The effect of ultrasound-guided lung recruitment maneuvers on atelectasis in lung-healthy patients undergoing laparoscopic gynecologic surgery: a randomized controlled trial

Abstract

Background Atelectasis is the primary cause of hypoxemia during general anesthesia. This study aimed to evaluate the impact of the combination of recruitment maneuvers (RM) and positive end-expiratory pressure (PEEP) on the incidence of atelectasis in adult women undergoing gynecologic laparoscopic surgery using pulmonary ultrasound. Methods In this study, 42 patients with healthy lungs undergoing laparoscopic gynecologic surgery were randomly divided into the recruitment maneuver group (RM group; 6 cm H2O PEEP and RM) or the control group (C group; 6 cm H2O PEEP and no RM), 21 patients in each group. Volume-controlled ventilation was used in all selected patients, with a tidal volume of 6–8 mL·kg−1 of ideal body weight. When atelectasis was detected, patients in the RM group received ultrasound-guided RM, while those in the C group received no intervention. The incidence and severity of atelectasis were determined using lung ultrasound scores. Results A total of 41 patients were investigated. The incidence of atelectasis was lower in the RM group (40%) than in the C group (80%) 15 min after arrival in the post-anesthesia care unit (PACU). Meanwhile, lung ultrasound scores (LUSs) were lower in the RM group compared to the C group. In addition, the differences in the LUS between the two groups were mainly due to the differences in lung ultrasound scores in the posterior regions. However, this difference did not persist after 24 h of surgery. Conclusions In conclusion, the combination of RM and PEEP could reduce the incidence of atelectasis in patients with healthy lungs 15 min after arrival at the PACU; however, it disappeared within 24 h after surgery. Trial registration (Prospectively registered): ChiCTR2000033529. Registered on 4/6/2020.

Effect of ultrasound-guided lung recruitment to reduce pulmonary atelectasis after non-cardiac surgery under general anesthesia: a systematic review and meta-analysis of randomized controlled trials

“…Whether the control group uses LRM is also worth further discussion. Although the control group in some studies using low tidal volume and PEEP, they did not undergo lung re-expansion during operation [6, 22,23,24,25,26,27], while the control group in the remaining studies used non-ultrasound-guided RM during operation [14,15]. Whether or not the control group had experienced postoperative atelectasis, the data demonstrated that the incidence of the condition was decreased in the ultrasound-guided group.…”

“…The incidence of postoperative atelectasis in adults and children were reported in the nine studies with 443 patients[6, 14,15,22,23,24,25,26,27]. The results showed that ultrasound-guided LRM reduced the incidence of postoperative atelectasis in adults (RR = 0.49; 95% CI: 0.36 to 0.67; p < 0.05; heterogeneity p > 0.10; I 2 = 0%)(Fig.…”

“…Three trials [6, 25,27] did not provide information about random assignment concealment. Two studies [23,27] did not blind the researcher or the subject, four studies [6, 22,25,26] did not describe whether to blind the researcher or the subject, ve studies [6, 22,25,26,27] did not describe whether to blind the outcome evaluator, and nine studies [6, 14,15,22,23,24,25,26,27] have a low risk of other biases.…”

“…Subgroup analysis of the effect of LRM type on postoperative atelectasis: 5 studies used sustained in ation [14,22,23,24,25], 3 studies used stepwise LRM through incremental PEEP[6, 15, 26], and 1 study used postural LRM [27]. The results showed that sustained in ation reduced the incidence of postoperative atelectasis, and stepwise LRM through incremental PEEP and postural LRM achieved this effect more signi cantly(Fig.…”

“…The reasons for the 15 exclusions were as follows: 4 were clinical registration trials, 2 were cardiac surgery, 5 did not report the results of postoperative atelectasis, 1 reported atelectasis was diagnosed by chest radiograph instead of lung ultrasound, and 3 performed ultrasound-guided or ultrasound-assessed LRM on both the experimental group and the control group. Finally, 9 randomized controlled trials were included in 443 patients [6, 14,15,22,23,24,25,26,27]. The detailed information of the included study is shown in Table 2.…”