I keep seeing pictures of people in Italian ICU’s who are lying face down. This is supposedly because that makes artificial respiration more effective, but also that it’s a last-ditch method.
I’ve never heard of this before, is it in any way a well known or standard practice in ICU?
How does it make respiration better?
How likely is it to work?
This called prone positioning or “proning” the patient. It’s used in the treatment of severe Acute Respiratory Distress Syndrome (ARDS). See here for a summary although this is aimed a medical professionals. Basically is changes some of the pressure differentials in the lungs, decreases the compression of the lung by the position of the heart and diaphragm and improves the blood flow to some areas of the lungs. It improves oxygenation and may have a mortality benefit. It’s not something we typically do in the ED so I my knowledge of the procedure is of the book-learning variety. I don’t actually remember if I had any proned patients during my residency ICU rotations ~10 years ago. If I recall, we have at least 1 intensivist around here so they may be able to provide more insight about how common it is in current practice.
Prone positioning is supposed to improve gas exchange thorough the lungs so there’s more oxygen flowing and to improve respiratory mechanics, among other benefits. The reason why it’s low on the list of options for use as therapy is because results of its efficacy through clinical testing has been mixed. Some patients’ conditions improved while others saw no change while still others deteriorated.
With that said, there seems to be a general consensus that restricting its usage to patients with specific conditions and phase of illness is reasonable and desirable with benefits outweighing the risks.
Thank you - I am now attempting to slog through the article.
One notes that in planet filled with vertebrates of all manner of shapes and sizes, humans seem to be one of very few that spend much time supine. Sloths and cats lying in the sun seem to be others that come to mind. Hard to imagine that there are not some basic features welded into our construction by evolution that being prone takes advantage of.
On the other hand, we used to put babies face down in their crib and now the universal advice is to have them face up.
That’s only because they have very weak necks and can literally smother themselves if their nose is smushed into the bedding.
The reason patients aren’t usually kept prone is largely because doing so is a PITA for the people trying to treat them. It makes a lot of important parts harder to get at, including the airway. It seems to be a sort-of last-ditch attempt to treat people with SARS2 right now. Assuming we get to the other side of this, I am curious if it will become standard practice for a lot of treatment after this, perhaps with beds like massage beds that are designed to make it easier.
NM
An alveolus, the gas-exchanging unit of the lung, is like a balloon. If it is already partly inflated, it is easy to move increments of air into and out of it with small changes in air pressure. Once it is fully collapsed, however, it requires more pressure to ‘pop’ it open that first little bit, after which lower pressures will work to continue moving air in.
The result of this is that alveoli that are open tend to stay open, while alveoli that collapse tend to stay collapsed. If there is a mix of fully-open and partially-open alveoli, for a given amount of pressure, air will move preferentially into the fully open alveoli. Your lung normally makes surfactant substances that mitigate this, and which help to spread the load among alveoli of different sizes. The body also tries to maintain a good match between blood flow and gas flow, so that well-ventilated portions of the lung get more than their share of blood flow, but this compensatory mechanism has its limits.
In a sick, waterlogged lung in a patient on a ventilator who is not moving much, these compensatory mechanisms get overwhelmed. The alveoli in the lower portions of the lungs get compressed over time by the weight of the soggy lungs; the surfactant can’t keep up; there are no big yawns or body movements to shake things up. Alveoli there collapse and don’t get popped back open. The alveoli in the uppermost portions of the lung get progressively more and more expanded, up to their elastic limit, but blood flow to those regions can’t be increased in perfect proportion. Less and less lung surface area is available for gas exchange, which is bad. Increasing the pressures on the ventilator now will cause the maximally-stretched parts to pop before it will open the collapsed portions. Bad.
Flipping someone prone is a way to try to combat this. Now the denser parts of the lung are at the top, and over time as fluids shift around the overexpanded areas will compress some while the underexpanded ones pop open. More surface area is available for gas exchange, and gas flow and blood flow can be matched better. In theory, and sometimes even in practice. Putting someone prone and leaving them there is not a one-time fix. Ideally you would flip them, wait for their lung function to improve, but keep a close eye on things so as soon as the bad old status quo started to reassert itself (dependent lung tissue collapsed, upper portions overexpanded) you would flip them back again. I suppose ideally they would be on a rotisserie, but God what a nightmare that would be for nursing care.
I like the rotisserie image, though.
Not quite a rotisserie but beds exist which do this: https://youtu.be/qP25GJg_eRM
RotoProne. Yep, heard of that.
There was also the Stryker frame, used in the old days for burn and spinal cord injury patients, as well as other people at high risk for bedsores. Here are some pictures, along with a history of the company that made it.
“Intensivist”?
UP next: Hospitalist? What is that?
CMC fnord!
Oh oh pick me pick me!
The doctor at a hospital who if not decides among a flock of specialists attending a patient, is responsible for keeping an eye on the case/status of everybody and is the point man for the patient.
Am I close?