Prone Positioning to Improve Cerebral Oxygenation in Patients With Acute Respiratory Distress Syndrome.

Abstract

Background: Acute respiratory distress syndrome (ARDS), a common condition among intensive care patients, is characterized by severe hypoxemia that may lead to acute brain injury. Although prone positioning has emerged as a lifesaving strategy in the management of ARDS, its effects on cerebral oxygenation remain insufficiently explored.

Objective: To evaluate the evolution of cerebral oxygenation during prone positioning in patients with ARDS.

Methods: This prospective, single-center study was done in the intensive care unit of a community hospital. Consecutive patients with moderate or severe ARDS were prospectively enrolled during a 12-month period. Cerebral oxygenation was assessed by near-infrared spectroscopy before and during an 18-hour period of prone positioning. Continuous variables were compared before and during prone positioning using the Wilcoxon signed rank test. Correlations were assessed using the Spearman rank test.

Results: Ten patients were included in the study, with 2 patients exiting at hours 6 and 12 after the start of prone positioning because of hemodynamic instability. Evidence of oxygenation improvement during prone positioning was indicated by an increase in regional cerebral oxygen saturation (rSo2) and the ratio of Pao2 to fraction of inspired oxygen (Fio2). The rSo2/Fio2 ratio was significantly increased from hour 3 to 12 (P = .049 at hour 3, P = .02 at hour 8, and P = .02 at hour 12). Also, rSo2 was significantly correlated with oxygen delivery (ρ = 0.811, P < .001) and cardiac index (ρ = 0.463, P < .001).

Conclusion: Prone positioning in patients with ARDS seems to be associated with improved cerebral oxygenation based on rSo2/Fio2 ratio.