Research shows administering of oxygen to intensive care unit (ICU) patients often makes no difference to their recovery, while, for some groups, less oxygen may improve recovery and survival rates.
Lead Researcher from Monash University’s Australian and New Zealand Intensive Care Research Centre, Professor Rinaldo Bellomo, says the findings are hugely significant for the use of oxygen in ICUs around the world.
“Everyone in intensive care gets oxygen – approximately four million patients a year in resource rich countries – so it’s a massive issue,” he said.
“There’s been an underlying assumption that oxygen is good for patients, and doctors should give it to them liberally and ensure the oxygen levels are high, but there’s never been any data, evidence or trial showing that’s actually true.”
In the study, 1,000 patients in Australian and New Zealand ICUs were assigned to one of two groups: one receiving the normal amount of oxygen, and the other a smaller, or ‘conservative’, amount.
Professor Bellomo says the results found no difference in outcomes between the groups, meaning there is no longer any reason to provide the high amount of oxygen typically given to ICU patients on breathing machines.
However, during the study, the researchers found some results that could suggest too much oxygen could be harmful in people who have suffered hypoxic brain injury due to cardiac arrest.
“These results showed that in those patients treated with conservative oxygen therapy, there is a signal to suggest increased survival with less oxygen” Professor Bellomo said.
“So even though the totality of ICU patients put together don’t appear to show a difference between these two treatments, in some specific subgroups of people, giving less oxygen may well be a good thing.”
The research team is now planning further investigation into this subgroup with bigger and more targeted trials.
“When you put liberal oxygen therapy under the crucible of a large, multicentre, randomised control trial, it doesn’t really seem to offer appreciable advantages and may even be dangerous for some patients,” Professor Bellomo said. “More large trials of oxygen therapy are now a global priority.”