Studies challenge long-held medical beliefs
McMaster research questions liberal use of oxygen, and assumption home care keeps people out of hospital
Two McMaster University studies turn traditional medical thinking on its head with research that has the potential to drastically change how care is provided.
The first paper concludes the common practice of liberally giving oxygen to acutely ill adults can actually increase the risk of death without improving other health outcomes in a meta-analysis study published in the Lancet April 26.
The other research found patients receiving home care were more likely to go to the emergency department the same day they received a nursing visit in a case-crossover study published Monday in the Canadian Medical Association Journal.
In both cases, there have long been suspicions that the conventional way of treating these patients is flawed.
“Even though this has been the standard mantra, there was some growing hints that oxygen itself may be harmful,” said Dr. Derek Chu, first author of the paper and a McMaster clinical fellow.
“But the skeptics had no strong basis to actually ground their argument in. There was just clues here and there. That is where the power of meta-analysis came in.”
The researchers searched electronic academic databases as recently as October 2017 for randomized controlled trials done worldwide and examined 25 of them accounting for more than 16,000 patients.
“If we take these individual clues and look at these individual studies on their own, it isn’t going to be conclusive enough,” said Chu. “Let’s put all the data together and maybe that can give us a clear answer and it actually did. Now this allows us to provide clear and strong guidance on how to use oxygen which we hope will change practice and save lives.”
A commentary written by three Toronto doctors in response to the McMaster home care study called the results “disappointing but not unexpected.”
“Sometimes it is the health-care system, rather than the patient, that is failing to
cope,” wrote Dr. Ryan Luther, Dr. Lisa Richardson and Dr. Allan Detsky in the commentary piece also published Monday in the CMAJ.
“When community-based nurses are neither integrated into primary care teams nor equipped with resources to manage patients’ problems effectively — perhaps by a limited scope of practice — patients have nowhere else to go but the emergency department.”
Both studies involve treatments given regularly to millions of patients a year so the results are expected to have widespread impact.
“The standard mantra in medicine passed down for generations and across disciplines is when someone is acutely ill ... you give them high amounts of oxygen,” said Chu. “It can improve the patients’ outcome, we’re going to maximize their physiology and it’s not harmful so we should do it. That’s been a long held assumption and belief.”
But the opposite is true, found Chu and his collaborators including Dr. Waleed Alhazzani, senior author of the paper and assistant professor of medicine at McMaster.
Both researchers received no outside funding for the study.
“The routine use of high amounts of oxygen actually increased death by about 20 per cent,” said Chu.
“For every 71 (patients) treated with a liberal oxygen strategy there would be one excess death. Even up to a year out, we saw harm. It didn’t improve anything else like whether or not patients got infections, how long they stayed in hospital or their level of disability.”
Next, they plan to look at what is the right amount of oxygen to give in situations such as emergency surgery, heart attack, stroke, sepsis, trauma and critical illness so patients get the treatment they need but don’t face such a risk.
“Now we have clear data that we should be quite cautious,” said Chu.
“We need to wean down how much oxygen we give. Many people haven’t thought of oxygen as a drug but it should be prescribed like a drug. It should be very carefully thought of as having adverse effects that are possible.”
Similarly, the home care study challenges longheld assumptions that innovations in community care will keep people out of hospital.
“Increased access to publicly funded home and community care has been suggested as a way to reduce or prevent unnecessary or avoidable visits to the emergency department,” states the study led by Dr. Andrew Costa, research chair in clinical epidemiology and aging at McMaster.
Again, the opposite was found to be true in the study of thousands of patients in the Hamilton Niagara Haldimand Brant Local Health Integration Network which includes Burlington.
“Receiving home care nursing visits during the day was associated with an increased likelihood of visiting the emergency department between 5 p.m. and midnight of the same day,” concludes the study funded by the Canadian Frailty Network and the Canadian Institutes of Health Research.
“An emergency department visit is not necessarily a negative outcome, but may be if patients could more appropriately receive treatment in the community setting by their usual providers ... The stronger association noted for nonhospital admission and less acute emergency department visits suggest that some patients likely could have received treatment in less acute settings.”
The study calls for more research into why these patients end up in the emergency department and raises questions about the quality of home care they are receiving.
“Our findings correspond with previous reports on the challenges of nursing care in the community such as limited time and the lack of direct management of clinical problems,” states the study.
“Currently, care and monitoring outside of the home care visits is predominantly assumed by the patient and family, who would require self-care knowledge and skills to prevent unplanned hospital admissions.”