Prone positioning for acute respiratory distress syndrome in the surgical intensive care unit: Who, when, and how long?

Background. We evaluated the effects of prone positioning (PP) on surgery a nd trauma patients with acute respiratory distress syndrome (ARDS). Methods. Patients with ARDS were studied. Exclusion criteria were contraind ications to PP. Patients were evaluated in the supine position and after be ing turned to the PP. After 6 hours, patients were returned to the supine p osition for 3 hours. One hour after each position change, arterial and mixe d venous blood was drawn and analyzed for blood gases and pH, and hemodynam ics were measured. Results. Over 20 months, 27 patients met the criteria, and 20 of the patien ts were entered into the study. On day 1, 18 of 20 patients (90 %) responde d with an increase in PaO2 during PP. On day 2, 16 of 17 patients (94 %) re sponded; on clay 3, 15 of 16 patients responded (94 %); on day 4, 11 of 13 patients responded (85 %); on day 5, 8 of 8 patients responded (100 %); and on day 6, 4 of 5 patients responded (80 %). PaPO2/FIO2 and Qs/Qt were sign ificantly improved (P <. 05) during PP. There were 91 periods of PP, lastin g 10.3 +/- 1.2 hours. Of 91 changes to PP, 78 changes (86%) resulted in an improvement in PaO2/FIO2 of more than 20%. Conclusions. PP improves oxygenation in ARDS for 6 days with few complicati ons.