Survival After Intravenous Versus Intraosseous Amiodarone, Lidocaine, or Placebo in Out-of-Hospital Shock-Refractory Cardiac Arrest

BACKGROUND

Antiarrhythmic drugs have not proven to significantly improve overall survival after out-of-hospital cardiac arrest from shock-refractory ventricular fibrillation/pulseless ventricular tachycardia. How this might be influenced by the route of drug administration is not known.

METHODS

In this prespecified analysis of a randomized, placebo-controlled clinical trial, we compared the differences in survival to hospital discharge in adults with shock-refractory ventricular fibrillation/pulseless ventricular tachycardia out-of-hospital cardiac arrest who were randomly assigned by emergency medical services personnel to an antiarrhythmic drug versus placebo in the ALPS trial (Resuscitation Outcomes Consortium Amiodarone, Lidocaine or Placebo Study), when stratified by the intravenous versus intraosseous route of administration.

RESULTS

Of 3019 randomly assigned patients with a known vascular access site, 2358 received ALPS drugs intravenously and 661 patients by the intraosseous route. Intraosseous and intravenous groups differed in sex, time-to-emergency medical services arrival, and some cardiopulmonary resuscitation characteristics, but were similar in others, including time-to-intravenous/intrasosseous drug receipt. Overall hospital discharge survival was 23%. In comparison with placebo, discharge survival was significantly higher in recipients of intravenous amiodarone (adjusted risk ratio, 1.26 [95% CI, 1.06-1.50]; adjusted absolute survival difference, 5.5% [95% CI, 1.5-9.5]) and intravenous lidocaine (adjusted risk ratio, 1.21 [95% CI, 1.02-1.45]; adjusted absolute survival difference, 4.7% [95% CI, 0.7-8.8]); but not in recipients of intraosseous amiodarone (adjusted risk ratio, 0.94 [95% CI, 0.66-1.32]) or intraosseous lidocaine (adjusted risk ratio, 1.03 [95% CI, 0.74-1.44]). Survival to hospital admission also increased significantly when drugs were given intravenously but not intraosseously, and favored improved neurological outcome at discharge. There were no outcome differences between intravenous and intraosseous placebo, indicating that the access route itself did not demarcate patients with poor prognosis. The study was underpowered to assess intravenous/intraosseous drug interactions, which were not statistically significant.

CONCLUSIONS

We found no significant effect modification by drug administration route for amiodarone or lidocaine in comparison with placebo during out-of-hospital cardiac arrest. However, point estimates for the effects of both drugs in comparison with placebo were significantly greater for the intravenous than for the intraosseous route across virtually all outcomes and beneficial only for the intravenous route. Given that the study was underpowered to statistically assess interactions, these findings signal the potential importance of the drug administration route during resuscitation that merits further investigation.

Variations in the application of exception from informed consent in a multicenter clinical trial

BACKGROUND

Exception from infor med consent (EFIC) is allowed using federal regulations 21 CFR 50.24 and facilitates research on patients with critical conditions such as cardiac arrest. Little is known regarding the differences in the application of EFIC requirements such as community consultation (CC), public disclosure (PD) and patient notification. We sought to characterize variations in the fulfillment of EFIC requirements in a national multicenter clinical trial in the United States.

METHODS

We determined the strategies for fulfillment of EFIC requirements at five regional coordinating centers of the Pragmatic Airway Resuscitation Trial (PART), a cluster-crossover randomized trial comparing airway devices in out-of-hospital cardiac arrest. We collected information from the including site demographics, how CC and PD were implemented, methods undertaken by the site investigative team to meet the local IRB's interpretation, and patient notification timing (post-enrollment). We analyzed the data using descriptive statistics.

RESULTS

Sites had multiple approaches to CC, including social media advertising, random digit dialing surveys, working with city officials, and websites with embedded surveys. All sites used more than one approach for conducting CC. Public Disclosure activities included press releases through various means, website documentation, and letters to community members and local officials. Time from CC to study approval ranged from 42 days to 253 days.

CONCLUSION

EFIC implementation varies across sites and highlight community and regional variation. Different EFIC approaches may be needed to effectively accomplish the goals of community consultation, public disclosure, and patient notification.