Effects of Changes in Driving Pressure on Intraoperative Pulmonary Dynamic Compliance and PaO₂/FiO₂ Ratio in Laparoscopic Sleeve Gastrectomy (PEEP)

Effects of Changes in Driving Pressure on Intraoperative Pulmonary Dynamic Compliance and PaO₂/FiO₂ Ratio in Patients Undergoing Laparoscopic Sleeve Gastrectomy

The goal of this prospective intervention study is to determine whether individualized positive end expiratory pressure (PEEP) titration targeting the minimum Driving pressure (ΔP) during LGS operation improves intraoperative pulmonary dynamic compliance (Cdyn), oxygenation, post operative pulmonary complication (PPCS) Participants will be assigned to two group (incremental - fixed )peep group Researchers will compare the two group to see if peep titration improve lung compliance, lung mechanics intraopertive and PPCS

Study Overview

• Status: Not yet recruiting
• Conditions: Dynamic Lung Compliance
• Intervention / Treatment: Other: incremental peep

Detailed Description

Obesity (BMI \ge 30 kg/m^2) significantly increases the risk of atelectasis and respiratory dysfunction under anesthesia. During Laparoscopic Sleeve Gastrectomy (LSG), the combination of pneumoperitoneum and the Trendelenburg position further impairs lung compliance. Standard lung-protective strategies often use a fixed PEEP, which may be insufficient for obese patients or cause hemodynamic instability if set too high.

Fixed PEEP (usually 5 cmH_2O) does not account for individual variations in chest wall mechanics during laparoscopy.

This prospective, randomized, double-blind study involving 46 patients (20-60 years old, BMI 35-40 kg/m^2).

The Intervention

• Control Group: Receives a fixed PEEP of 5 cmH_ throughout the procedure.
• Intervention Group: Receives individualized PEEP titration. After a recruitment maneuver, PEEP is adjusted (from 3 to 12 cmH_2O) to identify the level that achieves the minimum Driving Pressure . This optimal PEEP is then maintained for the surgery.

Key Outcomes

• Primary: Dynamic pulmonary compliance measured 10 minutes after pneumoperitoneum cessation (T3).
• Secondary: Oxygenation (PaO_2/FiO_2 ratio), driving pressure levels, postoperative pulmonary complications (PPCs) within 48 hours, and length of hospital stay.

• Study Type: Interventional
• Enrollment (Estimated): 46
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Eman G Radwan, master; Phone Number: +201278555771; Email: eman_gamal1@hotmail.com
• Study Contact Backup: Name: Samaa A Rashwan, Professor; Phone Number: +201270159125; Email: samaarashwan1971@gmail.com

Study Locations

• Egypt
  • Beni Suweif Governorate
    • Banī Suwayf, Beni Suweif Governorate, Egypt, 62511
      • Beni-suef university Hospital
      • Contact: Eman G Radwan, master; Phone Number: +201278555771; Email: eman_gamal1@hotmail.com
      • Contact: Samaa A Rashwan, Professor; Phone Number: +201270159125; Email: samaarashwan1971@gmail.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• BMI 35 -40kg·m-²
• ASA II-III
• Elective primary laparoscopic sleeve gastrectomy

Exclusion Criteria:

• Patient refusing consent
• ASA IV patients.
• Sever pulmonary disease
• Sever obstructive sleep apnea (OSA)
• Hepatic or cardic or renal imparment

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: incremental peep; after the pneumo- peritoneum- anti Trendelenburg position is established and RM is performed. PEEP will be gradually increased by 1 cmH2O starting from the lowest PEEP allowed by the anesthesia machine (3 cmH2O) to 12 cmH2O, and each PEEP level will be maintained for 10 respiratory cycles and the driving pressure values will be recorded. When driving pressure increased with increasing PEEP, downward PEEP titration will be per- formed until the minimum driving pressure appears. this optimal individualized PEEP will be maintained throughout the procedure.	Other: incremental peep; PEEP will be gradually increased by 1 cmH2O starting from the lowest PEEP allowed by the anesthesia machine (3 cmH2O) to 12 cmH2O, and each PEEP level will be maintained for 10 respiratory cycles and the driving pressure values will be recorded. When driving pressure increased with increasing PEEP, downward PEEP titration will be per- formed until the minimum driving pressure appears
No Intervention: fixed peep; Fixed PEEP = 5 cmH₂O through surgery

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
dynamic pulmonary compliance	Measurement of the lung's ability to stretch and expand during mechanical ventilation, calculated 10 minutes after the cessation of pneumoperitoneum. This measures the impact of individualized PEEP versus fixed PEEP on respiratory mechanics after the main surgical stressor is removed	Recorded at T3 (10 minutes after pneumoperitoneum cessation).

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Oxygenation Ratio (PaO_2/FiO_2)	Assessed via arterial blood gas analysis to evaluate gas exchange efficiency.	Recorded at T0(10 minutes after tracheal intubation), , T2(1 hour after pneumoperitoneum establishment), and T4 (15 minutes after extubation).
Driving Pressure	Calculated as Plateau pressure minus PEEP.	Recorded at T0 (10 minutes after intubation), T1 (10 minutes after pneumoperitoneum), T2 (1 hour after pneumoperitoneum), and T3 (10 minutes after pneumoperitoneum cessation).
Postoperative Pulmonary Complications (PPCs)	Incidence of hypoxia, bronchospasm, or chest infections (cough, fever, expectoration).	Within 48 hours postoperatively.

Collaborators and Investigators

• Sponsor: Beni-Suef University

Study record dates

Study Major Dates

• Study Start (Estimated): April 15, 2026
• Primary Completion (Estimated): September 15, 2027
• Study Completion (Estimated): October 15, 2027

Study Registration Dates

• First Submitted: March 15, 2026
• First Submitted That Met QC Criteria: March 20, 2026
• First Posted (Actual): March 27, 2026

Study Record Updates

• Last Update Posted (Actual): March 27, 2026
• Last Update Submitted That Met QC Criteria: March 20, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Other Study ID Numbers: FMBSUREC/06012026/Radwan

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No