Induced hypothermia is underused after resuscitation from cardiac arrest: a current practice survey

Impact of post-arrest care variation on hospital performance after out-of-hospital cardiac arrest

Background

Large variation exists for out-of-hospital-cardiac-arrest (OHCA) prehospital care, but less is known about variations in post-arrest care. We sought to evaluate variation in post-arrest care in Texas as well as factors associated with higher performing hospitals.

Methods

We analyzed data in Texas Cardiac Arrest Registry to Enhance Survival (TX-CARES), including all adult, non-traumatic OHCAs from 1/1/2014 through 12/31/ 2020 that survived to hospital admission. We first evaluated variability in provisions of post-arrest care and outcomes. We then stratified hospitals into quartiles based on their rate of survival and evaluated the association between improving quartiles and care. Lastly, we evaluated for outliers in post-arrest care and outcomes using a mixed-effect regression model.

Results

We analyzed 7,842 OHCAs admitted to 146 hospitals. We identified large variations in post-arrest care, including targeted temperature management (TTM) (IQR 7.0-51.1%), left heart catheterization (LHC) (IQ 0-25%), and percutaneous coronary intervention (PCI) (IQR 0-10.3%). Higher performing hospital quartiles were associated with higher rates of TTM (aOR 1.42, 95% CI 1.36-1.49), LHC (aOR 2.07, 95% CI 1.92-2.23), and PCI (aOR 2.02, 95% CI 1.81-2.25); but lower rates of bystander CPR (aOR 0.90, 95% CI 0.87-0.94). We identified numerous performance outlier hospitals; 39 for TTM, 34 for PCI, 9 for survival to discharge, and 24 for survival with good neurologic function.

Conclusions

Post-arrest care varied widely across Texas hospitals. Hospitals with higher rates of survival to discharge had increased rates of TTM, LHC, and PCI but not bystander CPR.

Simulation-based assessment of trainee's performance in post-cardiac arrest resuscitation

Objectives

To assess trainees’ performance in managing a patient with post-cardiac arrest complicated by status epilepticus.

Methods

In this prospective, observational, single-center simulation-based study, trainees ranging from sub interns to critical care fellows evaluated and managed a post cardiac arrest patient, complicated by status epilepticus. Critical action items were developed by a modified Delphi approach based on American Heart Association guidelines and the Neurocritical Care Society’s Emergency Neurological Life Support protocols. The primary outcome measure was the critical action item sum score. We sought validity evidence to support our findings by including attending neurocritical care physicians and comparing performance across four levels of training.

Results

Forty-nine participants completed the simulation. The mean sum of critical actions completed by trainees was 10/21 (49%). Eleven (22%) trainees verbalized a differential diagnosis for the arrest. Thirty-two (65%) reviewed the electrocardiogram, recognized it as abnormal, and consulted cardiology. Forty trainees (81%) independently decided to start temperature management, but only 20 (41%) insisted on it when asked to reconsider. There was an effect of level of training on critical action checklist sum scores (novice mean score [standard deviation (SD)] = 4.8(1.8) vs. intermediate mean score (SD) = 10.4(2.1) vs. advanced mean score (D) = 11.6(3.0) vs. expert mean score (SD) = 14.7(2.2))

Conclusions

High-fidelity manikin-based simulation holds promise as an assessment tool in the performance of post-cardiac arrest care.

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.

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.

The current temperature: A survey of post-resuscitation care across Australian and New Zealand intensive care units

Aim

Targeted temperature management (TTM) in post-resuscitation care has changed dramatically over the last two decades. However, uptake across Australian and New Zealand (NZ) intensive care units (ICUs) is unclear. We aimed to describe post-resuscitation care in our region, with a focus on TTM, and to gain insights into clinician's opinions about the level of evidence supporting TTM.

Methods

In December 2017, we sent an online survey to 163 ICU medical directors in Australia (n ​= ​141) and NZ (n ​= ​22).

Results

Sixty-one ICU medical directors responded (50 from Australia and 11 from NZ). Two respondents were excluded from analysis as their Private ICUs did not admit post-arrest patients. The majority of remaining respondents stated their ICU followed a post-resuscitation care clinical guideline (n ​= ​41/59, 70%). TTM was used in 57 (of 59, 97%) ICUs, of these only 64% had a specific TTM clinical guideline/policy and there was variation in the types of patients treated, temperatures targeted (range ​= ​33-37.5 ​°C), methods for cooling and duration of cooling (range ​= ​12-72 ​h). The majority of respondents stated that their ICU (n ​= ​45/57, 88%) changed TTM practice following the TTM trial: with 28% targeting temperatures >36 ​°C, and 23 (of 46, 50%) respondents expressed concerns with current level of evidence for TTM. Only 38% of post-resuscitation guidelines included prognostication procedures, few ICUs reported the use of electrophysiological tests.

Conclusions

In Australian and New Zealand ICUs there is widespread variation in post-resuscitation care, including TTM practice and prognostication. There also seems to be concerns with current TTM evidence and recommendations.

Usefulness of Therapeutic Hypothermia to Improve Survival in Out-of-Hospital Cardiac Arrest

Background

In recent years, therapeutic hypothermia (TH) has been used to improve outcomes in patients with out-of-hospital cardiac arrest (OHCA). Despite these recommendations, many centers are still hesitant to implement such hypothermia protocols. In this study, we assessed the effects of TH for OHCA patients.

Methods

A total of 58 OHCA patients who had return of spontaneous circulation after OHCA presumed to be due to cardiac causes were enrolled. Twenty-three patients underwent TH, which was performed using a large volume of ice crystalloid fluid infusions in the emergency room and conventional cooling blankets in the ICU to maintain a body temperature of 32-34 °C for 24 hours using a tympanic thermometer. Patients in the control group received standard supportive care without TH. Hospital survival and neurologic outcomes were compared.

Results

There were no significant differences between the groups in patient characteristics, underlying etiologies and disease severity. In the 23 patients who received TH, 17 were alive at hospital discharge. In the 35 patients who received supportive care, only 11 were alive at hospital discharge (73.91% vs. 31.43%, p = 0.0015). Approximately 52% of the patients in the TH group had good neurologic outcomes (12 of 23) compared with the 20% (7 of 35) of the patients in the supportive group (p = 0.01).

Conclusions

TH can improve the outcomes of OHCA patients. Further large-scale studies are needed to verify our results.

Temporal Trends in the Use of Therapeutic Hypothermia for Out-of-Hospital Cardiac Arrest

IMPORTANCE

Despite evidence that therapeutic hypothermia improves patient outcomes for out-of-hospital cardiac arrest, use of this therapy remains low.

OBJECTIVE

To determine whether the use of therapeutic hypothermia and patient outcomes have changed after publication of the Targeted Temperature Management trial on December 5, 2013, which supported more lenient temperature management for out-of-hospital cardiac arrest.

DESIGN, SETTING, AND PARTICIPANTS

A retrospective cohort was conducted between January 1, 2013, and December 31, 2016, of 45 935 US patients in the Cardiac Arrest Registry to Enhance Survival who experienced out-of-hospital cardiac arrest and survived to hospital admission.

EXPOSURES

Calendar time by quarter year.

MAIN OUTCOMES AND MEASURES

Use of therapeutic hypothermia and patient survival to hospital discharge.

RESULTS

Among 45 935 patients (17 515 women and 28 420 men; mean [SD] age, 59.3 [18.3] years) who experienced out-of-hospital cardiac arrest and survived to admission at 649 US hospitals, overall use of therapeutic hypothermia during the study period was 46.4%. In unadjusted analyses, the use of therapeutic hypothermia dropped from 52.5% in the last quarter of 2013 to 46.0% in the first quarter of 2014 after the December 2013 publication of the Targeted Temperature Management trial. Use of therapeutic hypothermia remained at or below 46.5% through 2016. In segmented hierarchical logistic regression analysis, the risk-adjusted odds of use of therapeutic hypothermia was 18% lower in the first quarter of 2014 compared with the last quarter of 2013 (odds ratio, 0.82; 95% CI, 0.71-0.94; P = .006). Similar point-estimate changes over time were observed in analyses stratified by presenting rhythm of ventricular tachycardia or ventricular fibrillation (odds ratio, 0.89; 95% CI, 0.71-1.13, P = .35) and pulseless electrical activity or asystole (odds ratio, 0.75; 95% CI, 0.63-0.89; P = .001). Overall risk-adjusted patient survival was 36.9% in 2013, 37.5% in 2014, 34.8% in 2015, and 34.3% in 2016 (P < .001 for trend). In mediation analysis, temporal trends in use of hypothermia did not consistently explain trends in patient survival.

CONCLUSIONS AND RELEVANCE

In a US registry of patients who experienced out-of-hospital cardiac arrest, the use of guideline-recommended therapeutic hypothermia decreased after publication of the Targeted Temperature Management trial, which supported more lenient temperature thresholds. Concurrent with this change, survival among patients admitted to the hospital decreased, but was not mediated by use of hypothermia.

Implementation of an Asthma Self-Management Education Guideline in the Emergency Department: A Feasibility Study

Patients often present to emergency departments (EDs) for the management of chronic asthma. Because of the nature of ED care, national guideline recommendations for asthma education are generally not initiated in the ED. There is evidence that asthma education can have a positive effect on patient outcomes (; ). This study examines the feasibility of implementing an asthma self-management guideline in a tertiary care center ED. Despite protocol utilization by physicians (87%), nurse practitioners and physician assistants (66.7%), and nurses (41.7%), total compliance with national guideline was accomplished in only 25.93% of cases. Barriers to protocol implementation included staff education, high workload, rapid turnover, and competing initiatives within the department. Linear regression analysis identified high daily census as a predictor of protocol noncompliance (p = 0.033).

Practice Patterns after the Therapeutic Hypothermia After Pediatric Cardiac Arrest Out-of-Hospital Trial: A Survey of Pediatric Critical Care Physicians

The Therapeutic Hypothermia After Pediatric Cardiac Arrest Out-of-Hospital (THAPCA-OH) Trial showed therapeutic hypothermia, versus normothermia, did not significantly improve 1-year survival with good neurobehavioral outcome. Our survey of pediatric critical care physicians, designed to assess the use of targeted temperature management (TTM) after publication of the main THAPCA-OH Trial results, found most respondents were aware of trial results, and over 90% agreed THAPCA-OH was well-designed with important clinical outcomes. While most respondents reported TTM usage consistent with THAPCA-OH results in different patient scenarios, 15% did not select TTM for fever management. Since trials prior to THAPCA-OH established that fever is harmful following brain injury, the continued incomplete adoption of TTM warrants further research on challenges and facilitators to the adoption of clinical trial findings.

Advanced Practice Registered Nurses on Therapeutic Hypothermia Response Teams

BACKGROUND

Therapeutic hypothermia can improve neurological recovery after cardiac arrest when implemented quickly.

OBJECTIVE

To determine whether outcomes are improved among patients undergoing therapeutic hypothermia by adding advanced practice registered nurses to a therapeutic hypothermia response team.

METHODS

A pilot quality improvement project was conducted in a Midwest community teaching hospital using a retrospective chart review of all adult patients undergoing therapeutic hypothermia before and after the addition of advanced practice registered nurses to the therapeutic hypothermia response team. Outcomes evaluated included time to target core body temperature, therapeutic hypothermia protocol initiation, discharge status, and hospital length of stay.

RESULTS

A total of 14 adult patients (preintervention n = 8, postintervention n = 6) comprised the sample. Length of stay decreased in the postintervention group (median 2.5 vs 6 days for the preintervention group; P = .05), but other outcomes did not differ.

CONCLUSIONS

This quality improvement project provides foundational data to evaluate advanced practice registered nurses specific metrics and to compare with future data using a larger longitudinal sample.

Changes in cardiac arrest patients' temperature management after the publication of 2015 AHA guidelines for resuscitation in China

A survey was performed to assess the current management of targeted temperature management (TTM) in patients following cardiac arrest (CA) and whether healthcare providers will change target temperature after publication of 2015 American Heart Association guidelines for resuscitation in China. 52 hospitals were selected from whole of China between August to November 2016. All healthcare providers in EMs and/or ICUs of selected hospitals participated in the study. 1952 respondents fulfilled the survey (86.8%). TTM in CA patients was declared by 14.5% of physicians and 6.7% of the nurses. Only 4 of 64 departments, 7.8% of physicians and 5.7% of the nurses had implemented TH for CA patients. Since the publication of 2015 AHA guidelines, 33.6% of respondents declared no modification of target temperature, whereas 51.5% declared a target temperature's change in future practice. Respondents were more likely to choose 35∼36 °C-TTM (54.7%) after guidelines publication, as compared to that before guidelines publication they preferred 32∼34 °C-TTM (54.0%). TTM for CA patients was still in the early stage in China. Publication of 2015 resuscitation guidelines did have impact on choice of target temperature among healthcare providers. They preferred 35∼36 °C-TTM after guidelines publication.

Factors Influencing the Quality of Standardized Treatment for Patients with Post-Cardiac Arrest Syndrome

Background and Objectives

For the present study, we investigated the factors that influence the quality of standardized treatment for patients with post-cardiac arrest syndrome (PCAS) to improve the quality of PCAS treatment.

Subjects and Methods

We collected data on patients with cardiac arrest (CA) who were admitted to the intensive care units (ICUs) of 11 hospitals-Class II Grade A or above-in Suzhou from January to October 2013. Indexes of standardized treatment were observed within 72 hrs of CA. We analyzed monitoring techniques, monitoring frequency, ICU human and material resources, and intensivists' knowledge of PCAS treatment to explore how those factors affected the management of patients with PCAS.

Results

The bed/nurse ratio and the frequency with which core temperature was recorded correlated closely with the implementation of therapeutic hypothermia (TH) within 6 hrs of CA. The bed/doctor ratio and intensivists' knowledge about PCAS correlated closely with high-quality blood glucose control within 6 hrs of CA. Furthermore, the frequency with which core temperature was recorded was an independent factor influencing the quality of TH implementation, and the number times blood gas was analyzed was an independent factor influencing how well partial pressure of carbon dioxide was kept within the normal range in the 6 hrs after CA.

Conclusion

The frequency of core temperature measurements and the number of times blood gas is analyzed are the most important factors influencing the quality of standardized treatment for patients with PCAS.

The Postcardiac Arrest Consult Team: Impact on Hospital Care Processes for Out-of-Hospital Cardiac Arrest Patients

OBJECTIVE

To evaluate whether a Post-Arrest Consult Team improved care and outcomes for patients with out-of-hospital cardiac arrest.

DESIGN

Prospective cohort study of Post-Arrest Consult Team implementation at two hospitals, with concurrent controls from 27 others.

SETTING

Twenty-nine hospitals within the Strategies for Post-Arrest Care Network of Southern Ontario, Canada.

PATIENTS

We included comatose adult nontraumatic out-of-hospital cardiac arrest patients surviving more than or equal to 6 hours after emergency department arrival who had no contraindications to targeted temperature management.

INTERVENTION

The Post-Arrest Consult Team was an advisory consult service to improve 1) targeted temperature management, 2) assessment for percutaneous coronary intervention, 3) electrophysiology assessment, and 4) appropriately delayed neuroprognostication.

MEASUREMENTS AND MAIN RESULTS

We used generalized linear mixed models to explore the association between Post-Arrest Consult Team implementation and performance of targeted processes. We included 1,006 patients. The Post-Arrest Consult Team was associated with a significant reduction over time in rates of withdrawal of life-sustaining therapy within 72 hours of emergency department arrival on the basis of predictions of poor neurologic prognosis (ratio of odds ratios, 0.13; 95% CI, 0.02-0.98). Post-Arrest Consult Team was not associated with improved successful targeted temperature management (ratio of odds ratios, 0.91; 95% CI, 0.31-2.65), undergoing angiography (ratio of odds ratios, 1.91; 95% CI, 0.17-21.04), receiving electrophysiology consultation (ratio of odds ratios, 0.93; 95% CI, 0.11-8.16), or functional survival (ratio of odds ratios, 0.75; 95% CI, 0.19-2.94).

CONCLUSIONS

Implementation of a Post-Arrest Consult Team reduced premature withdrawal of life-sustaining therapy but did not improve rates of successful targeted temperature management, coronary angiography, formal electrophysiology assessments, or functional survival for comatose patients after out-of-hospital cardiac arrest.

Association of serum lactate with outcome after out-of-hospital cardiac arrest treated with therapeutic hypothermia

Aims

Lactate reflects hypoxic insult in many conditions and is considered as a prognosis factor. But, after cardiac arrest, its interest is still debated. Our study aimed to assess the prognosis value of lactate in out-of-hospital cardiac arrest patients treated with therapeutic hypothermia.

Methods

This retrospective observational study included out-of-hospital cardiac arrest patients treated with therapeutic hypothermia in four ICUs. Lactate levels were compared at different times during the first 24 hours according to outcome at ICU discharge and to the type of death (multiorgan or neurologic failure).

Results

Two hundred and seventy-two patients were included, 89 good outcome and 183 poor outcome. In the latter group, 171 patients died, from multiorgan failure in 30% and neurologic failure in 70%. Lactate levels were higher in the poor compared to the good outcome patients at admission (5.4 (3.3–9.4) vs. 2.2 (1.5–3.6) mmol/L; p<0.01), 12 hours (2.5 (1.6–4.7) vs. 1.4 (1.0–2.2) mmol/L; p<0.01) and 24 hours (1.8 (1.1–2.8) vs. 1.3 (0.9–2.1) mmol/L; p<0.01). Patients succumbing from multiorgan failure exhibited higher lactate levels compared to those dying from neurologic failure at admission (7.9 (3.9–12.0) vs. 5.2 (3.3–8.8) mmol/L; p<0.01), H12 (4.9 (2.1–8.9) vs. 2.2 (1.4–3.4) mmol/L; p<0.01) and H24 (3.3 (1.8–5.5) vs. 1.4 (1.1–2.5) mmol/L; p<0.01). Initial lactate levels showed an increasing proportion of poor outcome from the first to fourth quartile.

Conclusions

After out-of-hospital cardiac arrest treated with therapeutic hypothermia, lactate levels during the first 24 hours seem linked with ICU outcome. Patients dying from multiorgan failure exhibit higher initial lactate concentrations than patients succumbing from neurological failure.

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.

Changes in cardiac arrest patients' temperature management after the 2013 "TTM" trial: results from an international survey

BACKGROUND

Therapeutic hypothermia (TH between 32 and 34 °C) was recommended until recently in unconscious successfully resuscitated cardiac arrest (CA) patients, especially after initial shockable rhythm. A randomized controlled trial published in 2013 observed similar outcome between a 36 °C-targeted temperature management (TTM) and a 33 °C-TTM. The main aim of our study was to assess the impact of this publication on physicians regarding their TTM practical changes.

METHODS

A declarative survey was performed using the webmail database of the French Intensive Care Society including 3229 physicians (from May 2014 to January 2015).

RESULTS

Five hundred and eighteen respondents from 264 ICUs in 11 countries fulfilled the survey (16 %). A specific attention was generally paid by 94 % of respondents to TTM (hyperthermia avoidance, normothermia, or TH implementation) in CA patients, whereas 6 % did not. TH between 32 and 34 °C was declared as generally maintained during 12-24 h by 78 % of respondents or during 24-48 h by 19 %. Since the TTM trial publication, 56 % of respondents declared no modification of their TTM practice, whereas 37 % declared a practical target temperature change. The new temperature targets were 35-36 °C for 23 % of respondents, and 36 °C for 14 %. The duration of overall TTM (including TH and/or normothermia) was declared as applied between 12 and 24 h in 40 %, and between 24 and 48 h in 36 %. In univariate analysis, the physicians' TTM modification seemed related to hospital category (university versus non-university hospitals, P = 0.045), to TTM-specific attention paid in CA patients (P = 0.008), to TH durations (<12 versus 24-48 h, P = 0.01), and to new targets temperature (32-34 versus 35-36 °C, P < 0.0001).

CONCLUSIONS

The TTM trial publication has induced a modification of current practices in one-third of respondents, whereas the 32-34 °C target temperature remained unchanged for 56 %. Educational actions are needed to promote knowledge translations of trial results into clinical practice. New international guidelines may contribute to this effort.

A survey-based study on the protocols for therapeutic hypothermia in cardiac arrest patients in Korea: focusing on the differences between level 1 and 2 centers

OBJECTIVE

We aimed to summarize the therapeutic hypothermia (TH) protocols used in emergency departments (EDs) in Korea and to investigate the differences between level 1 and 2 centers.

METHODS

The chief residents from 56 EDs were given a structured survey containing questions on the indications for TH, methods for TH induction, maintaining, and finalizing TH treatments. The participants were divided into 2 groups based on their work place (level 1 vs. level 2 centers).

RESULTS

We received 36 responses to the survey. The majority of the participants (94.4%) reported that they routinely used TH. An average of 5.9 (standard deviation, 3.4) and 3.3 (standard deviation, 2.9) TH procedures were performed monthly in level 1 and 2 centers, respectively (P=0.01). The majority of level 1 and 2 centers (80.0% and 73.1%, respectively) had written TH protocols. Rectal (50.0%) and esophageal probes (38.9%) were most commonly used to monitor the patients' body temperatures. Midazolam (80.6%) and remifentanyl (47.2%) were the most commonly used sedatives. For TH induction, external cooling devices (77.8%) and cold saline infusion (66.1%) were predominant. Between level 1 and 2 centers, only the number of TH, the usage of remifentanyl, and application of external cooling device showed significant differences (P<0.05).

CONCLUSION

Our study summarizes the TH protocols used in 36 EDs. The majority of study participants performed TH using a written protocol. We observed small number of differences in TH induction and maintenance methods between level 1 and 2 centers.

The Cardiovascular Intensive Care Unit-An Evolving Model for Health Care Delivery

Prior to the advent of the coronary care unit (CCU), patients having an acute myocardial infarction (AMI) were managed on the general medicine wards with reported mortality rates of greater than 30%. The first CCUs are believed to be responsible for reducing mortality attributed to AMI by as much as 40%. This drastic improvement can be attributed to both advances in medical technology and in the process of health care delivery. Evolving considerably since the 1960s, the CCU is now more appropriately labeled as a cardiac intensive care unit (CICU) and represents a comprehensive system designed for the care of patients with an array of advanced cardiovascular disease, an entity that reaches far beyond its early association with AMI. Grouping of patients by diagnosis to a common physical space, dedicated teams of health care providers, as well as the development and implementation of evidence-based treatment algorithms have resulted in the delivery of safer, more efficient care, and most importantly better patient outcomes. The CICU serves as a platform for an integrated, team-based patient care delivery system that addresses a broad spectrum of patient needs. Lessons learned from this model can be broadly applied to address the urgent need to improve outcomes and efficiency in a variety of health care settings.

Protective effects of cyclosporine A and hypothermia on neuronal mitochondria in a rat asphyxial cardiac arrest model

BACKGROUND

Cyclosporine A (CsA) was neuroprotective in the settings of traumatic brain injury and stroke. We sought to investigate the protective effects of CsA and hypothermia on neuronal mitochondria after cardiac arrest.

METHODS AND RESULTS

Five groups were included: sham (S), normothermia (N), CsA (C), hypothermia (H), and CsA plus hypothermia (C+H). Cardiac arrest was induced by 10min of asphyxia. CsA (10mg/kg) was administered immediately after return of spontaneous circulation in the CsA groups. Temperature of the rats was maintained at 33±0.5°C after return of spontaneous circulation in the hypothermia groups. Hippocampal mitochondria were measured after 2h of resuscitation. Mitochondrial transmembrane potential was significantly higher in the C, the H, and the C+H groups than in the N group and was higher in the C+H group than in the C and the H groups. Cytosolic cytochrome c was significantly higher in the N group. Superoxide dismutase activity was significantly lower in the N group than in the other groups and was higher in the C and the C+H groups than in the H group. Malondialdehyde concentration was significantly higher in the N group.

CONCLUSIONS

CsA or hypothermia used immediately after resuscitation enhanced mitochondrial transmembrane potential, kept cytochrome c from releasing out of the mitochondria, increased superoxide dismutase activity, and decreased malondialdehyde concentration in hippocampus. Moreover, the protective effects of CsA were reinforced by hypothermia. One of the mechanisms that hypothermia protected neuronal mitochondria from damage was inhibiting the opening of mitochondrial permeability transition pore.

Variability in Postarrest Targeted Temperature Management Practice: Implications of the 2015 Guidelines

In 2002 postarrest care was significantly altered when multiple randomized controlled trials found that therapeutic hypothermia at a goal temperature of 32-34°C significantly improved survival and neurologic outcomes. In 2013, targeted temperature management (TTM) was reexamined via a randomized controlled trial between 33°C and 36°C in post-cardiac arrest patients and found similar outcomes in both cohorts. Before the release of the 2015 American Heart Association (AHA) Guidelines, our group found that across hospitals in the United States, and even within the same institution, TTM protocol variability existed. After the 2013 TTM trial, it was anticipated that the 2015 Guidelines would clarify which target temperature should be used during postarrest care. The AHA released their updates for post-cardiac arrest TTM recently and, based on the literature available, have recommended the use of TTM at a goal temperature between 32°C and 36°C. Whether this variability has an effect on TTM implementation or patient outcomes is unknown.

Association between treatment at an ST-segment elevation myocardial infarction center and neurologic recovery after out-of-hospital cardiac arrest

BACKGROUND

For patients resuscitated from out-of-hospital cardiac arrest (OHCA), the American Heart Association recommends regionalized care at cardiac resuscitation centers that are aligned with ST-segment elevation myocardial infarction (STEMI) centers. The effectiveness of treatment at STEMI centers remains unknown.

OBJECTIVE

To evaluate whether good neurologic recovery after OHCA is associated with treatment at an STEMI center and if volume of admitted OHCA patients is associated with good neurologic recovery.

METHODS

We included patients in the 2011 California Office of Statewide Health Planning and Development database with a "present on admission" diagnosis of cardiac arrest. Primary outcome was good neurologic recovery at hospital discharge. Hierarchical multiple logistic regression models were used to determine the association between treating hospital and good neurologic recovery after adjusting for patient factors (age, sex, race, ethnicity, insurance type, and ventricular arrest rhythm) and hospital factors (hospital size, intensive care unit bed days, trauma center designation, and teaching status).

RESULTS

We included 7,725 patients; two-thirds (5,202) were treated at an STEMI center and 1,869 (24%, 95% CI 23%-25%) had good neurologic recovery. After adjustment, treatment at an STEMI center with ≥40 and <40 OHCA cases/year were associated with good neurologic recovery (odds ratio 1.32 [95% CI 1.06-1.64] and 1.63 [95% CI 1.35-1.97], respectively). Higher volume of admitted OHCA patients was associated with decreased odds of good neurologic recovery (adjusted odds ratio per 10 patients 0.96, 95% CI 0.92-1.00), but this association was not statistically significant after excluding the highest-volume outlier.

CONCLUSIONS

Treatment at an STEMI center-regardless of its annual OHCA volume-after resuscitation from OHCA is associated with good neurologic recovery. Regionalized systems of care should prioritize STEMI centers as destinations for resuscitated OHCA patients.

Electrocardiographic changes during induced therapeutic hypothermia in comatose survivors after cardiac arrest

AIM: To assess the safety of therapeutic hypothermia (TH) concerning arrhythmias we analyzed serial electrocardiograms (ECG) during TH.

METHODS: All patients recovered from a cardiac arrest with Glasgow < 9 at admission were treated with induced mild TH to 32-34 °C. TH was obtained with cool fluid infusion or a specific intravascular device. Twelve-lead ECG before, during, and after TH, as well as ECG telemetry data was recorded in all patients. From a total of 54 patients admitted with cardiac arrest during the study period, 47 patients had the 3 ECG and telemetry data available. ECG analysis was blinded and performed with manual caliper by two independent cardiologists from blinded copies of original ECG, recorded at 25 mm/s and 10 mm/mV. Coronary care unit staff analyzed ECG telemetry for rhythm disturbances. Variables measured in ECG were rhythm, RR, PR, QT and corrected QT (QTc by Bazett formula, measured in lead v2) intervals, QRS duration, presence of Osborn’s J wave and U wave, as well as ST segment displacement and T wave amplitude in leads II, v2 and v5.

RESULTS: Heart rate went down an average of 19 bpm during hypothermia and increased again 16 bpm with rewarming (P < 0.0005, both). There was a non-significant prolongation of the PR interval during TH and a significant decrease with rewarming (P = 0.041). QRS duration significantly prolonged (P = 0.041) with TH and shortened back (P < 0.005) with rewarming. QTc interval presented a mean prolongation of 58 ms (P < 0.005) during TH and a significant shortening with rewarming of 22.2 ms (P = 0.017). Osborn or J wave was found in 21.3% of the patients. New arrhythmias occurred in 38.3% of the patients. Most frequent arrhythmia was non-sustained ventricular tachycardia (19.1%), followed by severe bradycardia or paced rhythm (10.6%), accelerated nodal rhythm (8.5%) and atrial fibrillation (6.4%). No life threatening arrhythmias (sustained ventricular tachycardia, polymorphic ventricular tachycardia or ventricular fibrillation) occurred during TH.

CONCLUSION: A 38.3% of patients had cardiac arrhythmias during TH but without life-threatening arrhythmias. A concern may rise when inducing TH to patients with long QT syndrome.

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.

Availability and utilization of cardiac resuscitation centers

Introduction

The American Heart Association (AHA) recommends regionalized care following out-of-hospital cardiac arrest (OHCA) at cardiac resuscitation centers (CRCs). Key level 1 CRC criteria include 24/7 percutaneous coronary intervention (PCI) capability, therapeutic hypothermia capability, and annual volume of ≥40 patients resuscitated from OHCA. Our objective was to characterize the availability and utilization of resources relevant to post-cardiac arrest care, including level 1 CRCs in California.

Methods

We combined data from the AHA, the California Office of Statewide Health Planning and Development (OSHPD), and surveys to identify CRCs. We surveyed emergency department directors and nurse managers at all 24/7 PCI centers identified by the AHA to determine their post-OHCA care capabilities. The survey included questions regarding therapeutic hypothermia use and specialist availability and was pilot-tested prior to distribution. Cases of OHCA were identified in the 2011 OSHPD Patient Discharge Database using a “present on admission” diagnosis of cardiac arrest (ICD-9-CM code 427.5). We defined key level 1 CRC criteria as 24/7 PCI capability, therapeutic hypothermia, and annual volume ≥40 patients admitted with a “present on admission” diagnosis of cardiac arrest. Our primary outcome was the proportion of hospitals meeting these criteria. Descriptive statistics and 95% CI are presented.

Results

Of the 333 acute care hospitals in California, 31 (9.3%, 95% CI 6.4–13%) met level 1 CRC criteria. These hospitals treated 25% (1937/7780; 95% CI 24–26%) of all admitted OHCA patients in California in 2011. Of the 125 hospitals identified as 24/7 PCI centers by the AHA, 54 (43%, 95% CI 34–52%) admitted ≥40 patients following OHCA in 2011. Seventy (56%, 95% CI 47–65%) responded to the survey; 69/70 (99%, 95% CI 92–100%) reported having a therapeutic hypothermia protocol in effect by 2011. Five percent of admitted OHCA patients (402/7780; 95% CI 4.7–5.7%) received therapeutic hypothermia and 18% (1372/7780; 95% CI 17–19%) underwent cardiac catheterization.

Conclusion

Approximately 10% of hospitals met key criteria for AHA level 1 CRCs. These hospitals treated one-quarter of patients resuscitated from OHCA in 2011. The feasibility of regionalized care for OHCA requires detailed evaluation prior to widespread implementation.

Induction of therapeutic hypothermia via the esophagus: a proof of concept study

BACKGROUND

Induction of hypothermia (a 4 °C decrease from baseline) improves outcomes in adult cardiac arrest and neonatal hypoxic ischemic encephalopathy, and may benefit other conditions as well. Methods used to implement or prevent hypothermia typically require skin contact with blankets or pads or intravascular access with catheter devices. The study was to evaluate the potential to induce mild therapeutic hypothermia via an esophageal route in a porcine model.

METHODS

Single-animal proof-of-concept study of a prototype esophageal device in a 70 kg Yorkshire swine. We measured the rate of temperature change after placement of a prototype device to induce hypothermia via the esophagus, and compared this rate to known temperature changes that occur under similar laboratory conditions without a hypothermic device.

RESULTS

Swine temperature decreased from a starting temperature of 37.8 °C to 33.8 °C (achieving the goal of a 4 °C decrease) in 175 minutes, resulting in a cooling rate of 1.37 °C/h. Histopathology of the esophagus showed normal tissue without evidence of injury.

CONCLUSION

A prototype of an esophageal cooling device induced hypothermia effectively in a large single-swine model.

Survival and neurologic outcomes of out-of-hospital cardiac arrest patients who were transferred after return of spontaneous circulation for integrated post-cardiac arrest syndrome care: the another feasibility of the cardiac arrest center

It has been proven that safety and efficiency of out-of-hospital cardiac arrest (OHCA) patients is transported to specialized hospitals that have the capability of performing therapeutic hypothermia (TH). However, the outcome of the patients who have been transferred after return of spontaneous circulation (ROSC) has not been well evaluated. We conducted a retrospective observational study between January 2010 to March 2012. There were primary outcomes as good neurofunctional status at 1 month and the secondary outcomes as the survivals at 1 month between Samsung Medical Center (SMC) group and transferred group. A total of 91 patients were enrolled this study. There was no statistical difference between good neurologic outcomes between both groups (38% transferred group vs. 40.6% SMC group, P=0.908). There was no statistical difference in 1 month survival between the 2 groups (66% transferred group vs. 75.6% SMC group, P=0.318). In the univariate and multivariate models, the ROSC to induction time and the induction time had no association with good neurologic outcomes. The good neurologic outcome and survival at 1 month had no significant differences between the 2 groups. This finding suggests the possibility of integrated post-cardiac arrest care for OHCA patients who are transferred from other hospitals after ROSC in the cardiac arrest center.

Induction of a prolonged hypothermic state by drug-induced reduction in the thermoregulatory set-point

BACKGROUND

The marked improvement in outcome following induction of hypothermia after cardiac arrest has spurred the search for better methods to induce cooling. A regulated decrease in core temperature mediated by a drug-induced reduction in the set point for thermoregulation may be an ideal means of inducing hypothermia. To this end, the exploratory drug HBN-1 was assessed as a means to induce mild and prolonged hypothermia.

METHODS

Free moving rats were infused i.v. for 12 hours with: a vehicle at room temperature (normothermia), a vehicle chilled to 4°C (forced hypothermia), or HBN-1 (mixture of ethanol, lidocaine, and vasopressin) at room temperature. Core (intra-abdominal) temperature (Tc) was measured telemetrically, tail skin temperature (Ttail) by infrared thermography, metabolic rate (MR) was estimated with indirect calorimetery, and shivering was scored visually.

RESULTS

HBN-1 elicited a reduction in Tc from 37.5°C to 34°C within 80 minutes after initiation of the infusion; Tc was maintained between 33°C and 34°C for more than 13 hours. HBN-1 infusion was associated with a reduction in MR (p=0.0006), a slight reduction in Ttail, and no evidence of shivering (p<0.001). The forced hypothermia group displayed shivering (p<0.001), a significant increase in MR, and a decrease in Ttail, indicative of peripheral vasoconstriction to reduce heat loss.

CONCLUSION

HBN-1 infusion induced a mild and prolonged hypothermia in free moving, unanesthetized rats characterized by modulation of thermoeffectors to reduce heat gain and increase heat loss. HBN-1 thus appears to elicit regulated hypothermia and may provide a new method for achieving a prolonged state of therapeutic hypothermia.

Transpulmonary hypothermia: a novel method of rapid brain cooling through augmented heat extraction from the lungs

AIM

Delay in instituting neuroprotective measures after cardiac arrest increases death and decreases neuronal recovery. Current hypothermia methods are slow, ineffective, unreliable, or highly invasive. We report the feasibility of rapid hypothermia induction in swine through augmented heat extraction from the lungs.

METHODS

Twenty-four domestic crossbred pigs (weight, 50-55kg) were ventilated with room air. Intraparenchymal brain temperature and core temperatures from pulmonary artery, lower esophagus, bladder, rectum, nasopharynx, and tympanum were recorded. In eight animals, ventilation was switched to cooled helium-oxygen mixture (heliox) and perfluorocarbon (PFC) aerosol and continued for 90min or until target brain temperature of 32°C was reached. Eight animals received body-surface cooling with water-circulating blankets; eight control animals continued to be ventilated with room air.

RESULTS

Brain and core temperatures declined rapidly with cooled heliox-PFC ventilation. The brain reached target temperature within the study period (mean [SD], 66 [7.6]min) in only the transpulmonary cooling group. Cardiopulmonary functions and poststudy histopathological examination of the lungs were normal.

CONCLUSION

Transpulmonary cooling is novel, rapid, minimally invasive, and an effective technique to induce therapeutic hypothermia. High thermal conductivity of helium and vaporization of PFC produces rapid cooling of alveolar gases. The thinness and large surface area of alveolar membrane facilitate rapid cooling of the pulmonary circulation. Because of differences in thermogenesis, blood flow, insulation, and exposure to the external environment, the brain cools at a different rate than other organs. Transpulmonary hypothermia was significantly faster than body surface cooling in reaching target brain temperature.

A 4-year implementation strategy of aggressive post-resuscitation care and temperature management after cardiac arrest

BACKGROUND

target temperature management (TTM) not only improves neurological outcome and survival but has given momentum to a more aggressive and comprehensive treatment after resuscitation. Yet, implementation issues represent the main obstacle to systematic treatment with TTM and aggressive post-resuscitation care. We devised a strategy to introduce, monitor and improve the quality of aggressive treatment after resuscitation, including TTM.

METHODS

standard operative procedures on aggressive post-resuscitation care, written jointly by physicians and nurses, were introduced in November 2004. Data of all resuscitated patients admitted to the ICU were prospectively acquired for 4 years. Periodic audits (every 16 months) were programmed, leading to three equally long periods. Several critical issues were identified after each audit and addressed subsequently, leading to a growing complexity of care. Moreover, after 2 years we introduced an educational programme with medical credits for all staff attending critically ill patients. Neurological outcome and survival at hospital discharged were compared to historical controls of the preceding 22 months.

RESULTS

129 consecutively resuscitated patients were admitted to the ICU in the 4-year study period. Of these, 96 (74%) were treated with TTM and aggressive post-resuscitation care. Favourable neurological recovery among patients discharged alive significantly improved in the 4-year intervention period (81% vs. 50% in historical controls, p<0.01). A composite endpoint of mortality and poor neurological outcome also improved (64% vs. 82% respectively, p<0.05). Overall survival increased throughout the 4 years, leading to a significant improvement in the 3rd period compared to historical controls (60% vs. 35%; p<0.05).

CONCLUSIONS

we propose a strategy to successfully introduce and implement TTM and aggressive post-resuscitation care via standard operative procedures, periodic audits and feedback. Continuous education among other factors contributed to a significant improvement in neurological outcome and a progressive increase in survival.

Early coronary angiography and induced hypothermia are associated with survival and functional recovery after out-of-hospital cardiac arrest

BACKGROUND

The rate and effect of coronary interventions and induced hypothermia after out-of-hospital cardiac arrest (OHCA) are unknown. We measured the association of early (≤24h after arrival) coronary angiography, reperfusion, and induced hypothermia with favorable outcome after OHCA.

METHODS

We performed a secondary analysis of a multicenter clinical trial (NCT00394706) conducted between 2007 and 2009 in 10 North American regions. Subjects were adults (≥18 years) hospitalized after OHCA with pulses sustained ≥60min. We measured the association of early coronary catheterization, percutaneous coronary intervention, fibrinolysis, and induced hypothermia with survival to hospital discharge with favorable functional status (modified Rankin Score≤3).

RESULTS

From 16,875 OHCA subjects, 3981 (23.6%) arrived at 151 hospitals with sustained pulses. 1317 (33.1%) survived to hospital discharge, with 1006 (25.3%) favorable outcomes. Rates of early coronary catheterization (19.2%), coronary reperfusion (17.7%) or induced hypothermia (39.3%) varied among hospitals, and were higher in hospitals treating more subjects per year. Odds of survival and favorable outcome increased with hospital volume (per 5 subjects/year OR 1.06; 95%CI: 1.04-1.08 and OR 1.06; 95%CI: 1.04, 1.08, respectively). Survival and favorable outcome were independently associated with early coronary angiography (OR 1.69; 95%CI 1.06-2.70 and OR 1.87; 95%CI 1.15-3.04), coronary reperfusion (OR 1.94; 95%CI 1.34-2.82 and OR 2.14; 95%CI 1.46-3.14), and induced hypothermia (OR 1.36; 95%CI 1.01-1.83 and OR 1.42; 95%CI 1.04-1.94).

INTERPRETATION

Early coronary intervention and induced hypothermia are associated with favorable outcome and are more frequent in hospitals that treat higher numbers of OHCA subjects per year.

Use of therapeutic hypothermia in postcardiac arrest patients by emergency departments

Since 2003, resuscitation guidelines have recommended the use of induced hypothermia as a therapy for patients who achieve return of spontaneous circulation after cardiac arrest from ventricular fibrillation. The aim of this study was to survey emergency physicians across the United States on their use of therapeutic hypothermia (TH) after cardiac arrest. An 18-question survey was e-mailed to a sample of emergency physicians. Fifty-eight respondents completed the survey. Most (71%) were associated with an emergency medicine residency training program. Annual census ranged from 12,000 to >170,000 visits. TH is used by the majority (69%) of respondents, 79% of which report the presence of a formal institutional protocol. The majority of respondents use TH in arrest rhythms including but not limited to ventricular fibrillation, and 21% begin the process in the prehospital setting. To induce hypothermia, a majority of respondents use commercial cooling products. The average time to target temperature was 95 minutes. The majority of respondents report a goal temperature between 32°C and 34°C. A shivering protocol is used by 76% of respondents, and as a first line medication, 46% use benzodiazepines. For those who do not use TH or do not have a protocol in place, the reasons cited include "too expensive," "too difficult to implement," and "not enough science to warrant it." In this sample of practicing emergency physicians, TH after cardiac arrest is not being used as described in the original literature. Although awareness and implementation of TH have increased, there appears to be a wide variation in the application of this therapy.

Neurologic complications of cardiac arrest

Cardiac arrest is a common and serious medical emergency affecting upwards of 450000 Americans on an annual basis. It causes a substantial strain on the physical and financial resources of the medical system. The optimal management of patients requires the close collaboration of multiple specialists, including first responders, intensivists, cardiologists, and neurologists. The role of the neurologist for the post-arrest patient is to assist in management to minimize brain injury as well as to prognosticate long-term outcomes to help guide therapy decisions of families and physicians. This review focuses on epidemiologic data, current management recommendations, clinical and ancillary testing to suggest long-term prognosis, and common complications of cardiac arrest. Particular attention has been paid to updates, including therapeutic hypothermia, since this topic was last reviewed in 1993.

How effective is "code freeze" in post-cardiac arrest patients?

The use of therapeutic hypothermia or "code freeze" dates back to over 100 years in attempts to resuscitate injured soldiers, preserve limbs, and to provide analgesia for amputations. The purpose of this study was to determine the effectiveness of code freeze through a retrospective review of 187 charts of patients who had a cardiac arrest while hospitalized in a 1-year period. Data were collected to determine which post-cardiac arrest patients received the induced therapeutic hypothermia intervention and why they were selected for induced therapeutic hypothermia. The data were compared with post-cardiac arrest patients who did not receive the code-freeze intervention and why they were not eligible for the intervention. Mortality rates between the 2 patient populations were also compared. The results from this study are presented in this article.

The effect of hypothermia "dose" on vasopressor requirements and outcome after cardiac arrest

OBJECTIVES

We evaluated the association between TH use and "dose" and cumulative vasopressor and inotrope requirement, survival, and neurologic outcome.

BACKGROUND

Therapeutic hypothermia (TH) improves outcome after cardiac arrest, but may increase vasopressor and inotrope requirements.

METHODS

Chart review of in- and out-of-hospital cardiac arrests between 1/1/2005 and 3/15/2010. Data included demographic information, category of post-cardiac arrest illness severity ((I) awake, (II) coma (not following commands but intact brainstem responses)+mild cardiopulmonary dysfunction (SOFA [Sequential Organ Failure Assessment] cardiac+respiratory score<4), (III) coma+moderate-severe cardiopulmonary dysfunction (SOFA cardiac+respiratory score≥4), and (IV) coma without brainstem reflexes), cumulative vasopressor index (CVI), inotrope use, survival, and neurologic outcome. The "dose" of TH (hours*temperature below threshold) was calculated using thresholds of ≤34 °C and ≤35 °C. Data were analyzed using descriptive statistics, Student's t-test, Wilcoxon test, and chi-squared analysis. Linear and logistic regression evaluated the effect of hypothermia "dose" on total CVI, survival and neurologic outcome.

RESULTS

Among 361 comatose patients, 233 (65%) received TH. Vasopressor administration (measured by CVI) was higher in normothermic subjects (60.2% vs. 46.4%; p=0.016). Using a 34 °C threshold, SOFA respiratory subscore and PEA arrest predicted total CVI. Using a 35 °C threshold, severity of coma, SOFA respiratory subscore, PEA arrest and use of inotropic agents in addition to vasopressors predicted total CVI. Initial motor examination predicted survival and neurologic outcome, while TH "dose" did not.

CONCLUSIONS

TH delivery is not associated with vasopressor requirement. TH "dose" is not associated with total CVI, survival, or good outcome. Vasopressor or inotropic requirement should not contraindicate TH use.

A structured educational intervention to improve targeted temperature management utilization after cardiac arrest

PURPOSE

Post-arrest targeted temperature management (TTM) has been shown to dramatically improve outcomes after resuscitation, yet studies have revealed inconsistent and slow adoption. Little is known about barriers to TTM implementation and methods to increase adoption. We hypothesized that a structured educational intervention might increase TTM use.

MATERIALS AND METHODS

Subjects participated in mixed quantitative/qualitative surveys before and after attending a series of TTM educational courses from October 2010 to October 2011, to determine usage and barriers to implementation. A knowledge examination was also administered to participants before and after the course.

RESULTS

Clinicians completed 227 surveys (129 pre-training and 98 post-training) and 343 exams (165 pre-training and 178 post-training). A ranking survey (score range 1-7; 7 as most challenging) found that communication challenges (mean score 4.7 ± 1.5) and lacking adequate education (4.3 ± 1.9) were the 2 most emphasized barriers to implementation. Post-survey results found that 95% (93/98) of respondents felt more confident initiating TTM post-intervention. There was a statistically significant increase in self-reported TTM usage after participation in the program (P < .01).

CONCLUSIONS

A focused TTM program led to increased confidence and usage among participants. Future work will focus on targeted training to address specific barriers and increase TTM utilization.

Therapeutic hypothermia for out-of-hospital cardiac arrest: An analysis comparing cooled and not cooled groups at a Canadian center

BACKGROUND

Out of hospital cardiac arrest is a devastating event and is associated with poor outcomes; however, therapeutic hypothermia (TH) is a novel treatment which may improve neurological outcome and decrease mortality. Despite this, TH is not uniformly implemented across Coronary Care and Intensive Care Units in Canada.

OBJECTIVE

The purpose of this study was to compare cerebral recovery and mortality rates between patients in our Coronary Care Unit who received TH with a historical control group.

MATERIALS AND METHODS

A retrospective chart review was performed of patients admitted to a tertiary care center with out-of-hospital cardiac arrest. Twenty patients who were admitted and cooled after December 2006 were compared with 29 noncooled patients admitted in the 5 years prior as a historical control group. The primary outcomes of interest were in-hospital mortality and neurological outcome.

RESULTS

Eleven of 20 (11/20, 55%) patients who were cooled as per protocol survived to hospital discharge, all having a good neurological outcome. Eleven of 29 (11/29, 38%) noncooled patients survived to hospital discharge (Odds Ratio: 0.50, 95% CI: 0.16- 1.60, P=0.26). Eleven of 20 patients who were cooled had a good neurological outcome (CPS I-II, 11/20, 55%), versus 7 of 29 (7/29, 24%) of noncooled patients (Odds ratio: 3.84, 95% CI: 1.13- 13.1, P=0.03). One hundred percent (11/11) of survivors in the cooled group had a good neurological outcome.

CONCLUSION

In our center, the use of TH in out-of-hospital cardiac arrest survivors was associated with improved neurological outcome.

Therapeutic hypothermia for cardiac arrest: real-world utilization trends and hospital mortality

BACKGROUND

Therapeutic hypothermia (TH) improves outcomes following cardiac arrest in small clinical trials.

OBJECTIVE

To study real-world utilization and outcomes in US hospitals.

DESIGN

Retrospective cohort study.

SETTING

California hospitals.

PATIENTS

Patients eligible for therapeutic hypothermia after cardiac arrest.

INTERVENTIONS

We analyzed all discharges from California (1999-2008) to identify patients eligible for TH after cardiac arrest. Patients were considered eligible for TH if both cardiac arrest and anoxic brain injury were among the administrative diagnoses (n = 46,833). Patients undergoing TH (n = 204) were identified through billing codes.

MEASUREMENTS

TH utilization and in-hospital mortality.

RESULTS

Use of TH increased over the study period with 87.3% (178/204) of TH occurring between 2006 and 2008. Few hospitals appeared to perform TH over the study period (47/419, 11.2%). Utilization of TH was concentrated in a few centers, with the top 3 of 419 centers accounting for 31.4% (64/204) of cases. Patients undergoing TH were younger, less likely to be male, more likely to be treated at teaching centers, and had similar comorbidities compared to eligible individuals who did not undergo TH. The adjusted odds ratio for hospital mortality among patients undergoing TH was 0.80 (95% confidence interval [CI] 0.60-1.06, P = 0.11).

CONCLUSIONS

TH utilization appears low, but implementation is increasing. Case selection and referral biases limit the analysis of the relationship between center TH volume and in-hospital mortality.