Effects of Individualized PEEP Guided by Driving Pressure on Postoperative Atelectasis in Patients With Morbid Obesity

Not Applicable

Recruiting

• Conditions: Obesity, Morbid; Pulmonary Atelectasis
• Interventions: Procedure: Fixed PEEP group; Procedure: Individualized PEEP group

• Registration Number: NCT06181279
• Lead Sponsor: Yongtao Sun

Brief Summary

Atelectasis is a common complication in patients undergoing surgery under general anesthesia, particularly in obese patients. Postoperative atelectasis could last for more than 24h and contribute to a variety of other complications, including hypoxemia and pneumonia. We plan to conduct a single-center, randomized controlled trial in patients undergoing bariatric surgery to test the hypothesis that driving pressure guided PEEP could reduce the postoperative atelectasis.

Detailed Description

Positive end-expiratory pressure (PEEP) is a strategy that helps to keep alveoli open during surgery and to prevent postoperative atelectasis. A fixed PEEP without considering the respiratory mechanics in individual patients, however, is not optimal. Individualized PEEP therefore has been increasingly studied, and has been shown to improve oxygenation in both nonobese and obese patients. Studies have shown that the occurrence and prognosis of PPCs are significantly associated with high driving pressure (DP), but not with VT and PEEP. Driving pressure-guided individualized PEEP is expected to be a novel perioperative lung protection strategy. Consequently, the main aim of this study is to investigate the effect of a driving pressure-guided individualized PEEP ventilation strategy on postoperative pulmonary atelectasis in morbidly obese patients undergoing bariatric surgery.

Study Timeline

• Study First Submitted: 2023-12-12
• Study First Submitted QC: 2023-12-12
• Study First Posted: 2023-12-26
• Study Start: 2024-03-01
• Status Verified: 2024-06
• Last Update Submitted: 2024-06-01
• Last Update Posted: 2024-06-04
• Primary Completion: 2024-12-31
• Study Completion: 2024-12-31

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 52

Inclusion Criteria

• Age 18 to 60 years old;
• Body mass index (BMI) ≥ 40 kg/m2;
• ASA classification I to III;
• Signing the informed consent form for this clinical study;

Exclusion Criteria

• Respiratory infection within 4 weeks; severe respiratory system diseases; history of pulmonary and/or thoracic surgery; neuromuscular dysfunction;
• Serious cardiac, renal or haematopoietic diseases;
• Contraindications to PEEP；

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Fixed PEEP group	Fixed PEEP group	After recruitment maneuver, PEEP is fixed at 8cmH2O.
Individualized PEEP group	Individualized PEEP group	After recruitment maneuver, PEEP is titrated decreasingly using driving pressure guided individualised PEEP ventilation strategy, and the PEEP corresponding to the lowest driving pressure is the individualised PEEP.

Primary Outcome Measures

Name	Time	Method
Incidence of postoperative pulmonary atelectasis	After 30 minutes of extubation	The primary outcome of this study is postoperative atelectasis measured by lung ultrasound. Each hemithorax is divided into 6 regions using 3 longitudinal lines (parasternal, anterior and posterior axillary)and 2 axial lines (one above the diaphragm and the other 1 cm above the nipples). The 12 lung regions were scanned sequentially from right to left, cranial to caudal and anterior to posterior. Each region is assessed using a 2-dimen-sional view with the probe placed parallel to the ribs. It distinguishes four progressive steps of loss of aeration according to the artifacts visualized in a scan: score 0, normal aeration (A-lines or no more than two B-lines); score 1, moderate loss of aeration (three or more well-spaced B-lines); score 2, severe loss of aeration(coalescent B-lines); and score 3, complete loss of aeration(tissue-like pattern). We define atelectasis to be significant if any region had a lung consolidation score of ≥2.

Secondary Outcome Measures

Name	Time	Method
Postoperative pulmonary ultrasound score	After 30 minutes of extubation	Each hemithorax is divided into 6 regions using 3 longitudinal lines (parasternal, anterior and posterior axillary)and 2 axial lines (one above the diaphragm and the other 1 cm above the nipples). The 12 lung regions were scanned sequentially from right to left, cranial to caudal and anterior to posterior. Each region is assessed using a 2-dimen-sional view with the probe placed parallel to the ribs. It distinguishes four progressive steps of loss of aeration according to the artifacts visualized in a scan: score 0, normal aeration (A-lines or no more than two B-lines); score 1, moderate loss of aeration (three or more well-spaced B-lines); score 2, severe loss of aeration(coalescent B-lines); and score 3, complete loss of aeration(tissue-like pattern). We define atelectasis to be significant if any region had a lung consolidation score of ≥2. Based upon the LUS scoring system, each area is scored from 0-3, so a minimum zero or maximum 36 score is possible.

Trial Locations

Locations (1)

Qianfoshan Hospital, The First Hospital affiliated of Shandong First Medical University; 🇨🇳 Jinan, Shandong, China