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.
Clearing the air about oxygen
• Giving acutely sick patients too much oxygen could harm or kill them
• Oxygen should only be administered to patients with low oxygen levels
• The safe rate for oxygen therapy still needs to be determined
• Previous school of thought that high levels of oxygen were safe is incorrect
• Liberal administration of oxygen increased risk of patient death by 21 per cent
Source: New research published in The Lancet
