Awake prone positioning helps avoid mechanical ventilation in COVID-19

Keeping COVID-19 patients in the prone position even while they are awake appears to reduce the need for invasive mechanical ventilation (IMV), according to a recent Singapore study.

A meta-analysis of eight randomized controlled trials compared a total of 809 COVID-19 patients who underwent awake prone positioning (APP) vs 822 comparators who received standard care. In the former subgroup, 26.5 percent required IMV, as opposed to 30.9 percent among controls. This corresponded to a more than 20-percent drop in the odds of IMV after APP (odds ratio [OR], 0.77; p=0.03). [Prague Med Rep 2022;123:140-165]

In contrast, APP yielded no significant benefit on all-cause in-hospital mortality as opposed to standard care controls (OR, 0.90; p=0.45). Corresponding mortality rates were 16.5 percent and 17.5 percent.

Mortality rates continued to be comparable between APP and controls even when focusing on those on supplemental oxygen (four trials: 3.2 percent vs 1.5 percent, respectively; OR, 1.79; p=0.41) or on patients receiving noninvasive mechanical ventilation or high-flow nasal cannula (20.5 percent vs 22.6 percent, respectively; OR, 0.88; p=0.35).

Secondary endpoints were also mostly comparable between APP and control groups. Pooled analysis of five trials found no difference in length of hospital stay or intensive care unit stay. Meanwhile, four studies found that APP patients had higher ratio of oxygen saturation to fraction of inspired oxygen (SpO₂/FiO₂), but this failed to reach significance (mean difference, 24.30; p=0.09).

As expected, the total daily duration of proning was significantly longer in the APP group (mean difference, 4.11 hours; p=0.001).

“APP has emerged as an important and effective adjunct therapy in managing COVID-19 patients with acute hypoxic respiratory failure due to the known physiological benefits in gaseous exchange, prevention in respiratory support escalation, good safety profile, and ease of implementation, even in nonintensive care and resource-limited setting,” the researchers said.

“Despite the lack of statistical difference, the improvement in SpO₂/FiO₂ ratio in patients, mainly requiring supplemental oxygen and NRM, might create a false perception of clinical improvement and lead to the potential harm caused by delayed IMV initiation,” they added.

The present meta-analysis included eight trials retrieved from the online databases of PubMed, Scopus, and Cochrane, as well as from the preprint server medRxiv. Only those enrolling nonintubated COVID-19 patients with RT-PCR-confirmed COVID-19 were eligible.

Aside from the efficacy of APP, the researchers also investigated its safety profile. They found no difference in the incidence of vomiting or other adverse events such as pressure sores and invasive line dislodgements.

In assessing study quality, the researchers used the Cochrane Collaboration’s Risk of Bias Tool, which showed that such risk for the primary outcome of IMV or mortality was low for most studies included.

“When applied in an optimal manner and to the targeted COVID-19 population, APP is associated with a reduction in IMV requirement” the researchers said. “Current evidence cannot determine the optimal timing of initiation, duration, and frequency of APP sessions for COVID-19 patients.”