460 - Intramuscular versus intravenous epinephrine administration during cardiopulmonary resuscitation in a neonatal piglet model of asystole

Publication Number: 1442.460

Marwa Ramsie, University of Alberta Faculty of Medicine and Dentistry, Edmonton, AB, Canada; Po-Yin Cheung, University of Alberta Faculty of Medicine and Dentistry, Edmonton, AB, Canada; Tze-Fun Lee, University of Alberta Faculty of Medicine and Dentistry, Edmonton, AB, Canada; Megan O'Reilly, University of Alberta, Edmonton, AB, Canada; Georg Schmolzer, University of Alberta Faculty of Medicine and Dentistry, Edmonton, AB, Canada

Background: Epinephrine is currently recommended during neonatal resuscitation; its optimal route, timing, and dose is unknown. The preferable route intravenous (IV) or intraosseous (IO) administration of epinephrine, with 1 dose of endotracheal tube (ETT) administration until IV/IO access is established. However, establishing IV/IO access can take several minutes, thereby potentially reducing the odds of survival.
The intramuscular (IM) route provides rapid drug administration and is recommended as the first-line treatment with epinephrine for anaphylaxis and might be an alternative during neonatal resuscitation.

Objective: To compare the IM and IV routes of epinephrine administration in a well-established neonatal piglet model of asphyxia-induced asystole.

Design/Methods: Sixteen neonatal piglets (n=8/group) were anesthetized, intubated, instrumented, and exposed to 45 minutes of normocapnic hypoxia, followed by asphyxiation until asystole. Piglets were randomized to receive either 0.02mg/kg IV epinephrine or 0.2mg/kg IM epinephrine. Piglets randomized to “IM” were administered IM epinephrine 30 seconds and 2 minutes after CCs were initiated and IV epinephrine at 5 minutes and 8 minutes if no return of spontaneous circulation (ROSC) was observed. Piglets randomized to “IV” received a sham injection at 30 seconds and IV epinephrine 2 minutes after the start of CCs and every 3 minutes as needed if no ROSC was observed, to a maximum of three doses. Measurements of rates of ROSC and time to ROSC, hemodynamic, and blood gas changes were collected.

Results: Baseline parameters were similar between groups. There were no differences in rates of ROSC between piglets receiving IV (4/8 (50%)) or IM epinephrine (5/8 (63%)) (p=1.00). Time to ROSC was similar between IV and IM groups (177 (144-211) sec vs 237 (54-430) sec, respectively, p=0.538). There were no differences in the number of doses needed to achieve ROSC was similar between IV (2 (1-3)) and IM (3 (2-4)) groups (p=0.234).

Conclusion(s): IM epinephrine could be an alternative initial route of administration until IV access has been established. Piglets administered IM epinephrine had comparable time to and rates of ROSC to piglets treated with only IV epinephrine. Further studies are warranted.