Impact of Tracheostomy Modalities on Ventilatory Mechanics: a bench study

Tracheotomy poses management challenges due to patient frailty and complex interface modalities. The existing evidence on ventilatory decannulation criteria for tracheotomized patients is sparse. This study examined how tracheostomy modalities affect work of breathing (WOB), intrinsic positive expiratory pressure (PePi) and tidal volume (Vt). The following conditions were assessed: 1.cuff deflated with cap, 2.cuff deflated with speaking valve, 3.cuff inflated with artificial nose, 4.cuff deflated with artificial nose, 5.cuff deflated with high flow therapy (HFT), and 6.cuff inflated with HFT. We used a 7mm flexible tracheostomy cannula inserted into a model of simulated upper airways based on CT scans, connected to a mechanical lung. We used 3 lung models: normal, obstructive and restrictive; measurements were carried out and averaged over 150 respiratory cycles for each condition. There were no significant statistical differences in terms of WOB across the conditions tested and the type of pulmonary model did not alter the outcomes. However, HFT with the cuff inflated increased PePi in normal/obstructive models compared to the deflated cuff with cap (+1 cmH2O 95%CI[0.93 to 1.06] and +1 cmH2O 95%CI[1to1.1]). The inflation of the cuff resulted in a reduction in tidal volume (Vt) ranging from -35 mL (95%CI[−36to-35]), to -57 mL(95%CI[−60to-54]) according to the models. The WOB was not significantly affected accross the conditions tested. <fig><object-id>erj;64/suppl_68/PA2622/F1</object-id><object-id>F1</object-id><object-id>F1</object-id><graphic></graphic></fig>