Flow-Controlled Versus Volume-Controlled Ventilation During Balloon Dilatation Under Direct Laryngoscopy

NCT07430124 | Recruiting

• 1 other identifier: AEŞH-EK-2026-012
• Study Type: interventional
• Target: 40
• Locations: 1 country
• Sites: 1

Brief Summary

This prospective trial aims to compare the effects of flow-controlled ventilation (FCV) and volume-controlled ventilation (VCV) on airway pressures and oxygenation in adult patients undergoing balloon dilatation under direct laryngoscopy. Airway procedures performed under general anesthesia are associated with unique respiratory mechanics and limited ventilation conditions, making the choice of an optimal ventilation strategy particularly important. Adult patients aged 18-65 years with American Society of Anesthesiologists (ASA) physical status I-III will be allocated to receive either FCV or VCV during surgery. Ventilatory parameters, airway pressures, pulmonary compliance, and arterial blood gas values will be recorded at predefined intraoperative time points. The primary outcome is the PaO₂ measured 20 minutes under an FiO₂ of 0.8-1.0 after starting the ventilation under general anesthesia, reflecting early intraoperative oxygenation under stable conditions. By providing comparative data on respiratory mechanics and oxygenation, this study aims to contribute to the identification of lung-protective ventilation strategies in patients undergoing balloon dilatation under direct laryngoscopy.

Conditions

Airway Stenosis; Upper Airway Obstruction

Keywords

Direct Laryngoscopy; Flow-Controlled Ventilation; Volume-Controlled Ventilation

Outcome Measures

Primary Outcomes (1)

• The PaO₂ measured 20 minutes after intubation.

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

  20 minutes after intubation in the intraoperative period

Secondary Outcomes (3)

• The PaO₂ measured during perioperative period

  At the initiation of mechanical ventilation following intubation and at the first postoperative hour after extubation

• Peak airway pressure (Ppeak) values during perioperative period.

  At the initiation of mechanical ventilation following intubation and 20 minutes after intubation

• Plateau airway pressure (Pplateau) values during perioperative period

  At the initiation of mechanical ventilation following intubation and 20 minutes after intubation

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. 80-100% FiO₂ will be applied, and a driving pressure of 12 cmH₂O will be used. After the 20th minute, the patient's FiO₂ will be adjusted according to the clinical condition. 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 was 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. Patients will be started on ventilation after intubation with 80-100% FiO₂, 7 ml/ideal body weight tidal volume, PEEP 5, 12 breaths per minute frequency, and a 1:2 inspiration/expiration ratio. After the 20th minute, the patient's FiO₂ will be adjusted according to the clinical condition.

Procedure: VCV Group

Interventions

FCV Group PROCEDURE

Patients allocated to the FCV group will receive mechanical ventilation using a flow-controlled ventilation mode throughout the surgical procedure performed under general anesthesia. Ventilation will be managed according to routine clinical practice, with standardized anesthetic induction and monitoring. Ventilatory parameters, airway pressures, pulmonary compliance, and arterial blood gas values will be recorded at predefined intraoperative time points, including after starting the ventilation under general anesthesia and 20 minutes after intubation. This group aims to evaluate the effects of FCV on airway pressures and early intraoperative oxygenation during balloon dilatation performed under direct laryngoscopy.

FCV Group

VCV Group PROCEDURE

Patients allocated to the VCV group will receive mechanical ventilation using a conventional volume-controlled ventilation mode throughout the surgical procedure under general anesthesia. Anesthetic management and monitoring will follow standard clinical protocols identical to those applied in the FCV group. Ventilatory parameters, airway pressures, pulmonary compliance, and arterial blood gas measurements will be recorded at the same predefined intraoperative time points, including after starting the ventilation under general anesthesia and 20 minutes after intubation. This group serves as the comparator arm to assess the effects of volume-controlled ventilation on airway pressures and oxygenation during balloon dilatation under direct laryngoscopy.

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

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, 06000, Turkey (Türkiye)

RECRUITING

MeSH Terms

Conditions

Airway Obstruction

Condition Hierarchy (Ancestors)

Respiratory Insufficiency; Respiration Disorders; Respiratory Tract Diseases

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: February 18, 2026
• First Posted: February 24, 2026
• Study Start: February 24, 2026
• Primary Completion (Estimated): August 7, 2026
• Study Completion (Estimated): August 20, 2026
• Last Updated: February 25, 2026

Record last verified: 2026-02

Locations

TU (1)