Tracheostomy decannulation failure rate following critical illness : a prospective descriptive study

Background : Tracheostomy is a well established and practical approach to airway management for patients requiring extended periods of mechanical ventilation or airway protection. Little evidence is available to guide the process of weaning and optimal timing of tracheostomy tube removal. Thus, decannulation decisions are based on clinical judgement. The aim of this study was to describe decannulation practice and failure rates in patients with tracheostomy following critical illness.Methods : A prospective descriptive study was conducted of consecutive patients who received a tracheostomy at a tertiary metropolitan public hospital intensive care unit (ICU) between March 2002 and December 2006. Data were analysed using descriptive and inferential tests.Results : Of the 823 decannulation decisions, there were 40 episodes of failed decannulation, a failure rate of 4.8%. These 40 episodes occurred in 35 patients: 31 patients failed once, 3 patients failed twice and 1 patient failed three times. There was no associated mortality. Simple stoma recannulation was required in 25 episodes, with none of these patients readmitted to ICU. Translaryngeal intubation and readmission to ICU took place for the remaining 15 episodes. The primary reason for decannulation failure was sputum retention. Twenty-four patients (60%) failed decannulation within 24 h, with 14 of these occurring within 4 h.Conclusions : Clinical assessments coupled with professional judgement to decide the optimal time to remove tracheostomy tubes in patients following critical illness resulted in a failure rate comparable with published data. Although reintubation and readmission to ICU was required in just over one third of failed decannulation episodes, there was no associated mortality or other significant adverse events. Our data suggest nurses need to exercise high levels of clinical vigilance during the first 24 h following decannulation, particularly the first 4 h to detect early signs of respiratory compromise to avoid adverse outcomes.