June 2, 2022

Study explores positioning options to improve COVID mortality

Vanderbilt researchers found that prone positioning of patients with COVID-19-related hypoxemia not on mechanical ventilation offered no observed clinical benefit among these patients.

Prone positioning in the care of patients with acute respiratory distress syndrome (ARDS) receiving mechanical ventilation has been used since the 1970s and has been shown to improve mortality.

And in patients who are not receiving mechanical ventilation, it’s believed that changing position from supine (face up) to prone (face down) may improve their oxygen levels.

So early in the COVID-19 global pandemic, when effective treatments were unknown and physicians and nurses were learning more every day about what worked and what didn’t, prone positioning for awake patients who were not mechanically ventilated was one of the numerous treatments attempted.

A Vanderbilt University Medical Center-led study, recently published in JAMA Internal Medicine was conducted at two academic medical centers — VUMC and NorthShore University HealthSystem — and included 501 patients. Patients were randomized by their medical record number to provider recommendation of awake prone positioning versus usual care.

“During the pandemic when we were grasping at straws about treatment, dealing with hospital stress and utilization of resource issues, and worried about whether we had enough ventilators, health care workers around the world thought ‘we know it’s helpful for patients who are ventilated; why not go ahead and use it in patients who aren’t intubated to see if we can delay or stave off intubation,’” said Edward Qian, MD, clinical fellow in Pulmonary and Critical Care Medicine and the study’s lead author.

“We determined that awake prone positioning of patients with COVID-19-related hypoxemia not on mechanical ventilation offered no observed clinical benefit among these patients,” he said. “Moreover, there was substantial evidence of worsened clinical outcomes at study day five among patients recommended to receive the awake prone positioning intervention, suggesting potential harm,” he said.

Qian said the study’s results were surprising.

“Nobody goes into a study thinking they have something that could make people worse. We definitely thought it would make people better,” he said. “I think we entered the study thinking that using prone positioning in this group of patients seems to hold water, that we could extrapolate severe ARDS data to this patient population. That’s why we studied it, to see if this was really the case, but that’s not what we found.”

Qian said the study didn’t shed light on why it didn’t help, and in some cases made patients worse.

“We have our speculations. It could be the act of changing position dislodged medical equipment, but we had no reports of that for patients who got worse. It didn’t happen suddenly. It was a gradual decline,” he said. “We also wonder if you lose beneficial effect if you start prone positioning too early? If you do it too early, are you worsening lung damage?”

Qian said other studies are being completed looking at prone positioning in different ways. “I’ll be interested in what the data in aggregate show,” he said. n