EFFECTS OF PHENYLEPHRINE ON CEREBRAL AID MYOCARDIAL BLCCO FLAW DURING CPR IN INFANT PIGLETS

Abstract

We evaluated phenylephrine (PE) during CPR in an infant animal model to determine if cerebral (CBF) and myocardial (CBF) blood flow could be sustained for longer periods of CPR than in our previously published study using epinephrine (E)1. CPR was performed on 6 pentobarbital-anesthetized piglets (2 weeks old, 4-5 kg) by a pneumatic compressor at 100 coirpressions/min, 60% duty cycle, and 1:5 breath to compression ratio. Aortic pressure decreased after 10 min of CPR, while right artial pressure remained unchanged resulting in MBF of 28 and 35 ml/min/100 g at 5 and 10 min of CPR. CBF (ml/min/100 g) was maintained at prearrest values (34 ± 4) for 20 min (28 ± 9) of CPR but fell during prolonged CPR because of a decrease in cerebral perfusion pressure after that time. CMRO2 (ml/min/100 g) was sustained at control values (2.1 ± .2) for 10 min (2.4 ± .3) but thereafter decreased. Cerebral extraction (EXT) was elevated above prearrest levels, but not different than with E. In conclusion, PE sustained CMRO2 and CBF for 10 and 20 min of CPR, comparing favorably to E in our study. PE provided significant levels of MBF during early CPR, but less than with E. Therefore, in infant piglets, PE and E provide similar benefits on CBF and CMRO2 during early CPR, but are not sustained indefinitely in either group. MBF may be less with PE. 1. Schleien, C., et al. Circulation 73:809, 1986. (Supported by NS20020)