Is Facing Downward Better for the Lungs in Patients with COVID-19?

For patients hospitalized with coronavirus disease 2019 (COVID-19) and on ventilators, lying face down was better for the lungs, according to a research letter published in the American Thoracic Society’s American Journal of Respiratory and Critical Care Medicine.

Investigators from China and Canada retrospectively reported on 12 COVID-19 patients with severe cases in order to document the effect of body positioning in fighting against acute respiratory distress syndrome (ARDS), which some patients develop.

A majority of the patients admitted to the study author’s intensive care unit developed ARDS after testing positive for COVID-19. In a 35-bed intensive care unit in China, 12 patients were studied through the week of February 18, 2020. In the analysis, there were 5 females and 7 males, with a median age of 59 years.

Patients were ventilated in volume-controlled mode with tidal volume at 6 mL/kg of predicted body weight. The ventilators measured flow, volume, and airway pressure.

During the weeklong observation period, 7 patients received at least 1 day of prone positioning, while 3 patients received both prone positioning and extracorporeal membrane oxygenation (ECMO). Patients received prone positioning for 24-hour periods when they had persistently low levels of blood oxygenation.

The study authors reported that 3 patients died.

The patients without prone positioning had poor lung recruitability, the study authors said. Facing upward alternating with prone positioning was linked to increased lung recruitability, they added.

“This study is the first description of the behavior of the lungs in patients with severe COVID-19 requiring mechanical ventilation and receiving positive pressure,” study author Haibo Qiu, professor, Department of Critical Care Medicine, Zhangda Hospital, School of Medicine, Southeast University, Nanjing, China said in a press release. “It indicates that some patients do not respond well to high positive pressure and respond better to prone positioning in bed [facing downward].”

The study authors said that their study findings may not be generalizable to all cases of COVID-19 associated ARDS—both due to the sample size and the fact that the study was not randomized. Whie they called their findings surprising; they wrote that any relation to body position and increased lung recruitability should be further explored.

“It is only a small number of patients, but our study shows that many patients did not re-open their lungs under high positive pressure and may be exposed to more harm than benefit in trying to increase the pressure,” study author Chun Pan, MD, also a professor with Zhongda Hospital, School of Medicine, Southeast University, added in the statement. “By contrast, the lung improves when the patient is in the prone position. Considering this can be done, it is important for the management of patients with severe COVID-19 requiring mechanical ventilation.”

Importantly, the study authors showed that lung recruitability can be evaluated at bedside even during constrained environments. They also said that lung recruitability was low among their patients with COVID-19 induced ARDS. Their hope is that their findings may “incite clinicians to assess respiratory mechanics and lung recruitability in this population.”