Comparative analysis of respiratory systems compliance in three different positioning (lateral, dorsal and sitting) in patients in prolonged invasive mechanical ventilation.

OBJECTIVES This study is justified by the fact that in clinical practice, changes occur in patient's positioning in the bed during hospitalization in intensive care unity, it's necessary better understanding about possible adverse effects that such changes might cause mainly on the respiratory system condition. The objective this study was to evaluate if the patients positioning in bed can to alter the pulmonary complacency. METHODS All included patients were submitted to mechanical ventilation and were sedated and curarized respiratory system compliance was assessed in three different positioning: lateral, dorsal and sitting. After an alveolar recruitment maneuver, patients were placed to a position throughout two hours, and in the last five minutes the data was collected from the mechanical ventilator display. RESULTS twenty eight patients were prospectively assessed. Values of respiratory system compliance in the lateral position were 37,07 ± 12,9 in the dorsal were 39,2 ± 10,5 and in the sitting 43,4 ± 9,6 mL/cmH2O. There were a statistical difference when we compared to the sitting and dorsal with lateral positioning for respiratory system compliance (p = 0.0052) and tidal volume (p < 0.001). There was a negative correlation between mean values of positive end expiratory pressure a respiratory system compliance (r = 0.59, p = 0.002). The FIO2 administered was 0.6 for the lateral positioning and 0.5 for the dorsal and sitting positioning (p = 0.049). CONCLUSIONS That body positioning in patients restrained to a bed and submitted to invasive mechanical ventilation leads to pulmonary compliance, tidal volume and SpO2 oscillations. In the sitting position the pulmonary compliance is higher than in others positions.