Variability of Doppler flow velocity and cerebral perfusion pressure is reduced in the neonate by sedation and neuromuscular blockade.
Doppler flow velocity (DFV) in the anterior cerebral artery was recorded every 12 h and cerebral perfusion pressure (CPP) continuously in 21 sick, ventilated preterm neonates for 48 h from shortly after birth. Ten received a neuromuscular blocker, seven were sedated with morphine infusions and five received neither of these treatments. Variability of DFV and CPP was assessed by the coefficient of variation (CV) and the autocorrelation function (ACF). Variability of both signals was lowest in the group treated by neuromuscular blockade (DFV CV 3, s.d. = 0.8; CPP CV 9, s.d. = 2.2; CPP ACF 37, s.d. = 19.2), intermediate in the group receiving sedation by morphine infusion (DFV CV 3.4, s.d. = 0.7; CPP CV 11, s.d. = 2.2; CPP ACF 31, s.d. = 21.6) and highest in the group receiving neither treatment (DFV CV 5, s.d. = 1.8; CPP CV 14, s.d. = 2.3; CPP ACF 27, s.d. = 16.7). Variability also increased with decreasing gestational age, suggesting that immature cerebrovascular regulatory mechanisms were present in the least mature neonates.
Colditz
P B
PB
Department of Neonatology, Children's Hospital, Sydney, New South Wales, Australia.
Williams
G L
GL
Berry
A B
AB
Symonds
P J
PJ
D001724:Birth Weight; D002536:Cerebral Arteries / Q000187:drug effects; D002543:Cerebral Hemorrhage / Q000517:prevention & control; D002560:Cerebrovascular Circulation / Q000187:drug effects*; D005865:Gestational Age; D006801:Humans; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D007234:Infant, Premature; D009020:Morphine / Q000494:pharmacology*; D010197:Pancuronium / Q000494:pharmacology*; D014463:Ultrasonography
D009020:Morphine; D010197:Pancuronium