Tracheostomy decannulation: implication on respiratory mechanics.

Background: Tracheostomy decreases airway resistance and work of breathing. No comprehensive data are available on respiratory mechanics after tracheostomy decannulation. We evaluated respiratory mechanics after decannulation.

Methods: Twenty-five patients with tracheostomy were included. Measurement of arterial blood gases, air-flow, and esophageal pressure during spontaneous breathing were evaluated.

Results: Overall arterial blood gas parameters as well as flow and pressure measurements including work of breathing and airway resistance were not affected by the intervention. Inspiratory time fraction increased from 40.0 + or - 0.04 to 43% + or - 0.05% (p = .007). We observed marked individual differences. Postdecannulation change in work of breathing is best predicted by change in airway resistance (R = 0.869, R(2) = 0.755, p < .0001)

Conclusion: Inspiratory time increased after decannulation, and arterial blood gas levels and respiratory mechanics did not change for the whole cohort. Individual changes in work of breathing are considerable and correlate closely to changes in airway resistance.