Epinephrine for out of hospital cardiac arrest: A systematic review and meta-analysis of randomized controlled trials

Out-of-hospital cardiac arrest patients during the coronavirus disease 2019 pandemic

The coronavirus disease 2019 (COVID-19) pandemic had severe impact on the outcome of out-of-hospital cardiac arrest (OHCA) patients and the possibility of bystander cardiopulmonary resuscitation (CPR). Previous studies focused only on the short periods of the pandemic and reported a significant increase in the number of infections. In a retrospective cohort study we aimed to compare the outcomes of OHCA patients 1 year before and 1 year after the onset of COVID-19. Data of 519 OHCA patients during the pre-pandemic (January-December 2019; 262 patients) and intra-pandemic (April 2020-March 2021; 257 patients) periods in Yokohama Municipal Hospital, Japan were collected and analysed retrospectively. The study outcomes were the return of spontaneous circulation (ROSC), admission to hospital, survival to discharge, and cerebral performance category at discharge. The intra-pandemic period was associated with decreased bystander CPR (P = 0.004), prolonged transport time (P < 0.001), delayed first adrenaline administration (P < 0.001), and decrease in ROSC (P = 0.023). Logistic regression analysis revealed that the following factors were significantly associated with ROSC: "pandemic", "shockable initial waveform", and "witness presence".

Epinephrine in Out-of-Hospital Cardiac Arrest: A Network Meta-analysis and Subgroup Analyses of Shockable and Nonshockable Rhythms

BACKGROUND

Epinephrine is the most commonly used drug in out-of-hospital cardiac arrest (OHCA) resuscitation, but evidence supporting its efficacy is mixed.

RESEARCH QUESTION

What are the comparative efficacy and safety of standard dose epinephrine, high-dose epinephrine, epinephrine plus vasopressin, and placebo or no treatment in improving outcomes after OHCA?

STUDY DESIGN AND METHODS

In this systematic review and network meta-analysis of randomized controlled trials, we searched six databases from inception through June 2022 for randomized controlled trials evaluating epinephrine use during OHCA resuscitation. We performed frequentist random-effects network meta-analysis and present ORs and 95% CIs. We used the the Grading of Recommendations, Assessment, Development, and Evaluation approach to rate the certainty of evidence. Outcomes included return of spontaneous circulation (ROSC), survival to hospital admission, survival to discharge, and survival with good functional outcome.

RESULTS

We included 18 trials (21,594 patients). Compared with placebo or no treatment, high-dose epinephrine (OR, 4.27; 95% CI, 3.68-4.97), standard-dose epinephrine (OR, 3.69; 95% CI, 3.32-4.10), and epinephrine plus vasopressin (OR, 3.54; 95% CI, 2.94-4.26) all increased ROSC. High-dose epinephrine (OR, 3.53; 95% CI, 2.97-4.20), standard-dose epinephrine (OR, 3.00; 95% CI, 2.66-3.38), and epinephrine plus vasopressin (OR, 2.79; 95% CI, 2.27-3.44) all increased survival to hospital admission as compared with placebo or no treatment. However, none of these agents may increase survival to discharge or survival with good functional outcome as compared with placebo or no treatment. Compared with placebo or no treatment, standard-dose epinephrine improved survival to discharge among patients with nonshockable rhythm (OR, 2.10; 95% CI, 1.21-3.63), but not in those with shockable rhythm (OR, 0.85; 95% CI, 0.39-1.85).

INTERPRETATION

Use of standard-dose epinephrine, high-dose epinephrine, and epinephrine plus vasopressin increases ROSC and survival to hospital admission, but may not improve survival to discharge or functional outcome. Standard-dose epinephrine improved survival to discharge among patients with nonshockable rhythm, but not those with shockable rhythm.

TRIAL REGISTRY

Center for Open Science: https://osf.io/arxwq.

Impact of Number of Defibrillation Attempts on Neurologically Favourable Survival Rate in Patients with Out-of-Hospital Cardiac Arrest

AIM

of the study: Defibrillation plays a crucial role in early return of spontaneous circulation (ROSC) and survival of patients with out-of-hospital cardiac arrest (OHCA) and shockable rhythm. Prehospital adrenaline administration increases the probability of prehospital ROSC. However, little is known about the relationship between number of prehospital defibrillation attempts and neurologically favourable survival in patients treated with and without adrenaline.

METHODS

Using a nationwide Japanese OHCA registry database from 2006 to 2020, 1,802,084 patients with OHCA were retrospectively analysed, among whom 81,056 with witnessed OHCA and initial shockable rhythm were included. The relationship between the number of defibrillation attempts before hospital admission and neurologically favourable survival rate (cerebral performance category score of 1 or 2) at 1 month was evaluated with subgroup analysis for patients treated with and without adrenaline.

RESULTS

At 1 month, 18,080 (22.3%) patients had a cerebral performance category score of 1 or 2. In the study population, the probability of prehospital ROSC and favourable neurological survival rate were inversely associated with number of defibrillation attempts. Similar trends were observed in patients treated without adrenaline, whereas a greater number of defibrillation attempts was counterintuitively associated with favourable neurological survival rate in patients treated with prehospital adrenaline.

CONCLUSIONS

Overall, a greater number of prehospital defibrillation attempts was associated with lower neurologically favourable survival at 1 month in patients with OHCA and shockable rhythm. However, an increasing number of shocks (up to the 4th shock) was associated with better neurological outcomes when considering only patients treated with adrenaline.

Delayed administration of epinephrine is associated with worse neurological outcomes in patients with out-of-hospital cardiac arrest and initial pulseless electrical activity: insight from the nationwide multicentre observational JAAM-OHCA (Japan Association for Acute Medicine) registry

Aims

The delayed administration of epinephrine has been proven to worsen the neurological outcomes of patients with out-of-hospital cardiac arrest (OHCA) and shockable rhythm or asystole. We aimed to investigate whether the delayed administration of epinephrine might also worsen the neurological outcomes of patients with witnessed OHCA and initial pulseless electrical activity (PEA).

Methods and results

The JAAM-OHCA Registry is a multicentre registry including OHCA patients between 2014 and 2017. Patients with emergency medical services (EMS)-treated OHCA and initial PEA rhythm were included. The primary exposure was the time from the EMS call to the administration of epinephrine. The secondary exposure was the time to epinephrine dichotomized as early (≤15 min) or delayed (>15 min). The primary outcome was the achievement of a favourable neurological outcome, defined as Cerebral Performance Categories Scale 1–2 at 30 days after OHCA. Out of 34 754 patients with OHCA, 3050 patients were included in the present study. After adjusting for potential confounders, the delayed administration of the epinephrine was associated with a lower likelihood of achieving a favourable neurological outcome [adjusted odds ratio (OR) 0.96; 95% confidence interval (CI) 0.93–0.99; P = 0.016]. The percentage of patients who achieved a favourable neurological outcome in the delayed epinephrine group was lower than that in the early epinephrine group (1.3% vs. 4.7%; adjusted OR 0.33; 95% CI 0.15–0.72; P = 0.005). A restricted cubic spline analysis demonstrated that delayed epinephrine administration could decrease the likelihood of achieving a favourable neurological outcome; this was significant within the first 10 min.

Conclusions

The delayed administration of epinephrine was associated with worse neurological outcomes in patients with witnessed OHCA patients with initial PEA.

Decreasing the Stress of Medication Management During Cardiac Arrest

Cardiac arrest affects more than 500 000 people every year, with significant associated morbidity and mortality. In addition to high-quality cardiopulmonary resuscitation and early defibrillation, medications are included in treatment algorithms. Epinephrine and amiodarone are commonly used, with other medications being used in specific situations of cardiac arrest. Although participating in the care of a patient in cardiac arrest is complex and stressful, having a baseline understanding of the medications being used, routes of administration, and special considerations can be helpful in mitigating some of the stress in these situations.

Update on Cardiopulmonary Resuscitation in Small Animals

Cardiopulmonary arrest (CPA), the acute cessation of ventilation and systemic perfusion, leads to discontinuation of tissue oxygen delivery and death if not quickly reversed. Reported resuscitation rates suggest that the heart can be restarted in 40% to 50% of dogs and cats treated with cardiopulmonary resuscitation (CPR). However, approximately 80% of these animals do not survive to hospital discharge. To minimize mortality due to CPA a broad strategy is required including preparedness and prevention measures, basic and advanced life support as well as post-cardiac arrest care. This article summarizes the current guidelines on the treatment of small animals with CPA..