Kathleen Ryan Avery

Implementation of a Hospital-wide Protocol for Induced Hypothermia Following Successfully Resuscitated Cardiac Arrest.

Permanent neurologic impairment following cardiac arrest is often severely debilitating, even after successful resuscitation. Therapeutic hypothermia decreases anoxic brain injury and subsequent cognitive deficits. Current practice guidelines recommend therapeutic hypothermia in comatose survivors of cardiac arrest. To address the multifacets of therapeutic hypothermia, we assembled a multidisciplinary task force including members from various specialties to create an evidence-based guideline with transparency across disciplines and consistency of care. We describe our institutional guidelines for the initiation and management of induced hypothermia in patients successfully resuscitated from a cardiac arrest.

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.

Evaluation of glucose management during therapeutic hypothermia at a Tertiary Academic Medical Center

STUDY AIM Alterations in metabolic function during therapeutic hypothermia (TH) decrease responsiveness to insulin and increase the risk of hyperglycemia. Glycemic control is associated with improved outcomes in selected patients; however, glycemic management strategies during TH are not defined. The objective of this analysis was to evaluate the glycemic metrics and IV insulin administration in critically ill patients during the cooling and rewarming phases of TH. METHODS Data from 37 patients who received at least 6h of therapeutic hypothermia for cardiac arrest between January 2007 and January 2010 were retrospectively evaluated, 14 (37.8%) of whom had diabetes. RESULTS The mean blood glucose was 9.16±3.22mmol/L and 6.54±2.45mmol/L; p<0.01 during cooling and rewarming, respectively. Twelve (32.4%) patients experienced at least one hypoglycemic event, defined as a blood glucose <4mmol/L. Nineteen (51.4%) patients experienced at least one hyperglycemic event, defined as a blood glucose >11.11mmol/L and 15 (40.5%) patients received IV insulin therapy. Patients on IV insulin had a higher incidence of diabetes (9 vs. 5; p<0.05), higher admission blood glucose (13.89±6.13 vs. 11.03±4.65mmol/L; p=0.11), and a higher incidence of hyperglycemia (14 vs. 2; p<0.01) and hypoglycemia (8 vs. 4; p<0.05). Of the patients on IV insulin, mean insulin requirements during cooling and rewarming were 15.2±16.1 and 7±12.5units/h, respectively. CONCLUSION TH is commonly associated with hyperglycemia, hypoglycemia, and the use of IV insulin therapy. Further research is needed to determine optimal glycemic management strategies to prevent hyper- and hypoglycemia in patients during the different phases of TH.