Molly O’Brien

Outcomes in patients undergoing percutaneous ventricular assist device implantation for cardiogenic shock

Background: Percutaneous ventricular assist devices (PVADs) offer an important but resource-intensive option for management of severe cardiogenic shock (CS). Optimal selection of patients for PVAD support remains undefined. We investigated outcomes, including characteristics associated with in-hospital survival, during PVAD support for CS. Methods: We established a prospective quality improvement program among patients undergoing TandemHeart PVAD implantation for CS at Brigham and Women’s Hospital (Boston, MA). We evaluated 65 consecutive patients between 2006 and 2014, analyzing demographic, clinical, laboratory, hemodynamic, and survival data. Results: Thirty-two patients (49.2%) survived to hospital discharge, of which 12 received destination surgical therapy. Baseline characteristics associated with survival included younger age (47 ± 15 years vs 61 ± 11 years; p<0.001), non-ischemic cardiomyopathy (NICMP) vs ischemic CMP (survival 70.4% vs 34.2%, p=0.004), and, paradoxically, lower presenting left ventricular ejection fraction (LVEF) (survival 66.7% for LVEF ⩽15%, 41.2% for LVEF 16–25%, 25.0% for LVEF >25%; p=0.010). Younger age (p=0.026) and NICMP (p=0.034) remained independent predictors of survival. Twenty-four hours after PVAD placement, a more modest increase in cardiac index (⩽0.75 L/min/m2) was associated with higher in-hospital mortality (OR 6.3, 95% CI 1.8–22.1), as was lack of improvement in serum anion gap (⩽2 mEq/L; OR 5.1, 95% CI 1.6–16.6). Conclusions: Despite intensive care and provision of circulatory support, survival is poor in severe CS. Patients in CS with younger age and NICMP were more likely to survive to hospital discharge. Less robust hemodynamic improvement and persistent acidosis after 24 hours of PVAD support also identified patients less likely to survive.

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.

Effect of stimulus type and temperature on EEG reactivity in cardiac arrest

OBJECTIVE Electroencephalogram (EEG) background reactivity is a reliable outcome predictor in cardiac arrest patients post therapeutic hypothermia. However, there is no consensus on modality testing and prior studies reveal only fair to moderate agreement rates. The aim of this study was to explore different stimulus modalities and report interrater agreements. METHODS We studied a multicenter, prospectively collected cohort of cardiac arrest patients who underwent therapeutic hypothermia between September 2014 and December 2015. We identified patients with reactivity data and evaluated interrater agreements of different stimulus modalities tested in hypothermia and normothermia. RESULTS Of the 60 patients studied, agreement rates were moderate to substantial during hypothermia and fair to moderate during normothermia. Bilateral nipple pressure is more sensitive (80%) when compared to other modalities in eliciting a reactive background in hypothermia. Auditory, nasal tickle, nailbed pressure and nipple pressure reactivity were associated with good outcomes in both hypothermia and normothermia. CONCLUSIONS EEG reactivity varies depending on the stimulus testing modality as well as the temperature during which stimulation is performed, with nipple pressure emerging as the most sensitive during hypothermia for reactivity and outcome determination. SIGNIFICANCE This highlights the importance of multiple stimulus testing modalities in EEG reactivity determination to reduce false negatives and optimize prognostication.

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.