Impact of catecholamines in cardiac arrest due to acute asphyxia--a study in piglets.

BACKGROUND

Early intravenous epinephrine administration may help to achieve return of spontaneous circulation in cardiac arrest (CA). However, venous access can be challenging in small children. This study investigates the effect of intravenous and intramuscular epinephrine in treatment of asphyxial CA.

METHODS

Twenty-eight, 2-5-weeks-old, anesthetized piglets were asphyxiated by ventilation withdrawal. CA was untreated for 8 min, followed by 2 min of basic life support. Following this, epinephrine iv (10 μg·kg(-1) , group IV), epinephrine im (100 μg·kg(-1) , group IM), or normal saline (group NS) were administered. Further doses of epinephrine were given in group IV every 4 min, in group IM after 10 min if required. After twenty-two minutes of CA, iv epinephrine was given to all animals still in CA. Outcome measures were survival and epinephrine plasma concentrations.

RESULTS

Ten animals regained spontaneous circulation after 2 min of basic life support. Therefore, no drug treatment was administered (drop out). Resuscitation was effective in 2 pigs of group IM (n = 6), in 6 of group NS (n = 8) and in all of group IV (n = 4). Nonsurvivors had higher epinephrine (P < 0.01) and norepinephrine (P < 0.01) plasma concentrations prior to start of resuscitation. Median increase in epinephrine plasma concentration from T0 to T5 was 138, 134, and 29 nm in group IV, IM, and NS, respectively.

CONCLUSIONS

Intravenous and intramuscular administered epinephrine led to similar increase in plasma concentrations during resuscitation of asphyxial CA without hemodynamic or survival benefit. High endogenous epinephrine and norepinephrine plasma concentrations were negative predictors for survival.