Monash study reveals flawed data influenced WHO oxygen guidelines

by Anne Crawford

A study by a Monash University professor has exposed compromised data that was used by the World Health Organization (WHO) to support its guidelines on administering highly concentrated oxygen to all patients having surgery.

The WHO in 2016 recommended the practice of administering 80% supplemental oxygen to patients during and after surgery to prevent surgical wound infection – one of the most common serious postoperative complications.

However, a paper co-authored by Professor Paul Myles, Director of the Department of Anaesthesia and Perioperative Medicine at The Alfred Hospital and Monash University, says the WHO recommended practice may harm patients and that the evidence supporting it was false.

“High oxygen concentrations have been shown to cause lung inflammation and possibly harm other vital organs because of activation of superoxide radicals,” Professor Myles said.  “In fact, a systematic review published in The Lancet in 2018 found that this practice was associated with an increased risk of death in patients recovering from emergency surgery, trauma and others with critical illness,” he said.

Professor Myles’ paper, published in Anaesthesia, scrutinised data from numerous clinical studies conducted by Italian surgeon Dr Mario Schietroma, some of which strongly informed the WHO’s decision to recommend the oxygen guidelines.

Of the 40 papers by Dr Schietroma’s group that were analysed, 24 were randomised controlled trials and 16 observational studies. The study found the integrity of data was compromised in 38 out of 40 analysed papers, and that 98% of ‘p values’, measures of statistical significance, were wrong.

Five trials by the group have been retracted for duplication, plagiarism, statistical error and lack of ethical approval, it said.

The study’s findings challenged the veracity of “much, if not all” of the group’s published work.

Pooled data from trials by authors other than Dr Schietroma et al. did not support the use of supplemental oxygen to reduce surgical site infection rates, it said.

The WHO updated its guideline in December, downgrading the advice on supplemental oxygen after excluding data from trials by Dr Schietroma’s group. Professor Myles acknowledges these efforts, but remains very critical of their ongoing support for liberal oxygen therapy.

Beyond this, Professor Myles and his co-authors Drs John Carlisle and Bronwyn Scarr, have recommended that Dr Schietroma’s studies should not inform practice and that an investigation be carried out into his work.

It suggested that data in unretracted papers by Dr Schietroma is sufficiently compromised to warrant retraction.

Professor Myles has written previous papers that present evidence for changes to the WHO oxygen guidelines. He has been involved in a number of review of surgical procedures and practices aimed at improving methods and treatments.  

Myles PS, Carlisle JB, Scarr B. Evidence for compromised data integrity in studies of liberal peri-operative inspired oxygen. Anaesthesia. 2019 Feb 17. doi: 10.1111/anae.14584. [Epub ahead of print]

Myles PS, Kurz A. Supplemental oxygen and surgical site infection: getting to the truth. Br J Anaesth. 2017 Jul 1;119(1):13-15. doi: 10.1093/bja/aex096.