Short term effects of prone position in mechanically ventilated patients with acute respiratory failure

ABSTRACT

A major goal in treating patients with acute respiratory failure [ARF] is to provide adequate delivery of oxygen. Current supportive therapies, including mechanical ventilation, positive end expiratory pressure [PEEP] and administration of high concentrations of oxygen. often entail a substantial risk to these patients. Several studies have revealed that improvement in oxygenation can be achieved by placing patients in the prone position. The aim of this study was to evaluate the short term effects of prone position on oxygenation and lung mechanics in patients with ARF requiring mechanical ventilation, The present study was conducted, on 30 patients with ARF admitted to the Critical care Medicine Department of Alexandria Main university Hospital. They were differentiated into 3 groups namely ARDS group. COPD+ARDS group and COPD+ ACRF group All patients tolerated turning from supine to prone position rcmarkahjyremarkably well. There were significant increase in arterial oxygen tension [PaO2] when patients were turned prone. This improvement of PaO2 remained so until the patients were returned supine again. There was no significant retduction of the arterial carbon dioxide tension [PaCo2] throughout the study except when the patient were returned supine. A constant improvement in arterial oxygen saturation [SaO2] was observed throughout the study. The hypoxemic index [PaCO2/FiO2] improved significantly with prone positnnung and remained so in some patients [n=16] when they were returned supine. Twenty four patients were responders [achieved <20 mmHg increase of PaO2/FiO2] while, the other 6 patients were nan responders [achieved 20 mmHg increase of PaO2/FiO2]. Peak inspiratory pressure [P. I. P.] and plateau pressure [Ppl] were reduced significantly throughout the study. Dynamic lung compliance and static compliance showed significant increases throughout the study. Airway resistance as well as auto PEEP were reduced significantly. Prone positioning is a simple and safe procedure to improve oxygenation and lung mechanics in many critically ill patients with ARl, allowing for reduction of FiO2 and/or PEEP