Awake prone positioning of patients with hypoxaemic respiratory failure due to coronavirus disease 2019 (COVID-19) supported with high-flow nasal cannula reduced the incidence of treatment failure and the need for intubation without any signal of harm, according to a study published in The Lancet Respiratory Medicine.
“Awake prone positioning has been reported to improve oxygenation for patients with COVID-19 in retrospective and observational studies, but whether it improves patient-centred outcomes is unknown,” wrote Stephan Ehrmann, CHRU Tours, Médecine Intensive Réanimation, CIC INSERM 1415, Tours, France, and colleagues. “Moreover, there is concern that awake prone positioning might prove harmful if transient improvement of oxygenation leads to false reassurance and delayed intubation.”
“In this meta-trial of patients with acute hypoxaemic respiratory failure due to COVID-19 treated with high-flow nasal cannula, awake prone positioning appeared safe and had a favourable effect on the primary composite outcome of intubation or death within 28 days of enrolment,” the researchers reported, noting that the “findings support routine implementation of awake prone positioning in those patients.”
Between April 2, 2020 and January 26, 2021, the study, conducted in medical centres in the United States, Mexico, France, Canada, Ireland, and Spain, randomised 1,121 adult patients requiring respiratory support with high-flow nasal cannula for acute hypoxaemic respiratory failure due to COVID-19 to awake prone positioning (n = 564) or standard care (n = 557). Patients in the awake prone positioning group were instructed and assisted to lie in the prone position for as long and as frequently as possible each day. The duration of each proning session was recorded by bedside nurses.
Baseline demographic and disease characteristics were well balanced between the two groups. At enrolment, the mean ratio of peripheral arterial oxygen saturation to the fraction of inspired oxygen was 147.9 for the awake prone positioning group and 148.6 for the standard care group with similar high-flow nasal cannula settings. In the intervention group, the median daily duration of awake prone positioning was 5.0 hours (interquartile range 1.6–8.8), with variations among individual trials, from a median daily awake prone positioning duration of 1.6 hours in Spain to 8.6 hours in Mexico.
The primary composite outcome was treatment failure, defined as the proportion of patients intubated or dying within 28 days of enrolment. Overall, treatment failure occurred in 223 (40%) of 564 patients assigned to awake prone positioning and in 257 (46%) of 557 patients assigned to standard care (relative risk 0.86, 95% confidence interval [CI] 0.75−0.98, P = 0.02). The hazard ratio (HR) for intubation was 0.75 (95% CI 0.62−0.91), and the HR for mortality was 0.87 (95% CI 0.68−1.11) with awake prone positioning compared with standard care within 28 days of enrolment.
Meanwhile, the incidence of prespecified adverse events, including skin breakdown, vomiting, and central or arterial line dislodgement, was low and similar in both groups. No patient had a cardiac arrest during awake prone positioning or in relation to proning.
The researchers also found that mortality and duration of invasive mechanical ventilation were similar between groups among intubated patients, suggesting no signal for harm from awake prone positioning.
“Awake prone positioning is a safe intervention that reduces the risk of treatment failure in hypoxaemic patients with COVID-19 who require advanced respiratory support with high-flow nasal cannula oxygen,” the authors concluded. “These results support routine awake prone positioning of patients with COVID-19 who require support with high-flow nasal cannula.”