Treating coronavirus hospital patients who have acute respiratory failure with continuous positive airway pressure (CPAP) reduces the need for invasive mechanical ventilation, new research from Queen’s University Belfast suggests.
Preliminary data from the study also indicates the routine use of high-flow nasal oxygenation (HFNO) should be reconsidered, as it did not improve outcomes for Covid-19 patients compared with conventional oxygen therapy.
Researchers suggest their findings can help reduce pressure on intensive care units (ICUs).
The Respiratory Strategies in Covid-19, CPAP, High-flow, and Standard Care (Recovery-RS) trial, led by Queen’s and the University of Warwick is the world’s largest non-invasive respiratory support trial for Covid-19. More than 1,200 participants took part across 48 UK hospitals.
Danny McAuley, chief investigator and professor and consultant in intensive care medicine at the Royal Victoria Hospital and Queen’s University Belfast, said: “The results of this trial are really encouraging as they have shown that by using CPAP, invasive ventilation may not be needed for many patients with Covid-19 requiring high oxygen levels.
“Avoiding invasive ventilation is not only better for the patients, but it also has important resource implications as it frees up ICU capacity.
“This research should help healthcare professionals in the UK and beyond manage patients with Covid-19, to improve patient outcomes while helping to lessen the burden on resources.”
Researchers compared the use of CPAP (oxygen and positive pressure delivered via a tightly fitting mask), with HFNO (high pressure oxygen delivered up the nose), against standard care (standard oxygen therapy).
All three methods are commonly used to treat Covid patients before they are moved on to invasive ventilation in a critical care bed. But it was not known which, if any, resulted in a better outcome.
Patients
Between April 2020 and May 2021, 1,272 Covid-19 patients admitted to hospital with acute respiratory failure, aged over the age of 18, were recruited to the study.
They were randomly allocated to receive one of the three respiratory support interventions as part of their hospital care.
Some 380 (29.9 per cent) participants received CPAP, 417 (32.8 per cent) participants received HFNO, and 475 (37.3 per cent) received conventional oxygen therapy.
In the comparison of CPAP and conventional oxygen therapy, the likelihood of patients going on to require invasive mechanical ventilation or die within 30 days of treatment was significantly lower in those who were treated with CPAP, than those who received standard care.
In the CPAP group, 137 of 377 participants (36.3 per cent) either needed mechanical ventilation or died within 30 days, compared with 158 of 356 participants (44.4 per cent) in the conventional oxygen therapy group.
The study, which has not yet been peer-reviewed, found that there was no difference between patients in the HFNO and conventional oxygen therapy groups.
Based on these results, one person would avoid needing invasive ventilation within ICUs for every 12 people treated with CPAP instead of standard oxygen therapy, the researchers say. –PA