Dead Space in Mechanical Ventilation With Constant Expiratory Flow

NCT06024993 | Recruiting

• 1 other identifier: 003029
• Study Type: interventional
• Target: 13
• Locations: 1 country
• Sites: 1

Brief Summary

Conventional continuous mandatory mechanical ventilation relies on the passive recoil of the chest wall for expiration. This results in an exponentially decreasing expiratory flow. Flow controlled ventilation (FCV), a new ventilation mode with constant, continuous, controlled expiratory flow, has recently become clinically available and is increasingly being adopted for complex mechanical ventilation during surgery. In both clinical and pre-clinical settings, an improvement in ventilation (CO2 clearance) has been observed during FCV compared to conventional ventilation. Recently, Schranc et al. compared flow-controlled ventilation with pressure-regulated volume control in both double lung ventilation and one-lung ventilation in pigs. They report differences in dead space ventilation that may explain the improved CO2 clearance, although their study was not designed to compare dead space ventilation within the group of double lung ventilation. Dead space ventilation, or "wasted ventilation", is the ventilation of hypoperfused lung zones, and is clinically relevant, as it is a strong predictor of mortality in patients with the acute respiratory distress syndrome (ARDS) and is correlated with higher airway driving pressures which are thought to be injurious to the lung (lung stress). This trial aims to study the difference in dead space ventilation between conventional mechanical ventilation in volume-controlled mode and flow controlled-ventilation.

Conditions

Mechanical Ventilation; Artificial Respiration

Outcome Measures

Primary Outcomes (1)

• Change in Bohr dead space ventilation (VDBr/VT)

  Quantified by the Bohr approach with volumetric capnography

  During FCV and VCV measurements (20 minutes)

Secondary Outcomes (34)

• Change in Enghoff dead space ventilation (VDEng/VT)

  During FCV and VCV measurements (20 minutes)

• Change in physiological dead space volume (Vdfys)

  During FCV and VCV measurements (20 minutes)

• Change in airway dead space volume (Vdaw)

  During FCV and VCV measurements (20 minutes)

• Change in alveolar dead space volume (Vdalv)

  During FCV and VCV measurements (20 minutes)

• Ventilatory efficiency (VE/VCO2)

  During FCV and VCV measurements (20 minutes)

Study Arms (2)

FCV-VCV

EXPERIMENTAL

After titration of ventilation in baseline VCV (all arms), participants will first receive 20 min of baseline-matched FCV and subsequently 20 min of baseline-matched VCV.

Device: Flow-controlled ventilation (FCV); Device: Conventional volume-controlled ventilation (VCV)

VCV-FCV

EXPERIMENTAL

After titration of ventilation in baseline VCV (all arms), participants will first receive 20 min of baseline-matched VCV and subsequently 20 min of baseline-matched FCV.

Device: Flow-controlled ventilation (FCV); Device: Conventional volume-controlled ventilation (VCV)

Interventions

Flow-controlled ventilation (FCV) DEVICE

20 minutes of FCV, delivered with the CE-marked Evone ventilator (Ventinova medical, the Netherlands)

FCV-VCV; VCV-FCV

Conventional volume-controlled ventilation (VCV) DEVICE

20 minutes of conventional VCV, delivered with the CE-marked Aisys CS3 (GE Healthcare, USA) or Flow-i (Getinge, Sweden) ventilators.

FCV-VCV; VCV-FCV

Eligibility Criteria

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

You may qualify if:

• Adults \[18-70\] yrs
• General anaesthesia for elective surgery
• Arterial line, central venous line and endotracheal tube as part of standard of care
• Expected duration of controlled mechanical ventilation ≥ 60 minutes
• Supine position (0±10°)

You may not qualify if:

• One lung ventilation
• Known pregnancy
• Increased intra-abdominal pressure (pneumoperitoneum or obesity (BMI \> 30kg/m2))
• COPD GOLD IV or home oxygen dependence
• Cardiac pacemaker, implantable cardioverter-defibrillator (ICD) or thoracic neurostimulator
• Skin lesions (e.g. injury, inflammation) at the level where the Electrical Impedance Tomography (EIT) band is to be applied
• Clinical signs of raised intracranial pressure
• Potential interference with the surgery due to the setup of the study instruments.
• Patient refusal to participate

Sponsors & Collaborators

• University Hospital, Antwerp: lead
• Universiteit Antwerpen: collaborator

Study Sites (1)

Antwerp University Hospital (UZA)

Edegem, Antwerp, 2650, Belgium

RECRUITING

Study Officials

• Vera Saldien, M.D., Ph.D.

  Antwerp University Hospital / University of Antwerp

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Carine Smitz

CONTACT

+32 3 821 49 30; carine.smitz@uza.be

Joke De Wachter

CONTACT

+32 3 821 30 42; joke.dewachter@uza.be

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, OUTCOMES ASSESSOR
• Masking Details: During analysis the groups (flow-controlled ventilation and volume-controlled ventilation) will be blinded. Participants know that they will be exposed to both modes of ventilation, but are unaware of the randomized sequence (FCV-VCV or VCV-FCV). It is impossible to mask the investigators delivering the intervention.
• Purpose: BASIC SCIENCE
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: Crossover volume-controlled ventilation and flow-controlled ventilation

Study Record Dates

• First Submitted: April 3, 2023
• First Posted: September 6, 2023
• Study Start: July 22, 2024
• Primary Completion: December 30, 2025
• Study Completion: April 30, 2026
• Last Updated: January 22, 2025

Record last verified: 2025-01

Locations

BE (1)