Effects of Different Extubation Strategies on Atelectasis in Older Adults after Major Abdominal Surgery: A Prospective Randomized Controlled Trial

Background: Older patients are particularly vulnerable to age-related respiratory changes. This prospective randomized controlled trial studied the effects of high and low fractions of inspired oxygen (FiO(2)) with the recruitment maneuver (RM) during extubation on lung atelectasis postoperatively in older patients undergoing major abdominal surgery. Methods: We randomized a total of 126 patients aged >60 years who underwent both elective and emergency major abdominal surgeries and met the inclusion criteria into three groups (H, HR, and LR) using computer-generated block randomization. Group H received high FiO(2) (1), Group HR received high FiO(2) (1) with RM followed by a positive end-expiratory pressure of 5 cm H2O, and Group LR received low FiO(2) (0.4) with RM followed by a positive end-expiratory pressure of 5 cm H2O 10 minutes before extubation. Oxygenation and atelectasis were measured using the arterial partial pressure of oxygen (PaO2)/FiO(2) ratios and lung ultrasound score. Postoperative pulmonary complications were recorded up to 24 hours postoperatively. Results: The mean PaO2/FiO(2) at 30 minutes post-extubation was significantly higher in Groups LR and HR compared to that in Group H (390.71 +/- 29.55, 381.97 +/- 24.97, and 355.37 +/- 31.70; p<0.001). In the immediate postoperative period, the median lung ultrasound score was higher in Group H than that in Groups LR and HR (6 [5-7], 3 [3-5], and 3.5 [2.25-4.75]; p<0.001). The incidence of oxygen desaturation and oxygen requirements was higher in Group H during the postoperative period. Conclusion: The RM before extubation is beneficial in reducing atelectasis and postoperative pulmonary complications, irrespective of the FiO(2) concentration used in older adults undergoing major abdominal surgeries. (Trail registration number: Reference No. CTRI/2022/04/042115; date of CTRI registration 25/02/2022; and date of enrolment of the first research participant 05/05/2022)