BY PAMELA FAYERMAN
Not many people – outside those in health care – had heard of prone positioning before COVID-19.
Now it’s part of the pandemic parlance.
Prone positioning involves placing patients face down in their hospital beds to improve oxygenation in those struggling to breathe.
At Vancouver General Hospital and other designated hospitals for COVID patients, health professionals gingerly roll patients over onto their stomachs for up to 16 hours a day. But it requires a coordinated team effort of about five experienced health professionals including a nurse, physiotherapist, respiratory therapist, and physicians to get patients in such positions. All of them must be wearing full personal protective equipment.
Flipping patients over requires meticulous attention, ICU specialist Dr. Donald Griesdale told me.
Dr. Donald Griesdale, VGH anesthesiologist/ICU specialist
Hospital staff must ensure that endotracheal tubes, intravenous and catheter lines don’t get dislodged “because that could prove to be fatal.
“Fortunately, that is an exceedingly rare occurrence. We are so careful when we prone that I haven’t seen that happen,” he said, referring to critical tubes falling out during the act of proning a patient.
It’s a lot easier to do when patients are conscious; when heavily sedated, they can’t cooperate with the turning. If they are obese, it’s a whole lot harder for health professionals to flip patients.
Our lungs are complex workhorses, but at the same time, delicate. So when crude, infectious invaders like COVID-19 strike, our lungs can use a lot of extra help.
When we lay on our backs, in what’s known as the supine position, oxygen-carrying blood pools at the back of the thoracic cavity, largely because of the effects of gravity. The heart, which is almost completely surrounded by the lungs, may also put some compression pressure on the lungs when we lie on our backs, as can abdominal organs like the liver. When we lay face down, the heart rests against the sternum instead of on the lungs. The effects of gravity are relieved, easing lung function.
Comparison of the physiological effects of supine (face up) and prone (face down) positioning in hospitalized patients. Source: cmaj.ca Nov. 11, 2020
“Gravity is the inherent easy explanation but it also has to do with other factors,” Griesdale said, adding “it may even be more complicated than anyone understands.”
Prone positioning has been used in hospitalized pneumonia patients and those with acute respiratory distress syndrome for a few decades but it really came into vogue about seven years ago, after a study published in the New England Journal of Medicine showed a reduction in mortality among patients who were in prone positions for most of the day.
Research on its use during the COVID-19 pandemic is ongoing but Griesdale said his observations are that it’s helpful.
“Anecdotally, my impression is that proning can help with oxygenation in patients ventilated or breathing on their own.”
The downside of proning is that it’s not comfortable for some patients to remain face down for long periods so health professionals may have to turn them over periodically.
An early release article in the Canadian Medical Association Journal this week highlights the need for more studies to predict which patients with COVID-19 are most likely to benefit from prone positioning. Fortunately, the Toronto researchers are conducting research on that during the pandemic.
Their review of prone positioning offers insights into the difficulty of turning patients over when they have catheters, tubes, intravenous lines, and other medical devices attached to their bodies:
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