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Recruiting NCT06024993

Dead Space in Mechanical Ventilation With Constant Expiratory Flow

No phase Interventional Mechanical Ventilation Artificial Respiration

For patients and families

In plain language

An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.

What is being studied
The protocol lists: Flow-controlled ventilation (FCV), Conventional volume-controlled ventilation (VCV).
Who it may be relevant to
Registry conditions: Mechanical Ventilation, Artificial Respiration. Basic parameters: 18 years — 70 years · All.
What needs checking
Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
Where it takes place
Belgium
Next step
Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →

Unsure about the terms? Read our patient guide →

Overview

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.

Interventions

  • Device Flow-controlled ventilation (FCV)
    20 minutes of FCV, delivered with the CE-marked Evone ventilator (Ventinova medical, the Netherlands)
  • Device Conventional volume-controlled ventilation (VCV)
    20 minutes of conventional VCV, delivered with the CE-marked Aisys CS3 (GE Healthcare, USA) or Flow-i (Getinge, Sweden) ventilators.

Primary outcome measures

  • Change in Bohr dead space ventilation (VDBr/VT) [Time frame: During FCV and VCV measurements (20 minutes)]
Secondary outcome measures (12)
  • Change in Enghoff dead space ventilation (VDEng/VT) [Time frame: During FCV and VCV measurements (20 minutes)]
  • Change in physiological dead space volume (Vdfys) [Time frame: During FCV and VCV measurements (20 minutes)]
  • Change in airway dead space volume (Vdaw) [Time frame: During FCV and VCV measurements (20 minutes)]
  • Change in alveolar dead space volume (Vdalv) [Time frame: During FCV and VCV measurements (20 minutes)]
  • Ventilatory efficiency (VE/VCO2) [Time frame: During FCV and VCV measurements (20 minutes)]
  • Change in airway driving pressure (∆Paw) [Time frame: During FCV and VCV measurements (20 minutes)]
  • Change in transpulmonary shunt fraction (Qs/Qt) [Time frame: During FCV and VCV measurements (20 minutes)]
  • Change in global lung hyperdistention (hyperdistentionEIT) [Time frame: During FCV and VCV measurements (20 minutes)]
  • Change in anterio-posterior distribution of ventilation on EIT (AP) [Time frame: During FCV and VCV measurements (20 minutes)]
  • Change in right-left distribution of ventilation on EIT (RL) [Time frame: During FCV and VCV measurements (20 minutes)]
  • Change in 4-layered distribution of ventilation on EIT [Time frame: During FCV and VCV measurements (20 minutes)]
  • Change in centre of ventilation on EIT [Time frame: During FCV and VCV measurements (20 minutes)]

Eligibility criteria

Inclusion criteria

  • 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°)

Exclusion criteria

  • 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

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation
Randomized
Model
Crossover
Masking
Double blind
Primary purpose
Basic science

Study locations

Belgium · 1 center
  • Antwerp University Hospital (UZA) — Edegem

Identifiers

NCT: NCT06024993 · 003029

Primary sources (government registries)

View this study on ClinicalTrials.gov ↗