Prone position and recruitment manoeuvre: the combined effect improves oxygenation

INTRODUCTION: Among the various methods for improving oxygenation while decreasing the risk of ventilation-induced lung injury in patients with acute respiratory distress syndrome (ARDS), a ventilation strategy combining prone position (PP) and recruitment manoeuvres (RMs) can be practiced. We studied the effects on oxygenation of both RM and PP applied in early ARDS patients. METHODS: We conducted a prospective study. Sixteen consecutive patients with early ARDS fulfilling our criteria (ratio of arterial oxygen partial pressure to fraction of inspired oxygen (PaO(2)/FiO(2)) 98.3 ± 28 mmHg; positive end expiratory pressure, 10.7 ± 2.8 cmH(2)O) were analysed. Each patient was ventilated in both the supine position (SP) and the PP (six hours in each position). A 45 cmH(2)O extended sigh in pressure control mode was performed at the beginning of SP (RM1), one hour after turning to the PP (RM2) and at the end of the six-hour PP period (RM3). RESULTS: The mean arterial oxygen partial pressure (PaO(2)) changes after RM1, RM2 and RM3 were 9.6%, 15% and 19%, respectively. The PaO(2 )improvement after a single RM was significant after RM3 only (P < 0.05). Improvements in PaO(2 )level and PaO(2)/FiO(2 )ratio were transient in SP but durable during PP. PaO(2)/FiO(2 )ratio peaked at 218 mmHg after RM3. PaO(2)/FiO(2 )changes were significant only after RM3 and in the pulmonary ARDS group (P = 0.008). This global strategy had a benefit with regard to oxygenation: PaO(2)/FiO(2 )ratio increased from 98.3 mmHg to 165.6 mmHg 13 hours later at the end of the study (P < 0.05). Plateau airway pressures decreased after each RM and over the entire PP period and significantly after RM3 (P = 0.02). Some reversible side effects such as significant blood arterial pressure variations were found when extended sighs were performed. CONCLUSIONS: In our study, interventions such as a 45 cmH(2)O extended sigh during PP resulted in marked oxygenation improvement. Combined RM and PP led to the highest increase in PaO(2)/FiO(2 )ratio without major clinical side effects.