Optimal Interval for Periodic Alveolar Recruitment Maneuvers Achieving 90% Lung Re-expansion During Intraoperative Ventilation

NCT ID: NCT07239557

Last Updated: 2025-11-20

Basic Information

• Recruitment Status: NOT_YET_RECRUITING
• Clinical Phase: NA
• Total Enrollment: 52 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2026-01-01
• Study Completion Date: 2026-12-31

Brief Summary

This study aims to determine the optimal interval for periodic alveolar recruitment maneuvers (PARM) that can achieve effective lung re-expansion in 90% of patients undergoing intraoperative mechanical ventilation during abdominal laparoscopic surgery in the low Trendelenburg position. Identifying the most effective frequency of PARM is crucial for establishing lung-protective ventilation strategies, with the ultimate goal of reducing intraoperative atelectasis, decreasing postoperative pulmonary complications, and accelerating recovery.

Patients are randomized using a biased-coin sequential design. PARM is initially applied every 0.5 hours, and the effectiveness of lung re-expansion is evaluated before the end of surgery. The primary outcome is the effectiveness of recruitment, assessed by a combination of lung ultrasound scores and shunt fraction. Secondary outcomes include mechanical power at the end of surgery, time-weighted average mechanical power during ventilation, postoperative P/F ratio, dead space fraction, air test results, intraoperative adverse events, incidence of respiratory failure in the PACU and postoperative period, and postoperative length of stay.

This trial is expected to provide robust evidence for defining the optimal RM interval in protective ventilation protocols for patients undergoing laparoscopic abdominal surgery, thereby contributing to improved perioperative respiratory outcomes.

Detailed Description

This study is designed to evaluate the optimal interval of periodic alveolar recruitment maneuvers (PARM) to achieve effective lung re-expansion (defined as LUS ≤1 and shunt fraction <10%) in 90% of elderly patients undergoing laparoscopic anterior resection in low Trendelenburg position. This is a single-arm, biased-coin sequential design study. The initial PARM interval is 30 min, adjusted in 10 min increments based on response. The primary outcome is recruitment efficacy. Secondary outcomes include intraoperative mechanical power, P/F ratio, postoperative pulmonary complications, and length of hospital stay. This study aims to inform optimal RM intervals in protective ventilation protocols.

Conditions

Major Abdominal Surgery; Atelectasis; Lung-protective Ventilation; Lung Ultrasound Score; Postoperative Pulmonary Complications

Study Design

• Allocation Method: NA
• Intervention Model: SEQUENTIAL
• Primary Study Purpose: PREVENTION
• Blinding Strategy: NONE

Study Groups

PARM

Group Type: EXPERIMENTAL

Different interval of PARM

Intervention Type: PROCEDURE

The initial time interval of PARM was 0.5 hours/time, and the different interval of PARM was assigned by random partial coin sequential method.If the previous patient did not respond to postoperative assessment of lung opening, the interval between expansion of the lungs was shortened by 10 minutes for the next patient; If lung opening is effective, there is an 11% chance that the next patient will have an 10-minute expansion interval and an 89% chance that the time interval will remain unchanged.

Interventions

Different interval of PARM

The initial time interval of PARM was 0.5 hours/time, and the different interval of PARM was assigned by random partial coin sequential method.If the previous patient did not respond to postoperative assessment of lung opening, the interval between expansion of the lungs was shortened by 10 minutes for the next patient; If lung opening is effective, there is an 11% chance that the next patient will have an 10-minute expansion interval and an 89% chance that the time interval will remain unchanged.

Intervention Type: PROCEDURE

Eligibility Criteria

Inclusion Criteria

• Age 65-80 years
• Undergoing elective laparoscopic anterior resection (expected mechanical ventilation duration 2-5 hours)
• Intermediate risk for postoperative pulmonary complications
• Room air SpO₂ ≥94%

Exclusion Criteria

• History of pneumonia within 1 month or mechanical ventilation ≥1 hour
• Preoperative 12-zone LUS with any single zone score ≥2
• Preoperative shunt fraction ≥10%
• Progressive neuromuscular disease
• Severe emphysema/COPD or subpleural bullae ≥2 cm
• Intracranial hypertension
• Participation in other studies or refusal to participate

• Minimum Eligible Age: 65 Years
• Maximum Eligible Age: 80 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Sixth Affiliated Hospital, Sun Yat-sen University

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Central Contacts

Li Hong, MD

Role: CONTACT

lihong36@mail.sysu.edu.cn

Telephone: 0086-020-38254070

Xiao Ke Gu, MM

Role: CONTACT

guxk@mail.sysu.edu.cn

0086-020-38254070

Other Identifiers

E2025034

Identifier Type: -

Identifier Source: org_study_id