The impact of different targeted temperatures on out-of-hospital cardiac arrest outcomes in patients receiving extracorporeal membrane oxygenation: a nationwide cohort study

Comparison of hypothermic and normothermic targeted temperature management in out-of-hospital cardiac arrest patients with acute coronary syndrome: a nationwide retrospective study

BACKGROUND

Targeted temperature management (TTM) is considered a beneficial treatment for improving outcomes in patients with OHCA due to acute coronary syndrome (ACS). The comparative benefits of hypothermic TTM (32-34°C) versus normothermic TTM (35-36°C) are unclear. This study compares these TTM strategies in improving neurological outcomes and survival rates in OHCA patients with ACS.

METHODS

We conducted a retrospective analysis using data from the Japanese Association for Acute Medicine Out-of-Hospital Cardiac Arrest (JAAM-OHCA) registry, encompassing 68,110 OHCA patients between June 2014 and December 2020. After applying inclusion and exclusion criteria, 1,217 adult patients with ACS who received TTM were eligible for the study. Patients were categorized into two groups based on their TTM strategy: hypothermic TTM (32-34°C) and normothermic TTM (35-36°C). The primary outcome was 30-day favorable neurological outcome, defined by the Cerebral Performance Category (CPC) scale (CPC 1-2). Secondary outcomes included 30-day survival and adverse event incidence. Statistical analysis involved multivariable logistic regression and propensity score adjustments with inverse probability weighting (IPW) to account for potential confounders.

RESULTS

Of the 1,217 patients, 369 received normothermic TTM and 848 received hypothermic TTM. In both groups, most patients were male, with a median age in the 60s. Approximately 70% had a shockable rhythm at the scene, one-third had a shockable rhythm in-hospital, around 70% had ST segment elevation, and about half received extracorporeal membrane oxygenation. The proportions of patients with 30-day favorable neurological outcomes were 36.6% (135) in the normothermic group and 36.6% (310) in the hypothermic group. No difference in neurological outcomes was observed in the multivariable regression analysis (adjusted OR 1.14, 95% CI 0.84-1.54), and the result was consistent in the IPW analysis (OR 1.11, 95% CI 0.84-1.47). Other outcomes also showed no significant differences.

CONCLUSION

In this nationwide, retrospective study using the JAAM-OHCA registry, we found no significant differences in 30-day favorable neurological outcome, 30-day survival, and adverse event incidences between hypothermic TTM (32-34°C) and normothermic TTM (35-36°C) in adult patients with OHCA due to ACS.

What's the optimal temperature control strategy in patients receiving ECPR after cardiac arrest? A network meta-analysis

BACKGROUND

The optimal temperature control strategy in extracorporeal cardiopulmonary resuscitation (ECPR) patients is unknown, and several trials have reported conflicting results regarding its effectiveness. We aimed to conduct a systemic review and network meta-analysis (NMA) to assess the efficacy of temperature control in ECPR patients.

METHODS

Database searching of studies reporting data on temperature control strategy during ECPR in MEDLINE, EMBASE, Scopus, and Cochrane Library was performed. Primary outcomes were overall survival and neurological outcome. Pairwise meta-analysis and Bayesian NMA were performed on studies comparing outcomes among groups of moderate hypothermia (32-34 °C), mild hypothermia (34.1-36 °C) and normothermia (36.1-37.5 °C).

RESULTS

Nineteen retrospective studies were included (5622 patients). Statistically significant differences in good neurological outcome were observed in the direct comparison of moderate hypothermia and mild hypothermia (OR, 1.73; 95 % CI: 1.07-2.81) as well as moderate hypothermia and normothermia (OR, 2.14; 95 % CI: 1.24-3.67), but no significant differences were found in the NMA result. There was no difference in either survival outcome or the incidence of bleeding complications among any groups according to direct or indirect analysis.

CONCLUSIONS

Direct evidence suggests that moderate hypothermia might be associated with improved neurological outcomes in ECPR patients. However, no significant differences in survival outcomes were observed in either the direct or NMA results. Given the lower level of the evidence, interpretation should be made with caution.

Temperature Outcomes without heater cooler units in adult patients supported with extracorporeal membrane oxygenation: A retrospective cohort study

INTRODUCTION

Heater-cooler units (HCUs) are frequently incorporated into extracorporeal membrane oxygenation (ECMO) circuits to help maintain patient normothermia. However, these devices may be associated with increased cost and infection risk. This study describes our institution's experience managing adult ECMO patients without the routine use of in-circuit HCUs.

METHODS

We performed a retrospective analysis of adult patients treated with veno-venous (VV) or veno-arterial (VA) ECMO at our institution. The primary outcomes were rates of HCU use and the relative duration of the ECMO treatment course in which patients maintained normothermia (36-37.5°C), with and without HCUs. Secondary outcomes of mortality and ECMO-related complications were planned across HCU and non-HCU groups; exploratory analyses were performed across a 75% "ECMO time in normothermia" threshold.

RESULTS

Among a cohort of 71 patients, zero (0%) were managed with in-circuit HCUs. A majority of ECMO patient-hours were spent in the normothermic range. Median and mean percentages of ECMO normothermia time were 75% (IQR 49%-81%) and 62% (SD ± 27%). Twenty-nine patients (40%) met the threshold of 75% ECMO normothermia time, as used to evaluate secondary outcomes. At this threshold, mortality risk was significantly higher among the non-normothermic cohort; other ECMO-related complications did not vary significantly.

CONCLUSIONS

In the absence of HCU use, the majority of ECMO patient-hours were spent in normothermia. However, only a minority of patients achieved normothermia for at least 75% of their ECMO course. In-circuit HCUs may be required to maintain high percentages of normothermic time in adult EMCO patients.

Impact of center volume on in-hospital mortality in adult patients with out‑of‑hospital cardiac arrest resuscitated using extracorporeal cardiopulmonary resuscitation: a secondary analysis of the SAVE-J II study

Recently, patients with out-of-hospital cardiac arrest (OHCA) refractory to conventional resuscitation have started undergoing extracorporeal cardiopulmonary resuscitation (ECPR). However, the mortality rate of these patients remains high. This study aimed to clarify whether a center ECPR volume was associated with the survival rates of adult patients with OHCA resuscitated using ECPR. This was a secondary analysis of a retrospective multicenter registry study, the SAVE-J II study, involving 36 participating institutions in Japan. Centers were divided into three groups according to the tertiles of the annual average number of patients undergoing ECPR: high-volume (≥ 21 sessions per year), medium-volume (11-20 sessions per year), or low-volume (< 11 sessions per year). The primary outcome was survival rate at the time of discharge. Patient characteristics and outcomes were compared among the three groups. Moreover, a multivariable-adjusted logistic regression model was applied to study the impact of center ECPR volume. A total of 1740 patients were included in this study. The center ECPR volume was strongly associated with survival rate at the time of discharge; furthermore, survival rate was best in high-volume compared with medium- and low-volume centers (33.4%, 24.1%, and 26.8%, respectively; P = 0.001). After adjusting for patient characteristics, undergoing ECPR at high-volume centers was associated with an increased likelihood of survival compared to middle- (adjusted odds ratio 0.657; P = 0.003) and low-volume centers (adjusted odds ratio 0.983; P = 0.006). The annual number of ECPR sessions was associated with favorable survival rates and lower complication rates of the ECPR procedure.Clinical trial registration: https://center6.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000041577 (unique identifier: UMIN000036490).

Survival and neurological function in patients treated with extracorporeal membrane oxygenation and therapeutic hypothermia: a protocol for updating a systematic review

INTRODUCTION

The widespread application of extracorporeal membrane oxygenation (ECMO) has enhanced clinical outcomes for patients experiencing cardiac arrest. However, its effectiveness is still limited and falls short of the desired level. Therapeutic hypothermia, which maintains body temperatures between 32°C and 36°C in cardiac arrest patients treated with ECMO, has been proposed as a potential means of neuroprotection and increased survival rates. Nevertheless, it remains controversial, and its impact on patient complications has yet to be fully understood. Thus, this paper aims to update the protocol for a systematic review of patients treated with ECMO and therapeutic hypothermia, in order to explore its effects on survival and neurological function.

METHOD AND ANALYSIS

This protocol has been developed in compliance with the Preferred Reporting Items for Systematic Review and Meta-analysis Protocols 2015. The following databases will be systematically searched: PubMed, Web of Science, Cochrane Library, Embase, Ovid, CNKI, Wanfang and China Biology Medicine Disc. The database search strategy will use a combination of subject terms and free-text keywords. The search will encompass articles from the inception of each database up to 15 June 2023. Inclusion criteria encompass randomised controlled trials, cohort studies, case-control studies and quasi-experimental studies. Two researchers will independently review articles and extract relevant data based on these criteria. Any disagreements will be resolved through discussion. Data analysis will be performed using Review Manager software.

ETHICS AND DISSEMINATION

Since no patient data were collected in this study, ethical approval was not required. Research findings will be released in a peer-reviewed journal.

PROSPERO REGISTRATION NUMBER

CRD42023435353.

Intraoperative cardiac arrest caused by unexpected vasospastic angina requiring prolonged resuscitation using extracorporeal membrane oxygenation: a case report

BACKGROUND

Vasospastic angina (VSA) occurring during surgery is rare but can lead to sudden intraoperative cardiac arrest.

CASE PRESENTATION

A 77-year-old man with hypertension, and no history of coronary artery disease, displayed an abrupt ST-segment elevation on the electrocardiogram (ECG) during laparoscopic inguinal hernia surgery under general anesthesia. Subsequently, ventricular fibrillation (VF) occurred, with a finding suggesting ischemic myocardial contracture by transesophageal echocardiography. VF was refractory to cardiopulmonary resuscitation (CPR), and veno-arterial extracorporeal membrane oxygenation (VA ECMO) was introduced. Spontaneous circulation resumed 77 min post-cardiac arrest. VSA was confirmed through the patient's clinical course and coronary angiography. Subsequently, VA ECMO was terminated, and the patient was discharged uneventfully.

CONCLUSIONS

Extracorporeal CPR may be a valuable alternative to extended resuscitation for refractory ventricular arrhythmias by VSA.

The use of induced hypothermia in extracorporeal membrane oxygenation: A narrative review

Despite venovenous or venoarterial extracorporeal membrane oxygenation (ECMO) being increasingly used in patients with severe acute respiratory disease syndrome, severe cardiogenic shock, and refractory cardiac arrest, mortality rates still remain high mainly because of the severity of the underlying disease and the numerous complications associated with initiation of ECMO. Induced hypothermia might minimize several pathological pathways present in patients requiring ECMO; even though numerous studies conducted in the experimental setting have reported promising results, there are currently no recommendations suggesting the routine use of this therapy in patients requiring ECMO. In this review, we summarized the existing evidence on the use of induced hypothermia in patients requiring ECMO. Induced hypothermia was a feasible and relatively safe intervention in this setting; however, the effects on clinical outcomes remain uncertain. Whether controlled normothermia has an impact on these patients compared with no temperature control remains unknown. Further randomized controlled trials are required to better understand the role and impact of such therapy in patients requiring ECMO according to the underlying disease.