Update on prone positioning to improve ventilation perfusion ratio

Prone positioning has long been a standard approach to improve ventilation perfusion and reduce hypoxia in severe acute respiratory distress syndrome (ARDS). Experience during the COVID-19 pandemic alerted clinicians that the same strategy can be helpful in other situations, as well.

“We have been using prone positioning for decades, though mostly in the ICU,” said Ritwick Agrawal, MD, FCCP, Assistant Professor of Pulmonary Medicine at Baylor College of Medicine. “Once COVID-19 came, a lot of hospitals made awake prone positioning standard of care even though we didn’t yet have a lot of data supporting an improvement in mortality. The data we do have, plus several case reports, suggest that there is an advantage in terms of overall clinical improvement and need for intubation, but the results are not concrete when it comes to improvement in overall mortality.”

Dr. Agrawal will chair Changing Landscape of Prone Positioning Across Pulmonary Medicine on Wednesday at 9:15 am CT. Several of the presenters are investigators on Awake Prone Position for Early Hypoxemia in COVID-19 (APPEX-19), a large, pragmatic adaptive randomized controlled unblinded trial of prone positioning for non-ICU patients who have, or are suspected of having, COVID-19.

The decision to try prone positioning in the early days of COVID-19 was a pragmatic choice, Dr. Agrawal said. With no effective treatments available, clinicians were exploring a wide range of approaches.

“We had good clinical data that prone positioning works in ARDS, so it seemed reasonable to try it in COVID-19,” he explained. “We knew that patients tended to get better and have improved outcomes when we prone them.”

One early impression from the growing use of prone positioning is that time matters. The longer patients remain prone, the greater the benefit. Prone positioning is a relatively simple matter when patients are sedated and intubated, Dr. Agrawal noted.

“But if a patient is alert and oriented, all we can do is recommend a prone position for as long as they can tolerate it,” he said. “It really depends on how motivated a person is and how much better they feel when lying on their belly. Adherence has become another aspect of positioning.”

Patients generally split into two groups when it comes to proning. Some patients are perfectly comfortable, or at least satisfied, to spend hours, even days on their stomach.

Others balk, saying they can’t tolerate lying on their stomachs, or rebel after a few hours of discomfort. Maintaining a prone position can be difficult, for example, for patients with back problems or who are overweight or obese.

“Some patients we would like to prone are often on supplemental oxygen, so they have a nasal cannula,” Dr. Agrawal added. “They’re likely connected to an IV line and maybe a urinary catheter, so they just don’t feel comfortable while prone. Bottom line, prone positioning is a very important treatment modality with which we are familiar but have not used very aggressively. Our patients can benefit if we push proning a little harder.”