Effects of sleep state and feeding on cranial blood flow of the human neonate.

Jugular venous occlusion plethysmography was performed on sleeping babies. Cranial blood flow (CBF) was calculated by correcting for noncompressible drainage pathways. Sleep state of the baby was monitored using clinical and EEG criteria. In 20 babies CBF was consistently higher in rapid eye movement (REM) sleep compared with nonREM sleep (mean difference 24.2%). In 7 babies systolic blood pressure was consistently higher in REM sleep (mean 20.2%). There was no correlation between the degree of change in blood pressure and CBF. In 11 babies in whom CBF was measured at known times after feeding, there was a consistently lower flow rate during the first hour compared with 2 hours later (mean difference 34.5%). The degree of change was unrelated to amount of feed taken, despite the method of test weighing being demonstrably accurate.