Dynamic Compliance-Guided Ventilation in Lumbar Surgery

NCT07349719 | Recruiting

• 1 other identifier: 1-25-1645
• Study Type: interventional
• Target: 71
• Locations: 1 country
• Sites: 1

Brief Summary

Postoperative pulmonary complications are a frequent cause of morbidity following lumbar stabilization surgery. Conventional ventilation strategies may not adequately reflect intraoperative changes in respiratory mechanics, potentially leading to impaired postoperative pulmonary function. Dynamic compliance-guided ventilation provides a real-time, individualized approach by adjusting ventilatory parameters according to lung compliance. This prospective randomized controlled study aims to evaluate the effects of dynamic compliance-guided ventilation compared with standard ventilation strategies on postoperative pulmonary function in patients undergoing lumbar stabilization surgery. Eligible patients will be randomly assigned to either the compliance-guided group or the conventional ventilation group. In this study, the investigators aim to prospectively compare ventilation with the dynamic compliance (Cdyn) approach-one of the lung-protective ventilation strategies-with conventional ventilation methods in patients undergoing surgery in the prone position. The primary outcome will be evaluated using a modified lung ultrasound scoring system based on the most severely affected regions of aeration loss. Secondary objectives include the assessment of intraoperative hemodynamics, respiratory mechanics, and the effects on postoperative pulmonary function.

Conditions

Lumbar Spine Stenosis; Lumbar Disc Herniation; Ventilator-Induced Lung Injury; Postoperative Complications

Outcome Measures

Primary Outcomes (1)

• Modified Lung Ultrasound Score

  The assessment will be performed using the Modified Lung Ultrasound Scoring system. The scale ranges from a minimum of 0 to a maximum of 36 points. A score of 0 indicates normal aeration in all zones, while a score of 36 represents the worst possible aeration loss. Higher scores indicate a worse outcome (increased lung aeration loss/atelectasis).

  baseline, postoperative 1th hour, postoperative 24th hour

Secondary Outcomes (10)

• Incidence postoperative pulmonary complications(PPC)

  postoperative first 7 days

• Intraoperative Dynamic Compliance (Cdyn)

  intraoperative

• Intraoperative Plateau Pressure (Pplat)

  intraoperative

• Intraoperative Driving Pressure (ΔP)

  intraoperative

• Intraoperative Peak Pressure (Ppeak)

  intraoperative

Study Arms (2)

Dynamic Compliance Guided Ventilation

ACTIVE COMPARATOR

Patients receive intraoperative ventilation adjusted according to real time dynamic compliance monitoring

Procedure: Dynamic Compliance Guided Ventilation

Standart Ventilation

ACTIVE COMPARATOR

Patients receive intraoperative ventilation based on conventional standart settings without dynamic compliance adjustment

Procedure: Standard Ventilation

Interventions

Standard Ventilation PROCEDURE

After intubation, both groups will initially receive conventional ventilation in volume-controlled mode with a tidal volume of 7 ml/kg (predicted body weight), positive end expiratory pressure(PEEP) of 5 cmH₂O, and an inspiratory-to-expiratory ratio of 1:2. Respiratory rate will be adjusted to maintain end-tidal CO₂ between 35-45 mmHg. Following prone positioning, a recruitment maneuver will be performed using pressure-controlled ventilation, gradually increasing positive end expiratory pressure(PEEP) from 5 to 20 cmH₂O and holding for 20 seconds. After recruitment, the standard ventilation group will continue with the initial ventilator settings until the end of the surgery. Patients will be ventilated in volume-controlled ventilation (VCV) mode.

Standart Ventilation

Dynamic Compliance Guided Ventilation PROCEDURE

After intubation and prone positioning, both groups will undergo the same initial recruitment maneuver as described above. In the dynamic compliance-guided group, positive end expiratory pressure(PEEP) will then be titrated according to dynamic compliance (Cdyn = VT / \[Ppeak - PEEP\])(Ppeak: Peak airway pressure)(VT:Tidal volume). Tidal volume will be set at 7 ml/kg, respiratory rate 12/min, and positive end expiratory pressure(PEEP) reduced stepwise from 20 cmH₂O to 5 cmH₂O in increments of 2 cmH₂O. Each positive end expiratory pressure(PEEP) level (19, 17, 15, 13, 11, 9, 7, 5 cmH₂O) will be maintained for 10 respiratory cycles, with Cdyn measured at the end of each level. The positive end expiratory pressure(PEEP) corresponding to the highest dynamic compliance will be selected and maintained throughout the surgery.In both groups, a 30% t-pause will be applied throughout the operation after intubation. Patients will be ventilated in volume-controlled ventilation (VCV) mode.

Dynamic Compliance Guided Ventilation

Eligibility Criteria

• Age: 18 Years - 70 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Patients who will undergo lumbar stabilization in the prone position

You may not qualify if:

• Patients with ASA classification IV or higher
• Patients with obesity (BMI\>30) or cachexia (BMI\<18)
• Allergy to standard medications used during general anesthesia
• Contraindications to PEEP (high intracranial pressure, bronchopleural fistula, hypovolemic shock, right heart failure)
• Previous lung surgery (any)
• Known serious heart disease defined as New York Heart Association class III or higher
• Patients with severe asthma and COPD
• Acute myocardial infarction within the last 12 months before surgery
• Neuromuscular disease

Sponsors & Collaborators

• Ankara City Hospital Bilkent: lead

Study Sites (1)

Ankara Bilkent City Hospital

Ankara, 06800, Turkey (Türkiye)

RECRUITING

Related Publications (4)

• Bao C, Cao H, Shen Z, Hu Y, Huang J, Shu Q, Chen Q. Comparison of volume-controlled ventilation, pressure-controlled ventilation and pressure-controlled ventilation-volume guaranteed in infants and young children in the prone position: A prospective randomized study. J Clin Anesth. 2024 Aug;95:111440. doi: 10.1016/j.jclinane.2024.111440. Epub 2024 Mar 8.

  PMID: 38460413 BACKGROUND

• Chun EH, Baik HJ, Moon HS, Jeong K. Comparison of low and high positive end-expiratory pressure during low tidal volume ventilation in robotic gynaecological surgical patients using electrical impedance tomography: A randomised controlled trial. Eur J Anaesthesiol. 2019 Sep;36(9):641-648. doi: 10.1097/EJA.0000000000001047.

  PMID: 31306184 BACKGROUND

• Ruszkai Z, Kiss E, Laszlo I, Bokretas GP, Vizseralek D, Vamossy I, Surany E, Buzogany I, Bajory Z, Molnar Z. Effects of intraoperative positive end-expiratory pressure optimization on respiratory mechanics and the inflammatory response: a randomized controlled trial. J Clin Monit Comput. 2021 May;35(3):469-482. doi: 10.1007/s10877-020-00519-6. Epub 2020 May 9.

  PMID: 32388650 BACKGROUND

• Kim YJ, Kim BR, Kim HW, Jung JY, Cho HY, Seo JH, Kim WH, Kim HS, Hwangbo S, Yoon HK. Effect of driving pressure-guided positive end-expiratory pressure on postoperative pulmonary complications in patients undergoing laparoscopic or robotic surgery: a randomised controlled trial. Br J Anaesth. 2023 Nov;131(5):955-965. doi: 10.1016/j.bja.2023.08.007. Epub 2023 Sep 9.

  PMID: 37679285 BACKGROUND

MeSH Terms

Conditions

Intervertebral Disc Displacement; Ventilator-Induced Lung Injury; Postoperative Complications

Condition Hierarchy (Ancestors)

Spinal Diseases; Bone Diseases; Musculoskeletal Diseases; Hernia; Pathological Conditions, Anatomical; Pathological Conditions, Signs and Symptoms; Lung Injury; Lung Diseases; Respiratory Tract Diseases; Pathologic Processes

Central Study Contacts

Burak Nalbant

CONTACT

+905300148686; buraknalbant@gmail.com

Study Design

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

Study Record Dates

• First Submitted: December 29, 2025
• First Posted: January 20, 2026
• Study Start: January 22, 2026
• Primary Completion (Estimated): May 20, 2026
• Study Completion (Estimated): June 1, 2026
• Last Updated: January 27, 2026

Record last verified: 2026-01

Data Sharing

• IPD Sharing: Will not share

Locations

TU (1)