Pressure-controlled ventilation via a minitracheostomy tube: experimental study using a mechanical lung model

Area of Science:

• Mechanical Ventilation
• Respiratory Physiology

Background:

• Minitracheostomy tubes (MTTs) are used for airway management.
• Pressure-controlled ventilation (PCV) is a common ventilation mode.

Purpose of the Study:

• To evaluate the efficacy of PCV delivered through MTTs.
• To assess the impact of MTT diameter and lung compliance on ventilation.

Main Methods:

• Experimental study using a mechanical lung model.
• Tested MTTs with internal diameters of 4.0, 4.5, and 5.0 mm.
• Measured ventilated volumes and alveolar pressures at varying lung compliances (10-50 ml/cmH2O).

Main Results:

• Ventilated volumes and alveolar pressures were reduced with smaller MTTs compared to an 8.0-mm endotracheal tube.
• Air leakage further decreased ventilation by approximately 20%.
• Lower lung compliance (10 ml/cmH2O) resulted in a 60% reduction in ventilated volumes compared to normal compliance (50 ml/cmH2O).
• Higher inspiratory pressures were required to achieve target volumes with smaller MTTs.

Conclusions:

• PCV via MTT can achieve acceptable ventilation in models with air leakage.
• Low lung compliance poses a significant challenge, necessitating higher inspiratory pressures for effective ventilation with MTTs.