NCT05642832

Feasibility of Reducing Respiratory Drive Using the Through-flow System

Feasibility of Reducing Respiratory Drive in Patients with Acute Hypoxemic Respiratory Failure Using the Through-flow System

• Status: Recruiting
• Phase: N/A
• Study type: Interventional
• Enrollment: 15 (estimated)
• Sponsor: University Health Network, Toronto · Academic / Other
• Sex: All
• Age: 18 Years
• Healthy volunteers: Not accepted

Summary

Mechanical ventilation can lead to diaphragm and lung injury. During mechanical ventilation, the diaphragm could be completely rested or it could be overworked, either of which may cause diaphragm injury. Mechanical stress and strain applied by mechanical ventilation or by the patient's own respiratory muscles can also cause injury to the lungs. Diaphragm and lung injury are associated with increased morbidity and mortality. Throughflow is a novel system that can reduce dead space without the need to increase the tidal ventilation, reducing the ventilatory demands and respiratory drive.

Detailed description

Patients with acute respiratory failure often develop significant diaphragm weakness during mechanical ventilation. Diaphragm weakness is associated with prolonged duration of mechanical ventilation and higher risk of death. Clinical data and experimental evidence indicate that the ventilator injures the diaphragm via two opposing mechanisms, disuse and excessive loading. Cessation of diaphragm activity leads to rapid disuse atrophy within hours. On the other hand, high inspiratory loads result in myofibril edema, inflammation and contractile dysfunction. In light of this, studies found that patients with an intermediate level of inspiratory effort, similar to that of healthy subjects breathing at rest, exhibited the shortest duration of ventilation. Arterial CO2 (PaCO2) tension and physiological dead space play an important role in determining the ventilatory requirements and respiratory drive in patients with AHRF. Throughflow (Neurovent) is a novel system that reduces anatomical dead space by providing a constant flow of fresh gas (i.e., gas that is free of CO2) during inspiration in patients receiving invasive mechanical ventilation. By clearing the CO2 that normally remains in the upper airway after exhalation (anatomical dead space), TF can dramatically reduce anatomical dead space without the need to increase the delivered VT. Reducing dead space offers a theoretical benefit in mitigating the mechanisms of lung and diaphragm injury during spontaneous breathing by reducing the ventilation demands to the lungs. Animal studies using the TF have shown extremely promising results, however, the impact of reducing anatomical dead space using the TF on gas exchange, ventilation, and respiratory drive in critically ill patients with AHRF is unknown.

Conditions

• Respiratory Insufficiency
• Diaphragm Injury
• Lung Injury

Interventions

Type	Name	Description
DEVICE	Throughflow titration phase	Ventilation will be applied in the TF mode with TF set to 0 LPM for 10 minutes. Patients will receive assist through the NAVA line of the tri-piece (NAVA set to similar settings as Servo period, \~60-80 LPM flow). Ventilation with Throughflow will be started at a TF flow of 5 LPM, and the NAVA flow will be reduced by 5 LPM. After 10 minutes measurements will be collected. If Edi is greater than or equal to 4 µV, TF flow will be increased to 10 LPM and NAVA flow will be adjusted to keep total flow constant. Measurements will be collected again after 10 minutes. TF flow will be increased in steps of 5 LPM and measurements collected every 10 minutes until Edi is below 3 µV or TF flow reaches the total flow observed during the NAVA period. After either the Edi target has been met or TF flow has reached the total flow, ventilation with TF will be reduced in steps of 5 LPM every 10 minutes (the reverse of the above), while NAVA flow is accordingly adjusted to keep total flow constant.

Timeline

• Start date: 2024-01-01
• Primary completion: 2025-06-30
• Completion: 2025-08-31
• First posted: 2022-12-08
• Last updated: 2024-12-11

Locations

1 site across 1 country: Canada