Outcome variables
postoperative atelectasis, atelectasis, reflux
POSTOPERATIVE ATELECTASIS, ATELECTASIS, COMPLICATIONS, REFLUX
The primary outcomes were the incidence of postoperative atelectasis (Because grade 1 atelectasis is easy to recover, only patients with grade 2 or higher atelectasis were included in the calculation of the incidence of atelectasis) and the postoperative atelectasis score. Secondary outcomes were baseline data, duration of anesthesia, duration of surgery, vital signs at three-time points including after insertion of the laryngeal mask, intraoperative (10 min after the start of the operation), and before the removal of the laryngeal mask. In addition, whether encounter complications such as reflux aspiration etc. were also recorded. Vital signs mainly including respiratory rate, heart rate, blood pressure, PetCO