Incidence and determinants of malpositioning tracheostomy tubes in critically ill adult patients.

Tracheostomy tubes are chosen primarily based on their internal diameter; however, the length of the tube may also be important. We performed a prospective clinical audit of 30 critically ill patients following tracheostomy to identify the type of tracheostomy tube inserted, the incidence of malpositioning and the factors associated with the need to change the tracheostomy tube subsequently. Anthropometric neck measurements, distance between the skin and tracheal rings and the position of the tracheostomy cuff relative to the tracheal stoma were recorded and analysed. Malpositioning of the tracheostomy tube was noted in 20%, with a high riding cuff being the most common cause of malpositioning, resulting in an audible leak and a need to change the tracheostomy tube subsequently. A high riding cuff was more common when a small tracheostomy tube (e.g. Portex (Smiths Medical Australasia, Macquarie Park, NSW) ≤8.0 mm internal diameter with length <7.5 cm) was used, with risk further increased when the patient's skin to trachea depth was greater than 0.8 cm. Identifying a high riding cuff relative to the tracheal stoma confirmed by a translaryngeal bronchoscopy strongly predicted the risk of air leak and the need to change the tracheostomy tube subsequently. Our study suggests that when a small (and short) tracheostomy tube is planned for use, intraoperative translaryngeal bronchoscopy is warranted to exclude malpositioning of the tracheostomy tube with a high riding cuff.