Iatrogenic blood loss from phlebotomy during adult extracorporeal membrane oxygenation: A retrospective cohort study.

BACKGROUND: Adult extracorporeal membrane oxygenation (ECMO) patients are at high risk for allogeneic blood transfusion. Few studies have characterized iatrogenic blood loss from phlebotomy in adult ECMO patients. We hypothesized that iatrogenic phlebotomy would be a significant source of blood loss during ECMO. METHODS: Adults who had their entire ECMO run at our medical center between 2020 and 2022 were included. Average daily phlebotomy volume and total phlebotomy volume during ECMO were estimated based on the total number of laboratory tests that were processed. In addition, the crude and adjusted association between total phlebotomy volume during ECMO and RBC transfusion during ECMO was evaluated using linear regression and Loess curve analysis. RESULTS: A total of 161 patients who underwent 162 ECMO runs were included. Of the 162 ECMO runs, 88 (54.3%) were veno-arterial and 74 (45.7%) were veno-venous ECMO. Median duration of ECMO was 5 days [25th, 75th percentile = 2, 11]. Median daily phlebotomy volume was 130 mLs [25th, 75th percentile = 94, 170] and median total phlebotomy volume during ECMO was 579 mLs [25th, 75th percentile = 238, 1314]. There was a significant crude and adjusted association between total phlebotomy volume and RBC transfusion during ECMO (beta coefficient = 0.0023 and 0.0024 respectively, both p < .001) based on linear regression analysis. DISCUSSION: Phlebotomy for laboratory testing is a significant source of blood loss during ECMO in adults. Comprehensive patient blood management for adult ECMO patients should include strategies to reduce laboratory testing and/or phlebotomy volume during ECMO.

Shift Work and Heart Rate Variability Coherence: Pilot Study Among Nurses.

This study used ambient heart rate monitoring among health care workers to determine whether a novel measure of heart rate variability (HRV), as well as sleep disturbances, fatigue, or cognitive performance differed among non-rotating night shift nurses relative to those working permanent day shifts. Continuous ambulatory HRV monitoring was performed among night nurses (n = 11), and a comparison group of permanent day nurses (n = 7), over a 36-h period coinciding with the last two 12-h shifts of each participant's work week. Symptoms and psychomotor vigilance were assessed at the end of the ambient HRV monitoring period, and no differences between shifts were observed. Day nurses exhibited an increase in hourly mean HRV coherence ratios during their sleep period, suggesting a circadian pattern of cardiorespiratory phase coupling, whereas night nurses had no increase in HRV coherence ratios during their sleep period. The HRV coherence patterns were similar to high frequency HRV power among nurses on the same shift. To the authors knowledge, this study was the first to quantify patterns of the HRV coherence ratio among shiftworkers in a non-experimental (work/home) setting. The results suggest a pattern of autonomic dysregulation among night workers during their sleep period relative to those working day shifts. The HRV coherence ratio may serve as a novel indicator of HRV dysregulation among shift workers.