Head down stroke body positioning trial looks promising


By Mardi Chapman

26 Sep 2019

A head down position may improve blood flow to the brain in the critical time between a stroke and reperfusion, according to ‘promising’ early observations in a proof of principle trial.

Speaking to the limbic after his presentation at the Stroke Society of Australasia 2019 Conference in Canberra, Associate Professor Tim Kleinig said there was some suggestive evidence that body positioning might make a difference.

“There are a couple of small studies using ultrasound showing that blood flow to the brain improved by lying flat as opposed to sitting up, but no studies that directly look at blood flow within the brain.”

“We now have a means to be able to test that directly by using CT perfusion imaging and so the purpose of this study was to try and prove one way or the other, does head down positioning improve brain blood flow?”

He said that, if shown to be beneficial, head down positioning would be particularly useful where patients might have a long delay between stroke onset and reperfusion.

And with various projects attempting to get CT scanners into ambulances, head down positioning could potentially be introduced into pre-hospital management.

“There still needs to be some imaging done to show there is not a bleed on the brain as a cause of the patient’s symptoms. It’s not something we can do to everyone in the ambulance without imaging.”

“However there is definitely a need to try and develop therapies that improve blood flow to the brain while waiting for reperfusion to occur.”

“People are generally receptive to the idea. It makes a good deal of physiological sense but obviously we need to have proof before it becomes routine practice.”

The trial at Royal Adelaide Hospital has 13 patients so far and another 12 to recruit.

“We are about half way through the study and the results at this stage are promising. I’d hope that the more patients we do, the stronger the statistical proof of the benefit,” he said.

He said patients have not expressed any significant discomfort either at the time of the positioning or when asked subsequently after the acute stage of their stroke.

Patients enrolled in the study have to have an acute stroke, less than 24 hours of symptoms, brain imaging demonstrating ischaemia and excluding ICH, and be over 60 years due to concerns about radiation exposure from multiple scans in younger patients.

“And they have to have no heart failure or swallowing difficulties that might make that positioning dangerous,” he said.

Patients are positioned at 15 degrees head down – the maximum tilt on a hospital bed – and 20 degrees head down for the CT scan.

The major outcome is improvement of blood flow in the brain using CT image processing software.

Associate Professor Kleinig said they were hoping to introduce some extra centres into the study in order to to show the results were consistent across sites and CT scanners.

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