Newly developed ultrasound technology that monitors cerebral blood flow in vulnerable newborn babies could prevent premature brain damage, researchers say.
In the first study to assess monitor cerebral blood flow in newborn babies under general anaesthesia, researchers and neonatal specialists at the Norwegian University of Science and Technology (NTNU) NTNU and St Olavs Hospital the team says their findings mean they are closer to preventing brain damage in those vulnerable patients.
The study is published in the British Journal of Anaesthesia.
In a two-year study, PhD student and paediatrician Sigrid Dannheim Vik, used NeoDoppler technology to measure cerebral blood flow in 30 newborn babies under general anaesthesia, some of whom were born very prematurely – weighing less than 1000 grams – while others were born around their due date, but had congenital defects. Most had gastrointestinal complications, such as lack of passage through the small intestine.
The one-centimetre diameter NeoDoppler ultrasound probe is attached to a cap and placed over the fontanelle.
Although adults have a protective mechanism that enables them to maintain stable cerebral circulation, infants do not, which makes them particularly vulnerable to variations in blood pressure that in turn can lead to unstable cerebral blood flow.
The longest courses of continuous ultrasound measurements lasted 10-11 hours and Vik said the NeoDoppler equipment provided important additional information compared with today’s standard monitoring equipment.
Blood pressure, pulse measurements and general clinical assessments are currently used to see if the child has adequate blood circulation, but there is no reliable measurement method for monitoring the brain.
Vik and her research colleagues found cerebral blood flow speed was more than halved during anaesthesia compared with when the patients were awake.
NeoDoppler measurements are taken continuously before, during and after surgery and the technology detects changes in cerebral blood flow, which means measures that can prevent brain damage and that are adapted to the individual child can be implemented immediately.
It also helps doctors make individual assessments and tailor treatment, rather than having to rely on general recommendations.
“I am in no doubt that we are now moving closer to preventing brain damage,” said Vik, adding that the NeoDoppler technology is a huge advance in neonatal medicine.
“It is an extremely important tool – both for the anaesthetist monitoring the child under general anaesthesia and for the rest of us involved in neonatal medicine,” she said. “It will help us make direct assessments and take measures, thereby avoiding both undertreatment and overtreatment.”
Although the NeoDoppler measures speeds, resulting in constantly changing images and graphs, it does not measure the exact amount of blood passing through the blood vessels.
However, the researchers refer to studies showing there is a good correlation between speed measurements and the blood flow itself – as long as the speeds are measured continuously.
The team call for further clinical trials before NeoDoppler becomes standard monitoring equipment in neonatal care.
Vik SD, Torp HG, Jarmund AH et al. Continuous monitoring of cerebral blood flow during general anaesthesia in infants. British Journal of Anaesthesia May 2023; doi: 10.1016/j.bjao.2023.100144
Leave a Reply