Abstract
Recently it has been revealed that when patients with dependent lung disease (DLD) are placed in the prone position with the healthy lung dependent, there is an improvement of pulmonary oxygenation which is positively correlated with the duration of prone position (8∼46h). However, since there are potential deleterious consequences of prologed duration of prone position and the optimal time of this therapeutic position is not well defined, we studied therefore the effect of short-period prone position on gas exchange in the early stage of acute respiratory failure.
The prone position was kept for a period of less than 2h (49.5±14.5min) in 19 critically ill patients with DLD. The mean PaO2/FIO2 ratio rose significantly from 202.7±60.1 to 297.7±88.4, but decreased slightly in only 2 cases with chronic obstructive lung disease. On changing back to the supine position, 14 (73.7%) patients could maintain better pulmonary function than the pretreatment values even at 4h later. Additionally it caused no significant changes in the efficacy of CO2 elimination (VP-index), respiratory volume (VT and VE) as well as lung compliance (Ceff).
In conclusion, as a posture for chest physiotherapy, short-period prone position was found to be therapeutically effective, better tolerated and less troublesome than long-period prone position. Consequently it may be employed more frequently to restore respiratory function to normal in critically ill patients. Pathophysiological aspects of DLD and the effect of the prone position was discussed.
