Tracheostomy Discontinuation: Impact of Tube Selection on Resistance during Tube Occlusion

Abstract

During tracheostomy discontinuance trials when tracheostomy tubes are occluded, it may be expected that the transition from tracheostomy to laryngeal ventilation will be accompanied by an increase in airways resistance (Raw) caused by the pres- ence of the tracheostomy tube in the trachea. Because successful decannulation may be affected by this added resistance, we studied the extent to which various tracheostomy tube configurations contribute to Raw. Raw was determined using model tracheas with three types of tracheostomy tubes in place and at varying gas flowrates. Raw was least for uncuffed fenestrated tubes (0.33 cm H2Os L-¹ [0.03 kPas L-¹] at 0.33 L/s) and greatest for cuffed fenestrated tubes with the cuff in- flated (1.61 cm H2Os L-¹ [0.16 kPas L-¹] at 0.33 L/s). With the cuff de- flated, Raw was less than 0.79 cm H2Os L-¹ [0.08 kPas L¹] at 0.33 L/s but still significantly greater (p < 0.05) than with the uncuffed tubes. These results sug- gest that when tracheostomy tubes are occluded during the process of trach- eostomy decannulation, the presence of a cuff, whether inflated or deflated, can in- crease the amount of ventilatory work required of the patient (ie, Raw is one of the variables affecting the work of breathing) and that uncuffed tubes should be ex- pected to increase the likelihood of success and improve patient comfort during the process of tracheostomy decannulation.