New research reveals that an easy, non-invasive way of predicting the risk of stroke or hemorrhage among children who are receiving cardiac or respiratory support via ECMO is by measuring blood flow to the brain. The finding was published in the journal Pediatric Critical Care Medicine.

Stroke is the leading cause of death among young cardiac patients receiving support through extracorporeal membrane oxygenation (ECMO).

When a patient can’t sustain sufficient oxygen levels in their blood, because of conditions such as heart failure, ECMO is sometimes required. It is only used when traditional therapies fail to work.

ECMO works by carrying blood from the patient through the machine where it directly oxygenates and removes carbon dioxide from the blood – it is conventionally used for both respiratory and cardiac failure.

Researchers at the Perelman School of Medicine at the University of Pennsylvania, found a potential role for ECMO to save patients who are unable to be resuscitated through conventional measures.

However, there is an increased risk of bleeding in the brain associated with ECMO. Only 36% of patients survive this complication.

Nicole O’Brien, MD, lead author of the study and associate professor of clinical medicine at The Ohio State University College of Medicine, said:

“Most of these patients are critically ill before they go on ECMO and often have low oxygen levels, low blood pressure and poor heart function, all of which can certainly lead to strokes. Still, some patients develop problems and others don’t and we don’t understand why.”

Researchers at the Nationwide Children’s Hospital conducted a study that measured cerebral blood flow using a transcranial doplar ultrasound machine, that uses sound-waves to measure the amount and speed of blood flow in the brain.

Changes in blood flow in the brain occur in all patients on ECMO. However, the researchers wanted to find out why some patients experience medical complications while others don’t.

A total of 18 ECMO patients had their cranial blood flows measured. The researchers measured the blood flow on their first day on the machine, as well as each day they were on the treatment and after the therapy.

There were major differences between the cerebral blood flow rates of the ECMO patients compared to healthy children of the same age.

Thirteen of the patients didn’t develop any neurologic complications while on ECMO, their cerebral blood flow was 40 percent to 50 percent lower than normal.

However, five of the ECMO patients suffered from either stroke or brain hemorrhage, with their cerebral blood flow being 100 percent higher than normal.

Factors such as age or any underlying illness didn’t make any difference.

The team pointed out that an increase in blood flow had started days before bleeding in the brain began. “(This) could give us a lot of lead time to prevent the brain bleeds or hemorrhages.”

O’Brien said “We still need to understand why these kids bleed and why they stroke. This little piece of information is the very tip of the iceberg in terms of why that happens.”

Written by Joseph Nordqvist