Evaluation of factors that delay initial epinephrine administration in patients with in-hospital cardiac arrest: a single-center retrospective study

Background Epinephrine significantly enhances the rate of return of spontaneous circulation, and its early administration during cardiac arrest is recommended in both domestic and international resuscitation guidelines. However, the specific timing of epinephrine administration for patients with in-hospital cardiac arrest in Japan remains unclear. Furthermore, cases in which this initial administration has been delayed have been reported, although the causes for this remain poorly understood. This study investigated the time to initial epinephrine administration during in-hospital cardiac arrest at Japanese emergency hospitals and its association with 24-h survival rates, as well as examined factors contributing to delays in initial administration. Methods A retrospective study using electronic medical records was conducted at Kyoto Okamoto Memorial Hospital, focusing on cases of cardiac arrest that occurred between April 2020 and March 2023 in which the initial electrocardiogram (ECG) waveform was either asystole or pulseless electrical activity. The cases were grouped based on the time to initial epinephrine administration: 0–3 min, 4–6 min, 7–9 min, and >10 min, and the 24-h survival rates were calculated. Additionally, the cases were grouped based on whether the time to first epinephrine administration was within 3 min. Factors associated with delayed administration were explored using multivariable logistic regression analysis. Results The median time to first epinephrine administration during in-hospital cardiac arrest was 5 min. The overall 24-h survival rate was 28.8%, with a shorter time to first epinephrine administration linked to a higher 24-h survival rate. Moreover, multivariate logistic regression analysis revealed a significant delay in the initial administration of epinephrine in cases where an ECG monitor was not attached at the time of discovery (odds ratio = 6.49; 95% confidence interval = 1.24–34.10). Conclusions We revealed that in cases of in-hospital cardiac arrest, earlier initial administration of epinephrine tended to be linked with higher 24-h survival rates. Furthermore, our exploratory analysis suggested that the absence of ECG monitoring at the time of discovery may be associated with delayed administration of epinephrine. Further research is warranted to establish a reliable method for identifying patients at high risk of cardiac arrest, which may help optimize the use of ECG monitoring.