Tracheostomy Tube Manometry Can Predict Capping Test Success in Subjects Undergoing Decannulation

Decannulation represents the final phase of temporary tracheostomy, started once clinical criteria for cannula removal are met. A key indicator of decannulation readiness is the patient's ability to tolerate breathing through a capped uncuffed cannula (capping test). Since tracheal pressure manometry can be of help during placement of speaking valves and plugs, it is likely that it can also discriminate between patients who tolerate or do not tolerate a capping test. This study explores how tracheal pressure measurement during tidal breathing through a plugged cannula can be predictive of a successful capping test.

We enrolled subjects with tracheostomy following acute respiratory failure, admitted to our Respiratory Rehabilitation Unit. After meeting decannulation criteria, each subject underwent a 48-h capping test. During this period, tracheal pressures were recorded via manometry throughout the respiratory cycle. The test was deemed successful if subjects did not develop dyspnea, tachypnea, oxygen desaturation, or hypercapnia.

Over an 18-month period (November 2022-April 2024), 68 tracheostomized patients were admitted, and 40 subjects met inclusion criteria. Of these, 31 successfully passed the capping test, while 9 failed. Mean tracheal pressure was significantly lower in the successful group (4 cm H₂O) compared with the failed group (24 cm H₂O), with statistical significance (P < .01). Finally, 36 subjects (90%) were decannulated, and 11 required cannula downsizing (27.5%). Receiver operating characteristic curve analysis revealed that a tracheal pressure below 10 cm H₂O predicted successful capping with 100% (IC: 0.88-1) specificity and 89% (IC: 0.52-1) sensitivity.

Tracheal pressure measurement during tidal breathing with a capped cannula was a reliable predictor of capping test success and may enhance clinical decision-making in the decannulation process.