Improved oxygenation using the prone position in patients with ARDS.

Abstract

The prone position is known to increase oxygen uptake in patients with Adult Respiratory Distress Syndrome (ARDS). In this clinical study from 1995-96, 14 ARDS patients with severe respiratory failure were treated for at least 1 h in the prone position. Responders, defined as having more than 10% increase in PaO2/FiO2 ratio from baseline after 1 h, were treated at least 6 h in the prone position. 11 patients responded during the first period of the prone position (primary responders). Two of the 3 non-responders were turned prone a second time with increase in the PaO2/FiO2 ratio (secondary responders). Mean PaO2/FiO2 ratio (mean +/- SEM) in the supine position was 11.7 +/- 0.8 kPa, increasing to 16.6 +/- 1.8 kPa and 18.0 +/- 1.4 kPa after 1 and 6 h respectively (P = 0.009). Mean time spent in the prone position was 69 h (range 3-256 h), and mean ventilatory time was 17 d (3-52 d). The mortality in this subgroup of our patients with ARDS was 42%, compared to 58% in 19 patients not turned prone in the same period. The prone position together with PEEP appears to improve ventilation-perfusion matching. The prone position is simple, effective and readily available and could be used early in most patients with ARDS.