Optimal PEEP Level for Minimizing the Risk of Postoperative Atelectasis: A Retrospective Cohort Study Based on Lung Ultrasound Monitoring

NCT07211074 | Completed

• 1 other identifier: NMSC-03-25
• Study Type: observational
• Target: 450
• Locations: 1 country
• Sites: 1

Brief Summary

Background: After surgery with general anesthesia, it is common for parts of the lungs to collapse, a condition called atelectasis. This can lead to low blood oxygen levels and other lung complications. Doctors use a setting on the breathing machine called PEEP (Positive End-Expiratory Pressure) to help keep the lungs open, but the best level to use is still debated. Purpose of the Study: The goal of this research is to find a PEEP level that minimizes the risk of lung collapse and low oxygen levels after surgery. The investigators will use lung ultrasound, a safe and non-invasive imaging method, to check the health of the lungs at the patient's bedside. The investigators will not assign treatments; they will observe the outcomes based on the PEEP level chosen by the patient's anesthesiologist during routine care. A simplified ultrasound scan will be used to score the amount of lung collapse before and after surgery. The main outcomes will be the frequency of lung collapse and the frequency of low oxygen levels (defined as SpO₂ of 90% or less).

Conditions

Postoperative Atelectasis; Postoperative Pulmonary Complications (PPCs); Lung Ultrasound

Keywords

Postoperative Atelectasis; Lung Ultrasound; Postoperative Desaturation; Postoperative Pulmonary Complications

Outcome Measures

Primary Outcomes (1)

• Frequency of Postoperative Atelectasis

  The measure assesses the presence of postoperative atelectasis, defined as a lung ultrasound (LUS) score greater than 0. The assessment is conducted using a simplified 2-zone LUS protocol, with aeration evaluated on a 4-point scale (from 0 for normal aeration to 3 for major consolidation). The outcome is the percentage of patients who develop any degree of atelectasis (LUS score \> 0) following surgery

  The ultrasound measurement is performed within the first few hours after the completion of the surgical procedure

Secondary Outcomes (2)

• Frequency of Postoperative Desaturation

  Within the first few hours after completion of surgery

• Severity of Postoperative Atelectasis Measured by Lung Ultrasound Score

  The final LUS score is measured within the first few hours after completion of surgery

Study Arms (3)

ETT with PEEP ≤7 cm H₂O

This cohort consists of patients who underwent surgery with general anesthesia managed with an endotracheal tube (ETT) and a positive end-expiratory pressure (PEEP) of 7 cm H₂O or less. This group will include 250 patients in the final analysis

ETT with PEEP ≥8 cm H₂O

This cohort consists of patients who underwent surgery with general anesthesia managed with an endotracheal tube (ETT) and a positive end-expiratory pressure (PEEP) of 8 cm H₂O or greater. This group will include 119 patients in the final analysis

Laryngeal Mask

This cohort consists of patients who underwent surgery with general anesthesia managed with a laryngeal mask (LM) for airway protection. This group will include 81 patients in the final analysis

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Probability Sample

Study Population

The study population consists of 450 adult patients who underwent surgical procedures under general anesthesia with mechanical ventilation. Data will be collected from patients treated at the Department of Anesthesiology and Resuscitation of the National Medical and Surgical Center n.a. N.I. Pirogov. The cohort will be formed using a time-stratified randomization method to ensure a representative sample over the study period. All included patients will have a normal lung ultrasound before their procedure. The population will be divided based on the method of airway protection: * patients managed with an endotracheal tube (ETT). * patients managed with a laryngeal mask (LM).

You may qualify if:

• Patients undergoing surgical intervention under general anesthesia with mechanical ventilation.
• Airway protection managed with either an endotracheal tube or a laryngeal mask.
• A normal baseline ultrasound of the posterior-basal lung regions, corresponding to a score of 0 on the lung ultrasound scale.

You may not qualify if:

• Patients undergoing cardiac or thoracic surgery.
• Presence of a perioperatively identified pneumothorax.
• Inability to obtain adequate ultrasound visualization of the target lung zones.
• Presence of hydrothorax.
• Confirmed perioperative pulmonary aspiration.
• Presence of any pathological findings on the initial baseline ultrasound of the posterior-basal lung regions.
• Requirement for massive blood transfusion during the operation.
• Patients undergoing surgery on the diaphragm.
• Prolonged residual sedation lasting more than 2 hours post-operation

Sponsors & Collaborators

• State Budgetary Healthcare Institution, National Medical Surgical Center N.A. N.I. Pirogov, Ministry of Health of Russia: lead

Study Sites (1)

Pirogov National Medical and Surgical Cente

Moscow, 105203, Russia

Location

Related Publications (8)

• Writing Committee for the PROBESE Collaborative Group of the PROtective VEntilation Network (PROVEnet) for the Clinical Trial Network of the European Society of Anaesthesiology; Bluth T, Serpa Neto A, Schultz MJ, Pelosi P, Gama de Abreu M; PROBESE Collaborative Group; Bluth T, Bobek I, Canet JC, Cinnella G, de Baerdemaeker L, Gama de Abreu M, Gregoretti C, Hedenstierna G, Hemmes SNT, Hiesmayr M, Hollmann MW, Jaber S, Laffey J, Licker MJ, Markstaller K, Matot I, Mills GH, Mulier JP, Pelosi P, Putensen C, Rossaint R, Schmitt J, Schultz MJ, Senturk M, Serpa Neto A, Severgnini P, Sprung J, Vidal Melo MF, Wrigge H. Effect of Intraoperative High Positive End-Expiratory Pressure (PEEP) With Recruitment Maneuvers vs Low PEEP on Postoperative Pulmonary Complications in Obese Patients: A Randomized Clinical Trial. JAMA. 2019 Jun 18;321(23):2292-2305. doi: 10.1001/jama.2019.7505.

  PMID: 31157366 BACKGROUND

• Mazzinari G, Zampieri FG, Ball L, Campos NS, Bluth T, Hemmes SNT, Ferrando C, Librero J, Soro M, Pelosi P, Gama de Abreu M, Schultz MJ, Serpa Neto A; for REPEAT on behalf of the PROVHILO, iPROVE, and PROBESE investigators and the PROVE Network investigators. High Positive End-expiratory Pressure (PEEP) with Recruitment Maneuvers versus Low PEEP during General Anesthesia for Surgery: A Bayesian Individual Patient Data Meta-analysis of Three Randomized Clinical Trials. Anesthesiology. 2025 Jan 1;142(1):72-97. doi: 10.1097/ALN.0000000000005170.

  PMID: 39042027 BACKGROUND

• Yoon HK, Kim BR, Yoon S, Jeong YH, Ku JH, Kim WH. The Effect of Ventilation with Individualized Positive End-Expiratory Pressure on Postoperative Atelectasis in Patients Undergoing Robot-Assisted Radical Prostatectomy: A Randomized Controlled Trial. J Clin Med. 2021 Feb 19;10(4):850. doi: 10.3390/jcm10040850.

  PMID: 33669526 BACKGROUND

• Cho S, Oh HW, Choi MH, Lee HJ, Woo JH. Effects of Intraoperative Ventilation Strategy on Perioperative Atelectasis Assessed by Lung Ultrasonography in Patients Undergoing Open Abdominal Surgery: a Prospective Randomized Controlled Study. J Korean Med Sci. 2020 Oct 12;35(39):e327. doi: 10.3346/jkms.2020.35.e327.

  PMID: 33045769 BACKGROUND

• Young CC, Harris EM, Vacchiano C, Bodnar S, Bukowy B, Elliott RRD, Migliarese J, Ragains C, Trethewey B, Woodward A, Gama de Abreu M, Girard M, Futier E, Mulier JP, Pelosi P, Sprung J. Lung-protective ventilation for the surgical patient: international expert panel-based consensus recommendations. Br J Anaesth. 2019 Dec;123(6):898-913. doi: 10.1016/j.bja.2019.08.017. Epub 2019 Oct 3.

  PMID: 31587835 BACKGROUND

• Ma J, Sun M, Song F, Wang A, Tian X, Wu Y, Wang L, Zhao Q, Liu B, Wang S, Qiu Y, Hou H, Deng L. Effect of ultrasound-guided individualized positive end-expiratory pressure on the severity of postoperative atelectasis in elderly patients: a randomized controlled study. Sci Rep. 2024 Nov 15;14(1):28128. doi: 10.1038/s41598-024-79105-8.

  PMID: 39548165 BACKGROUND

• Liao B, Liao W, Yin S, Liu S, Wu X. 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. Perioper Med (Lond). 2024 Mar 27;13(1):23. doi: 10.1186/s13741-024-00379-7.

  PMID: 38539248 BACKGROUND

• Wu XZ, Xia HM, Zhang P, Li L, Hu QH, Guo SP, Li TY. 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. BMC Anesthesiol. 2022 Aug 16;22(1):261. doi: 10.1186/s12871-022-01798-z.

  PMID: 35974310 BACKGROUND

Related Links

• Official website of the Pirogov National Medical and Surgical Center

Study Officials

• Boris Teplykh, MD

  Pirogov National Medical and Surgical Center

  STUDY DIRECTOR

• Ivan Shcheparev, MD, PhD

  Pirogov National Medical and Surgical Center

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: RETROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: September 29, 2025
• First Posted: October 7, 2025
• Study Start: September 22, 2025
• Primary Completion: December 31, 2025
• Study Completion: January 31, 2026
• Last Updated: February 12, 2026

Record last verified: 2026-02

Data Sharing

• IPD Sharing: Will share
• Shared Documents: CSR
• Time Frame: 2 months after completion of the study
• Access Criteria: upon the request

Locations

RU (1)