Communications Biophysics

Contains reports on three research projects.National Institutes of Health (Grant 5 P01 GM14940-04

How do predisposing factors differ between delirium motor subtypes? A systematic review and meta-analysis

BACKGROUND: Delirium is a common neurocognitive disorder in hospitalised older adults with vast negative consequences. The predominant method of subtyping delirium is by motor activity profile into hypoactive, hyperactive and mixed groups. OBJECTIVE: This systematic review and meta-analysis investigated how predisposing factors differ between delirium motor subtypes. METHODS: Databases (Medline, PsycINFO, Embase) were systematically searched for studies reporting predisposing factors (prior to delirium) for delirium motor subtypes. A total of 61 studies met inclusion criteria (N = 14,407, mean age 73.63 years). Random-effects meta-analyses synthesised differences between delirium motor subtypes relative to 22 factors. RESULTS: Hypoactive cases were older, had poorer cognition and higher physical risk scores than hyperactive cases and were more likely to be women, living in care homes, taking more medications, with worse functional performance and history of cerebrovascular disease than all remaining subtypes. Hyperactive cases were younger than hypoactive and mixed subtypes and were more likely to be men, with better cognition and lower physical risk scores than all other subtypes. Those with no motor subtype (unable to be classified) were more likely to be women and have better functional performance. Effect sizes were small. CONCLUSIONS: Important differences in those who develop motor subtypes of delirium were shown prior to delirium occurrence. We provide robust quantitative evidence for a common clinical assumption that indices of frailty (institutional living, cognitive and functional impairment) are seen more in hypoactive patients. Motor subtypes should be measured across delirium research. Motor subtyping has great potential to improve the clinical risk assessment and management of delirium

Cognitive outcomes following coronary artery bypass grafting: a systematic review and meta-analysis of 91,829 patients

BACKGROUND:Cognitive impairments, including delirium, are common after coronary artery bypass grafting (CABG) surgery, as described in over three decades of research. Our aim was to pool estimates across the literature for the first-time, relative to time (from pre- to post-CABG) and diagnosis (cognitive impairment, delirium and dementia). METHODS:A systematic search of four databases was undertaken. 215 studies incorporating data from 91,829 patients were used to estimate the prevalence of cognitive impairments pre- and post-CABG, including delirium and dementia post-CABG, using random effects meta-analyses. RESULTS:Pre-surgical cognitive impairment was seen in 19% of patients. Post-operatively, cognitive impairment was seen in around 43% of patients acutely; this resolved to 19% at 4-6 months and then increased to 25% of patients between 6-months to 1-year post-operatively. In the long term, between 1 and 5-years post-operatively, cognitive impairment increased and was seen in nearly 40% of patients. Post-operative delirium was apparent in 18% of CABG patients which increased to 24% when a diagnostic instrument was utilized alongside clinical criteria. Dementia was present in 7% of patients 5-7 years post-surgery. CONCLUSION:The results of this meta-analysis demonstrate that cognitive impairment and delirium are major issues in CABG patients which require specific attention. It is imperative that appropriate methods for investigating cognitive impairment, and screening for delirium using a diagnostic instrument, occur in both pre-and post-CABG settings.Danielle Greaves, Peter J.Psaltis, Tyler J.Ross, Daniel Davis, Ashleigh E.Smith, Monique S.Boord, Hannah A.D.Keag

Effects of an educational program and a standardized insulin order form on glycemic outcomes in non-critically ill hospitalized patients

BACKGROUND: The optimal approach to managing hyperglycemia in noncritically ill hospital patients is unclear. OBJECTIVE: To investigate the effects of targeted quality improvement interventions on insulin prescribing and glycemic control. DESIGN: A cohort study comparing an intervention group (IG) to a concurrent control group (CCG) and an historic control group (HCG). SETTING: University of Michigan Hospital. PATIENTS: Hyperglycemic, noncritically ill hospital patients treated with insulin. INTERVENTION: Physician and nurse education and a standardized insulin order form based on the principles of physiologic insulin use. MEASUREMENTS: Glycemic control and insulin prescribing patterns. RESULTS: Patients in the IG were more likely to be treated with a combination of scheduled basal and nutritional insulin than in the other groups. In the final adjusted regression model, patients in the IG were more likely to be in the target glucose range (odds ratio [OR], 1.72; P = 0.01) and less likely to be severely hyperglycemic (OR, 0.65; P < 0.01) when compared to those in the CCG. Patients in the IG were also less likely to experience hypoglycemia than those in the CCG ( P = 0.06) or the HCG ( P = 0.01). Over 80% of all patient-days for all groups contained glucose readings outside of the target range. CONCLUSIONS: Standardized interventions encouraging the physiologic use of subcutaneous insulin can lead to significant improvements in glycemic control and patient safety in hospitalized patients. However, the observed improvements are modest, and poor metabolic control remains common, despite these interventions. Additional research is needed to determine the best strategy for safely achieving metabolic control in these patients. Journal of Hospital Medicine 2010. © 2010 Society of Hospital Medicine.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/78247/1/780_ftp.pd

Serum Levels of Adipocyte Fatty Acid-Binding Protein Are Associated with the Severity of Coronary Artery Disease in Chinese Women

BACKGROUND: Adipocyte fatty acid-binding protein (A-FABP) has been described as a novel adipokine, playing an important role in the development of metabolic syndrome, type 2 diabetes and atherosclerosis. In this study, we investigated the relationship between serum levels of A-FABP and the presence and severity of coronary artery disease (CAD) in Chinese subjects. METHODOLOGY/PRINCIPAL FINDINGS: Circulating A-FABP level was determined by ELISA in 341 Chinese subjects (221 men, 120 women) who underwent coronary angiography. A-FABP levels in patients with CAD were significantly higher compared with non-CAD subjects (P = 0.029 in men; P = 0.031 in women). Serum A-FABP increased significantly in multi-vessel diseased patients than in non-CAD subjects (P = 0.011 in men, P = 0.004 in women), and showed an independent correlation with coronary atherosclerosis index (standardized β = 0.173, P = 0.025). In multiple logistic regression analysis, serum A-FABP was an independent risk factor for CAD in women (OR = 5.637, 95%CI: 1.299-24.457, P = 0.021). In addition, amino terminal pro-brain natriuretic peptide (NT-proBNP) was demonstrated to be positively and independently correlated with A-FABP (standardized β = 0.135, P = 0.027). CONCLUSIONS/SIGNIFICANCE: Serum A-FABP is closely associated with the presence and severity of CAD in Chinese women

Implementation and evaluation of a nurse-centered computerized potassium regulation protocol in the intensive care unit - a before and after analysis

<p>Abstract</p> <p>Background</p> <p>Potassium disorders can cause major complications and must be avoided in critically ill patients. Regulation of potassium in the intensive care unit (ICU) requires potassium administration with frequent blood potassium measurements and subsequent adjustments of the amount of potassium administrated. The use of a potassium replacement protocol can improve potassium regulation. For safety and efficiency, computerized protocols appear to be superior over paper protocols. The aim of this study was to evaluate if a computerized potassium regulation protocol in the ICU improved potassium regulation.</p> <p>Methods</p> <p>In our surgical ICU (12 beds) and cardiothoracic ICU (14 beds) at a tertiary academic center, we implemented a nurse-centered computerized potassium protocol integrated with the pre-existent glucose control program called GRIP (Glucose Regulation in Intensive Care patients). Before implementation of the computerized protocol, potassium replacement was physician-driven. Potassium was delivered continuously either by central venous catheter or by gastric, duodenal or jejunal tube. After every potassium measurement, nurses received a recommendation for the potassium administration rate and the time to the next measurement. In this before-after study we evaluated potassium regulation with GRIP. The attitude of the nursing staff towards potassium regulation with computer support was measured with questionnaires.</p> <p>Results</p> <p>The patient cohort consisted of 775 patients before and 1435 after the implementation of computerized potassium control. The number of patients with hypokalemia (<3.5 mmol/L) and hyperkalemia (>5.0 mmol/L) were recorded, as well as the time course of potassium levels after ICU admission. The incidence of hypokalemia and hyperkalemia was calculated. Median potassium-levels were similar in both study periods, but the level of potassium control improved: the incidence of hypokalemia decreased from 2.4% to 1.7% (P < 0.001) and hyperkalemia from 7.4% to 4.8% (P < 0.001). Nurses indicated that they considered computerized potassium control an improvement over previous practice.</p> <p>Conclusions</p> <p>Computerized potassium control, integrated with the nurse-centered GRIP program for glucose regulation, is effective and reduces the prevalence of hypo- and hyperkalemia in the ICU compared with physician-driven potassium regulation.</p

Computer-assisted glucose control in critically ill patients

Objective: Intensive insulin therapy is associated with the risk of hypoglycemia and increased costs of material and personnel. We therefore evaluated the safety and efficiency of a computer-assisted glucose control protocol in a large population of critically ill patients. Design and setting: Observational cohort study in three intensive care units (32 beds) in a 1,300-bed university teaching hospital. Patients: All 2,800 patients admitted to the surgical, neurosurgical, and cardiothoracic units; the study period started at each ICU after implementation of Glucose Regulation for Intensive Care Patients (GRIP), a freely available computer-assisted glucose control protocol. Measurements and results: We analysed compliance in relation to recommended insulin pump rates and glucose measurement frequency. Patients were on GRIP-ordered pump rates 97% of time. Median measurement time was 5 min late (IQR 20 min early to 34 min late). Hypoglycemia was uncommon (7% of patients for mild hypoglycemia, <3.5 mmol/l; 0.86% for severe hypoglycemia, <2.2 mmol/l). Our predefined target range (4.0 - 7.5 mmol/l) was reached after a median of 5.6h (IQR 0.2 - 11.8) and maintained for 89% (70 - 100%) of the remaining stay at the ICU. The number of measurements needed was 5.9 (4.8 - 7.3) per patient per day. In-hospital mortality was 10.1%. Conclusions: Our computer-assisted glucose control protocol provides safe and efficient glucose regulation in routine intensive care practice. A low rate of hypoglycemic episodes was achieved with a considerably lower number of glucose measurements than used in most other schemes