Phase 2 Study of the Alveolar Recruitment Maneuver in Cesarean Section

The investigators used recruitment maneuver during cesarean section and in women under general anesthesia. The primary end point of the study is the improvement of the lung compliance measured as volume difference/pressure difference (dv/dp) or ml/cmH2O after the recruitment maneuver. The investigators used 2 groups of patients. In the first group the investigators used pressure control ventilation for the recruitment maneuver. After the ventilator was switched to pressure control mode the investigators increased the inspiratory time to 50% and the inspiratory pressure above Positive End Expiratory Pressure (Ppeak) to 20 cmH2O. Then the investigators progressively increased Positive End Expiratory Pressure (PEEP) to have a peak inspiratory pressure (Ppeak) to 45 cm H2O. The whole recruitment maneuver lasts 2 minutes. After the recruitment maneuver the investigators used volume control ventilation again (with the baseline settings)and PEEP step wised decreased to 8 cmH20but. PEEP (8cmH2O) was left until the end of the operation. In the second group the investigators did not used lung recruitment maneuver at all. In both groups lung compliance was measured (dynamic and static)as dv/dp (ml/cmH2O). Measures were assessed 1 minute after delivery (but before recruitment), 3 minutes after recruitment (first group) at 10 and at 20 minutes after recruitment. The investigators also measured Ppeak (cmH2O) and Pplateau (cmH2O)inspiratory pressures , blood pressure (mmHG), beats per minute, oxygen saturation, end-tidal CO2 according to the above time frame, blood Gases before and 3 minutes after recruitment etc.