EFFECT OF POSITIVE END-EXPIRATORY PRESSURE ON POSTOPERATIVE ATELECTASIS FOR OPEN ABDOMINAL SURGERY: A PROSPECTIVE RANDOMIZED CONTROLLED STUDY

Abstract

Introduction: Lung atelectasis is a commonly encountered post-operative problem in patients who undergo general anaesthesia, particularly for upper abdominal and thoracic surgeries. Positive endexpiratory pressure (PEEP) is a crucial strategy for preventing atelectasis, particularly in high-risk patients. Though PEEP offers benefits, its use is not without potential drawbacks. Objectives: The primary objective was to compare the effect of PEEP in patients undergoing general anaesthesia for open abdominal surgeries on postoperative atelectasis. The study also aimed to determine the incidence and degree of hypotension during intraoperative mechanical ventilation and estimated the incidence of barotrauma and increased airway pressures during intraoperative mechanical ventilation. Methods: A prospective randomized controlled trial was conducted in the Department of Anaesthesiology, in Sri Devaraj urs Medical College, Tamaka, Kolar in Karnataka between January 2023 and May 2024 among adult patients (>18 years) who were posted for open abdominal surgeries per inclusion and exclusion criteria. A total of 50 patients were xx randomized equally into two groups- one group (PEEP 4) received PEEP of 4cm of H2O & the other group (PEEP 8) received PEEP of 8 cm of H2O. Results: The mean age of participants was 41.7 years. The two groups’ baseline characteristics were similar. None of the two groups developed post-operative atelectasis in our study's 30 minutes in the postoperative anaesthesia care unit (PACU). The two groups were comparable in terms of Duration of Surgery, Duration of Anaesthesia, Fluid requirement, and tidal volume. We observed that PEEP 8 was associated with more hypotension than PEEP 4 (24% vs 4%, p<0.05). Only one patient in the PEEP 8 group required a blood transfusion, whereas no blood transfusion was required in the PEEP 4 group. Conclusion: PEEP might have a direct role in preventing postoperative atelectasis. PEEP 4 has a greater hemodynamic advantage than PEEP 8. Individual pre-operative assessment is important while deciding between PEEP 4 and PEEP 8