Oxygen no longer ‘holy water’ for ICU: study

The ‘Conservative Oxygen Therapy during Mechanical Ventilation in the ICU’ study was conducted in partnership with the Medical Research Institute of New Zealand.

It found ICU patients receive unnecessary levels of oxygen that make no difference to recovery – and that, in some cases, less oxygen may improve recovery and survival rates.

“The findings are hugely significant for the use of oxygen in ICUs around the world because everyone in intensive care gets oxygen – around four million patients annually in resource-rich countries,” said Wellington ICU co-clinical lead and study lead investigator Dr Paul Young (pictured).

“There has been an underlying assumption that oxygen is good for patients, and doctors should give it liberally to ensure oxygen levels are high – but there’s never been data or evidence that it’s true.”

The study saw 1000 patients in Australian and New Zealand ICUs assigned to two groups – one receiving the normal amount of oxygen, and the other a smaller or ‘conservative’ amount.

“There was no difference in outcomes between and, in those patients treated with conservative oxygen therapy, there is a suggestion that may signal increased survival with less oxygen.”

With results also suggesting that too much oxygen could be harmful in people who have suffered hypoxic brain injury due to cardiac arrest, the study shows that there is no longer reason to provide the high amounts of oxygen typically given to ICU patients on breathing machines.

“ICUs treated oxygen a bit like holy water but it’s increasingly being shown to something that seemed like a good idea at the time, but which now needs rigorous testing for safety and efficacy.

“When you put liberal oxygen therapy under the crucible of a large, multi-centre randomised control trial, it doesn’t appear to offer appreciable advantages and may be dangerous for some patients. More large trials of oxygen therapy are now a global priority.”

‘Conservative Oxygen Therapy during Mechanical Ventilation in the ICU’ has been published in the New England Journal of Medicine and presented at the World Conference of Intensive Care in Melbourne.

Media contact: Chas Te Runa – 027 230 9571