Pulmonary Disorders I

MV

Lung-protective strategies using low tidal volume ventilation are considered the standard of care

and cornerstone in managing ARDS.

The landmark multicenter trial by the Acute Respiratory Distress Syndrome Network (ARDSNet)

showed a survival benefit over conventional ventilation using higher tidal volumes (12 mL/kg) (N

Engl J Med 2000;342:1301-8). Clinical practice guidelines recommend limiting tidal volumes (4–8

Med 2023;49:727-759) and inspiratory pressures (plateau pressure less than 30 cm H2O) (Am Respir

identical, clinicians often apply ideal body weight for tidal volumes for ease of use and familiarity.

Prone over supine positioning improves gas exchange and may reduce ventilator-induced lung injury.

Compression atelectasis attributed to the weight of the heart, ventral lungs, and abdominal viscera

may be exacerbated in the supine position in patients with ARDS. The gravitational effects by

placing a patient in the prone position improve ventilation/perfusion matching and end-expiratory

The PROSEVA study group represents the most recently published randomized clinical trial

comparing prone and supine positioning in ARDS. In this trial, prone positioning for at least 16

hours/day compared with supine positioning in early ARDS decreased 28-day (adjusted hazard ratio

[HR] 0.42; 95% confidence interval [CI], 0.26–0.66) and 90-day (adjusted HR 0.48; 95% CI, 0.32–

0.72) mortality (N Engl J Med 2013;368:2159-68). Significantly more ventilator-free days at days 28

and 90 were observed with proning. Furthermore, 90-day extubation rates were significantly higher

in patients in the prone position.

Several meta-analyses have suggested an overall mortality benefit associated with prone positioning

most meta-analyses have shown a survival benefit with proning in patients with moderate to severe

ARDS (i.e., Pao2/Fio2 less than 150 mm Hg) compared with mild hypoxemia (i.e., Pao2/Fio2 greater

2017;14(suppl 4):(S280-S8). Similarly, mortality was reduced in patients with ARDS with prone

positioning and concurrent lung-protective MV strategies compared with pronation and high tidal

and severe ARDS has been associated with the greatest reduction in mortality compared with other

2019;32:347-60). Contraindicated criteria of use should be established to mitigate any adverse

events (e.g., spinal cord injury, elevated intracranial pressure [ICP]). Health care providers should

be trained on appropriate movement of patients between supine and prone positioning to ensure

securing of central lines as well as the endotracheal tube. Institutions should also consider the need

for manual maneuvering of patients compared with specialized rotating beds. One important patient

safety consideration is rapid health care staff access to patients in specialized beds during medical

emergencies (e.g., cardiopulmonary arrest, self-extubation).