Effects of ultrasound-guided alveolar recruitment manoeuvres compared with sustained inflation or no recruitment manoeuvres on atelectasis in laparoscopic gynaecological surgery as assessed by ultrasonography: a randomized clinical trial

Abstract

Background: The majority of patients may experience atelectasis under general anesthesia, and the Trendelenburg position and pneumoperitoneum can aggravate atelectasis during laparoscopic surgery, which promotes postoperative pulmonary complications. Lung recruitment manoeuvres have been proven to reduce perioperative atelectasis, but it remains controversial which method is optimal. Ultrasonic imaging can be conducive to confirming the effect of lung recruitment manoeuvres. The purpose of our study was to assess the effects of ultrasound-guided alveolar recruitment manoeuvres by ultrasonography on reducing perioperative atelectasis and to check whether the effects of recruitment manoeuvres under ultrasound guidance (visual and semiquantitative) on atelectasis are superior to sustained inflation recruitment manoeuvres (classical and widely used) in laparoscopic gynaecological surgery.

Methods: In this randomized, controlled, double-blinded study, women undergoing laparoscopic gynecological surgery were enrolled. Patients were randomly assigned to receive either lung ultrasound-guided alveolar recruitment manoeuvres (UD group), sustained inflation alveolar recruitment manoeuvres (SI group), or no RMs (C group) using a computer-generated table of random numbers. Lung ultrasonography was performed at four predefined time points. The primary outcome was the difference in lung ultrasound score (LUS) among groups at the end of surgery.

Results: Lung ultrasound scores in the UD group were significantly lower than those in both the SI group and the C group immediately after the end of surgery (7.67 ± 1.15 versus 9.70 ± 102, difference, -2.03 [95% confidence interval, -2.77 to -1.29], P < 0.001; 7.67 ± 1.15 versus 11.73 ± 1.96, difference, -4.07 [95% confidence interval, -4.81 to -3.33], P < 0.001;, respectively). The intergroup differences were sustained until 30 min after tracheal extubation (9.33 ± 0.96 versus 11.13 ± 0.97, difference, -1.80 [95% confidence interval, -2.42 to -1.18], P < 0.001; 9.33 ± 0.96 versus 10.77 ± 1.57, difference, -1.43 [95% confidence interval, -2.05 to -0.82], P < 0.001;, respectively). The SI group had a significantly lower LUS than the C group at the end of surgery (9.70 ± 1.02 versus 11.73 ± 1.96, difference, -2.03 [95% confidence interval, -2.77 to -1.29] P < 0.001), but the benefit did not persist 30 min after tracheal extubation.

Conclusions: During general anesthesia, ultrasound-guided recruitment manoeuvres can reduce perioperative aeration loss and improve oxygenation. Furthermore, these effects of ultrasound-guided recruitment manoeuvres on atelectasis are superior to sustained inflation recruitment manoeuvres.

Trial registration: Chictr.org.cn, ChiCTR2100042731, Registered 27 January 2021, www.chictr.org.cn .

Keywords: Atelectasis; General anesthesia; Recruitment manoeuvres; Sustained inflation; Ultrasound-guided.

Fig. 1

CONSORT flow diagram

Fig. 2

Schematic diagram of the study protocol. LUS: lung ultrasound score; RMs: recruitment manoeuvres; PACU: postanaesthesia care unit; UD: ultrasound-guided; SI: sustained inflation; T0: immediately before induction; T1:immediately after induction; T2: immediately after the end of surgery; T3: 30 min after tracheal extubation

Fig. 3

Lung ultrasound images of one representative patient in the lateral chest wall at different time points. T0: immediately before induction; T1: immediately after induction; T2: immediately after the end of surgery; T3: 30 min after tracheal extubation; C group: control group; SI group: sustained inflation recruitment manoeuvres group; UD group: ultrasound-guided recruitment manoeuvres group

Fig. 4

Temporal evolution of the mean LUS results per quadrant per group. LUS of the lung in the anterior chest area were all 0, thus no statistical analysis was made. T0: immediately before induction; T1: immediately after induction; T2: immediately after the end of surgery; T3: 30 min after tracheal extubation; C group: control group; SI group: sustained inflation recruitment manoeuvres group; UD group: ultrasound-guided recruitment manoeuvres group. *Denotes significant difference compared with C group (P < 0.05); #denotes significant difference compared with SI group (P < 0.05)

Fig. 5

Temporal evolution of the Visual model of LUS results per quadrant per group. C group: control group; SI group: sustained inflation recruitment manoeuvres group; UD group: ultrasound-guided recruitment manoeuvres group. ANT:anterior; LAT:lateral; POST: posterior