Less is more: Conservative Oxygen Therapy during Mechanical Ventilation in the ICU
Editorial illustration by Dr Ciléin Kearns
Our latest research may soon change how intensive care units use oxygen to support patients around the world.
The “Conservative Oxygen Therapy during Mechanical Ventilation in the ICU” study was led by researchers at the Medical Research Institute of New Zealand and Wellington Hospital. It found that ICU patients on mechanical ventilation are being given unnecessary levels of oxygen that make no difference to their recovery, and in some specific groups less oxygen may actually improve recovery and survival rates.
The findings were published in the New England Journal of Medicine and presented at the World Conference of Intensive Care in Melbourne on October 15th by Dr Paul Young, the co-clinical leader of the Wellington ICU.
“The findings are hugely significant for the use of oxygen in ICUs around the world because everyone in intensive care gets oxygen – approximately four million patients a year in resource-rich countries”
“There has been an underlying assumption that oxygen is good for patients and doctors should give it to them liberally…but there’s never been any data or evidence or trial that that’s actually true.”
In the study, 1000 patients in Australian and New Zealand ICUs were assigned to two groups – one receiving the normal amount of oxygen, and the other a smaller, or “conservative”, amount of oxygen.
The results found that there was 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, Dr Young said.
During the study the researchers found some results that suggest too much oxygen could actually be harmful in people who have suffered hypoxic brain injury due to cardiac arrest. The research team is now planning further investigation into this sub-group with more targeted trials.
“In ICU, oxygen has been treated a bit like holy water, but it’s increasingly being shown as something that ‘seemed like a good idea at the time’, but now needs to be rigorously tested for safety and efficacy.
“When you put liberal oxygen therapy under the crucible of a large, multi-centre randomised control trial, it doesn’t really seem to offer appreciable advantages and may be dangerous for some patients. More large trials of oxygen therapy are now a global priority”.
The findings were published in the New England Journal of Medicine and presented at the World Conference of Intensive Care in Melbourne on October 15th by Dr Paul Young, the co-clinical leader of the Wellington ICU.