Abstract Body: Background
Current neonatal resuscitation guidelines recommend epinephrine preferably be given via intravenous (IV) or intraosseous (IO) routes during cardiac arrest. Vasopressin might be an alternative during asphyxial cardiac arrest; however, whether it remains effective when administered via IO is unclear.

Objective
We aimed to compare IO with IV vasopressin or epinephrine on incidence and time to return of spontaneous circulation (ROSC) in asphyxiated newborn piglets.

Design/Methods
Thirty-two newborn piglets (n=8/group) were anesthetized, intubated, instrumented, and exposed to 45 minutes of normocapnic hypoxia, followed by asphyxiation till asystolic cardiac arrest. Piglets were randomized to 0.4IU/kg IV or IO vasopressin, or 0.02mg/kg IV or IO epinephrine. Drug was administered via IV or IO 1 minute after the start of chest compressions (CCs) and administered every 3 minutes as needed if no return of spontaneous circulation (ROSC) was observed, to a maximum of three doses.

Results
Rates of ROSC were not different between IV or IO vasopressin, 5/8(63%) vs 3/8(38%), respectively (p=0.619), or between IV or IO epinephrine, 2/8(25%) vs 6/8(75%), respectively (p=0.132). Rates of ROSC were similar between all four groups (p=0.233). Median (IQR) time to ROSC was 254 (220-473)sec and 215 (200-240)sec for IV and IO vasopressin, respectively (p=0.143), and 272 (265-278)sec and 233 (203-266)sec for IV and IO epinephrine, respectively (p=0.286). Time to ROSC was similar amongst all groups (p=0.312).

Conclusions
In a neonatal piglet model of asystolic cardiac arrest, administration of IO vasopressin or epinephrine resulted in similar resuscitative outcomes to IV vasopressin or epinephrine. Our findings suggest that IO vasopressor administration is effective during neonatal resuscitation, and that IO vasopressin is a feasible alternative to IV vasopressin.