title: Diagnostic accuracy of the rapid shallow breathing index to predict a successful spontaneous breathing trial outcome in mechanically ventilated patients with chronic obstructive pulmonary disease.
abstract: OBJECTIVE
  To evaluate the diagnostic accuracy of 2 threshold values (105 breaths per minute [bpm]/L and 130 bpm/L) of the rapid shallow breathing index (RSBI) to predict a successful weaning trial outcome in a homogenous group of patients with chronic obstructive pulmonary disease (COPD).
  
  
  METHODS
  A consecutive population of patients with COPD who were intubated for hypercapnic respiratory failure during a 2-year period were studied prospectively. RSBI was measured by 2 investigators at minute 5 of the T-piece trial, whereas 2 other physicians evaluated the 30 minute T-piece trial as successful or unsuccessful, according to clinical criteria.
  
  
  RESULTS
  Of 64 patients with COPD (53 male, 11 female) who constituted the study population, 42 patients (35 male, 7 female; aged 70 ± 9.2 years) completed the spontaneous breathing trial (SBT) and remained clinically stable (group 1). The remaining 22 patients (18 male, 4 female; aged 71.9 ± 4.7 years) had to return to ventilatory support by the end of the SBT because of clinical deterioration (group 2). The 2 threshold values that were evaluated had low specificity (38.1% for < 105 bpm/L and 66.7% for < 130 bpm/L), low sensitivity (63.6% for < 105 bpm/L and 54.5% for < 130 bpm/L), and low diagnostic accuracy (46.8% for < 105 bpm/L and 65.6% for < 130 bpm/L) in predicting a successful T-piece trial outcome.
  
  
  CONCLUSIONS
  RSBI measured early during an SBT cannot accurately predict the successful outcome of a T-piece trial in a homogenous population of patients with COPD.
authors.affiliation: Respiratory Failure Unit, G Papanikolaou Hospital, Aristotle University of Thessaloniki, Greece. afboutou@yahoo.com
authors.forename: Afroditi K
authors.initials: AK
authors.lastname: Boutou
authors.forename: Fotini
authors.initials: F
authors.lastname: Abatzidou
authors.forename: Stavros
authors.initials: S
authors.lastname: Tryfon
authors.forename: Chrysanthi
authors.initials: C
authors.lastname: Nakou
authors.forename: Georgia
authors.initials: G
authors.lastname: Pitsiou
authors.forename: Paraskevi
authors.initials: P
authors.lastname: Argyropoulou
authors.forename: Ioannis
authors.initials: I
authors.lastname: Stanopoulos
mesh_terms: D018806:APACHE; D000368:Aged; D005260:Female; D015600:Glasgow Coma Scale; D006305:Health Status Indicators; D006801:Humans; D008297:Male; D010101:Oxygen Consumption; D011237:Predictive Value of Tests; D011446:Prospective Studies; D029424:Pulmonary Disease, Chronic Obstructive / Q000534:rehabilitation / Q000628:therapy*; D012119:Respiration; D012121:Respiration, Artificial; D012129:Respiratory Function Tests; D012680:Sensitivity and Specificity; D018709:Statistics, Nonparametric; D013997:Time Factors; D016896:Treatment Outcome