Continuous electrodermal activity as a potential novel neurophysiological biomarker of prognosis after cardiac arrest--A pilot study.

AIMS: Neurological outcome prognosis remains challenging in patients undergoing therapeutic hypothermia (TH) after cardiac resuscitation. Technological advances allow for a novel wrist-worn device to continuously record electrodermal activity (EDA), a measure of pure sympathetic activity. METHODS: A prospective cohort study was performed to determine the yield of continuous EDA in patients treated with TH for coma after cardiac arrest during hypothermia and normothermia. Association between EDA parameters (event-related and nonspecific electrodermal responses (ER-EDR, NS-EDR)) and outcome measures (cerebral performance category [CPC]) (Full Outline in UnResponsivenss (FOUR) score) were assessed. RESULTS: Eighteen patients were enrolled. Total number of EDR (66.4 vs 12.0/24h, p = 0.02), ER-EDR (39.5 vs 11.2/24h, p = 0.009), median amplitude change of all EDR (0.08 vs 0.03 µSI, p = 0.03) and ER-EDR (0.14 vs 0.05 µSI, p = 0.025) were higher in patients with favorable (CPC 1-2) versus poor outcome (CPC 3-5) during hypothermia. Greater differences in EDA parameters were observed during hypothermia than normothermia. The FOUR score was correlated to the number of all EDR and median amplitudes. CONCLUSIONS: Continuous EDA potentially opens a new avenue for autonomic function monitoring in neurocritically ill patients. It is feasible in the ICU setting, even during hypothermic states. As a measure of a complete neurophysiological circuit, it may be a novel neurophysiologic biomarker of outcome after cardiac resuscitation.

Evaluation of a clinical pathway for sedation and analgesia of mechanically ventilated patients in a cardiac intensive care unit (CICU): The Brigham and Women's Hospital Levine CICU sedation pathways.

BACKGROUND: Intravenous sedation and analgesia are important therapies during mechanical ventilation (MV). However, daily interruption of these medications is associated with improved outcomes in mechanically ventilated patients. We tested a clinical pathway for the use of sedation and analgesia during MV in a cardiac intensive care unit (CICU). METHODS AND RESULTS: We evaluated all mechanically ventilated patients in a CICU during two phases: phase 1 prior to pathway implementation (PRE) and phase 2 post-pathway implementation (POST). A total of 198 patients (98 PRE and 100 POST) and 1012 days of intubation (574 PRE and 434 POST) were included in this analysis. We found an increase in the frequency of daily interruptions of sedation post-implementation (49.3% PRE and 58.4% POST, p=0.0041). There was a significant decrease in the mean duration of MV in the POST vs PRE periods (5.0±2.3 vs 6.1±2.8 days, p=0.015). There was also a significant decrease in total neuroimaging studies (9 vs 49, p=0.001) and a trend toward a decrease in tracheostomies (3.0% vs 6.1%, p=0.33). Mean CICU length of stay (LOS) and hospital LOS respectively were 10.4 days and 16.8 days PRE and 10.4 days and 17.9 days POST (p=0.99 and p=0.55). Mortality did not differ (PRE 36.7% vs POST 32.0% p=0.55). CONCLUSIONS: Implementation of a pragmatic pathway for sedation and analgesia in a CICU was associated with an increase in the daily interruption of sedation and a corresponding decrease in the duration of MV days and the need for neuroimaging.