Therapeutic Hypothermia After Cardiac Arrest is Underutilized in the United States

Hispanic/Latino-Serving Hospitals Provide Less Targeted Temperature Management Following Out-of-Hospital Cardiac Arrest

Background Variation exists in outcomes following out-of-hospital cardiac arrest, but whether racial and ethnic disparities exist in postarrest provision of targeted temperature management (TTM) is unknown. Methods and Results We performed a retrospective analysis of a prospectively collected cohort of patients who survived to admission following out-of-hospital cardiac arrest from the Cardiac Arrest Registry to Enhance Survival, whose catchment area represents ≈50% of the United States from 2013 to 2019. Our primary exposure was race or ethnicity and primary outcome was utilization of TTM. We built a mixed-effects model with both state of arrest and admitting hospital modeled as random intercepts to account for clustering. Among 96 695 patients (24.6% Black patients, 8.0% Hispanic/Latino patients, and 63.4% White patients), a smaller percentage of Hispanic/Latino patients received TTM than Black or White patients (37.5% versus 45.0% versus 43.3%, P<0.001) following out-of-hospital cardiac arrest. In the mixed-effects model, Black patients (odds ratio [OR], 1.153 [95% CI, 1.102-1.207], P<0.001) and Hispanic/Latino patients (OR, 1.086 [95% CI, 1.017-1.159], P<0.001) were slightly more likely to receive TTM compared with White patients, perhaps because of worse neurological status on admission. We did find community- level disparity because Hispanic/Latino-serving hospitals (defined as the top decile of hospitals that cared for the highest proportion of Hispanic/Latino patients) provided less TTM (OR, 0.587 [95% CI, 0.474-0.742], P<0.001). Conclusions Reassuringly, we did not find evidence of intrahospital or interpersonal racial or ethnic disparity in the provision of TTM. However, we did find interhospital, community-level disparity. Hispanic/Latino-serving hospitals provided less guideline-recommended TTM after out-of-hospital cardiac arrest.

Women receive less targeted temperature management than men following out-of-hospital cardiac arrest due to early care limitations - A study from the CARES Investigators

BACKGROUND

Women experience worse neurological outcomes following out-of-hospital cardiac arrest (OHCA). It is unknown whether sex disparities exist in the use of targeted temperature management (TTM), a standard of care treatment to improve neurological outcomes.

METHODS

We performed a retrospective study of prospectively collected patients who survived to hospital admission following OHCA from the Cardiac Arrest Registry to Enhance Survival from 2013 through 2019. We compared receipt of TTM by sex in a mixed-effects model adjusted for patient, arrest, neighborhood, and hospital factors, with the admitting hospital modeled as a random intercept.

RESULTS

Among 123,419 patients, women had lower rates of shockable rhythms (24.4 % vs. 39.2%, P < .001) and lower rates of presumed cardiac aetiologies for arrest (74.3% vs. 81.1%, P < .001). Despite receiving a similar rate of TTM in the field (12.1% vs. 12.6%, P = .02), women received less TTM than men upon admission to the hospital (41.6% vs. 46.4%, P < .001). In an adjusted mixed-effects model, women were less likely than men to receive TTM (Odds Ratio 0.91, 95% Confidence Interval 0.89 to 0.94). Among the 27,729 patients with data indicating the reason for not using TTM, a higher percentage of women did not receive TTM due to Do-Not-Resuscitate orders/family requests (15.1% vs. 11.4%, p < .001) and non-shockable rhythms (11.1% vs. 8.4%, p < .001).

CONCLUSIONS

We found that women received less TTM than men, likely due to early care limitations and a preponderance of non-shockable rhythms.

Implementation of Targeted Temperature Management After Out-of-Hospital Cardiac Arrest: Observations From the Los Angeles County Regional System

Background

Despite the benefits of targeted temperature management (TTM) for out‐of‐hospital cardiac arrest), implementation within the United States remains low. The objective of this study was to evaluate the prevalence and factors associated with TTM use in a large, urban‐suburban regional system of care.

Methods and Results

This was a retrospective analysis from the Los Angeles County regional cardiac system of care serving a population of >10 million residents. All adult patients aged ≥18 years with non‐traumatic out‐of‐hospital cardiac arrest transported to a cardiac arrest center from April 2011 to August 2017 were included. Patients awake and alert in the emergency department and patients who died in the emergency department before consideration for TTM were excluded. The primary outcome measure was prevalence of TTM use. The secondary analysis were annual trends in TTM use over the study period and factors associated with TTM use. The study population included 8072 patients; 4154 patients (51.5%) received TTM and 3767 patients (46.7%) did not receive TTM. Median age was 67 years, 4780 patients (59.2%) were men, 4645 patients (57.5%) were non‐White, and the most common arrest location was personal residence in 4841 patients (60.0%). In the adjusted analysis, younger age, male sex, an initial shockable rhythm, witnessed arrest, and receiving coronary angiography were associated with receiving TTM.

Conclusions

Within this regional system of care, use of TTM was higher than previously reported in the literature at just over 50%. Use of integrated systems of care may be a novel method to increase TTM use within the United States.

Outcomes and Utilization of Therapeutic Hypothermia in Post-Cardiac Arrest Patients in Teaching Versus Non-Teaching Hospitals: Retrospective Study of the Nationwide Inpatient Sample Database (2016)

Background Using therapeutic hypothermia (TH) reduces the core body temperature of survivors of cardiac arrest to minimize the neurological damage caused by severe hypoxia. The TH protocol is initiated following return of spontaneous circulation (ROSC) in non-responsive patients. Clinical trials examining this technique have shown significant improvement in neurological function among survivors of cardiac arrests. Though there is strong evidence to support TH use to improve the neurologic outcomes in shockable and nonshockable rhythms, predictors of TH utilization are not well-characterized. Our study tried to evaluate TH utilization, as well as the effect of the teaching status of hospitals, on outcomes, including mortality, length of stay, and total hospitalization charges. Method We conducted a retrospective analysis of the Healthcare Cost and Utilization Project - Nationwide Inpatient Sample (HCUP-NIS) database. Patients with an admitting diagnosis of cardiac arrest, as identified by the corresponding International Classification of Disease, 10th Revision (ICD-10) code for the year 2016 were analyzed. In addition, we identified TH using the ICD-10 procedure code. A weighted descriptive analysis was performed to generate national estimates. Groups of patients admitted to teaching hospitals were compared to those admitted in non-teaching hospitals. Patients were stratified by age, sex, race, and demographic and clinical data, including the Charlson Comorbidity Index (CCI), for these two groups, and statistical analysis was done for the primary outcome, in-hospital mortality, as well as the secondary outcomes, including length of stay (LOS) and total hospitalization charges. Fisher's exact test was used to compare proportions and student's t-test for continuous variables. Statistical analysis was completed by linear regression analysis. Results A total of 13,780 patients met the inclusion criteria for cardiac arrest admission. The number of patients with cardiac arrest admitted to a teaching hospital was 9285. A total of 670 patients received TH, with 495 admissions to teaching hospitals. The population of females in the hypothermia group was 270. The mean age of patients received TH was 59.4 years. In patients who received TH, 65% were Caucasians followed by Hispanics (16%), with no significant statistical racial differences in groups (p=0.30). The majority of patients with TH in both groups (teaching vs. non-teaching admissions) had Medicare (58.8% vs 49.5%; p=0.75). Hospitals in the southern region had the most admissions in both groups (45.7% and 31.3%), with the northeast region having the least non-teaching hospital admissions (8.5%) and approximately similar teaching hospital admissions in other regions (~22%) (p=0.27). The total number of deaths in this group was 510, out of which 370 were in a teaching hospital. After adjusting for age, sex, race, income, the CCI, hospital location, and bed size, mortality was not significantly different between these two groups (p=0.797). We found increased LOS in patients admitted to teaching hospitals (p=0.021). With a p-value of 0.097, there were no differences in total hospitalization charges in both groups. Conclusion There were no significant differences in mortality or total hospitalization charge between patients admitted with cardiac arrest to a teaching hospital and received TH as compared to a non-teaching hospital although patients admitted to teaching hospitals stayed longer.

Retrospective Analysis of Esophageal Heat Transfer for Active Temperature Management in Post-cardiac Arrest, Refractory Fever, and Burn Patients

Core temperature management is an important aspect of critical care; preventing unintentional hypothermia, reducing fever, and inducing therapeutic hypothermia when appropriate are each tied to positive health outcomes. The purpose of this study is to evaluate the performance of a new temperature management device that uses the esophageal environment to conduct heat transfer. De-identified patient data were aggregated from three clinical sites where an esophageal heat transfer device (EHTD) was used to provide temperature management. The device was evaluated against temperature management guidelines and best practice recommendations, including performance during induction, maintenance, and cessation of therapy. Across all active cooling protocols, the average time-to-target was 2.37 h and the average maintenance phase was 22.4 h. Patients spent 94.9% of the maintenance phase within ±1.0°C and 67.2% within ±0.5°C (574 and 407 measurements, respectively, out of 605 total). For warming protocols, all of the patient temperature readings remained above 36°C throughout the surgical procedure (average 4.66 h). The esophageal heat transfer device met performance expectations across a range of temperature management applications in intensive care and burn units. Patients met and maintained temperature goals without any reported adverse events.

Use of therapeutic hypothermia among patients with coagulation disorders - A Nationwide analysis

OBJECTIVES

The study aimed to assess the impact of therapeutic hypothermia (TH) on bleeding and in-hospital mortality among patients with coagulation disorders (CD).

BACKGROUND

TH affects coagulation factors and platelets putting patients at risk for bleeding and worse outcomes. Effect of TH among patients with CD remains understudied.

METHODS

Between 2009 and 2014, a total of 6469 cases of TH were identified using the National Inpatient Sample out of which 1036 (16.02%) had a CD. The incidence of bleeding events, blood product transfusion and in-hospital mortality was compared between patients with and without CD using one to one propensity score matching.

RESULTS

Proportion of patients with CD increased during study duration from 13.0% to 17.4% from 2009 to 2014. Propensity matching was performed to adjust for baseline differences with 799 patients in both groups depending on presence or absence of CD. Patients with CD had a higher rate of bleeding events (13% vs. 8.5%; adjusted odds ratio 1.60; 95% confidence interval 1.16-2.23; P = 0.004), and blood product transfusion (25.0% vs. 14.1%; aOR 2.03; 95% CI 1.56-2.63; p < 0.001) compared to those without CD. There was no difference in rate of intracranial bleeding or hemorrhagic strokes between those with and without CD (3.3% vs. 3.2%; p = 0.88). There was no difference in mortality between patients with CD and those without (74.5% vs. 74.8%, aOR 0.98, 95% CI 0.78-1.23; P = 0.86).

CONCLUSIONS

Use of TH with CD resulted in more bleeding events and blood product transfusion but there was no difference in hospital mortality.

Outcomes of ST Elevation Myocardial Infarction Complicated by Out-of-Hospital Cardiac Arrest (from the Los Angeles County Regional System)

The objective of this study was to evaluate the time to primary percutaneous coronary intervention (PCI) and the outcome for patients with ST elevation myocardial infarction (STEMI) complicated by out-of-hospital cardiac arrest (OHCA). In this regional system, all patients with STEMI and/or OHCA with return of spontaneous circulation were transported to STEMI Receiving Centers. The outcomes registry was queried for patients with STEMI with underwent primary PCI from April 2011 to December 2014. Patients with STEMI complicated by OHCA were compared with a reference group of STEMI without OHCA. The primary end point was the first medical contact-to-device time. Of 4,729 patients with STEMI who underwent primary PCI, 422 patients (9%) suffered OHCA. Patients with OHCA were on average 2 years (95% confidence interval 0.7 to 3.0) older and had a slightly higher male predominance. The first medical contact-to-device time was longer in STEMI with OHCA compared with STEMI alone (94 ± 37 vs. 86 ± 34 minutes, p < 0.0001). In-hospital mortality was higher after OHCA, 38% versus 6% in STEMI alone, odds ratio 6.3 (95% confidence interval 5.3 to 7.4). Among OHCA survivors, 193 (73%) were discharged with a cerebral performance category score of 1 or 2. In conclusion, despite longer treatment intervals, neurologic outcome was good in nearly half of the surviving patients with STEMI complicated by OHCA, suggesting that these patients can be effectively treated with primary PCI in a regionalized system of care.

Relationship between timing of cooling and outcomes in adult comatose cardiac arrest patients treated with targeted temperature management

AIM OF THE STUDY

Studies examining associations between time to target temperature and outcomes in cardiac arrest patients who underwent targeted temperature management (TTM) have shown inconsistent results. We examined these associations separately for time from restoration of spontaneous circulation to TTM initiation (pre-induction time) and time from TTM initiation to target temperature (induction time). Furthermore, we examined whether critical time thresholds exist if there is an association.

METHODS

This was a single-centre retrospective observational study including adult cardiac arrest patients treated with TTM from 2008 to 2015. We tested the associations of pre-induction time and induction time with outcomes at hospital discharge using multivariate logistic regression analysis. We then performed additional multivariate analyses, each with the significant timing variable at different binary cutoffs.

RESULTS

A total of 515 patients were analysed. At hospital discharge, 357 patients (69.3%) were alive, of whom 161 (31.3%) had a favourable neurologic outcome. In multivariate analysis, a shorter pre-induction time was independently associated with a favourable neurologic outcome (odds ratio [OR], 1.110; 95% confidence interval [CI], 1.025-1.202), whereas the induction time was not (OR, 0.954; 95% CI, 0.852-1.067). We found two pre-induction time thresholds (120 and 360min) that were associated with neurologic outcome.

CONCLUSION

We found that a shorter pre-induction time was independently associated with a favorable neurologic outcome at hospital discharge, whereas induction time was not. We also found two time thresholds at 120 and 360min, after which initiation of cooling was associated with a worse neurologic outcome.

Implementation of the guidelines for targeted temperature management after cardiac arrest: a longitudinal qualitative study of barriers and facilitators perceived by hospital resuscitation champions

OBJECTIVES

To identify the barriers to and facilitators of implementing guidelines for targeted temperature management (TTM) after cardiac arrest perceived by hospital resuscitation champions and to investigate the changes in their perceptions over the early implementation period.

DESIGN

A longitudinal qualitative study (up to 2 serial semistructured interviews over 1 year and focus groups). The individual interviews and focus groups were transcribed and coded by 2 independent assessors. Contents were analysed thematically; group interaction was also examined.

SETTING

21 hospitals, including community and tertiary care centres in South Korea.

PARTICIPANTS

21 hospital champions (14 acting champions and 7 managerial champions).

RESULTS

The final data set included 40 interviews and 2 focus groups. The identified barriers and facilitators could be classified into 3 major themes: (1) healthcare professionals' perceptions of the guidelines and protocols, (2) interdisciplinary and interprofessional collaboration and (3) organisational resources. Lack of resources was the most commonly agreed on barrier for the acting champions, whereas lack of interdisciplinary collaboration was the most common barrier for the managerial champions. Educational activities and sharing successfully treated cases were the most frequently identified facilitators. Most of the participants identified and agreed that cooling equipment was an important barrier as well as a facilitator of successful TTM implementation. Perception of the guidelines and protocols has improved with the accumulation of clinical experience over the study period.

CONCLUSIONS

Healthcare professionals' internal barriers to TTM implementation may be influenced by new guidelines and can be changed with the accumulation of successful clinical experiences during the early implementation period. Promoting interprofessional and interdisciplinary collaboration through educational activities and the use of cooling equipment with an automated feedback function can improve adherence to guidelines in hospitals with limited human resources in critical care.

The impact of prehospital resuscitation research on in-hospital care

Since their introduction over 40 years ago, paramedics have been trained to deliver select advanced life support interventions in the community with the goal of reducing morbidity and mortality from cardiovascular disease and trauma. The ensuing decades witnessed a great deal of interest in paramedic care, with an exponential growth in prehospital resuscitation research. As part of the CJEM series on emergency medical services (EMS), we review recent prehospital research in out-of-hospital cardiac arrest and discuss how, in a novel departure from the origins of EMS, prehospital research is beginning to influence in-hospital care. We discuss emerging areas of study related to cardiopulmonary resuscitation (CPR) quality, therapeutic hypothermia, termination of resuscitation, and the use of end-tidal carbon dioxide measurement, as well as the subtle ripple effects that prehospital research is having on the broader understanding of the management of these critically ill patients.

Impact of case volume on outcome and performance of targeted temperature management in out-of-hospital cardiac arrest survivors

PURPOSE

This study aimed to determine the effect of case volume on targeted temperature management (TTM) performance, incidence of adverse events, and neurologic outcome in comatose out-of-hospital cardiac arrest (OHCA) survivors treated with TTM.

METHODS

We used a Web-based, multicenter registry (Korean Hypothermia Network registry), to which 24 hospitals throughout the Republic of Korea participated to study adult (≥18 years) comatose out-of-hospital cardiac arrest patients treated with TTM between 2007 and 2012. The primary outcome was neurologic outcome at hospital discharge. The secondary outcomes were inhospital mortality, TTM performance, and adverse events. We extracted propensity-matched cohorts to control for bias. Multivariate logistic regression analysis was performed to assess independent risk factors for neurologic outcome.

RESULTS

A total of 901 patients were included in this study; 544 (60.4%) survived to hospital discharge, and 248 (27.5%) were discharged with good neurologic outcome. The high-volume hospitals initiated TTM significantly earlier and had lower rates of hyperglycemia, bleeding, hypotension, and rebound hyperthermia. However, neurologic outcome and inhospital mortality were comparable between high-volume (27.7% and 44.6%, respectively) and low-volume hospitals (21.1% and 40.5%) in the propensity-matched cohorts. The adjusted odds ratio for the high-volume hospitals compared with low-volume hospitals was 1.506 (95% confidence interval, 0.875-2.592) for poor neurologic outcome.

CONCLUSIONS

Higher TTM case volume was significantly associated with early initiation of TTM and lower incidence of adverse events. However, case volume had no association with neurologic outcome and inhospital mortality.