To the Editor: The randomized controlled trial by Dr Taccone and colleagues1 studied prone positioning in patients with acute respiratory distress syndrome (ARDS). The article raises questions about cardiovascular alterations and treatment of sepsis in study patients.
Shock and hemodynamic instability make prone positioning more difficult and potentially less safe. Furthermore, hemodynamic alterations and vasoactive agents (such as α- and β-adrenergic agents used clinically, including norepinephrine, dopamine, and dobutamine) can change perfusion distribution in the lung, alter gas exchange, and worsen oxygenation. Thus, over time a patient could move out of a state of being ineligible for the trial, and could also move from a classification of moderate to severe hypoxemia, with no change in the underlying ARDS pathology.
Russell JA. Prone Positioning in Patients With Acute Respiratory Distress Syndrome. JAMA. 2010;303(9):832-833. doi:10.1001/jama.2010.183