THE EFFECT OF PATIENT POSITIONING ON DYNAMIC LUNG COMPLIANCE

Background: Side-stream spirometry offers a non-invasive method to mon itor continuously respiratory mechanics in intubated patients. We stud ied the effects of different positions on dynamic lung compliance duri ng anaesthesia. Methods: The study consisted of 56 patients, operated in supine, prone, kneeling or lateral park-bench position. Dynamic lun g compliance and inspiratory peak pressure were recorded after inducti on of anaesthesia, 15 min and 1 h after posturing the patient. Results : The first measured compliances were comparable in all groups. The co mpliance in the lateral and the prone positions was significantly lowe r than in the supine position at 15 min (P<0.01) and 1 h (P<0.001) aft er the posture change. The peak inspiratory pressure was significantly lower in the kneeling position than in the other groups (P<0.01 at th e first measurement, P<0.001 at the later measurements). No correlatio n was found between body mass index and compliance. Conclusion: We fou nd that dynamic lung compliance decreased significantly upon change of posture from supine to lateral or prone position, whereas in the knee ling position no change in compliance was observed. We suggest that th e kneeling position might be preferable to the prone position. (C) Act a Anaesthesiologica Scandinavica 41 (1997).