Dynamic cerebral autoregulation in infants undergoing major non-cardiac surgery

Area of Science:

• Neurology
• Pediatric Critical Care
• Biomedical Engineering

Background:

• Dynamic cerebral autoregulation (CAR) is crucial for maintaining stable cerebral blood flow (CBF) despite blood pressure (BP) fluctuations.
• Assessing CAR in infants, especially during major surgery, is vital for preventing neurological complications.
• Novel ultrasound systems like NeoDoppler offer continuous monitoring of cerebral blood flow velocity (CBFV).

Purpose of the Study:

• To evaluate dynamic CAR using continuous Doppler monitoring (NeoDoppler) in infants undergoing major non-cardiac surgery.
• To compare time- and frequency-domain analyses of the pressure-flow relationship derived from NeoDoppler data.
• To compare NeoDoppler's CAR assessment with near-infrared spectroscopy (NIRS) for regional oxygenation.

Main Methods:

• Continuous CBFV monitoring via NeoDoppler through an open fontanel.
• Synchronized invasive BP monitoring and regional oxygenation measurements (NIRS).
• Analysis of the pressure-flow relationship in both time and frequency domains.

Main Results:

• Impaired CAR was most prevalent during surgery (59%) compared to pre-surgery anesthesia (41%) and recovery (25%).
• No significant difference was found between time- and frequency-domain CAR analysis using NeoDoppler.
• NeoDoppler CAR assessment showed no significant difference compared to NIRS, but NeoDoppler allowed direct evaluation of cerebrovascular reactivity.

Conclusions:

• Continuous Doppler monitoring with invasive BP monitoring provides a direct method for evaluating dynamic CAR and cerebrovascular reactivity in infants.
• NeoDoppler is a valuable tool for assessing CAR during major surgery in infants.
• The study highlights the utility of NeoDoppler in understanding cerebral hemodynamics in vulnerable pediatric populations.