Sudden Cardiac Arrest: Novel Uses of Risk Standardization and Post-Arrest Body Temperature to Improve Outcomes

Sudden cardiac arrest is a leading cause of death and disability in the US, with over 500,000 events annually and \u3c20% surviving to hospital discharge. Half of survivors suffer some degree of neurologic disability from massive ischemic injury and subsequent reperfusion processes. It therefore is vital to evaluate cardiac arrest at both population and clinical levels to improve outcomes. In response, this dissertation had three objectives. First, we examined whether hospital performance could be benchmarked using administrative data, which is more common than registry data. Two risk standardization models were developed using logistic regression involving 2453 patients treated from 2000-2015 at University of Pennsylvania Health System hospitals. Registry and administrative data were accessed for all patients and used to develop separate risk standardization models with survival to hospital discharge as the outcome and the registry model considered the “gold standard.” The administrative model had a receiver operating characteristic (ROC) area of 0.891 (95% CI: 0.876-0.905) compared to a registry area of 0.907 (95% CI: 0.895-0.919), indicating that risk standardization can be performed using administrative data. Second, serial temperatures were collected during the 72 hours following targeted temperature management (TTM) and rewarming on 465 TTM-treated patients from the Penn Alliance for Therapeutic Hypothermia (PATH) registry, of whom 179 (38.5%) had at least one pyrexic temperature (≥38oC). Higher maximum temperature was associated with worse neurologic outcome and lower survival in pyrexic patients. Pyrexia duration and outcomes were not related, unless duration was calculated as hours at or above 38.8oC; at those elevated temperatures, longer duration was associated with worse neurologic and survival outcomes. Third, serial temperatures were collected during the 72 hours post-arrest on 578 PATH patients not treated with TTM; 228 (39.5%) had at least one pyrexic temperature. Worse neurologic and survival outcomes were associated with increasing maximum temperature, the combination of higher maximum temperatures and longer durations at an elevated temperature, and timing of onset of pyrexia between 10.2-24.5 hours post-arrest. This work establishes the potential for using administrative data to create new opportunities to compare hospital performance regarding cardiac arrest and extends knowledge on clinical implications of post-arrest temperature on outcomes

Myocardial dysfunction after out-of-hospital cardiac arrest: predictors and prognostic implications.

We aim to determine the incidence of early myocardial dysfunction after out-of-hospital cardiac arrest, risk factors associated with its development, and association with outcome. A retrospective chart review was performed among consecutive out-of-hospital cardiac arrest (OHCA) patients who underwent echocardiography within 24 h of return of spontaneous circulation at three urban teaching hospitals. Our primary outcome is early myocardial dysfunction, defined as a left ventricular ejection fraction \u3c 40% on initial echocardiogram. We also determine risk factors associated with myocardial dysfunction using multivariate analysis, and examine its association with survival and neurologic outcome. A total of 190 patients achieved ROSC and underwent echocardiography within 24 h. Of these, 83 (44%) patients had myocardial dysfunction. A total of 37 (45%) patients with myocardial dysfunction survived to discharge, 39% with intact neurologic status. History of congestive heart failure (OR 6.21; 95% CI 2.54-15.19), male gender (OR 2.27; 95% CI 1.08-4.78), witnessed arrest (OR 4.20; 95% CI 1.78-9.93), more than three doses of epinephrine (OR 6.10; 95% CI 1.12-33.14), more than four defibrillations (OR 4.7; 95% CI 1.35-16.43), longer duration of resuscitation (OR 1.06; 95% CI 1.01-1.10), and therapeutic hypothermia (OR 3.93; 95% CI 1.32-11.75) were associated with myocardial dysfunction. Cardiopulmonary resuscitation immediately initiated by healthcare personnel was associated with lower odds of myocardial dysfunction (OR 0.40; 95% CI 0.17-0.97). There was no association between early myocardial dysfunction and mortality or neurological outcome. Nearly half of OHCA patients have myocardial dysfunction. A number of clinical factors are associated with myocardial dysfunction, and may aid providers in anticipating which patients need early diagnostic evaluation and specific treatments. Early myocardial dysfunction is not associated with neurologically intact survival

The association between hemoglobin concentration and neurologic outcome after cardiac arrest.

PURPOSE: The purpose of the study is to determine the association between hemoglobin concentration (Hgb) and neurologic outcome in postarrest patients. METHODS: We conducted a retrospective cohort study using the Penn Alliance for Therapeutic Hypothermia (PATH) cardiac arrest registry. Inclusion criteria were resuscitated cardiac arrest (inhospital or out of hospital) and an Hgb value recorded within 24 hours of return of spontaneous circulation. The primary outcome was favorable neurologic status at hospital discharge. Survival to hospital discharge was a secondary outcome. RESULTS: There were 598 eligible patients from 21 hospitals. Patients with favorable neurologic outcome had significantly higher median Hgb in the first 2 hours (12.7 vs 10.5 g/dL; P \u3c .001) and 6 hours (12.6 vs 10.6 g/dL; P \u3c .001) postarrest. Controlling for age, pulseless rhythm, etiology, location of arrest, receipt of targeted temperature management, hematologic or metastatic malignancy, or preexisting renal insufficiency, there was a significant relationship between Hgb and neurologic outcome within the first 6 hours after arrest (odds ratio, 1.23; 95% confidence interval, 1.09-1.38) and survival to hospital discharge (odds ratio, 1.20; 95% confidence interval, 1.08-1.34). CONCLUSION: Higher Hgb after cardiac arrest is associated with favorable neurologic outcome, particularly within the first 6 hours. It is unclear if this effect is due to impaired oxygen delivery or if Hgb is a marker for more severe illness

Inter-rater reliability of post-arrest cerebral performance category (CPC) scores.

PURPOSE: Cerebral Performance Category (CPC) scores are often an outcome measure for post-arrest neurologic function, collected worldwide to compare performance, evaluate therapies, and formulate recommendations. At most institutions, no formal training is offered in their determination, potentially leading to misclassification. MATERIALS AND METHODS: We identified 171 patients at 2 hospitals between 5/10/2005 and 8/31/2012 with two CPC scores at hospital discharge recorded independently - in an in-house quality improvement database and as part of a national registry. Scores were abstracted retrospectively from the same electronic medical record by two separate non-clinical researchers. These scores were compared to assess inter-rater reliability and stratified based on whether the score was concordant or discordant among reviewers to determine factors related to discordance. RESULTS: Thirty-nine CPC scores (22.8%) were discordant (kappa: 0.66), indicating substantial agreement. When dichotomized into favorable neurologic outcome (CPC 1-2)/ unfavorable neurologic outcome (CPC 3-5), 20 (11.7%) scores were discordant (kappa: 0.70), also indicating substantial agreement. Patients discharged home (as opposed to nursing/other care facility) and patients with suspected cardiac etiology of arrest were statistically more likely to have concordant scores. For the quality improvement database, patients with discordant scores had a statistically higher median CPC score than those with concordant scores. The registry had statistically lower median CPC score (CPC 1) than the quality improvement database (CPC 2); p\u3c0.01 for statistical significance. CONCLUSIONS: CPC scores have substantial inter-rater reliability, which is reduced in patients who have worse outcomes, have a non-cardiac etiology of arrest, and are discharged to a location other than home

Factors associated with post-arrest withdrawal of life-sustaining therapy.

INTRODUCTION: Most successfully resuscitated cardiac arrest patients do not survive to hospital discharge. Many have withdrawal of life sustaining therapy (WLST) as a result of the perception of poor neurologic prognosis. The characteristics of these patients and differences in their post-arrest care are largely unknown. METHODS: Utilizing the Penn Alliance for Therapeutic Hypothermia Registry, we identified a cohort of 1311 post-arrest patients from 26 hospitals from 2010 to 2014 who remained comatose after return of spontaneous circulation. We stratified patients by whether they had WLST post-arrest and analyzed demographic, arrest, and post-arrest variables. RESULTS: In our cohort, 565 (43%) patients had WLST. In multivariate regression, patients who had WLST were less likely to go to the cardiac catheterization lab (OR 0.40; 95% CI: 0.26-0.62) and had shorter hospital stays (OR 0.93; 95% CI: 0.91-0.95). When multivariate regression was limited to patient demographics and arrest characteristics, patients with WLST were older (OR 1.18; 95% CI: 1.07-1.31 by decade), had a longer arrest duration (OR 1.14; 95% CI: 1.05-1.25 per 10min), more likely to be female (OR: 1.41; 95% CI: 1.01-1.96), and less likely to have a witnessed arrest (OR 0.65; 95% CI: 0.42-0.98). CONCLUSION: Patients with WLST differ in terms of demographic, arrest, and post-arrest characteristics and treatments from those who did not have WLST. Failure to account for this variability could affect both clinical practice and the interpretation of research

Magnesium Depletion in Patients Treated with Therapeutic Hypothermia After Cardiac Arrest

Magnesium (Mg2+) depletion can have detrimental effects in postcardiac arrest patients through multiple potential mechanisms. Therapeutic hypothermia (TH) produces a Mg2+ diuresis, but the effects of postcardiac arrest TH on serum Mg2+ levels in patients with postcardiac arrest syndrome (PCAS) are yet to be systematically quantified. We conducted a retrospective chart review of 119 consecutive comatose PCAS patients treated with TH between 2005 and 2010 and compared them to 33 matched historic controls (HCs) seen at the same institution between 2002 and 2005 who were not treated with TH. We abstracted data from the first 96 hours postarrest, including date, time, and value of serum Mg2+ levels and date, time, and amount of Mg2+ repletion, along with outcomes at discharge. The median Mg2+ level of TH patients was 2.0?mg/dL [interquartile range (IQR), 1.9?2.2?mg/dL] (0.82 mmol/L [IQR, 0.78?0.90 mmol/L]) versus 2.2?mg/dL [IQR, 1.9?2.4?mg/dL] (0.90 mmol/L [IQR, 0.82?0.99 mmol/L]) (p=0.2) in HCs. In addition, 42.9% (520/1214) of Mg2+ levels in TH patients versus 31.9% (43/135) (p=0.014) in HC patients were below 2.0?mg/dL [0.82 mmol/L]. The average number of times the Mg2+ level was checked in TH patients was 10.2 (range 1?18) versus 4.1 (range 1?10) in HCs. The TH patients were more likely to receive supplemental Mg2+ than HCs (81.5% [97/119] vs. 27.3% [9/33] [p<0.01]). The mean supplemental Mg2+ dose was 1.9?g for TH patients versus 0.5?g for HC patients. Mortality in patients treated with TH was 53.1% (60/113) versus 78.6% (22/28) (p=0.014) in HCs. Low serum Mg2+ levels with subsequent Mg2+ supplementation were more common in comatose patients with PCAS treated with TH compared to normothermic HC patients. The effect of untreated hypomagnesemia on postcardiac arrest outcomes remains to be determined.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140255/1/ther.2014.0012.pd

Right ventricular dysfunction after resuscitation predicts poor outcomes in cardiac arrest patients independent of left ventricular function.

OBJECTIVE: Determination of clinical outcomes following resuscitation from cardiac arrest remains elusive in the immediate post-arrest period. Echocardiographic assessment shortly after resuscitation has largely focused on left ventricular (LV) function. We aimed to determine whether post-arrest right ventricular (RV) dysfunction predicts worse survival and poor neurologic outcome in cardiac arrest patients, independent of LV dysfunction. METHODS: A single-center, retrospective cohort study at a tertiary care university hospital participating in the Penn Alliance for Therapeutic Hypothermia (PATH) Registry between 2000 and 2012. PATIENTS: 291 in- and out-of-hospital adult cardiac arrest patients at the University of Pennsylvania who had return of spontaneous circulation (ROSC) and post-arrest echocardiograms. MEASUREMENTS AND MAIN RESULTS: Of the 291 patients, 57% were male, with a mean age of 59 ± 16 years. 179 (63%) patients had LV dysfunction, 173 (59%) had RV dysfunction, and 124 (44%) had biventricular dysfunction on the initial post-arrest echocardiogram. Independent of LV function, RV dysfunction was predictive of worse survival (mild or moderate: OR 0.51, CI 0.26-0.99, p CONCLUSIONS: Echocardiographic findings of post-arrest RV dysfunction were equally prevalent as LV dysfunction. RV dysfunction was significantly predictive of worse outcomes in post-arrest patients after accounting for LV dysfunction. Post-arrest RV dysfunction may be useful for risk stratification and management in this high-mortality population

Click Worthy: Stories Encourage Emergency Physicians to Learn More About Opioid Prescribing Guidelines

Narrative vignettes outperform standard summaries in promoting engagement with opioid prescription guidelines among a national sample of emergency physicians

Comparing Attending and Patient Evaluation of Medical Student Communication Skills on an Emergency Medicine Clerkship

Learning Objective: To determine how attending and patient assessment of medical student communication skills correlate.Background: Accurately assessing medical student (MS) patient communication skills is an essential component of undergraduate medical education. There are different methods used to evaluate MSs, including supervising attending physician ratings as well as patient assessment. However, it is unclear how these distinct types of evaluators compare with each other.Objectives: To determine how attending and patient assessment of MS communication skills correlate. We hypothesized the two would closely correlate.Methods: This was a retrospective study of rotating fourth-year MSs on an elective EM clerkship. From 7/16–10/17, ED attending physicians and patients assessed MS communication skills during the students’ ED shifts. Attendings rated MS communication skills with patients using a 1-5 Likert scale. Patients evaluated MSs using the modified Communication Assessment Tool (CAT), a 14-item questionnaire based on a 1-5 Likert scale. Mean attending ratings and patient CAT scores were calculated for each MS. Due to nonparametric distribution, means were divided into tertiles and scores weighted to assign adjacent tertiles partial agreement. Agreement between attending and CAT scores was measured using a Cohen’s kappa.Results: 25 MSs were included. A total of 217 supervising attending evaluations with a median of 9 evaluations per MS (interquartile range (IQR) 8-10, min 6) and 102 CAT questionnaires with a median of 4 evaluations per MS (IQR 3-5, min 3) were completed. Attending and CAT scores showed slight agreement (k 0.196).Conclusions: Attending and patient ratings of MS communication skills show only slight agreement. It is possible that utilizing only one type of evaluator during a clerkship may miss important communication issues that could be addressed with the MS. Utilizing a multimodal approach that includes both attending and patient evaluations may be beneficial in fully assessing and subsequently educating MSs on their patient communication skills