The role of polysomnography in tracheostomy decannulation of the paediatric patient.

INTRODUCTION: Tracheostomy decannulation in the paediatric patient is usually considered when there is resolution or significant improvement in the original indication for the tracheostomy. The child's cardiorespiratory function needs to be optimized and assessment of the readiness for decannulation is generally by endoscopic evaluation to confirm airway patency and vocal cord mobility. Functional airway assessment procedures include downsizing the tracheostomy, adding fenestration, speaking valves and capping the tracheostomy tube. Few objective measures have been demonstrated to accurately predict the likelihood of successful decannulation. This study aims to evaluate the usefulness of polysomnography (PSG) with a capped tracheostomy tube, as an adjunct to airway endoscopy and traditional decannulation procedures, to predict decannulation outcome.

METHODS: A retrospective review was conducted for patients who underwent "capped" PSG prior to a trial of tracheostomy decannulation at the Sydney Children's Hospitals Network. The charts were reviewed for clinical data and PSG results.

RESULTS: 30 children with a total of 40 PSG reports were included in this study. There was a statistically significant difference in mean oxygen saturation, minimum oxygen saturation, total apnoea/hypopnoea index, desaturations >3%, and desaturations >3% index between those that had successful decannulation compared to failed decannulation. The measures with the greatest significance, and therefore, the best predictors of decannulation outcome were total apnoea/hypopnoea index (3.35events/h vs. 18.5events/h, p=0.004) and desaturation events (20.33 events vs. 192 events, p=0.001).

CONCLUSIONS: PSG with a capped tracheostomy tube is a useful, objective tool to complement endoscopy and functional airway assessment in the consideration of decannulation in the paediatric population.