h) compared to the no-BSI group (127 h, 95% CI: 106-148). Six BSI patients died on ECLS (35%; 4 congenital diaphragmatic hernias, 1 hypoplastic left heart syndrome and 1 after a tetralogy repair). BCCH survival on ECLS was 71 and 58% at discharge, which is comparable to previous reports. No patient died primarily because of BSI. No BSI predictor was identified, although lactate may show a decreasing trend before BSI (P = 0.102). CONCLUSION: Compared with ELSO, the studied BSI incidence was higher with a comparable mortality. We speculate that our BSI rate is explained by underreporting of "contaminants" in the literature, the use of broad-spectrum antibiotic prophylaxis and a higher yield with daily monitoring BC. We support daily surveillance blood cultures as an alternative to antibiotic prophylaxis in the management of patients on ECLS.

Monitoring thrombin generation by electrochemistry: development of an amperometric biosensor screening test for plasma and whole blood

BACKGROUND: Complete investigation of thrombophilic or hemorrhagic clinical presentations is a time-, apparatus-, and cost-intensive process. Sensitive screening tests for characterizing the overall function of the hemostatic system, or defined parts of it, would be very useful. For this purpose, we are developing an electrochemical biosensor system that allows measurement of thrombin generation in whole blood as well as in plasma. METHODS: The measuring system consists of a single-use electrochemical sensor in the shape of a strip and a measuring unit connected to a personal computer, recording the electrical signal. Blood is added to a specific reagent mixture immobilized in dry form on the strip, including a coagulation activator (e.g., tissue factor or silica) and an electrogenic substrate specific to thrombin. RESULTS: Increasing thrombin concentrations gave standard curves with progressively increasing maximal current and decreasing time to reach the peak. Because the measurement was unaffected by color or turbidity, any type of blood sample could be analyzed: platelet-poor plasma, platelet-rich plasma, and whole blood. The test strips with the predried reagents were stable when stored for several months before testing. Analysis of the combined results obtained with different activators allowed discrimination between defects of the extrinsic, intrinsic, and common coagulation pathways. Activated protein C (APC) predried on the strips allowed identification of APC-resistance in plasma and whole blood samples. CONCLUSIONS: The biosensor system provides a new method for assessing thrombin generation in plasma or whole blood samples as small as 10 microL. The assay is easy to use, thus allowing it to be performed in a point-of-care setting.

Functional Multiparametric Magnetic Resonance Imaging of the Kidneys Using Blood Oxygen Level-Dependent and Diffusion-Weighted Sequences: a Reliable Tool for Monitoring Acute Upper Urinary Tract Obstruction.

PURPOSE Little data is available on noninvasive MRI-based assessment of renal function during upper urinary tract (UUT) obstruction. In this study, we determined whether functional multiparametric kidney MRI is able to monitor treatment response in acute unilateral UUT obstruction. MATERIAL AND METHODS Between 01/2008 and 01/2010, 18 patients with acute unilateral UUT obstruction due to calculi were prospectively enrolled to undergo kidney MRI with conventional, blood oxygen level-dependent (BOLD) and diffusion-weighted (DW) sequences on emergency admission and after release of obstruction. Functional imaging parameters of the obstructed and contralateral unobstructed kidneys derived from BOLD (apparent spin relaxation rate [R2*]) and DW (total apparent diffusion coefficient [ADCT], pure diffusion coefficient [ADCD] and perfusion fraction [FP]) sequences were assessed during acute UUT obstruction and after its release. RESULTS During acute obstruction, R2* and FP values were lower in the cortex (p=0.020 and p=0.031, respectively) and medulla (p=0.012 and p=0.190, respectively) of the obstructed compared to the contralateral unobstructed kidneys. After release of obstruction, R2* and FP values increased both in the cortex (p=0.016 and p=0.004, respectively) and medulla (p=0.071 and p=0.044, respectively) of the formerly obstructed kidneys to values similar to those found in the contralateral kidneys. ADCT and ADCD values did not significantly differ between obstructed and contralateral unobstructed kidneys during or after obstruction. CONCLUSIONS In our patients with acute unilateral UUT obstruction due to calculi, functional kidney MRI using BOLD and DW sequences allowed for the monitoring of pathophysiologic changes of obstructed kidneys during obstruction and after its release.

Children's and adolescent's self - assessment of metabolic control versus professional judgment: a cross-sectional retrospective and prospective cohort study

BACKGROUND Morbidity and mortality in T1DM depend on metabolic control, which is assessed by HbA1c measurements every 3-4 months. Patients' self-perception of glycemic control depends on daily blood glucose monitoring. Little is known about the congruence of patients' and professionals' perception of metabolic control in T1DM. OBJECTIVE To assess the actual patients' self-perception and objective assessment (HbA1c) of metabolic control in T1DM children and adolescents and to investigate the possible factors involved in any difference. METHODS Patients with T1DM aged 8 - 18 years were recruited in a cross-sectional, retrospective and prospective cohort study. Data collection consisted of clinical details, measured HbA1c, self-monitored blood glucose values and questionnaires assessing self and professionals' judgment of metabolic control. RESULTS 91 patients participated. Mean HbA1c was 8.03%. HbA1c was higher in patients with a diabetes duration > 2 years (p = 0.025) and in patients of lower socioeconomic level (p = 0.032). No significant correlation was found for self-perception of metabolic control in well and poorly controlled patients. We found a trend towards false-positive memory of the last HbA1c in patients with a HbA1c > 8.5% (p = 0.069) but no difference in patients' knowledge on target HbA1c between well and poorly controlled patients. CONCLUSIONS T1DM patients are aware of a target HbA1c representing good metabolic control. Ill controlled patients appear to have a poorer recollection of their HbA1c. Self-perception of actual metabolic control is similar in well and poorly controlled T1DM children and adolescents. Therefore, professionals should pay special attention that ill controlled T1DM patients perceive their HbA1c correctly.

Therapeutic drug monitoring of once daily aminoglycoside dosing: comparison of two methods and investigation of the optimal blood sampling strategy.

PURPOSE Therapeutic drug monitoring of patients receiving once daily aminoglycoside therapy can be performed using pharmacokinetic (PK) formulas or Bayesian calculations. While these methods produced comparable results, their performance has never been checked against full PK profiles. We performed a PK study in order to compare both methods and to determine the best time-points to estimate AUC0-24 and peak concentrations (C max). METHODS We obtained full PK profiles in 14 patients receiving a once daily aminoglycoside therapy. PK parameters were calculated with PKSolver using non-compartmental methods. The calculated PK parameters were then compared with parameters estimated using an algorithm based on two serum concentrations (two-point method) or the software TCIWorks (Bayesian method). RESULTS For tobramycin and gentamicin, AUC0-24 and C max could be reliably estimated using a first serum concentration obtained at 1 h and a second one between 8 and 10 h after start of the infusion. The two-point and the Bayesian method produced similar results. For amikacin, AUC0-24 could reliably be estimated by both methods. C max was underestimated by 10-20% by the two-point method and by up to 30% with a large variation by the Bayesian method. CONCLUSIONS The ideal time-points for therapeutic drug monitoring of once daily administered aminoglycosides are 1 h after start of a 30-min infusion for the first time-point and 8-10 h after start of the infusion for the second time-point. Duration of the infusion and accurate registration of the time-points of blood drawing are essential for obtaining precise predictions.

General Practitioners' vitamin K antagonist monitoring is associated with better blood pressure control in patients with hypertension - a cross-sectional database study.

BACKGROUND Patients requiring anticoagulation suffer from comorbidities such as hypertension. On the occasion of INR monitoring, general practitioners (GPs) have the opportunity to control for blood pressure (BP). We aimed to evaluate the impact of Vitamin-K Antagonist (VKA) monitoring by GPs on BP control in patients with hypertension. METHODS We cross-sectionally analyzed the database of the Swiss Family Medicine ICPC Research using Electronic Medical Records (FIRE) of 60 general practices in a primary care setting in Switzerland. This database includes 113,335 patients who visited their GP between 2009 and 2013. We identified patients with hypertension based on antihypertensive medication prescribed for ≥6 months. We compared patients with VKA for ≥3 months and patients without such treatment regarding BP control. We adjusted for age, sex, observation period, number of consultations and comorbidity. RESULTS We identified 4,412 patients with hypertension and blood pressure recordings in the FIRE database. Among these, 569 (12.9 %) were on Phenprocoumon (VKA) and 3,843 (87.1 %) had no anticoagulation. Mean systolic and diastolic BP was significantly lower in the VKA group (130.6 ± 14.9 vs 139.8 ± 15.8 and 76.6 ± 7.9 vs 81.3 ± 9.3 mm Hg) (p < 0.001 for both). The difference remained after adjusting for possible confounders. Systolic and diastolic BP were significantly lower in the VKA group, reaching a mean difference of -8.4 mm Hg (95 % CI -9.8 to -7.0 mm Hg) and -1.5 mm Hg (95 % CI -2.3 to -0.7 mm Hg), respectively (p < 0.001 for both). CONCLUSIONS In a large sample of hypertensive patients in Switzerland, VKA treatment was independently associated with better systolic and diastolic BP control. The observed effect could be due to better compliance with antihypertensive medication in patients treated with VKA. Therefore, we conclude to be aware of this possible benefit especially in patients with lower expected compliance and with multimorbidity.

Influence of two types of self-retaining retractors on multifidus muscle blood flow during dorsolateral thoracolumbar hemilaminectomy in dogs

OBJECTIVES To assess the influence of the use of Gelpi and Grevel retractors on multifidus muscle blood flow during hemilaminectomy, using a dorsolateral approach, for acute disc extrusion in dogs as measured by laser speckle contrast imaging (LSCI). METHODS Blood flow in the multifidus muscles was measured intra-operatively using LSCI prior to insertion of the retractors, immediately after hemilaminectomy and removal of the retractors, and after 10 minutes of lavage of the surgical site. Plasma creatine kinase levels were measured preoperatively and 12-24 hours postoperatively. RESULTS Muscular blood flow was significantly decreased following retraction and remained lower than initial values 10 minutes after lavage in all dogs. The decrease in blood flow was significantly greater with Gelpi retractors (n = 8) than with Grevel retractors (n = 10). No significant relation was found between the duration of retraction and postoperative changes in creatine kinase levels or blood flow. CLINICAL SIGNIFICANCE Findings in this study demonstrate a drop in blood flow within the multifidus muscles using the dorsolateral approach regardless of retractor type used. Gelpi retractors seem to have greater influence on muscular blood flow than Grevel retractors. Further studies are warranted to confirm this second finding.

A plasma global metabolic profiling approach applied to an exercise study monitoring the effects of glucose, galactose and fructose drinks during post-exercise recovery

A global metabolic profiling methodology based on gas chromatography coupled to time-of-flight mass spectrometry (GC-TOFMS) for human plasma was applied to a human exercise study focused on the effects of beverages containing glucose, galactose, or fructose taken after exercise and throughout a recovery period of 6 h and 45 min. One group of 10 well trained male cyclists performed 3 experimental sessions on separate days (randomized, single center). After performing a standardized depletion protocol on a bicycle, subjects consumed one of three different beverages: maltodextrin (MD)+glucose (2:1 ratio), MD+galactose (2:1), and MD+fructose (2:1), consumed at an average of 1.25 g of carbohydrate (CHO) ingested per minute. Blood was taken straight after exercise and every 45 min within the recovery phase. With the resulting blood plasma, insulin, free fatty acid (FFA) profile, glucose, and GC-TOFMS global metabolic profiling measurements were performed. The resulting profiling data was able to match the results obtained from the other clinical measurements with the addition of being able to follow many different metabolites throughout the recovery period. The data quality was assessed, with all the labelled internal standards yielding values of <15% CV for all samples (n=335), apart from the labelled sucrose which gave a value of 15.19%. Differences between recovery treatments including the appearance of galactonic acid from the galactose based beverage were also highlighted.