Dead Space in Mechanical Ventilation With Constant Expiratory Flow

Mechanical Ventilation Clinical Trial

— DeXFLoW  

Official title:

Dead Space in Mechanical Ventilation With Constant Expiratory Flow

Clinical Trial Details — Status: Not yet recruiting

Administrative data

• NCT number: NCT06024993
• Other study ID #: 003029
• Status: Not yet recruiting
• Phase: N/A
• Start date: June 1, 2024
• Est. completion date: December 31, 2024

Study information

• Verified date: April 2024
• Source: University Hospital, Antwerp
• Contact: Carine Smitz
• Phone: +32 3 821 49 30
• Email: carine.smitz[@]uza.be
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial 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.

Recruitment information / eligibility

• Status: Not yet recruiting
• Enrollment: 13
• Est. completion date: December 31, 2024
• Est. primary completion date: November 1, 2024
• Accepts healthy volunteers: No
• Gender: All
• Age group: 18 Years to 70 Years

Eligibility

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 abdominal pressure (laparoscopy or BMI > 30kg/m2)

• COPD GOLD IV or home oxygen dependence

• Clinical signs of raised intracranial pressure

Related Conditions & MeSH terms

• Artificial Respiration
• Mechanical Ventilation

Intervention

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

Locations

Country	Name	City	State
Belgium	Antwerp University Hospital (UZA)	Edegem	Antwerp

Sponsors (2)

Lead Sponsor	Collaborator
University Hospital, Antwerp	Universiteit Antwerpen

Country where clinical trial is conducted

Belgium, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Change in Bohr dead space ventilation (VDBr/VT)	Quantified by the Bohr approach with volumetric capnography	During FCV and VCV measurements (30 minutes)
Secondary	Change in Enghoff dead space ventilation (VDEng/VT)	Quantified by the Enghoff approach with volumetric capnography	During FCV and VCV measurements (30 minutes)
Secondary	Change in physiological dead space volume (Vdfys)	Measured with volumetric capnography and Enghoff's approach	During FCV and VCV measurements (30 minutes)
Secondary	Change in airway dead space volume (Vdaw)	Measured with volumetric capnography and Fletcher's approach	During FCV and VCV measurements (30 minutes)
Secondary	Change in alveolar dead space volume (Vdalv)	As measured with volumetric capnography and Fletcher's approach	During FCV and VCV measurements (30 minutes)
Secondary	Ventilatory efficiency (VE/VCO2)	Ratio of minute ventilation to carbon dioxide output	During FCV and VCV measurements (30 minutes)
Secondary	Change in airway driving pressure (?Paw)	Calculated as the difference between the plateau pressure (Pplat) during an inspiratory pause and the dynamic positive end-expiratory pressure (PEEP), as no expiratory hold is possible on the Evone.	During FCV and VCV measurements (30 minutes)
Secondary	Change in transpulmonary shunt fraction (Qs/Qt)	calculated with the modified Berggren equation	During FCV and VCV measurements (30 minutes)
Secondary	Change in global lung hyperdistention (hyperdistentionEIT)	Calculated from electric impedance tomography	During FCV and VCV measurements (30 minutes)
Secondary	Change in anterio-posterior distribution of ventilation on EIT (AP)	% anterior / % posterior	During FCV and VCV measurements (30 minutes)
Secondary	Change in right-left distribution of ventilation on EIT (RL)	% right / % left	During FCV and VCV measurements (30 minutes)
Secondary	Change in 4-layered distribution of ventilation on EIT		During FCV and VCV measurements (30 minutes)
Secondary	Change in centre of ventilation on EIT		During FCV and VCV measurements (30 minutes)
Secondary	Change in cardiac index (CI)	Calculated from the arterial waveform (pulse contour analysis) by the HemoSphere monitor	During FCV and VCV measurements (30 minutes)
Secondary	Change in mean arterial pressure (MAP)	Measured on a radial artery line	During FCV and VCV measurements (30 minutes)
Secondary	Change in partial pressure of arterial CO2 (PaCO2)	Measured on an arterial blood gas	During FCV and VCV measurements (30 minutes)
Secondary	Change in peak expiratory flow (PEF)	As measured by the citrex respiratory monitor	During FCV and VCV measurements (30 minutes)
Secondary	Change in peak inspiratory flow (PIF)	As measured by the citrex respiratory monitor	During FCV and VCV measurements (30 minutes)
Secondary	Change in mean airway pressure (MPaw)	As measured by the citrex respiratory monitor	During FCV and VCV measurements (30 minutes)
Secondary	Change in tidal volume (TV)	As measured by the citrex respiratory monitor	During FCV and VCV measurements (30 minutes)
Secondary	Change in respiratory rate (RR)	As measured by the citrex respiratory monitor	During FCV and VCV measurements (30 minutes)
Secondary	Change in minute ventilation (MV)	As measured by the citrex respiratory monitor	During FCV and VCV measurements (30 minutes)
Secondary	Change in inspiratory time (Ti)	As measured by the citrex respiratory monitor	During FCV and VCV measurements (30 minutes)
Secondary	Change in expiratory time (Te)	As measured by the citrex respiratory monitor	During FCV and VCV measurements (30 minutes)
Secondary	Change in ratio of inspiratory time to total breath time (Ti / Tt)	As measured by the citrex respiratory monitor	During FCV and VCV measurements (30 minutes)
Secondary	Change in positive end-expiratory pressure (PEEP)	As measured by the citrex respiratory monitor	During FCV and VCV measurements (30 minutes)
Secondary	Change in peak inspiratory pressure (PIP)	As measured by the citrex respiratory monitor	During FCV and VCV measurements (30 minutes)
Secondary	Change in plateau pressure (Pplat)	As measured by the citrex respiratory monitor	During FCV and VCV measurements (30 minutes)
Secondary	Change in static airway compliance (Caw)	Calculated as tidal volume / airway driving pressure	During FCV and VCV measurements (30 minutes)
Secondary	Change in end-tidal CO2 (ETCO2)	As measured by the citrex respiratory monitor	During FCV and VCV measurements (30 minutes)
Secondary	Change in global airway resistance (Raw)	As measured by the citrex respiratory monitor	During FCV and VCV measurements (30 minutes)
Secondary	Change in global airway time constant (TAUaw)	Calculated as global airway resistance x global airway compliance	During FCV and VCV measurements (30 minutes)
Secondary	Change in total energy	As calculated from monitoring data	During FCV and VCV measurements (30 minutes)
Secondary	Change in dissipated energy	As calculated from monitoring data	During FCV and VCV measurements (30 minutes)
Secondary	Change in P/F ratio	Calculated as partial pressure of arterial oxygen divided by inspiratory fraction of oxygen	During FCV and VCV measurements (30 minutes)