Dynamic Hyperinflation: Comparison of Jet Ventilation versus Conventional Ventilation in Patients with Severe End-Stage Obstructive Lung Disease

Positive pressure ventilation in patients with obstructive lung disease may result in over-inflation of the relatively compliant lungs, resulting in dynamic hyperinflation (DHI). Using a crossover trial design, we compared high-frequency jet ventilation (HFJV) versus “optimal” intermittent positive pressure ventilation (IPPV) in ten patients undergoing lung transplantation for severe, end-stage obstructive lung disease. We measured haemodynamics and the degree of DHI after both modes of ventilation. There were no significant differences between IPPV and HFJV, with respect to efficiency of ventilation (PaCO₂), haemodynamic effects (stroke volume, blood pressure and cardiac output), or lung hyperinflation (trapped gas volume). This study suggests that HFJV, when compared with optimal IPPV, is no better at minimizing DHI in patients with severe, end-stage obstructive lung disease.