title: Tracheostomy is associated with decreased hospital mortality after moderate or severe isolated traumatic brain injury.
abstract: BACKGROUND
  Data regarding the impact and timing of tracheostomy in patients with isolated traumatic brain injury (TBI) are ambiguous. Our goal was to evaluate the impact of tracheostomy on hospital mortality in patients with moderate or severe isolated TBI.
  
  
  METHODS
  We performed a retrospective cohort analysis of data prospectively collected at 87 Austrian intensive care units (ICUs). All patients continuously admitted between 1998 and 2010 were evaluated for the study. In total, 4,735 patients were admitted to ICUs with isolated TBI. Of these patients, 2,156 had a moderate or severe TBI (1,603 patients were endotracheally intubated only, 553 patients underwent tracheostomy). Epidemiological data (trauma severity, treatment, and outcome) of the two groups were compared.
  
  
  RESULTS
  Patients with moderate or severe isolated TBI undergoing tracheostomy had a similar Glasgow Coma Scale score, median (interquartile range): 6 (3-8) vs 6 (3-8); p = 0.90, and Simplified Acute Physiology Score II, 45 (37-54) vs 45 (35-56); p = 0.86, compared with intubated patients not undergoing tracheostomy. Furthermore, patients undergoing tracheostomy exhibited higher Abbreviated Injury Scale Head scores and had a longer ICU stay for survivors, 30 (22-42) vs 9 (3-17) days; p < 0.0001). In contrast, risk-adjusted mortality was lower in patients undergoing tracheostomy compared with patients who remained intubated, observed-to-expected mortality ratio (95 % confidence interval): 0.62 (0.53-0.72) vs 1.00 (0.95-1.05) respectively.
  
  
  CONCLUSIONS
  Despite the greater severity of head injury, patients with isolated TBI who underwent tracheostomy had a lower risk-adjusted mortality than patients who remained intubated. Reasons for this difference in outcome may be multifactorial and require further investigation.
authors.affiliation: Department of Anesthesiology, General Intensive Care and Pain Management, Medical University of Vienna, Vienna, Austria.
authors.forename: David Marek
authors.initials: DM
authors.lastname: Baron
authors.affiliation: Department of Medical Statistics, Medical University of Vienna, Vienna, Austria.
authors.forename: Helene
authors.initials: H
authors.lastname: Hochrieser
authors.affiliation: Department of Anesthesiology and Intensive Care Medicine, Medical University of Graz, Graz, Austria. philipp@metnitz.biz.
authors.forename: Philipp G H
authors.initials: PG
authors.lastname: Metnitz
authors.affiliation: Department of Anesthesia and Critical Care Medicine, Trauma Hospital "Lorenz Boehler", Vienna, Austria.
authors.forename: Walter
authors.initials: W
authors.lastname: Mauritz
mesh_terms: D000328:Adult; D000368:Aged; D001317:Austria / Q000453:epidemiology; D000070642:Brain Injuries, Traumatic / Q000175:diagnosis / Q000401:mortality* / Q000601:surgery*; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D012131:Respiratory Insufficiency / Q000401:mortality / Q000517:prevention & control*; D012189:Retrospective Studies; D012307:Risk Factors; D015996:Survival Rate; D014139:Tracheostomy / Q000401:mortality* / Q000706:statistics & numerical data*; D015599:Trauma Severity Indices; D016896:Treatment Outcome
keywords: Hospital mortality; Isolated traumatic brain injury; Outcome; Tracheostomy