Prone ventilation, a quintessentially ICUish technique of manipulating respiratory physiology, has really entered the mainstream following the COVID pandemic. It's cheap, widely available, relatively safe, and it increases FRC, improves the drainage of secretions, decreases oxygen requirements and improves mortality (the PROSEVA trial demonstrated a mortality improvement from 32% to 16%). Thinking about the benefits, one comes to the conclusion that we should all be positioned prone, all the time.
Past CICM exam questions about prone ventilation have included:
Unfortunately, the older of these questions had preceded the wildly awesome PROSEVA trial, which makes the college answers somewhat useless to the revising CICM exam candidate, as the contemporary studies which those college answers were based on were largely negative owing to weird patient selection.
The best resource to revise this topic is the relevant LITFL CCC page. Of academic literature, a good article to read about the mechanisms of improved oxygenation from prone positioning was "Pragmatics of Prone Ventilation" by Messerole et al. (2002).
LITFL have an excellent literature summary section on their prone ventilation page, which has been pillaged for references. In brief, three contemporary studies (Gattinoni, Beuret and Guerin) were available to the trainees at the time of writing Question 15 from the first paper of 2004 and Question 11 from the first paper of 2003, in addition to early pioneering work by champions of "extreme positioning".
Piehl et al (1976) were the first to play with prone position: their study had 5 patients in it.
Gattinoni et al (2001): multicentre RCT - 304 patients with ARDS
Beuret (2002): single centre RCT - 54 patients with coma (not ARDS)
Guerin (2004): multicentre RCT - 791 patients with acute respiratory failure
On the basis of the available evidence, the college answer to the 2004 question mentioned the 2001 Gattinoni paper, lamenting the negative data. The college answer was fairly optimistic; they quoted an opinion piece by Alain Broccard from 2003, who also felt that there were "good reasons not to regard the recent negative prone positioning study as indicating that the prone position is of no interest". Broccard pointed out that it took five RCTs to finally arrive at the correct conclusion that low tidal volume ventilation improved survival in ARDS. This was prescient. Many trials followed.
Sud et al (2010) collected the data into a meta-analysis (n=1,867).
PROSEVA (2013); multicentre RCT - 466 patients with severe ARDS, dissected by The Bottom Line
ARDS Definition Task Force. "Acute Respiratory Distress Syndrome." Jama307.23 (2012): 2526-2533.
De Campos, T. "Ventilation with lower tidal volumes as compared with traditional tidal volumes for acute lung injury and the acute respiratory distress syndrome. The Acute Respiratory Distress Syndrome Network." N Engl J Med342.18 (2000): 1302-130g.
Villar, Jesús, et al. "A Clinical Classification of the Acute Respiratory Distress Syndrome for Predicting Outcome and Guiding Medical Therapy*." Critical care medicine 43.2 (2015): 346-353.
Lai-Fook, STEPHEN J., and JOSEPH R. Rodarte. "Pleural pressure distribution and its relationship to lung volume and interstitial pressure." Journal of Applied Physiology 70.3 (1991): 967-978.
Tobin, A., and W. Kelly. "Prone ventilation-it's time." Anaesthesia and intensive care 27 (1999): 194-201.
Douglas, William W., et al. "Improved Oxygenation in Patients with Acute Respiratory Failure: The Prone Position 1–3." American Review of Respiratory Disease 115.4 (1977): 559-566.
Oczenski, Wolfgang, et al. "Recruitment maneuvers during prone positioning in patients with acute respiratory distress syndrome." Critical care medicine 33.1 (2005): 54-61.
Takahashi, Naoaki, et al. "Anatomic evaluation of postural bronchial drainage of the lung with special reference to patients with tracheal intubation: Which combination of postures provides the best simplification?." CHEST Journal 125.3 (2004): 935-944.
Mackenzie, Colin F. "Anatomy, physiology, and pathology of the prone position and postural drainage." Critical care medicine 29.5 (2001): 1084-1085.
Lamm, W. J., Michael M. Graham, and Richard K. Albert. "Mechanism by which the prone position improves oxygenation in acute lung injury." American journal of respiratory and critical care medicine 150.1 (1994): 184-193.
Lamm, W. J., Michael M. Graham, and Richard K. Albert. "Mechanism by which the prone position improves oxygenation in acute lung injury." American journal of respiratory and critical care medicine 150.1 (1994): 184-193.
Pelosi, Paolo, et al. "Effects of the prone position on respiratory mechanics and gas exchange during acute lung injury." American journal of respiratory and critical care medicine 157.2 (1998): 387-393.
Mancebo, Jordi, et al. "A multicenter trial of prolonged prone ventilation in severe acute respiratory distress syndrome." American journal of respiratory and critical care medicine 173.11 (2006): 1233-1239.
Sud, Sachin, et al. "Prone ventilation reduces mortality in patients with acute respiratory failure and severe hypoxemia: systematic review and meta-analysis." Intensive care medicine 36.4 (2010): 585-599.
Cho, Young-Jae, et al. "411: The Efficacy and Safety of Prone Positional Ventilation in Acute Respiratory Distress Syndrome." Critical Care Medicine41.12 (2013): A99.
Messerole, Erica, et al. "The pragmatics of prone positioning." American journal of respiratory and critical care medicine 165.10 (2002): 1359-1363.
Gattinoni, Luciano, et al. "Effect of prone positioning on the survival of patients with acute respiratory failure." New England Journal of Medicine 345.8 (2001): 568-573.
Sud, Sachin, et al. "Prone ventilation reduces mortality in patients with acute respiratory failure and severe hypoxemia: systematic review and meta-analysis." Intensive care medicine 36.4 (2010): 585-599.
Beuret, Pascal, et al. "Prone position as prevention of lung injury in comatose patients: a prospective, randomized, controlled study." Intensive care medicine 28.5 (2002): 564-569.
Guerin, Claude, et al. "Effects of systematic prone positioning in hypoxemic acute respiratory failure: a randomized controlled trial." Jama 292.19 (2004): 2379-2387.
Broccard, Alain F. "Prone position in ARDS: are we looking at a half-empty or half-full glass?." CHEST Journal 123.5 (2003): 1334-1336.
PIEHL, MARGARET A., and ROBERT S. BROWN. "Use of extreme position changes in acute respiratory failure." Critical care medicine 4.1 (1976): 13-14.
Sodhi, Kanwalpreet, and Gunjan Chanchalani. "Awake proning: current evidence and practical considerations." Indian journal of critical care medicine: peer-reviewed, official publication of Indian Society of Critical Care Medicine 24.12 (2020): 1236.
Koeckerling, David, et al. "Awake prone positioning in COVID-19." Thorax 75.10 (2020): 833-834.