A Study on the Effect of Intraoperative Continuous Positive Airway Pressure (CPAP) on the Postoperative Pulmonary Function in Overweight Patients Undergoing Lower Limb, Lower Abdominal or Vaginal Surgeries under Spinal Anesthesia

Introduction: Spinal anaesthesia, supine position and higher BMI are risk factors for pulmonary atelectasis. NIV, PEEP and CPAP are employed in ICU’s to treat atelectasis postoperatively. However, we wanted to investigate whether CPAP was protective against atelectasis when used intraoperatively, in high risk patients. Material and methods: This study was a randomized controlled trial. Overweight patients, who were to undergo surgeries under spinal anesthesia were included in the study. After informed consent, 126 patients underwent preoperative pulmonary function tests (PFT: FEV1, FVC, PEFR). Following the onset of spinal anaesthesia patients were randomised into group E (n = 63, received CPAP) and control group, group C ( n =63, received nil intervention). Postoperative PFT was done at 20 minutes, 1 hour, 2 hours and 3 hours after surgery. Patients were followed up till discharge for pulmonary complications. Results: We observed significant reduction in pulmonary function (FEV1, FVC and PEFR) postoperatively compared to base-line. CPAP group had better pulmonary function when compared to control group, the difference being significant 20 minu-tes after the surgery (p < 0.05). No postoperative pulmonary complication was reported among the 126 patients studied. Conclusion: Intraoperative use of CPAP in overweight patients undergoing surgeries under spinal anaesthesia could be beneficial in improving pulmonary function in the immediate post-operative period.