Awake Prone Positioning: Which COVID Patients Benefit?

Awake prone positioning reduced need for intubation in selected patients with severe COVID-19, a meta-analysis showed.

In pooled randomized controlled trials (RCTs), awake prone positioning significantly reduced the need for intubation in COVID-19 patients with acute hypoxemic respiratory failure (RR 0.84, 95% CI 0.72-0.97), according to Jie Li, PhD, of Rush University in Chicago, and colleagues.

However, when separated by patient condition at enrollment, the benefit was only observed among patients on advanced respiratory support (RR 0.83, 95% CI 0.71-0.97) or in the ICU (RR 0.83, 95% CI 0.71-0.97), the study authors reported in Lancet Respiratory Medicine.

“Since the early phases of the COVID-19 pandemic, awake prone positioning has been broadly performed worldwide” and recommended in the NIH COVID-19 treatment guidelines and by other expert panels, the authors noted. However, the data on whether awake prone positioning prevents intubation have been conflicting.

Previous research has suggested that having patients lie in this position on their abdomen may improve gas exchange and decrease lung stress.

In this study, while prone positioning reduced the risk of intubation for patients with more severe COVID-19, it did not significantly reduce mortality (RR 1.00, 95% CI 0.70 to 1.44).

The meta-analysis included data from a 2021 meta-trial (comprised of six randomised controlled open-label superiority trials) with a total of more than 1,000 COVID patients using high-flow nasal cannulas, mostly in the ICU, that did find awake prone positioning to reduce the need for intubation. It also included data from seven RCTs that did not find a difference in intubation risk among their combined total of almost 700 patients on conventional oxygen therapy.

“The provision of advanced respiratory support and an ICU setting are directly correlated,” the researchers wrote. “Taken together, the apparent lack of efficacy of awake prone positioning in less severely ill patients (non-ICU or receiving conventional oxygen therapy) could be related to a lower event rate, less intensive monitoring, lower nursing to patient ratios, lower adherence to awake prone positioning, and differences in the patient’s disease severity,” they said.

“In addition, invasive ventilation was more commonly implemented during the early phase of the pandemic,” the study authors noted. As a result, some studies designed early in the pandemic were underpowered by the time they were completed, and other studies could not recruit enough COVID patients, they said.

The review included studies published in English between January 2020 and early November 2021 without geographical restrictions. In total, 29 studies were included in the review, 10 of which were RCTs (three yet-to-be-published), and 19 of which were observational studies. Observational studies were only included in a sensitivity analysis.

RCTs were excluded if they enrolled children or patients intubated prior to enrollment or if they did not have a control group in supine position. Of the included studies, the time patients spent in prone position varied greatly, ranging anywhere from 1 to 16 hours or as long as the patient could tolerate, Li and colleagues noted. Results with lower acuity patients (on conventional oxygen therapy or treated outside of the ICU) also had wider confidence intervals, the researchers said.

The study authors acknowledged a few limitations of their meta-analysis: results were driven primarily by three RCTs with large sample sizes, only some of the studies reported the duration of prone positioning, and of those that did report the durations, the values may not have been accurate since they were “observed and recorded unsystematically and with unknown accuracy by bedside clinicians.”