Effects of Positive End-Expiratory Pressure Levels on Lung Recruitment Duration and Hemodynamics After Alveolar Recruitment Maneuver: A Randomized Clinical Trial

NCT07161466 | Completed

• 1 other identifier: 2024ky380
• Study Type: interventional
• Target: 101
• Locations: 1 country
• Sites: 1

Brief Summary

During general anesthesia surgery, the role of positive end-expiratory pressure (PEEP) in mechanical ventilation remains uncertain. Pressure levels above 0 cm H₂O can prevent postoperative pulmonary complications but may also cause intraoperative circulatory depression and lung injury due to overdistension. Using very low levels of PEEP may lead to atelectasis. However, high levels of PEEP can not only trigger complications such as intraoperative circulatory depression but also promote hyperinflation. Positive end-expiratory pressure (PEEP) is required to prevent atelectasis during lung-protective ventilation, and different levels of PEEP exhibit varying physiological and clinical effects when used alone or in combination with alveolar recruitment maneuvers (ARM). Alveolar recruitment maneuvers (ARM) are used to open atelectatic lung parenchyma, but the duration of their benefits has not been clearly determined. This study aims to determine the effectiveness of different PEEP levels after ARM in general anesthesia surgery, the duration of their time-dependent responses, and their hemodynamic effects, providing a reference for how often recruitment maneuvers should be performed during general anesthesia and further refining the specific details of lung-protective ventilation strategies.

Conditions

Dynamic Lung Compliance; Alveolar Recruitment Maneuver

Outcome Measures

Primary Outcomes (1)

• the duration of improvement in lung compliance

  during the surgery

Study Arms (4)

A: PEEP=0 cmH2O

PLACEBO COMPARATOR

Baseline respiratory mechanics parameters (driving pressure \[DP\], dynamic lung compliance \[Cdyn\]) and hemodynamic parameters (mean arterial pressure \[MAP\], SV, CO, CI) were recorded before ARM. Ten minutes after insufflation of the peritoneum with CO2 and positioning of the patient for surgery, an ARM was performed using the built-in protocol of the Mindray anesthesia machine, applying a continuous positive pressure of 30 cmH2O for 30 seconds. Immediately afterwards, the PEEP level was adjusted to 0 cmH2O. Respiratory and hemodynamic parameters were recorded at 5, 10, 15, 20, 25, 30, 35, and 40 minutes after ARM. The PEEP level was set back to 4 cmH2O forty minutes after ARM until the end of surgery.

Behavioral: lung recruitment maneuvre; PEEP

B: PEEP=4cmH2O

EXPERIMENTAL

Baseline respiratory mechanics parameters (driving pressure \[DP\], dynamic lung compliance \[Cdyn\]) and hemodynamic parameters (mean arterial pressure \[MAP\], SV, CO, CI) were recorded before ARM. Ten minutes after insufflation of the peritoneum with CO2 and positioning of the patient for surgery, an ARM was performed using the built-in protocol of the Mindray anesthesia machine, applying a continuous positive pressure of 30 cmH2O for 30 seconds. Immediately afterwards, the PEEP level was adjusted to 4 cmH2O. Respiratory and hemodynamic parameters were recorded at 5, 10, 15, 20, 25, 30, 35, and 40 minutes after ARM. The PEEP level was set back to 4 cmH2O forty minutes after ARM until the end of surgery.

Behavioral: lung recruitment maneuvre; PEEP

C: PEEP=8cmH2O

EXPERIMENTAL

Baseline respiratory mechanics parameters (driving pressure \[DP\], dynamic lung compliance \[Cdyn\]) and hemodynamic parameters (mean arterial pressure \[MAP\], SV, CO, CI) were recorded before ARM. Ten minutes after insufflation of the peritoneum with CO2 and positioning of the patient for surgery, an ARM was performed using the built-in protocol of the Mindray anesthesia machine, applying a continuous positive pressure of 30 cmH2O for 30 seconds. Immediately afterwards, the PEEP level was adjusted to 8 cmH2O. Respiratory and hemodynamic parameters were recorded at 5, 10, 15, 20, 25, 30, 35, and 40 minutes after ARM. The PEEP level was set back to 4 cmH2O forty minutes after ARM until the end of surgery.

Behavioral: lung recruitment maneuvre; PEEP

D: PEEP=12cmH2O

EXPERIMENTAL

Baseline respiratory mechanics parameters (driving pressure \[DP\], dynamic lung compliance \[Cdyn\]) and hemodynamic parameters (mean arterial pressure \[MAP\], SV, CO, CI) were recorded before ARM. Ten minutes after insufflation of the peritoneum with CO2 and positioning of the patient for surgery, an ARM was performed using the built-in protocol of the Mindray anesthesia machine, applying a continuous positive pressure of 30 cmH2O for 30 seconds. Immediately afterwards, the PEEP level was adjusted to 12 cmH2O. Respiratory and hemodynamic parameters were recorded at 5, 10, 15, 20, 25, 30, 35, and 40 minutes after ARM. The PEEP level was set back to 4 cmH2O forty minutes after ARM until the end of surgery.

Behavioral: lung recruitment maneuvre; PEEP

Interventions

lung recruitment maneuvre; PEEP BEHAVIORAL

After the patient enters the operating room, routine monitoring of ECG, non-invasive blood pressure, and SpO₂ is performed. Local anesthesia is used for radial artery puncture and catheterization to monitor invasive blood pressure. After 3 minutes of pre-oxygenation, tracheal intubation is performed with the following ventilation parameters: VT 6-8 ml/kg, FiO₂ 60%, RR 15 breaths/min, I/E 1:2, and PEEP 4 cmH₂O. Ten minutes after the establishment of pneumoperitoneum during surgery, baseline levels of respiratory mechanical parameters and hemodynamic variables are recorded. Subsequently, alveolar recruitment is performed at a pressure of 30 cmH₂O for 30 seconds. Immediately after recruitment, the PEEP level is adjusted according to the group. The changes in respiratory mechanics parameters and hemodynamic variables after recruitment are recorded. After the outcome indicators recover to the new baseline level, the PEEP is readjusted to 4 cmH₂O.

A: PEEP=0 cmH2O; B: PEEP=4cmH2O; C: PEEP=8cmH2O; D: PEEP=12cmH2O

Eligibility Criteria

• Age: 18 Years - 80 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• ASA physical status classification: Ⅰ or Ⅱ or Ⅲ
• Adults aged 18 to 80 years, regardless of gender.
• Patients undergoing elective laparoscopic colorectal cancer surgery under general anesthesia.
• Patients who have provided written informed consent after understanding the study purpose, procedures, and potential risks.

You may not qualify if:

• Recent thoracic surgery; radiographic evidence of pneumothorax, emphysema, or pulmonary bullae;
• Pulmonary diseases: asthma or severe obstructive ventilatory dysfunction; preoperative pulse oxygen saturation (SpO2) \< 90% on room air or \< 95% with supplemental oxygen; contraindications to ARMs (e.g., intracranial hypertension, hypovolemic shock, or right heart failure);
• severe cardiac disease (NYHA class III/IV, acute coronary syndrome, sustained ventricular tachycardia); concurrent participation in another trial; or refusal to provide informed consent

Sponsors & Collaborators

• Northern Jiangsu People's Hospital: lead

Study Sites (1)

Northern Jiangsu People's Hospital

Yangzhou, Jiangsu, China

Location

MeSH Terms

Interventions

Positive-Pressure Respiration

Intervention Hierarchy (Ancestors)

Respiration, Artificial; Airway Management; Therapeutics; Respiratory Therapy

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, INVESTIGATOR
• Purpose: OTHER
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Study Director

Study Record Dates

• First Submitted: August 30, 2025
• First Posted: September 8, 2025
• Study Start: August 30, 2025
• Primary Completion: November 30, 2025
• Study Completion: November 30, 2025
• Last Updated: March 24, 2026

Record last verified: 2025-08

Data Sharing

• IPD Sharing: Will not share

Locations

CN (1)