Cerebral and systemic hemodynamic effects of intravenous bolus administration of propofol in neonates

Objectives: To assess variability of systemic hemodynamics and its covariates following bolus propofol administration in (pre)term neonates, and to analyze the effect of propofol on cerebral tissue oxygenation index (TOI) and fractional tissue oxygen extraction measured by near-infrared spectroscopy. Methods: In (pre)term neonates, we recorded mean arterial blood pressure (MABP), saturation (SaO₂), heart rate (HR) and TOI from 5 min before up to 60 min after intravenous bolus propofol (3 mg kg^-1) administration during elective chest tube removal. Covariate analysis included postmenstrual age (PMA ≤ or >37 weeks), postnatal age (PNA ≤ or >10 days), comedication (fentanyl +/- midazolam) and congenital cardiopathy (yes/no). Fractional tissue oxygen extraction was calculated as (SaO₂ - TOI)/SaO₂. Results: Twenty recordings in 19 neonates were assessed. Following propofol administration, an abrupt, minor decrease in HR and SaO ₂ was seen with fast recovery, while MABP decreased up to 1 h. TOI decreased during the first 3 min, reflecting an imbalance between cerebral oxygen delivery and demand. Despite sustained decrease in MABP, TOI then returned to baseline, suggesting a better balance between oxygen delivery and demand. PNA ≤10 days, comedication and absence of cardiopathy were associated with more subtle decreases in cerebral oxygenation and faster recovery. Conclusions: Propofol-induced decrease in HR, SaO₂ and cerebral oxygenation is short lasting while a decrease in MABP is observed up to 60 min. The variability in the effects of propofol is influenced by PNA, comedication or cardiopathy. Near-infrared spectroscopy can be used to assess hemodynamic effects of hypnotics on the cerebral oxygenation.