Lung ultrasound score to determine the effect of fraction inspired oxygen during alveolar recruitment on absorption atelectasis in laparoscopic surgery: a randomized controlled trial.

Bo Rim Kim, Seohee Lee, Hansu Bae, Minkyoo Lee, Jae-Hyon Bahk, Susie Yoon

BMC anesthesiology 2020 Jul 18

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Although the intraoperative alveolar recruitment maneuver (RM) efficiently treats atelectasis, the effect of FIO2 on atelectasis during RM is uncertain. We hypothesized that a high FIO2 (1.0) during RM would lead to a higher degree of postoperative atelectasis without benefiting oxygenation when compared to low FIO2 (0.4). In this randomized controlled trial, patients undergoing elective laparoscopic surgery in the Trendelenburg position were allocated to low- (FIO2 0.4, n = 44) and high-FIO2 (FIO2 1.0, n = 46) groups. RM was performed 1-min post tracheal intubation and post changes in supine and Trendelenburg positions during surgery. We set the intraoperative FIO2 at 0.4 for both groups and calculated the modified lung ultrasound score (LUSS) to assess lung aeration after anesthesia induction and at surgery completion. The primary outcome was modified LUSS at the end of the surgery. The secondary outcomes were the intra- and postoperative PaO2 to FIO2 ratio and postoperative pulmonary complications. The modified LUSS before capnoperitoneum and RM (P = 0.747) were similar in both groups. However, the postoperative modified LUSS was significantly lower in the low FIO2 group (median difference 5.0, 95% CI 3.0-7.0, P < 0.001). Postoperatively, substantial atelectasis was more common in the high-FIO2 group (relative risk 1.77, 95% CI 1.27-2.47, P < 0.001). Intra- and postoperative PaO2 to FIO2 were similar with no postoperative pulmonary complications. Atelectasis occurred more frequently when RM was performed with high than with low FIO2; oxygenation was not benefitted by a high-FIO2. CONCLUSIONS: In patients undergoing laparoscopic surgery in the Trendelenburg position, absorption atelectasis occurred more frequently with high rather than low FIO2. No oxygenation benefit was observed in the high-FIO2 group. ClinicalTrials.gov, NCT03943433 . Registered 7 May 2019.

Citation

Bo Rim Kim, Seohee Lee, Hansu Bae, Minkyoo Lee, Jae-Hyon Bahk, Susie Yoon. Lung ultrasound score to determine the effect of fraction inspired oxygen during alveolar recruitment on absorption atelectasis in laparoscopic surgery: a randomized controlled trial. BMC anesthesiology. 2020 Jul 18;20(1):173