title: Use of Cough Peak Flow Measured by a Ventilator to Predict Re-Intubation When a Spirometer Is Unavailable.
abstract: BACKGROUND
  A ventilator includes the function to measure flow velocity. We aimed to compare the predictive accuracy for re-intubation diagnosed by cough peak flow (CPF) measured by a spirometer and a ventilator.
  
  
  METHODS
  Endotracheally intubated subjects who passed a spontaneous breathing trial were enrolled. Before extubation, CPF was measured by a spirometer and a ventilator, respectively. Re-intubation was recorded at 72 h after extubation.
  
  
  RESULTS
  A total of 126 subjects were enrolled. Among them, 15 subjects (12%) experienced re-intubation. CPF was lower in re-intubated subjects than those without re-intubation (measured by a spirometer: 54 ± 30 L/min vs 86 ± 37 L/min,P< .001; and measured by a ventilator: 50 ± 22 L/min vs 80 ± 26 L/min,P< .001). CPF measured by a spirometer and a ventilator had similar area under the curve of receiver operating characteristic (0.79 vs 0.83,P= .26). When a CPF of 56.4 L/min was measured by a spirometer as cutoff value, the sensitivity and specificity to distinguish re-intubation was 73 and 87%, respectively. When it was measured by a ventilator, the cutoff value, sensitivity, and specificity were 56 L/min, 73%, and 85%, respectively.
  
  
  CONCLUSIONS
  CPF measurement by a ventilator was convenient, affordable, and safe. It had a predictive accuracy for re-intubation similar to that of a spirometer.
authors.affiliation: Department of Respiratory Medicine, First Affiliated Hospital of Chongqing Medical University, Chongqing, China.
authors.forename: Linfu
authors.initials: L
authors.lastname: Bai
authors.affiliation: Department of Respiratory Medicine, First Affiliated Hospital of Chongqing Medical University, Chongqing, China. duanjun412589@163.com.
authors.forename: Jun
authors.initials: J
authors.lastname: Duan
mesh_terms: D000328:Adult; D060666:Airway Extubation; D003371:Cough / Q000503:physiopathology*; D005260:Female; D006801:Humans; D007442:Intubation, Intratracheal / Q000379:methods / Q000706:statistics & numerical data*; D008297:Male; D010366:Peak Expiratory Flow Rate / Q000502:physiology*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012372:ROC Curve; D012680:Sensitivity and Specificity; D013147:Spirometry / Q000379:methods / Q000706:statistics & numerical data*; D012122:Ventilators, Mechanical / Q000706:statistics & numerical data*
keywords: cough peak flow; extubation; re-intubation; spontaneous breathing trial