Comparison of Standard Versus Dynamic Compliance-Guided Individualized PEEP in Obese Patients Undergoing Spinal Surgery

NCT07388719 | Completed

• 1 other identifier: NEU-2024-5206
• Study Type: interventional
• Target: 80
• Locations: 1 country
• Sites: 1

Brief Summary

This study aims to compare standard positive end-expiratory pressure (PEEP) with dynamic compliance-guided individualized PEEP in obese patients undergoing elective spinal surgery under general anesthesia. Obesity and prone positioning during spinal surgery are associated with reduced lung compliance, atelectasis, and an increased risk of postoperative pulmonary complications. Participants will be allocated to receive either a fixed standard PEEP or an individualized PEEP level determined according to intraoperative dynamic lung compliance. Intraoperative oxygenation, respiratory mechanics, arterial blood gas parameters, and hemodynamic variables will be assessed at predefined time points. Postoperative pulmonary complications within the first 24 hours after surgery will also be evaluated. The study seeks to determine whether individualized PEEP titration based on dynamic compliance offers physiological or clinical advantages compared with a standard PEEP strategy in this patient population.

Conditions

Obesity; Postoperative Pulmonary Complications; Mechanical Ventilation

Outcome Measures

Primary Outcomes (1)

• Intraoperative Oxygenation (PaO₂/FiO₂ Ratio)

  The primary outcome is intraoperative oxygenation assessed by the arterial partial pressure of oxygen to fraction of inspired oxygen (PaO₂/FiO₂) ratio during mechanical ventilation.

  From induction of anesthesia until the end of surgery

Secondary Outcomes (4)

• Dynamic Lung Compliance

  From induction of anesthesia until the end of surgery

• Static Lung Compliance

  From induction of anesthesia until the end of surgery

• Peak Airway Pressure

  From induction of anesthesia until the end of surgery

• Plateau Airway Pressure

  From induction of anesthesia until the end of surgery

Study Arms (2)

Standard PEEP

ACTIVE COMPARATOR

Patients assigned to this arm receive a fixed positive end-expiratory pressure (PEEP) of 5 cmH₂O throughout the intraoperative period during mechanical ventilation.

Device: Standard PEEP

Dynamic Compliance-Guided Individualized PEEP

EXPERIMENTAL

Patients assigned to this arm receive individualized positive end-expiratory pressure (PEEP) titrated according to intraoperative dynamic lung compliance, with the aim of optimizing respiratory mechanics while avoiding overdistension.

Device: Standard PEEP

Interventions

Standard PEEP DEVICE

Application of a fixed positive end-expiratory pressure of 5 cmH₂O during intraoperative mechanical ventilation.

Dynamic Compliance-Guided Individualized PEEP; Standard PEEP

Eligibility Criteria

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

You may qualify if:

• Adult patients aged 18-65 years
• Body mass index (BMI) ≥30 kg/m²
• Scheduled for elective spinal surgery under general anesthesia
• Requirement for intraoperative mechanical ventilation
• American Society of Anesthesiologists (ASA) physical status II-III
• Provision of written informed consent

You may not qualify if:

• Pre-existing severe pulmonary disease (e.g., COPD GOLD stage III-IV, restrictive lung disease)
• Severe cardiac disease (e.g., heart failure with reduced ejection fraction, significant valvular disease)
• History of thoracic surgery affecting lung mechanics
• Pregnancy
• Emergency surgery
• Intraoperative need for deviation from the planned ventilation protocol

Sponsors & Collaborators

• Konya City Hospital: lead

Study Sites (1)

Konya City Hospital

Konya, 42090, Turkey (Türkiye)

Location

MeSH Terms

Conditions

Obesity

Condition Hierarchy (Ancestors)

Overweight; Overnutrition; Nutrition Disorders; Nutritional and Metabolic Diseases; Body Weight; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Associate Professor, Department of Anesthesiology and Reanimation

Model Details: Participants are assigned to one of two parallel groups receiving either standard fixed PEEP or dynamic compliance-guided individualized PEEP during surgery.

Study Record Dates

• First Submitted: January 28, 2026
• First Posted: February 5, 2026
• Study Start: February 2, 2025
• Primary Completion: December 12, 2025
• Study Completion: December 12, 2025
• Last Updated: February 5, 2026

Record last verified: 2026-02

Data Sharing

• IPD Sharing: Will not share

Locations

TU (1)