The chances of dying in an intensive care unit (ICU) went from 43 per cent before the pandemic peaked to 34 per cent in the period after.
In a report yesterday, the Intensive Care National Audit & Research Centre said that no new drugs nor changes to clinical guidelines were introduced in that period that could account for the improvement. However, the use of mechanical ventilators fell dramatically.
Before the peak in admissions on April 1, 75.9 per cent of Covid-19 patients were intubated within 24 hours of getting to an ICU, a proportion which fell to 44.1 per cent after the peak.
Meanwhile, the proportion of ICU patients put on a ventilator at any point dropped 22 percentage points to 61 per cent either side of the peak.
Researchers suggested this could have been a result of “informal learning” among networks of doctors that patients on ventilators were faring worse than expected.
Dr Charlotte Summers, lecturer in intensive care medicine at the University of Cambridge, said: “Humans are designed to get the oxygen into their lungs by sucking it in – negative pressure – whereas the ventilator blows the oxygen into your lungs by positive pressure.
“Millions of years of evolution have conspired to deliver oxygen into your lungs in a very different way to a mechanical ventilator.
“So every person who goes on a ventilator, it’s a suboptimal way of breathing compared to what you’re designed to do, and like every therapy that’s given to anyone for any disease, there are undoubtedly downsides of it.”