Therapeutic hypothermia utilization among physicians after resuscitation from cardiac arrest*

Temperature Control in the Era of Personalized Medicine: Knowledge Gaps, Research Priorities, and Future Directions

Hypoxic-ischemic brain injury (HIBI) is the leading cause of death and disability after cardiac arrest. To date, temperature control is the only intervention shown to improve neurologic outcomes in patients with HIBI. Despite robust preclinical evidence supporting hypothermia as neuroprotective therapy after cardiac arrest, there remains clinical equipoise regarding optimal core temperature, therapeutic window, and duration of therapy. Current guidelines recommend continuous temperature monitoring and active fever prevention for at least 72 h and additionally note insufficient evidence regarding temperature control targeting 32 °C-36 °C. However, population-based thresholds may be inadequate to support the metabolic demands of ischemic, reperfused, and dysregulated tissue. Promoting a more personalized approach with individualized targets has the potential to further improve outcomes. This review will analyze current knowledge and evidence, address research priorities, explore the components of high-quality temperature control, and define critical future steps that are needed to advance patient-centered care for cardiac arrest survivors.

Variation in the Use of Targeted Temperature Management for Cardiac Arrest

Targeted temperature management (TTM) is recommended for patients who do not respond after return of spontaneous circulation after cardiac arrest. However, the degree to which patients with cardiac arrest have access to this therapy on a national level is not known. Understanding hospital- and patient-level factors associated with receipt of TTM could inform interventions to improve access to this treatment among appropriate patients. Therefore, we performed a retrospective analysis using National Inpatient Sample data from 2016 to 2019. We used International Classification of Diseases, Tenth Edition diagnosis and procedure codes to identify adult patients with in-hospital and out-of-hospital cardiac arrest and receipt of TTM. We evaluated patient and hospital factors associated with receiving TTM. We identified 478,419 patients with cardiac arrest. Of those, 4,088 (0.85%) received TTM. Hospital use of TTM was driven by large, nonprofit, urban, teaching hospitals, with less use at other hospital types. There was significant regional variation in TTM capabilities, with the proportion of hospitals providing TTM ranging from >21% in the Mid-Atlantic region to <11% in the East and West South Central and Mountain regions. At the patient level, age >74 years (odds ratio [OR] 0.54, p <0.001), female gender (OR 0.89, p >0.001), and Hispanic ethnicity (OR 0.74, p <0.001) were all associated with decreased odds of receiving TTM. Patients with Medicare (OR 0.75, p <0.001) and Medicaid (OR 0.89, p = 0.027) were less likely than patients with private insurance to receive TTM. Part of these differences was driven by inequitable access to TTM-capable hospitals. In conclusion, TTM is rarely used after cardiac arrest. Hospital use of TTM is predominately limited to a subset of academic hospitals with substantial regional variation. Older age, female gender, Hispanic ethnicity, and Medicare or Medicaid insurance are all associated with a decreased likelihood of receiving TTM.

Veno-venous extracorporeal membrane oxygenation support in the resuscitation from extreme metabolic acidosis (pH < 6.5) after drowning cardiac arrest: a case report

BACKGROUND

Resuscitation in drowning victim with cardiac arrest is difficult because of severe metabolic acidosis and multiple organ dysfunction. There is insufficient evidence to support that veno-venous extracorporeal membrane oxygenation (VV-ECMO) is beneficial for patient.

CASE PRESENTATION

A 44-year-old female was trapped under river when she attempted to rescue her drowning father. Furthermore, she underwent a loss of consciousness, with extreme metabolic acidosis, hypothermia and hypotension. Hence, the VV-ECMO, continuous renal replacement therapy (CRRT) and other resuscitative infusion were required. In this case, the patient did not experience any complication or neurologic deficit and reaching a complete recovery after 21 days of hospitalization.

CONCLUSIONS

Our case adds further concerns in supporting a patient with extreme metabolic acidosis (pH < 6.5) and hypothermia after severe drowning cardiac arrest, including extracorporeal life support, renal support, targeted temperature management, cerebral resuscitation, etc., due to the reversible nature of this condition.

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.

Trends in survival and introduction of the 2010 and 2015 guidelines for adult in-hospital cardiac arrest

AIMS

To examine trends in survival from 2006 to 2018 and to assess whether the introduction of resuscitation guidelines was associated with a change in survival after adult in-hospital cardiac arrest.

METHODS

Using the Get With The Guidelines® - Resuscitation registry, we included adult patients with an in-hospital cardiac arrest between 2006 and 2018. The primary outcome was survival to hospital discharge. An interrupted time series analysis was used to compare survival before and after publication of the 2010 and 2015 resuscitation guidelines.

RESULTS

The analysis included 231,739 patients. Survival changed annually by 1.09% (95% CI, 0.74% to 1.43%; P < 0.001) from 2006 to 2010, 0.26% (95% CI, -0.11% to 0.64%; P = 0.17) from 2011 to 2015, and -0.43% (95% CI, -0.96% to 0.11%; P = 0.12) from 2016 to 2018. The survival trend was lower within the post-2010 compared to the pre-2010 period (risk difference, -0.82% per year; 95% CI, -1.35% to -0.30%; P = 0.002) and within the post-2015 compared to the pre-2015 period (risk difference, -0.69% per year; 95% CI, -1.33% to -0.04%; P = 0.04). There was no immediate change in survival after publication of the 2010 and 2015 guidelines.

CONCLUSIONS

In-hospital cardiac arrest survival increased from 2006 to 2010, after which the trend plateaued. The annual survival trend was lower following publication of the 2010 and 2015 guidelines. Research targeting in-hospital cardiac arrest as a unique entity may be necessary to improve outcomes.

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.

Targeted Temperature Management for In-Hospital Cardiac Arrest: 6 Years of Experience

Targeted temperature management (TTM) is widely used for postcardiac arrest management of patients with out-of-hospital cardiac arrest. However, the use of TTM for patients with in-hospital cardiac arrest (IHCA) is controversial. The aim of this study was to investigate the role of TTM in the management of patients with IHCA. The medical records of all IHCA patients who were resuscitated and returned to spontaneous circulation from January 2011 to December 2016 were reviewed. After excluding patients with new do not resuscitate orders and those who died within 24 hours, 262 patients were eligible for analysis. Thirty-five of the 262 patients (13.3%) received TTM after IHCA. Patients who received TTM and standard supportive care (SSC) had similar baseline epidemiological status. The TTM patients were older and had a longer cardiac pulmonary resuscitation duration; however, the differences were not statistically significant. The 28-day survival rate was not significantly different between groups (12/35 in the TTM group [34%] vs. 114/225 in the SSC group [50%], p = 0.079). In the patients with good neurological status before arrest (Glasgow-Pittsburgh cerebral performance category [GP-CPC] scores: 1-2), there was no significant difference in the 28-day survival between groups (11/26 in the TTM group [42.3%] vs. 81/154 [52.6%] in the SSC group; p = 0.332). In this subgroup, the TTM patients had poorer neurological outcomes at discharge (GP-CPC score 1-2) than the SSC patients (1/26 in the TTM group [3.8%] vs. 57/154 in the SSC group [37%]; p = 0.001). TTM was not associated with better 28-day survival than usual care among the patients with IHCA in this study, and the TTM patients had less favorable neurological outcomes at discharge. Randomized clinical trials are needed to assess the efficacy of TTM for IHCA patients.

In-hospital Outcomes of Patients with ST-segment Elevation Myocardial Infarction who were Intubated before Primary Percutaneous Intervention: Experience of a tertiary center

OBJECTIVES

ST-segment elevation myocardial infarction (STEMI) complicated by respiratory failure is associated with a greater number of in-hospital and out-of-hospital adverse cardiovascular events (CVEs). The aim of this study was to analyze in-hospital outcomes and the factors affecting the outcomes of intubated patients diagnosed with STEMI who underwent primary percutaneous coronary intervention (pPCI) at a single tertiary care center.

METHODS

The data of 592 patients diagnosed with acute STEMI who were admitted to the emergency department between May 2017 and January 2019 and subsequently underwent pPCI were retrospectively reviewed. Cardiovascular risk factors as well as biochemical and angiographic characteristics of patients who were intubated in the emergency room or ambulance due to cardiac arrest and those who were not intubated were compared. Adverse CVEs were defined as in-hospital death, cerebrovascular stroke, and acute stent thrombosis.

RESULTS

A total of 60 patients (70% male; mean age: 63.6±14.0 years) who were intubated and 532 non-intubated patients (81% male; mean age: 60.2±12.1 years) were included in the study. The angiographic features of the 2 groups were similar. An adverse CVE was experienced by 43.3% of the intubated patients and 3.6% of the non-intubated patients. Multivariate analysis indicated that age (odds ratio [OR]: 1.065; p<0.001), serum lactate level (OR: 1.308; p<0.001), and left ventricle ejection fraction (OR: 0.946; p<0.001) were independent predictors of in-hospital adverse CVE in the intubated patient group.

CONCLUSION

The results of this single-center study showed that 1 in 10 patients hospitalized with STEMI were intubated, and approximately 4 in 10 intubated STEMI patients had an in-hospital CVE.

Guideline removal of atropine and survival after adult in-hospital cardiac arrest with a non-shockable rhythm

AIM

To determine whether the removal of atropine from the 2010 ACLS guidelines for non-shockable cardiac arrests was associated with a change in survival.

METHODS

Using the Get With The Guidelines^®-Resuscitation registry, we included adults with an index in-hospital cardiac arrest between 2006 and 2015. The primary outcome was survival to hospital discharge. Secondary outcomes included return of spontaneous circulation and favorable functional outcome. An interrupted time-series analysis was used to compare survival before (pre-guidelines) and after (post-guidelines) introduction of the 2010 guidelines. A difference-in-difference approach was used to compare the interrupted time-series results between the non-shockable and shockable cohorts to account for guideline changes unrelated to atropine.

RESULTS

We included 20,499 non-shockable and 3968 shockable cardiac arrests. Patient characteristics were similar between the pre-guidelines and post-guidelines period. Atropine was used for 8653 (87%) non-shockable and 680 (35%) shockable cardiac arrests in the pre-guidelines period and 3643 (35%) non-shockable and 320 (16%) shockable cardiac arrests in the post-guidelines period. The change over time in survival from the pre-guidelines to the post-guidelines period was not significantly different for the non-shockable compared to the shockable cohort (risk difference: 2.0% [95%CI: -0.8, 4.8] per year, p = 0.17). The immediate change in survival after introducing the guidelines was also not different between the cohorts (risk difference: 3.5% [95%CI: -2.6, 9.7], p = 0.26). Results were similar for the secondary outcomes and in multiple sensitivity analyses.

CONCLUSIONS

The removal of atropine from the 2010 guidelines was not associated with a significant change in survival.

Repetitive anodal transcranial direct current stimulation improves neurological outcome and survival in a ventricular fibrillation cardiac arrest rat model

BACKGROUND

Transcranial direct current stimulation (tDCS) modulates neuronal activity and is a potential therapeutic tool for many neurological diseases. However, its beneficial effects on post cardiac arrest syndrome remains uncertain.

OBJECTIVE/HYPOTHESIS

We investigated the effects of repetitive anodal tDCS on neurological outcome and survival in a ventricular fibrillation (VF) cardiac arrest rat model.

METHODS

Cardiopulmonary resuscitation was initiated after 6 min of VF in 36 Sprague-Dawley rats. The animals were randomized into three groups immediately after resuscitation (n = 12 each): no-treatment control (NTC) group, targeted temperature management (TTM) group, and tDCS group. For tDCS, 1 mA anodal tDCS was applied on the dorsal scalp for 0.5 h. The stimulation was repeated for four sessions with 1-h resting interval under normothermia. Post-resuscitation hemodynamic, cerebral, and myocardial injuries, 96-h neurological outcome, and survival were evaluated.

RESULTS

Compared with the NTC group, post-resuscitation serum astroglial protein S100 beta and cardiac troponin T levels and 96-h neuronal and myocardial damage scores were markedly reduced in the tDCS and TTM groups. Myocardial ejection fraction, neurological deficit score, and 96-h survival rate were also significantly better for the tDCS and TTM groups. The period of post-resuscitation arrhythmia with hemodynamic instability was considerably shorter in the tDCS group, but no differences were observed in neurological outcome and survival between the tDCS and TTM groups.

CONCLUSIONS

In this cardiac arrest rat model, repeated anodal tDCS commenced after resuscitation improves 96-h neurological outcome and survival to an extent comparable to TTM by attenuating post-resuscitation cerebral and cardiac injuries.

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).

Influence of comorbidities and clinical prediction model on neurological prognostication post out-of-hospital cardiac arrest

Background

Survival with good neurological function post out-of-hospital cardiac arrest (OHCA), defined as cerebral performance category (CPC) 1-2, ranges from 1.6% to 3% in Asia. We aim to study the influence of comorbidities and peri-OHCA event factors on neurological recovery and develop a model that can help clinicians predict neurological function among patients with post-OHCA admitted to the hospital.

Methods

This was a retrospective cohort study. All patients admitted post-OHCA from 1 January 2011 to 31 December 2015 to a tertiary centre were identified through the hospital OHCA registry. Patients who survived till hospital admission were included. Logistic regression was used to identify patient and peri-arrest factors that were significantly associated with survival with CPC 1-2. The significant factors for survival with CPC 1-2 were then put into a multivariable model and the discriminative ability was tested using the receiver operator characteristic (ROC) curve. Calibration and internal validation of the model were also performed. External validation in a small prospective cohort was also performed.

Results

In our derivation cohort of 129 patients, 30.23% survived with CPC 1-2. Significant factors associated with survival with good neurological outcomes were age-adjusted Charlson Comorbidity Index ≤5, time to first return of spontaneous circulation ≤40 min, the presence of immediate bystander cardiopulmonary resuscitation and shockable rhythms. We also developed a nomogram which showed good internal (ROC curve 0.84; 95% CI 0.77 to 0.91) and external validation (ROC curve 0.90; 95% CI 0.81 to 1.00).

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.

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.

Regional Variation in Outcomes of Hospitalized Patients Having Out-of-Hospital Cardiac Arrest

The aim of this study was to investigate patient outcomes after hospitalization for out-of-hospital cardiac arrest in the United States. We used the 2002 to 2013 Nationwide Inpatient Sample database to identify adults ≥18 years with an International Classification of Diseases, Ninth Revision, Clinical Modification, principal diagnosis code of cardiorespiratory arrest (427.5) or ventricular fibrillation (VF) (427.41). In 4 predefined federal geographic regions: Northeast, Midwest, South, and West, means and proportions of survival, survival stratified by initial rhythm, hospital charges, and cost were estimated. Multiple linear and logistic regression models were conducted. Of the 154,177 patients with out-of-hospital cardiac arrest hospitalized in the United States, 25,873 (16.8%) were in the Northeast, 38,296 (24.8%) in the Midwest, 57,305 (37.2%) in the South, and 32,703 (21.2%) in the West. Variability in survival was noted in VF arrests; compared with the Northeast, survival was higher in the Midwest and South (adjusted odds ratio [AOR] 1.16, 95% confidence interval [CI] 1.02 to 1.32 and AOR 1.24, 95% CI 1.09 to 1.40, respectively), with no difference detected in the West (AOR 0.93, 95% CI 0.82 to 1.06). No variability in survival was noted after non-VF arrests (p >0.05). Hospital charges rose significantly across all regions of the United States (p-trend < 0.001) and were higher in the West compared with the Northeast (hospital charges >$109,000/admission, AOR 1.76; 95% CI 1.50 to 2.06). In conclusion, nationwide, we observed significant regional variability in survival of hospitalized patients after out of hospital VF cardiac arrest, no survival variability after non-VF arrests, and a steady increase in hospital charges.

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.

Emulsified isoflurane combined with therapeutic hypothermia improves survival and neurological outcomes in a rat model of cardiac arrest

Emulsified isoflurane (EIso), when introduced following cardiopulmonary resuscitation (CPR), significantly improves survival and neurological outcomes in a rat model of cardiac arrest (CA). The present study aimed to examine whether EIso combined with therapeutic hypothermia (TH) confers an additive neuroprotective effect. Adult male Sprague-Dawley rats that were subjected to return of spontaneous circulation (ROSC) after a 6-min asphyxia-induced CA were randomized to five groups: Sham group, control group under normothermic conditions, EIso group (4 ml/kg for 30 min under normothermic conditions), TH group (33°C for 2 h), and EIso plus TH group. Survival conditions and neurological outcomes were evaluated at 1 day and 7 days after ROSC. Animal survival rate at 7 days after ROSC was 30.7% in the CPR group, 60% in the EIso group, 63.6% in the TH group and 72.7% in the EIso plus TH group. EIso, TH and EIso plus TH yielded significant improvements in survival rates, neural deficit score and cognitive function, and ameliorated hippocampal CA1 region cell injury and apoptosis at 1 day and 7 days after ROSC compared with the CPR group. Combined therapy of EIso and TH was superior to EIso or TH alone, suggesting that combined EIso and TH treatment results in significant improvements in survival and neurological outcomes, and was more effective than independent EIso or TH treatment.

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.

Rapid Induction of Therapeutic Hypothermia Using Transnasal High Flow Dry Air

Early induction of therapeutic hypothermia (TH) is recommended in out-of-hospital cardiac arrest (CA); however, currently no reliable methods exist to initiate cooling. We investigated the effect of high flow transnasal dry air on brain and body temperatures in adult porcine animals. Adult porcine animals (n = 23) under general anesthesia were subject to high flow of transnasal dry air. Mouth was kept open to create a unidirectional airflow, in through the nostrils and out through the mouth. Brain, internal jugular, and aortic temperatures were recorded. The effect of varying airflow rate and the air humidity (0% or 100%) on the temperature profiles were recorded. The degree of brain cooling was measured as the differential temperature from baseline. A 10-minute exposure of high flow dry air caused rapid cooling of brain and gradual cooling of the jugular and the aortic temperatures in all animals. The degree of brain cooling was flow dependent and significantly higher at higher airflow rates (0.8°C ± 0.3°C, 1.03°C ± 0.6°C, and 1.3°C ± 0.7°C for 20, 40, and 80 L, respectively, p < 0.05 for all comparisons). Air temperature had minimal effect on the brain cooling over 10 minutes with similar decrease in temperature at 4°C and 30°C. At a constant flow rate (40 LPM) and temperature, the degree of cooling over 10 minutes during dry air exposure was significantly higher compared to humid air (100% saturation) (1.22°C ± 0.35°C vs. 0.21°C ± 0.12°C, p < 0.001). High flow transnasal dry air causes flow dependent cooling of the brain and the core temperatures in intubated porcine animals. The mechanism of cooling appears to be evaporation of nasal mucus as cooling is mitigated by humidifying the air. This mechanism may be exploited to initiate TH in CA.

Glibenclamide Is Comparable to Target Temperature Management in Improving Survival and Neurological Outcome After Asphyxial Cardiac Arrest in Rats

Background

We previously have shown that glibenclamide (GBC), a sulfonylurea receptor 1–transient receptor potential M4 (SUR1‐TRPM4) channel inhibitor, improves survival and neurological outcome after asphyxial cardiac arrest and cardiopulmonary resuscitation (ACA/CPR). Here, we further compare the efficacy of GBC with target temperature management (TTM) and determine whether the efficacy of GBC is affected by TTM.

Methods and Results

Male Sprague‐Dawley rats (n=213) subjected to 10‐minute ACA/CPR were randomized to 4 groups after return of spontaneous circulation (ROSC): normothermia control (NT); GBC; TTM; and TTM+GBC. Survival, neurodeficit scores, histological injury, as well as the expressions of SUR1 and TRPM4 were evaluated. The 7‐day survival rate was 34.4% (11 of 32) in the NT group, 65% (13 of 20) in the GBC group, 50% (10 of 20) in the TTM group, and 70% (14 of 20) in the TTM+GBC group. Rats that received either GBC, TTM alone, or in combination showed less neurological deficit than NT control at 24, 48, and 72 hours and 7 days after ROSC. Moreover, TTM or GBC ameliorated neuronal degeneration and glial activation in the hippocampal CA1 region with similar efficacy, whereas the combination of them had a trend toward better effect. The subunits of SUR1‐TRPM4 heterodimers were both strongly upregulated after ACA/CPR and expressed in multiple types of brain cells, but partly suppressed by TTM.

Conclusions

GBC is comparable to TTM in improving survival and neurological outcome after ACA/CPR. When GBC is given along with TTM, less histological injury tended to be achieved.

Feasibility and Safety of Hydrogen Gas Inhalation for Post-Cardiac Arrest Syndrome - First-in-Human Pilot Study

BACKGROUND

Hydrogen gas inhalation (HI) ameliorates cerebral and cardiac dysfunction in animal models of post-cardiac arrest syndrome (PCAS). HI for human patients with PCAS has never been studied.

METHODS AND RESULTS

Between January 2014 and January 2015, 21 of 107 patients with out-of-hospital cardiac arrest achieved spontaneous return of circulation. After excluding 16 patients with specific criteria, 5 patients underwent HI together with target temperature management (TTM). No undesirable effects attributable to HI were observed and 4 patients survived 90 days with a favorable neurological outcome.

CONCLUSIONS

HI in combination with TTM is a feasible therapy for patients with PCAS. (Circ J 2016; 80: 1870-1873).

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.

An Assessment of Emergency Department Post-Cardiac Arrest Care Variation in Michigan

Implementation of postarrest care by individual physicians and systems has been slow. Deadoption, or discontinuation of therapeutic hypothermia (TH) treatment targets, after recent prospective study results has not been well reported. This study assesses practices in the early stages of postarrest care across emergency departments (EDs) in Michigan. A 27-question Internet-based survey was distributed to EDs in Michigan in September 2013. To assess changes in practice after publication of Nielsen et al., we sent follow-up questions to all original respondents a year later. Observational data and descriptive statistics are reported. From the 142 EDs identified, we excluded critical access hospitals (N = 35), free standing EDs (N = 7), EDs that transfer critical patients to tertiary centers (N = 21), and exclusive children's hospitals (N = 3). Of the remaining 76 hospitals, we received 64 (84.2%) responses. We identified 15 respondents with a protocol to specifically initiate ED TH and transfer patients to a higher level of care. The 49 remaining were mostly teaching institutions (N = 34, 69%) and gave the ED physician the ability to initiate TH (N = 40, 82%). On follow-up 12 months later, we received 33/40 (83%) responses, of which only 5 indicated formal or informal change in TH practice or target temperature. There is substantial variation in the practice of ED postarrest care and initiation of TH across the state of Michigan, but few ED TH protocols were changed in a year's time. The consequences of postarrest treatment variability at the state and ED levels are likely under-recognized as an influence on outcome variation between regions.

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.

Postcardiac Arrest Management

Cardiac arrest afflicts more than 300,000 persons annually in North America alone. Advances in systematic, regimented postresuscitation care have lowered mortality and improved neurologic outcomes in select cohorts of patients over the last decade. Postcardiac arrest care now comprises its own link in the chain of survival. For most patients, high-quality postcardiac arrest care begins in the Emergency Department. This article reviews the evidence and offers treatment strategies for the key components of postcardiac arrest care.

Association between hospital post-resuscitative performance and clinical outcomes after out-of-hospital cardiac arrest

BACKGROUND

Survival varies among those resuscitated from out-of-hospital cardiac arrest (OHCA). Evidence-based performance measures have been used to describe hospital quality of care in conditions such as acute coronary syndrome and major trauma. It remains unclear if adherence to performance measures is associated with better outcome in patients hospitalized after OHCA.

OBJECTIVES

To assess whether a composite performance score based on evidence-based guidelines for care of patients resuscitated from OHCA was independently associated with clinical outcomes.

METHODS

Included were 3252 patients with OHCA who received care at 111 U.S. and Canadian hospitals participating in the Resuscitation Outcomes Consortium (ROC-PRIMED) study between June 2007 and October 2009. We calculated composite performance scores for all patients, aggregated these at the hospital level, then associated them with patient mortality and favorable neurological status at discharge.

RESULTS

Composite performance scores varied widely (median [IQR] scores from lowest to highest hospital quartiles, 21% [20%, 25%] vs. 59% [55%, 64%]. Adjusted survival to discharge increased with each quartile of performance score (from lowest to highest: 16.2%, 20.8%, 28.5%, 34.8%, P<0.01), with similar findings for adjusted rates of good neurologic status. Hospital score was significantly associated with outcome after risk adjustment for established baseline factors (highest vs. lowest adherence quartile: adjusted OR of survival 1.64; 95% CI 1.13, 2.38).

CONCLUSIONS

Greater survival and favorable neurologic status at discharge were associated with greater adherence to recommended hospital based post-resuscitative care guidelines. Consideration should be given to measuring, reporting and improving hospital adherence to guideline-based performance measures, which could improve outcomes following OHCA.

Effect of a pharmacologically induced decrease in core temperature in rats resuscitated from cardiac arrest

AIM

Hypothermia is recommended by international guidelines for treatment of unconscious survivors of cardiac arrest to improve neurologic outcomes. However, temperature management is often underutilized because it may be difficult to implement. The present study evaluated the efficacy of pharmacologically induced hypothermia on survival and neurological outcome in rats resuscitated from cardiac arrest.

METHODS

Cardiac arrest was induced for 10 min in 120 rats. Sixty-one rats were resuscitated and randomized to normothermia, physical cooling or pharmacological hypothermia 5 min after resuscitation. Pharmacological hypothermia rats received a combination of ethanol, vasopressin and lidocaine (HBN-1). Physical hypothermia rats were cooled with intravenous iced saline and cooling pads. Rats in the pharmacological hypothermia group received HBN-1 at ambient temperature (20 °C). Normothermic rats were maintained at 37.3 ± 0.2 °C.

RESULTS

HBN-1 (p < 0.0001) shortened the time (85 ± 71 min) to target temperature (33.5 °C) versus physical hypothermia (247 ± 142 min). The duration of hypothermia was 17.0 ± 6.8h in the HBN-1 group and 17.3 ± 7.5h in the physical hypothermia group (p = 0.918). Survival (p = 0.034), neurological deficit scores (p < 0.0001) and Morris Water Maze performance after resuscitation (p = 0.041) was improved in the HBN-1 versus the normothermic group. HBN-1 improved survival and early neurological outcome compared to the physical hypothermia group while there was no significant difference in performance in the Morris water maze.

CONCLUSION

HBN-1 induced rapid and prolonged hypothermia improved survival with good neurological outcomes after cardiac arrest suggesting that pharmacologically induced regulated hypothermia may provide a practical alternative to physical cooling.

Targeted temperature management processes and outcomes after out-of-hospital cardiac arrest: an observational cohort study*

OBJECTIVES

Targeted temperature management has been shown to improve survival with good neurological outcome in patients after out-of-hospital cardiac arrest. The optimal approach to inducing and maintaining targeted temperature management, however, remains uncertain. The objective of this study was to evaluate these processes of care with survival and neurological function in patients after out-of-hospital cardiac arrest.

DESIGN

An observational cohort study evaluating the association of targeted temperature management processes with survival and neurological function using bivariate and generalized estimating equation analyses.

SETTING

Thirty-two tertiary and community hospitals in eight urban and rural regions of southern Ontario, Canada.

PATIENTS

Consecutive adult (≥ 18 yr) patients admitted between November 1, 2007, and January 31, 2012, and who were treated with targeted temperature management following nontraumatic out-of-hospital cardiac arrest.

INTERVENTIONS

Evaluate the association of targeted temperature management processes with survival and neurologic function using bivariate and generalized estimating equation analyses.

MEASUREMENTS AND MAIN RESULTS

There were 5,770 consecutive out-of-hospital cardiac arrest patients, of whom 747 (12.9%) were eligible and received targeted temperature management. Among patients with available outcome data, 365 of 738 (49.5%) survived to hospital discharge and 241 of 675 (35.7%) had good neurological outcomes. After adjusting for the Utstein variables, a higher temperature prior to initiation of targeted temperature management was associated with improved neurological outcomes (odds ratio, 1.27 per °C; 95% CI, 1.08-1.50; p = 0.004) and survival (odds ratio, 1.26 per °C; 95% CI, 1.09-1.46; p = 0.002). A slower rate of cooling was associated with improved neurological outcomes (odds ratio, 0.74 per °C/hr; 95% CI, 0.57-0.97; p = 0.03) and survival (odds ratio, 0.73 per °C/hr; 95% CI, 0.54-1.00; p = 0.049).

CONCLUSIONS

A higher baseline temperature prior to initiation of targeted temperature management and a slower rate of cooling were associated with improved survival and neurological outcomes. This may reflect a complex relationship between the approach to targeted temperature management and the extent of underlying brain injury causing impaired thermoregulation in out-of-hospital cardiac arrest patients.

Adipose-derived mesenchymal stem cells reduce neuronal death after transient global cerebral ischemia through prevention of blood-brain barrier disruption and endothelial damage

Global cerebral ischemia (GCI) is the leading cause of a poor prognosis even after successful resuscitation from cardiac arrest. Therapeutic induction of hypothermia (TH) is the only proven therapy-and current standard care-for GCI after cardiac arrest; however, its application has been significantly limited owing to technical difficulties. Mesenchymal stem cells (MSCs) are known to suppress neuronal death after cerebral ischemia. The prevention of blood-brain barrier (BBB) disruption has not been suggested as a mechanism of MSC treatment but has for TH. We evaluated the therapeutic effect of MSC administration on BBB disruption and neutrophil infiltration after GCI. To evaluate the therapeutic effects of MSC treatment, rats were subjected to 7 minutes of transient GCI and treated with MSCs immediately after reperfusion. Hippocampal neuronal death was evaluated at 7 days after ischemia using Fluoro-Jade B (FJB). BBB disruption, endothelial damage, and neutrophil infiltration were evaluated at 7 days after ischemia by immunostaining for IgG leakage, Rat endothelial antigen-1, and myeloperoxidase (MPO). Rats treated with MSCs showed a significantly reduced FJB+ neuron count compared with the control group. They also showed reduced IgG leakage, endothelial damage, and MPO+ cell counts. The present study demonstrated that administration of MSCs after transient GCI provides a dramatic protective effect against hippocampal neuronal death. We hypothesized that the neuroprotective effects of MSC treatment might be associated with the prevention of BBB disruption and endothelial damage and a decrease in neutrophil infiltration.

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.

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.