Oxygen therapy given to sick patients could do more harm than good

By Nikki Preston

NZ Herald·

5 Jun, 2018 05:00 PM4 mins to read

Oxygen therapy study has raised serious questions. Photo / 123RF

Giving too much oxygen to extremely sick patients could be doing more harm than good, new research has found.

Groundbreaking research has revealed high levels of oxygen administered to acutely sick patients in hospital could increase the risk of patient death by 21 per cent.

Wellington Hospital Intensive Care specialist Dr Paul Young and co-author of the report which supports a conservative use of oxygen therapy said the latest research dispelled the belief that no amount of oxygen was harmful.

Dr Paul Young has been involved in ground breaking research which has found that administering too much oxygen to sick patients could harm of even kill them. Photo / Supplied

The practice of administering oxygen was first introduced in 1885 and was often given to patients to reverse the affects of hyperoxaemia, an abnormally low concentration of oxygen in the blood. In other cases it was seen as a harmless and beneficial therapy.

But Young, who worked with researchers at McMaster University in Ontario, found some levels were safer than others and that it should only be given to patients whose oxygen levels were low.

"They [the findings] in fact show that administering too much oxygen is potentially harmful, even deadly."

The higher the amount of oxygen given could also be linked to the higher the risk of death.

The oxygen therapy research, which has been published in the prestigious medical journal The Lancet, was based on 25 worldwide trials involving 16,000 patients over 18 years old with sepsis, stroke, trauma, emergency surgery or cardiac arrest.

"If your oxygen levels are low there's really no question that there's a role for supplemental oxygen. People can die from having too little oxygen - we are utterly dependent on oxygen to survive. But on the other hand, people who have normal oxygen levels are unlikely to benefit from the provision of supplemental oxygen and may well be harmed."

Rather than patients being alarmed by the new evidence, Dr Young said patients should be pleased it could improve patient outcome.

The findings could have massive implications on how medical experts treated acutely unwell patients and result in a change of practice where a more cautious approach around giving oxygen was adopted.

"The message that has come across clearly and it's the message that people are starting to hear at the coalface is that more oxygen or giving oxygen liberally without thought has the potential to cause harm and that too much oxygen can be harmful. But at the same time exactly how to administer oxygen to get the best outcome for patients isn't necessarily clear," Young said.

Currently standard practice in New Zealand would be to administer supplementary oxygen to patients whose oxygen saturation levels fell below 90 per cent.

Auckland Hospital Intensive Care specialist Dr Colin McArthur said the study confirmed doctors needed to take a more cautious approach.

McArthur said previous studies had indicated giving too much oxygen could be hazardous, but the hazard was not well recognised.

Work now needed to be done to identify what the optimum oxygen therapy was, which could vary depending on the type of illness the patient had, he said.

Medical Research Institute of NZ research, led by Young, is due out next year and will identify the right levels of oxygen therapy for what he described as the sickest patients in the hospital - those on life support.

The study involved 1000 patients from 24 intensive care units in New Zealand and Australia.