In patients hospitalised with COVID-19, the use of CPAP for those in acute respiratory failure reduced the need for tracheal intubation.
Patients are hospitalised with COVID-19 because of breathing difficulties due to a lack of oxygen as the virus induces damage in the lungs. Among those who deteriorate further, respiratory failure leads to the need for invasive ventilation within critical care units. Early in the pandemic, the increasing number of severely ill patients placed an enormous strain on critical care units, prompting the need to explore viable alternatives to invasive ventilation. Possible alternatives that could help to reduce the need for invasive mechanical ventilation include continuous positive airway pressure (CPAP) and high-flow nasal oxygen (HFNO). The use of CPAP and HFNO have been perceived as attractive alternative treatment options although there is a lack of data on whether either CPAP or HFNO are clinically effective in comparison to conventional oxygen in reducing the need for intubation. This led the Recovery-respiratory Support collaborators from Warwick Clinical Trials Unit, Warwick Medical School, Coventry, UK, to undertake an open-label, randomised trial among hospitalised patients with COVID-19. The study was designed to evaluate the effectiveness of either CPAP, HFNO or conventional oxygen, in hospitalised patients with acute respiratory failure caused by COVID-19. All adult patients (18 years and older) with acute respiratory failure, deemed suitable for tracheal intubation if treatment escalation was required, were included in the study. The treating clinician randomised between CPAP, HFNO or conventional oxygen and patients were followed-up throughout their hospital stay. The primary outcome was a composite of tracheal intubation or mortality within 30 days of randomisation.
During a 13-month period, 1,272 patients were randomised, 380 (29.9%) to CPAP, 417 (32.8%) to HFNO and the remainder to conventional oxygen therapy. The mean age of participants was 57.4 years (66.4% male) and 65.3% were of white ethnicity. The need for tracheal intubation occurred in 36.3% of CPAP patients and 44.4% of those receiving conventional oxygen, giving an adjusted odds ratio (OR) of 0.72 (95% CI 0.53–0.96, p = 0.03). For HFNO in comparison to conventional oxygen, there was no significant difference with an adjusted OR of 0.97 (95% CI 0.73–1.29, p = 0.85). With respect to 30-day mortality, there was no difference between CPAP and conventional oxygen (OR = 0.91, 95% CI 0.59–1.39) or for HFNO and oxygen (OR = 0.96, 95% CI 0.64–1.45).
The authors concluded that their data clearly demonstrated that the use CPAP reduced the need for tracheal intubation compared with the use of conventional oxygen. However, they also noted that neither CPAP or HFNO led to a reduction in mortality.
Perkins GD et al. An adaptive randomised controlled trial of non-invasive respiratory strategies in acute respiratory failure patients with COVID-19. MedRxiv 2021