Effect of Pressure Support Ventilation During Anesthetic Emergence on Postoperative Atelectasis in Infant


Atelectasis occurs in patients of all ages who receive mechanical ventilation under general anesthesia, and although fatal cases are rare, it is known as a cause of postoperative hypoxia or fever. In pediatric patients, it has a particularly high incidence of 68-100%, and the incidence is inversely proportional to age. Pediatric patients,compared to adults, have a small capacity for functional residual capacity while a high metabolic demand, making them fundamentally vulnerable to hypoxia. Increased atelectasis during anesthesia causes hypoxia not only during anesthesia but also during recovery after anesthesia. Therefore, it is important to establish and apply a strategy to minimize the occurrence of atelectasis during mechanical ventilation under general anesthesia in pediatric patients. The aim of this study is to investigate whether pressure support ventilation at emergence period could reduce the incidence of postoperative atelectasis in infants undergoing surgery under general anesthesia.

Study Type

  • Study Type: Interventional
  • Study Design
    • Allocation: Randomized
    • Intervention Model: Parallel Assignment
    • Primary Purpose: Other
    • Masking: Triple (Participant, Care Provider, Outcomes Assessor)
  • Study Primary Completion Date: February 2023


  • Other: conventional ventilation, group C
    • In the conventional ventilation group, after stopping the administration of the inhalation gas, the emergence process is performed by the anesthesiologist assigned to the room. Basically, until spontaneous respiration of the patient is restored, an anesthesiologist can assist respiration by intermittent manual assistance if necessary.
  • Other: pressure support, group PS
    • In the pressure support group, after stopping the administration of the inhalation gas, switch to the pressure support mode at the emergence period. PEEP 5cmH20 is applied, and the safety backup ventilation rate is set to 12 breaths/min. The flow trigger is set to 1L/min, and the degree of support is made to be 7-8ml of the predicted body weight, and is decreased as the patient’s spontaneous breathing is restored.

Arms, Groups and Cohorts

  • Experimental: group C
  • Experimental: group PS

Clinical Trial Outcome Measures

Primary Measures

  • Frequency of atelectasis
    • Time Frame: Within 5 minutes of arriving at the recovery room
    • Immediately after arriving at the recovery room, lung ultrasound is performed to check for atelectasis.

Secondary Measures

  • Frequency of atelectasis
    • Time Frame: After 30 minutes of stay in the recovery room
    • After 30 minutes of staying in the recovery room, lung ultrasound was performed to check for atelectasis.
  • scoring of atelectasis
    • Time Frame: at the time of admission and after 30 minutes of stay in the recovery room
    • Perform atelectasis scoring on 12 parts of the lung
  • Frequency of desatuation
    • Time Frame: at the time of admission and after 30 minutes of stay in the recovery room
    • Check the frequency of desaturation (<95%) during the stay in the recovery room.

Participating in This Clinical Trial

Inclusion Criteria

1. infant patients aged 0 day to 13 month 2. American Society of Anesthesiologists (ASA) classification 1~2 who are scheduled for elective surgery under general anesthesia Exclusion Criteria:

1. patients with symptomatic bronchopulmonary dysplasia 2. patients with uncorrected congenital heart or pulmonary disease 3. Hemodynamically unstable requiring preoperative vasopressor administration 4. fever (>37.5°) or URI symptoms on the day of surgery

Gender Eligibility: All

Minimum Age: N/A

Maximum Age: 1 Year

Are Healthy Volunteers Accepted: Accepts Healthy Volunteers

Investigator Details

  • Lead Sponsor
    • Yonsei University
  • Provider of Information About this Clinical Study
    • Sponsor
  • Overall Contact(s)
    • Jeong-Rim Lee, 82-2-2224-4135, manya@yuhs.ac

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