Optimal PEEP for Postoperative Oxygenation and Lung Aeration (ULTRASVENT-2)

NCT07613177 | Not Yet Recruiting

• 1 other identifier: ULTRASVENT-2
• Study Type: interventional
• Target: 360
• Locations: 1 country
• Sites: 1

Brief Summary

The purpose of this multicenter, randomized controlled trial (ULTRASVENT-2) is to evaluate the effect of different positive end-expiratory pressure (PEEP) levels on postoperative oxygenation and lung aeration in adult patients undergoing elective non-cardiac and non-thoracic surgery under general anesthesia. Moving away from traditional binary outcomes, this study utilizes a continuous functional metric, the non-invasive oxygenation index SpO2/FiO2 (S/F ratio), as the primary endpoint to precisely capture the degree of respiratory function preservation. Patients will be stratified into four distinct surgical cohorts based on the type and aggressiveness of the procedure: non-abdominal surgery, major open abdominal surgery, major laparoscopic abdominal surgery, and low-trauma laparoscopic surgery. This adaptive design aims to investigate how protective PEEP strategies interact with varying degrees of surgical trauma and intraoperative pneumoperitoneum, allowing the optimization of mechanical ventilation parameters for routine clinical practice.

Conditions

Postoperative Complications; Respiratory Insufficiency; Pulmonary Atelectasis; Positive-End Expiratory Pressure; Hypoxemia

Keywords

Lung ultrasound; S/F ratio; Perioperative lung protection; Laparoscopic surgery; Open laparotomy

Outcome Measures

Primary Outcomes (1)

• Non-invasive oxygenation index (SpO2/FiO2 ratio)

  The primary functional outcome is the SpO2/FiO2 (S/F) ratio, a continuous metric indicating the degree of lung oxygenation. The S/F ratio is calculated by dividing the peripheral capillary oxygen saturation (SpO2) by the fraction of inspired oxygen (FiO2). To ensure standardization, postoperative measurements are performed on room air in a supine position. Measurements are recorded strictly when the patient achieves full wakefulness, which is verified using the modified Post Anesthesia Recovery Score (PARS) as a readiness criteria. The PARS scale ranges from a minimum of 0 to a maximum of 10, where higher scores indicate a better clinical recovery. Note: The reported outcome is solely the S/F ratio value; the PARS score is used exclusively as a clinical condition to initiate the S/F measurement and is not aggregated into the final outcome value.

  Assessed at 3 time points: preoperatively (baseline); exactly 2 hours post-extubation; and 24 hours post-operation.

Secondary Outcomes (3)

• Incidence of Postoperative Pulmonary Complications (PPCs)

  From the end of surgery up to 7 days post-operation.

• Postoperative lung ultrasound score and aeration patterns

  Exactly 2 hours post-extubation in the Post-Anesthesia Care Unit (PACU) or Intensive Care Unit (ICU).

• Incidence of Intraoperative Hemodynamic Instability

  Intraoperatively (from the moment of endotracheal intubation until extubation).

Study Arms (2)

Standard PEEP Strategy

ACTIVE COMPARATOR

Patients randomized to this arm will receive a fixed, standard (lower) level of Positive End-Expiratory Pressure (PEEP) throughout the intraoperative period (from intubation to extubation). The specific PEEP value is determined strictly by the surgical stratum: 5 cm H2O for Strata 1 (Non-abdominal surgery), 5 cm H2O for Strata 2 (Major open abdominal surgery), 5 cm H2O for Strata 3 (Major laparoscopic abdominal surgery), and 5 cm H2O for Strata 4 (Low-trauma laparoscopic surgery). All other mechanical ventilation parameters remain standardized (tidal volume 6-8 mL/kg of ideal body weight).

Procedure: Intraoperative Positive End-Expiratory Pressure (PEEP) Regulation

Higher PEEP Strategy

EXPERIMENTAL

Patients randomized to this arm will receive a fixed, higher level of Positive End-Expiratory Pressure (PEEP) designed for protective lung ventilation throughout the intraoperative period. The specific PEEP value is tailored to the surgical stratum and abdominal risk: 8 cm H2O for Strata 1 (Non-abdominal surgery), 8 cm H2O for Strata 2 (Major open abdominal surgery), 12 cm H2O for Strata 3 (Major laparoscopic abdominal surgery), and 12 cm H2O for Strata 4 (Low-trauma laparoscopic surgery). All other mechanical ventilation parameters remain standardized (tidal volume 6-8 mL/kg of ideal body weight).

Procedure: Intraoperative Positive End-Expiratory Pressure (PEEP) Regulation

Interventions

Intraoperative Positive End-Expiratory Pressure (PEEP) Regulation PROCEDURE

Application of fixed PEEP levels calculated according to surgical aggressiveness and the presence of pneumoperitoneum. Standard PEEP arm utilizes PEEP values of 5 cm H2O. Higher PEEP arm utilizes protective PEEP values of 8 or 12 cm H2O. The assigned PEEP strategy is initiated immediately following endotracheal intubation and maintained continuously until extubation.

Higher PEEP Strategy; Standard PEEP Strategy

Eligibility Criteria

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

You may qualify if:

• Age greater than or equal to 18 years.
• Planned elective non-cardiac and non-thoracic surgical intervention requiring general anesthesia with mechanical ventilation.
• Airway protection utilizing an endotracheal tube.
• Assignment to one of the four specific surgical strata: non-abdominal, major open abdominal, major laparoscopic abdominal, or low-trauma laparoscopic surgery.
• Baseline lung ultrasound showing no pathological findings, corresponding to a total preoperative LUS score of 0.
• Technical feasibility of performing a postoperative lung ultrasound within the first 2 hours after the completion of surgery.
• Signed written informed consent to participate in the clinical trial.

You may not qualify if:

• Planned cardiac or thoracic surgery (e.g., coronary artery bypass grafting, valve replacement, heart transplantation, lung resection, esophageal surgery).
• Pneumothorax diagnosed before or during the surgical procedure.
• Inability to adequately visualize the target dorsal-basal lung zones by ultrasound due to physical limitations (e.g., morbid obesity, massive surgical dressings, anatomical anomalies, or dermatological lesions in the scanning area).
• Presence of hydrothorax detected on the baseline preoperative ultrasound.
• Confirmed perioperative aspiration of gastric contents or other foreign material.
• Any pathological changes identified during the baseline ultrasound of the dorsal-basal lung regions (a total preoperative LUS score greater than 0).
• Requirement for massive blood transfusion during the surgery, defined according to local institutional criteria.
• Surgical interventions directly involving or violating the diaphragm.
• Expected inability to conduct reliable postoperative clinical and ultrasound assessments (e.g., need for deep sedation preventing wakefulness and contact, or planned transfer to another facility).

Sponsors & Collaborators

• Moscow Multidisciplinary Clinical Center "Kommunarka": lead

Study Sites (1)

Moscow Multi-disciplinary Clinical Center "Kommunarka"

Moscow, Moscow, 108814, Russia

Location

Related Publications (7)

• L D, Kumar R, Patel N, Ayub A, Rewari V, Subramaniam R, Roy KK. Effect of Lung Compliance-Based Optimum Pressure Versus Fixed Positive End-Expiratory Pressure on Lung Atelectasis Assessed by Modified Lung Ultrasound Score in Laparoscopic Gynecological Surgery: A Prospective Randomized Controlled Trial. Cureus. 2023 Jun 12;15(6):e40278. doi: 10.7759/cureus.40278. eCollection 2023 Jun.

  PMID: 37448389 BACKGROUND

• Miskovic A, Lumb AB. Postoperative pulmonary complications. Br J Anaesth. 2017 Mar 1;118(3):317-334. doi: 10.1093/bja/aex002.

  PMID: 28186222 BACKGROUND

• Zhang Y, Zhu J, Xi C, Wang G. Effect of driving pressure-guided individualized positive end-expiratory pressure (PEEP) ventilation strategy on postoperative atelectasis in patients undergoing laparoscopic surgery as assessed by ultrasonography: study protocol for a prospective randomized controlled trial. Trials. 2025 Mar 26;26(1):106. doi: 10.1186/s13063-025-08819-5.

  PMID: 40140868 BACKGROUND

• Frassanito L, Sonnino C, Pitoni S, Zanfini BA, Catarci S, Gonnella GL, Germini P, Vizzielli G, Scambia G, Draisci G. Lung ultrasound to monitor the development of pulmonary atelectasis in gynecologic oncologic surgery. Minerva Anestesiol. 2020 Dec;86(12):1287-1295. doi: 10.23736/S0375-9393.20.14687-X. Epub 2020 Nov 11.

  PMID: 33174404 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

MeSH Terms

Conditions

Postoperative Complications; Respiratory Insufficiency; Pulmonary Atelectasis; Hypoxia

Interventions

Positive-Pressure Respiration; Social Control, Formal

Condition Hierarchy (Ancestors)

Pathologic Processes; Pathological Conditions, Signs and Symptoms; Respiration Disorders; Respiratory Tract Diseases; Lung Diseases; Signs and Symptoms, Respiratory; Signs and Symptoms

Intervention Hierarchy (Ancestors)

Respiration, Artificial; Airway Management; Therapeutics; Respiratory Therapy; Health Care Economics and Organizations

Study Officials

• Ivan Shcheparev, MD, PhD

  Moscow Multi-disciplinary Clinical Center "Kommunarka"

  PRINCIPAL INVESTIGATOR

• Denis Protsenko, MD, PhD, Professor

  Moscow Multi-disciplinary Clinical Center "Kommunarka"

  STUDY DIRECTOR

• Efim Shifman, MD, PhD, Professor

  Moscow Multi-disciplinary Clinical Center "Kommunarka"

  STUDY CHAIR

Central Study Contacts

Ivan Shcheparev, MD, PhD

CONTACT

+7 901 908 90 88; is22@list.ru

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: QUADRUPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
• Masking Details: The automated intraoperative positive end-expiratory pressure (PEEP) settings are completely hidden from the post-anesthesia care unit (PACU) nursing staff, ward physicians, and investigators. All parameters are documented in a separate file inaccessible during the evaluation period. The clinical operators performing both the preoperative and postoperative lung ultrasound (LUS) examinations, as well as the personnel calculating the primary functional outcome (SpO2/FiO2 ratio), are strictly blinded to the assigned PEEP strategy and the patient's intraoperative ventilator settings.
• Purpose: PREVENTION
• Intervention Model: PARALLEL
• Sponsor Type: OTHER GOV
• Responsible Party: SPONSOR

Model Details: Prospective, multicenter, stratified, parallel-group randomized controlled trial. Participants are independently stratified into 4 parallel surgical strata based on the procedure type: Strata 1 (Non-abdominal surgery), Strata 2 (Major open abdominal surgery), Strata 3 (Major laparoscopic abdominal surgery), and Strata 4 (Low-trauma laparoscopic surgery). Within each distinct stratum, participants are randomized in a 1:1 ratio to receive either a fixed standard PEEP or a fixed higher PEEP strategy from intubation to extubation.

Study Record Dates

• First Submitted: May 19, 2026
• First Posted: May 29, 2026
• Study Start (Estimated): July 1, 2026
• Primary Completion (Estimated): December 1, 2026
• Study Completion (Estimated): December 20, 2026
• Last Updated: May 29, 2026

Record last verified: 2026-05

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, ICF, CSR
• Time Frame: Data will become available immediately following the official publication of the primary trial results, with no specified end date.
• Access Criteria: The dataset will be openly accessible to any researcher, clinician, or analyst interested in replicating the study findings, conducting systematic reviews, or performing secondary meta-analyses. The data will be hosted publicly, and no formal research proposal review or data use agreements are required for access.

Locations

RU (1)