Expiratory airflow obstruction due to tracheostomy tube: A spirometric study in 50 patients

Abstract

Objectives Tracheostomy is commonly used in intensive care units and in head and neck departments. Airway obstruction due to occluded cuffless tracheostomy tubes themselves remains unknown, although capping trials are commonly used before decannulation. The aim of this study was to evaluate the extent to which airway obstruction can be caused by occluded cuffless tubes in patients who underwent head and neck surgery. Design Prospective Research Outcome. Settings University teaching hospital. Participants Fifty patients requiring transient tracheostomy after head and neck surgery. Main outcome measures A flow‐volume loop (FVL) through the mouth using a portable spirometer, with the occluded fenestrated cuffless tube, was measured before and immediately after decannulation, by obstructing the orifice of tracheostomy tube. The measurement of FVL recorded the forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), peak expiratory flow (PEF), forced expiratory flow at 50% of FVC, peak inspiratory flow (PIF) and forced inspiratory flow at 50% of FVC. Results A statistically significant difference between all spirometric parameters was found. Mean PEF and PIF, respectively, increased from 2.8 to 4.5 L/s (P < .0001) and 2.3 to 2.7 L/s (P < .01) before and after decannulation, with a strong positive correlation (r = 0.7; P < .05). A mean expiratory (34%) and inspiratory (9%) airflow reduction was observed due to cannula. Conclusions Occluded cuffless tracheostomy tubes cause a dramatic airflow obstruction, mainly in the expiratory phase of FVL. This should be taken into account during capping trials.

Aerodynamic measures of patients with tracheostomy capping before and after decannulation

“…They used a portable spirometer to measure vital capacity, forced expiratory volume, and peak flow rate in two settings before and immediately after decannulation through mouth breathing. They found a significant increase of studied respirometer parameters after decannulation and concluded that capped tracheostomy causes a remarkable airflow obstruction, mostly in the expiratory phase [16].…”

Tracheal airway pressure in tracheostomy tube capping trials: an experimental study

“…In a clinical spirometry investigation, a dramatic airflow obstruction was found, mainly in expiration, due to occluded TTs during capping trials [ 6 ]. There are no standardized recommendations for decannulation and capping.…”

“…A systematic review has shown the use of capping for assessing readiness for decannulation in 63.7% of the patients [ 5 ]. However, capped TTs create an impairment of airflow [ 6 ]. Therefore, test decannulation using a SB may be performed [ 7 ].…”

Pediatric tracheostomy tube decannulation with or without polysomnography: A PRO‐CON debate

“…In young children, the smallest tracheostomy tube may completely fill the trachea and capping trials are generally recommended for children 2 years or older 25 . The tracheostomy tube occupies a significant percentage of the airway and thereby decreases the cross‐sectional area of the trachea, limits airflow, 26 and increases airway resistance. The occluded tracheostomy can then lead to increased respiratory effort 27 favoring collapse of the oropharyngeal tissues.…”