Modified Lung Ultrasound Score to Determine the Degree of Perioperative Atelectasis in Adults Undergoing Elective Laparoscopic Surgery Under General Anaesthesia- A Prospective Observational Study

Background: Lung ultrasound score (LUS) is a semiquantitative assessment tool that has been proposed to assess lung aeration changes in mechanically ventilated patients after therapeutic interventions. In anaesthetized patient, LUS not only detects intraoperative atelectasis, but it also correlates with perioperative oxygenation impairment. The aim of this study was to assess the incidence and degree of atelectasis in patients undergoing laparoscopic surgery using LUS score. Methods: Total patients selected in our study were 60 aged between 18-60 years who underwent laparoscopic surgery under general anaesthesia. According to the lung ultrasound protocol, a total of 12 areas were divided and scanned in both hemithorax at four-time intervals preoperative period (T1), immediately after intubation (T2), before extubation (T3) and one hour after extubation (T4). The image was assessed by anaesthesiologist experienced in lung ultrasound based on modified lung ultrasound scoring system. Results: LUS at all four-time intervals were compared. We observed an increase in total LUS score T3 and T4 time period compared with preoperative (T1). LUS scores at posterior quadrants 5 and 6 on either side also increased at T3 & T4 time period (p< 0.001). The incidence of atelectasis was 6.6%, 6.6%, 78%, and 80% at T1, T2, T3, and T4, respectively. No change in hemodynamics and oxygen saturations were observed in all patients at various time periods. Conclusion: This study concluded that incidence and degree of atelectasis was found to be higher in the dependent lung zones as demonstrated by lung ultrasound score in adults undergoing laparoscopic surgeries under general anesthesia.