Sleep-wake cycling and cerebral oxygen metabolism among critically Ill neonates

Among adults, wakefulness and rapid eye movement (REM) sleep, compared to non-REM sleep, require higher overall brain metabolism, but in neonates analogous data are not available. Behavioral states with higher metabolic demand could increase vulnerability to hypoperfusion or hypoxia in the compromised neonatal brain. Using cerebral oximetry (near-infrared spectroscopy), and simultaneous polysomnography, we evaluated whether brain oxygen metabolism varies by sleep-wake state among critically ill newborns. For each of 10 infants, sleep-wake cycling was detectable and cerebral oximetry varied (P <.0001) across behavioral states, but the patterns differed among subjects. We conclude that cerebral oxygen metabolism varies with sleep-wake states in high-risk newborns. The direction and degree of these changes are variable and subject-specific in this initial sample, but could reflect or affect brain injury and vulnerability.