Improving inpatient venous thromboembolism prophylaxis.

OBJECTIVES: The number and types of inpatients given inadequate prophylaxis for venous thromboembolism (VTE) are not known; patients receive less than appropriate prophylaxis with some frequency. METHODS: Initially we evaluated VTE prophylaxis at a community hospital by comparing prophylaxis patterns in adult inpatients for whom some prophylaxis was indicated. Patients were categorized as medical, general surgery, and orthopedic, then categorized as "appropriate," "suboptimal," or "none" in terms of VTE prophylaxis. After initial data collection, we performed an intervention on medical patients using a VTE risk assessment tool; a printed evaluation containing the VTE risk assessment score with related VTE prophylaxis regimens was placed in the patients' charts, after which prophylaxis patterns were compared between preintervention and postintervention medical patients. RESULTS: Initial data collected from 116 medical, 110 general surgery, and 72 orthopedic patients (n = 298) showed that there was a significant association between diagnosis category and level of observed appropriate VTE prophylaxis (P < 0.0001). Fifty-six medical patients (48%) received no prophylaxis, compared to 40 (36%) general surgery patients and 12 (17%) orthopedic patients. In the second phase, 74 medical patients on whom the intervention was performed were compared to 116 preintervention medical patients (n = 190). The findings showed that intervention status had a significant association with level of appropriate VTE prophylaxis (P < 0.0001). CONCLUSION: An increase in appropriate VTE prophylaxis was observed after a system-level intervention.

Detection of cardiac variability in the isolated rat heart.

Cardiac variability can be assessed from two perspectives: beat-to-beat performance and continuous performance during the cardiac cycle. Linear analysis techniques assess cardiac variability by measuring the physical attributes of a signal, whereas nonlinear techniques evaluate signal dynamics. This study sought to determine if recurrence quantification analysis (RQA), a nonlinear technique, could detect pharmacologically induced autonomic changes in the continuous left ventricular pressure (LVP) and electrographic (EC) signals from an isolated rat heart-a model that theoretically contains no inherent variability. LVP and EC signal data were acquired simultaneously during Langendorff perfusion of isolated rat hearts before and after the addition of acetylcholine (n = 11), norepinephrine (n = 12), or no drug (n = 12). Two-minute segments of the continuous LVP and EC signal data were analyzed by RQA. Findings showed that%recurrence,%determinism, entropy, maxline, and trend from the continuous LVP signal significantly increased in the presence of both acetylcholine and norepinephrine, although systolic LVP significantly increased only with norepinephrine. In the continuous EC signal, the RQA trend variable significantly increased in the presence of norepinephrine. These results suggest that when either the sympathetic or parasympathetic division of the autonomic nervous system overwhelms the other, the dynamics underlying cardiac variability become stationary. This study also shows that information concerning inherent variability in the isolated rat heart can be gained via RQA of the continuous cardiac signal. Although speculative, RQA may be a tool for detecting alterations in cardiac variability and evaluating signal dynamics as a nonlinear indicator of cardiac pathology.