The Respiratory Strategies in Covid-19; CPAP, High-flow, and Standard Care (RECOVERY-RS) trial[1] has demonstrated that treating hospitalised Covid-19 patients who have acute respiratory failure with continuous positive airway pressure (CPAP) reduces the need for invasive mechanical ventilation.
Preliminary data from the trial also suggests that the routine use of high flow nasal oxygenation (HFNO), which can consume large amounts of oxygen, should be reconsidered as it did not improve outcomes for Covid-19 patients compared with conventional oxygen therapy.
RECOVERY-RS, led by the University of Warwick and Queen’s University Belfast, is the world’s largest non-invasive respiratory support trial for Covid-19 – with over 1200 participants taking part across 48 UK hospitals. The multi-centre, adaptive, randomised controlled trial 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).
Commenting on the study, Professor Danny McAuley, Chief Investigator and Professor and Consultant in Intensive Care Medicine at the Royal Victoria Hospital and Queen’s University Belfast said: “Over the Covid pandemic, we’ve seen a large number of patients requiring high levels of oxygen and admission to ICU for invasive ventilation, causing a huge strain on staff and beds.
“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.”
Results
Over 13 months, between April 2020 and May 2021, a total of 1,272 hospitalised Covid-19 patients with acute respiratory failure, aged over the age of 18, were recruited to the study and randomly allocated to receive one of three respiratory support interventions as part of their hospital care.
380 (29.9%) participants received CPAP; 417 (32.8%) participants received HFNO; and 475 (37.3%) received conventional oxygen therapy.
The primary outcomes assessed through the trial were whether the patient went on to require tracheal intubation (invasive mechanical ventilation) or died within 30-days of beginning treatment through the trial.
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%) either needed mechanical ventilation or died within 30 days, compared with 158 of 356 participants (44.4%) in the conventional oxygen therapy group.
There was no difference in primary out- comes between patients in the HFNO and conventional oxygen therapy groups. In the HFNO group, 184 of 414 participants
(44.4%) went on to require mechanical ventilation or die, compared with 166 of
368 participants (45.1%) in the conventional oxygen therapy group.
Based on these results, one person would avoid needing invasive ventilation within intensive care units for every twelve people treated with CPAP instead of standard oxygen therapy.
Commenting on the study, Professor Gavin Perkins, Chief Investigator and Professor in Critical Care Medicine at Warwick Medical School at the University of Warwick, said: “The RECOVERY-RS trial showed that CPAP was effective at reducing the need for invasive ventilation, thus reducing pressures on critical care beds. The routine use of high flow nasal oxygenation, which can consume large amounts of oxygen, should be reconsidered as it did not improve outcomes. By giving patients the most effective treatment to begin with, we can help prevent resource shortages in our NHS and make sure the right type of ventilation is available to patients when it is required.
“This is the first large trial of different types of ventilation in Covid-19. While it is encouraging that these results can help reduce the number of people who require invasive ventilation, it is important to stress that, where it is needed, invasive ventilation can be lifesaving.”
• [1]The preliminary results of this evaluation of the data are available as a pre-print on medRxiv. doi: https://doi.org/10.1101/2021.08.02.21261379
