A national trial involving more than 8,000 patients has revealed that giving oxygen to stroke victims makes no difference to their recovery or chances of survival.
The researchers noted that, during and after a stroke, blood supply to part of the brain was reduced, leading to a lack of oxygen.
“We found that this intervention did not make a real difference”
The nine-year Stoke Oxygen Study looked at whether or not giving patients oxygen soon after their stroke could prevent further brain damage and reduce the risk of disability or even death.
Three treatments were tested – 8,003 patients with acute stroke were randomised within 24 hours of admission to three days of continuous oxygen, nocturnal oxygen only, or no routine oxygen.
The results found that providing routine oxygen did not improve functional outcome in any patients, and there was still no difference in results after 90 days.
The research is one of the largest stroke studies conducted in the UK and over half of all hospitals admitting stroke patients in England took part.
The findings, published this week in the Journal of the American Medical Association, will now help clinicians to better understand how stroke patients should be treated when they first present at hospital, said the researchers.
“We now believe that it may be more important to address the underlying cause”
The study as led by Keele University stroke specialist Professor Christine Roffe, along with North Staffordshire Combined Healthcare NHS Trust and researchers from the University of Oxford and the University of Birmingham. It was funded by the National Institute for Health Research.
Professor Roffe said: “At present, it is common when a stroke patient first receives care that they are given an oxygen mask, but our results provide clear and unambiguous evidence that patients admitted to hospital with a stroke do not need routine prophylactic oxygen treatment.
“Our study provided low-dose oxygen to keep the patient’s oxygen levels within the normal range to test whether this would help to maintain brain function and help recovery, but we found that this intervention did not make a real difference,” she noted.
UK study ‘settles debate’ over routine oxygen after stroke
She added: “It remains important to monitor oxygen levels but it is not necessary to give patients oxygen routinely after a stroke – it did not improve patients’ brain function, level of disability, quality of life or chances of survival.”
However, Professor Roffe highlighted that it was known that stroke patients whose oxygen levels fell below normal levels recovered less well.
Low oxygen levels were caused by underlying airway, lung and heart problems, with the most common cause being pneumonia, she noted.
“We now believe that it may be more important to address the underlying cause rather than just to treat the hypoxia by administering oxygen,” she said.