Effect of early epinephrine administration on survival outcome among out-of-hospital cardiac arrest patients: a retrospective cohort study

Title:

Effect of early epinephrine administration on survival outcome among out-of-hospital cardiac arrest patients: a retrospective cohort study

Introduction:

Out-of-hospital cardiac arrest (OHCA) is one of major public health concerns, because of high incidence globally but low survival probability. Several factors play an important role to increase survival: high-quality chest compression, early defibrillation, or advanced resuscitation strategies. Epinephrine has been used for decades during resuscitation. Recently, international guideline by the American Heart Association suggests use of epinephrine as soon as possible for non-shockable, and after unsuccessful initial defibrillation for shockable rhythm. In EMS-treated patients, previous studies found that epinephrine was delayed administer, usually >10 minutes after EMS arrival. This will result to detrimental outcome for OHCA patient.

Objective:

This study aims to determine the association of early epinephrine administration and survival outcome among OHCAs patients.

Methods:

This was a retrospective cohort study. OHCA patients responded by doctor-lead ALS teams of Ramathibodi Emergency Medical Operation Unit from January 2020 to June 2021, with age >16 years and received at least one dose of epinephrine during resuscitation were enrolled. Data including patient characteristics, prehospital interventions, time to first epinephrine administration and survival outcome (defined as sustained return of spontaneous circulation (ROSC) from scene to emergency department (ED) arrival) were extracted from prehospital medical records. Participants who the first epinephrine administered within 5 minutes from initiation of advanced cardiovascular life support (ACLS) were categorized to early group, while the others were categorized to late group.  Multivariable Poisson regression with robust correction was used to quantify effect size of early epinephrine administration and survival outcome.

Results:

There were 80 OHCA patients enrolled in this study. Of these, 29 (36.35%) categorized to early group and 51 (63.75%) categorized to late group. Average time to first epinephrine administered in early and late group were 3.59±1.12 and 10.06±4.37 minutes, respectively (p-value=0.553). Intravenous was primary route of fluid/drug administration for early group (29, 86.66%), whereas intraosseous was primary for late group (17, 33.33%). After covariate adjustment, early epinephrine administration increases the 5 folds of survival probability among OHCA patients (RR_adj 5.12; 95% CI 1.63-16.10; P-value=0.005).

Conclusion:

Early epinephrine administration, within 5 minutes after ACLS initiation, increases the survival probability among OHCA patients.