Failed extubation in a tertiary-level hospital intensive care unit, Pretoria, South Africa

Background A prospective cohort study sought to measure the incidence and outcomes of failed extubation in Dr George Mukhari Academic Hospital intensive care unit (ICU), as well as to identify possible factors associated with failed extubation. Methods Data were collected over a 6-month period from 1 July 2015 to 31 December 2015. Pre-intubation parameters recorded on the data collection sheet included secretions, Glasgow Coma Scale (GCS), fluid balance, Tobin index, partial pressure of carbon dioxide (pCO2 ), partial pressure of oxygen (PaO2 ), comorbidities and weaning method. Results A total of 242 patients were enrolled over the 6-month study period. Of the 242 patients, 86 were excluded owing to pre-set exclusion criteria (death before extubation; tracheostomy before extubation; re-intubation >72 hours post extubation). An extubation failure rate of 16.7% (n=26) was observed. The incidence of ventilator-associated pneumonia in the failed extubation group was 19.23%, whereas death was recorded in 42.31% of patients who failed extubation. The average length of ICU stay in the reintubated group was 11.58 days, and 4.04 days for successfully extubated patients. Only low GCS had a statistically significant impact on failed extubation: p=0.0025; odds ratio (OR) for low v. normal 5.13 (95% confidence interval (CI) 1.78 - 14.79). Other predictor variables measured did not reach statistical significance. Weaning method: p=0.3737, OR for No T-piece v. T-piece 1.65 (95% CI 0.547 - 4.976); comorbidities: p=0.5914, OR for two or more comorbidities v. no comorbidities 2.079 (95% CI 0.246 - 17.539), no comorbidities v. single comorbidity 0.802 (95% CI 0.211 - 3.043); fluid balance: p=0.6625, OR for negative v. positive fluid balance 0.571 (95% CI 0.170 - 1.916), OR for neutral v. positive fluid balance <0.001 (95% CI <0.001 - >999.999); pCO2 : p=0.7510, OR for high v. normal pCO2 1.344 (95% CI 0.346 - 5.213), OR for low v. normal pCO2 1.515 (95% CI 0.501 - 4.576); PaO2 : p=0.4405, OR for high v. normal 1.156 (95% CI 0.382 - 3.494); OR for low v. normal PaO2 2.638 (95% CI 0.553 - 12.587); Tobin index (Fischer’s exact test): p=0.7476. Conclusion Low pre-extubation GCS is a predictor of failed extubation. Contributions of the study The study is a prospective observational study conducted in a high-volume referral hospital. It adds valuable scientific information to a growing body of data on the topic of extubation failure. It further reinforces the importance of extubation failure and the requirement for due diligence to be paid before a patient is extubated.