Perioperative lung ultrasound pattern changes in patients undergoing gynecological procedures - a prospective observational study

Objectives: General anesthesia and positive pressure ventilation are associated with perioperative pulmonary complications. Lung ultrasound (LUS) is a method used to evaluate lung parenchyma. The purpose of this study was to evaluate LUS patterns in a cohort of women undergoing gynecological surgery with uncomplicated general anesthesia. Material and methods: Patients were assessed according to the 8-zone LUS assessment protocol used to detect lung sliding, A-lines, B-lines, interstitial syndrome and lung consolidation. Each patient was screened at specific time intervals: before induction of anesthesia, at induction, 30 and 60 minutes after induction and within two hours after recovery. Results: A total of 99 patients undergoing gynecological surgery with uneventful anesthesia from November 2017 to November 2018 were included in this study. A total of 426 LUS records were retained for further analysis. Overall, no significant changes to patients' A-line appearance were detected, regardless of the time of assessment. There was, however, an increase in the number of B-lines at the screening times of 30 and 60 minutes after induction, as compared to initial assessments (p = 0.011 and p < 0.001 respectively), and an increase in the number of positive regions (= 3 B-lines) at 30 and 60 minutes after induction and after recovery, as compared to initial assessment (p < 0.001; p < 0.001 and p = 0.001 respectively). Conclusions: An uneventful anesthesia may predispose to abnormal LUS findings and should be considered while interpreting of LUS results in cases with perioperative pulmonary complications.