Flow-Controlled Versus Volume-Controlled Ventilation in Lumbar Disc Herniation Surgery

NCT07614555 | Recruiting

• 1 other identifier: AEŞH-EK-2026-096
• Study Type: interventional
• Target: 80
• Locations: 1 country
• Sites: 1

Brief Summary

This prospective randomized trial aims to compare the effects of flow-controlled ventilation (FCV) and volume-controlled ventilation (VCV) on intraoperative airway pressures and oxygenation in patients undergoing lumbar disc herniation surgery under general anesthesia. Adult patients aged 18-65 years, with ASA physical status I-III and a body mass index of 18-30 kg/m², will be allocated to receive either FCV or VCV during routine intraoperative mechanical ventilation. Ventilatory parameters, including peak airway pressure, plateau pressure, pulmonary compliance, EtCO₂, SpO₂, and arterial blood gas variables, will be recorded at predefined time points after intubation. The primary endpoint is the PaO₂ value measured after 20 minutes in the prone position. By comparing respiratory mechanics and oxygenation between the two ventilation modes, this study aims to contribute to the optimization of intraoperative ventilatory management in lumbar disc herniation surgery.

Conditions

Lumbar Disc Herniation Surgery; Mechanical Ventilation

Keywords

Flow-Controlled Ventilation; Volume-Controlled Ventilation; Lumbar Disc Herniation Surgery

Outcome Measures

Primary Outcomes (1)

• The PaO₂ measured 20 minutes after prone position.

  The primary outcome measure will be the PaO₂ derived from arterial blood gas analysis at 20 minutes after the prone position.

  20 minutes after the prone position, in the intraoperative period.

Secondary Outcomes (3)

• The PaO₂ measured during perioperative period

  Day 1

• Peak airway pressure (Ppeak) values during perioperative period

  Day 1

• Plateau airway pressure (Pplateau) values during perioperative period

  Day 1

Study Arms (2)

FCV Group

ACTIVE COMPARATOR

Patients allocated to the FCV group will receive intraoperative mechanical ventilation using a flow-controlled ventilation mode during surgery under general anesthesia. %50 FiO₂ will be applied, and a driving pressure of 12 cmH₂O will be used. After intubation, the patient will be placed in the prone position. Following the prone position, the patient's FiO₂ will be maintained between 0.8 and 1.0 for 20 minutes. After the 20th minute, ventilator settings will be returned to the baseline values. Tidal volume will be generated and recorded by the ventilator according to the driving pressure and the patient's lung mechanics. Minute ventilation will be adjusted based on the target tidal volume. The target tidal volume will be set at 6-8 mL/kg (7 mL/kg) with a respiratory rate of 12 breaths/min. Positive end-expiratory pressure (PEEP) will be maintained at 5 cmH₂O. The respiratory rate will be further titrated to maintain ETCO₂ between 35 and 40 mmHg.

Procedure: FCV Group

VCV Group

ACTIVE COMPARATOR

Patients allocated to the VCV group will receive intraoperative mechanical ventilation using a conventional volume-controlled ventilation mode throughout surgery under general anesthesia. Anesthetic induction, monitoring, and perioperative management will follow the same standardized clinical protocols as those used in the FCV group. Ventilatory parameters, including peak and plateau airway pressures and arterial blood gas measurements, will be collected at identical predefined intraoperative time points. This group serves as the comparator arm for evaluating the effects of volume-controlled ventilation on airway pressures and oxygenation in these patients.

Procedure: VCV Group

Interventions

FCV Group PROCEDURE

Patients allocated to the FCV group will receive intraoperative mechanical ventilation using a flow-controlled ventilation mode during surgery under general anesthesia. Patients will be started on ventilation after intubation with 50% oxygen, driving pressure 12, PEEP 5, and a 1:1 inspiration/expiratory ratio.

FCV Group

VCV Group PROCEDURE

Patients allocated to the VCV group will receive intraoperative mechanical ventilation using a conventional volume-controlled ventilation mode throughout surgery under general anesthesia. Patients will be started on ventilation after intubation with 50% oxygen, 7 ml/ideal body weight tidal volume, PEEP 5, 12 breaths per minute frequency, and a 1:2 inspiration/expiration ratio.

VCV Group

Eligibility Criteria

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

You may qualify if:

• Age between 18 and 65 years
• ASA physical status I-III
• Body Mass Index between 18 and 30 kg/m²

You may not qualify if:

• Age \< 18 years or \> 65 years
• Known or previously diagnosed pulmonary disease
• Patients with severe preoperative pulmonary function impairment (e.g., FEV₁ \< 50% predicted, severe restrictive or obstructive pathology)
• Patients with markedly altered lung anatomy or function due to prior major thoracic surgery
• Patients who were dependent on supplemental oxygen therapy in the preoperative period
• ASA physical status IV or higher
• Refusal or inability to provide informed consent

Sponsors & Collaborators

• Ankara Etlik City Hospital: lead

Study Sites (1)

Ankara Etlik City Hospital

Ankara, 06170, Turkey (Türkiye)

RECRUITING

Central Study Contacts

Atakan Sezgi

CONTACT

00905323327000; kansezgi@gmail.com

Musa Zengin

CONTACT

00905307716235; musazengin@gmail.com

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: PARTICIPANT
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER GOV
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principal Investigator

Study Record Dates

• First Submitted: May 18, 2026
• First Posted: May 29, 2026
• Study Start: May 28, 2026
• Primary Completion (Estimated): November 12, 2026
• Study Completion (Estimated): November 26, 2026
• Last Updated: June 1, 2026

Record last verified: 2026-05

Locations

TU (1)