Effects of morphine and midazolam on sleep-wake cycling in amplitude-integrated electroencephalography in post-surgical neonates ≥ 32 weeks of gestational age.

BACKGROUND

Studies of children who undergo major non-cardiac surgery in the neonatal period are needed so that subsequent abnormal neurodevelopment can be better understood.

OBJECTIVE

It was the aim of our study to describe the influence of analgesic and sedative medication on the predominant background pattern and the development of sleep-wake cycling (SWC), as measured on amplitude-integrated electroencephalography (aEEG), in newborn infants born ≥ 32 weeks' gestation after major non-cardiac surgery.

METHODS

This prospective study included infants ≥ 32(+0) weeks' gestation admitted to the Neonatal Intensive Care Unit at The Royal Children's Hospital in Melbourne who were undergoing major non-cardiac surgery. Data on morphine and midazolam given after surgery were recorded and the BrainZ Monitor was applied post-operatively. The maximum levels of morphine and midazolam were assessed as predictors of time to aEEG outcomes using linear regression.

RESULTS

Forty-seven eligible infants were included. Emergence of SWC was observed at a mean of 13 h after surgery. The maximum dose of morphine or midazolam was not predictive of time to either any or developed SWC.

CONCLUSIONS

Despite high doses of morphine and midazolam, SWC was observed on aEEG in neonates ≥ 32 weeks' gestational age soon after major non-cardiac surgery. The aEEG background pattern was not affected by the maximum dose of either morphine or midazolam.