title: Prediction of extubation outcome in infants using the tension time index.
abstract: OBJECTIVE
  Approximately one-third of ventilated infants fail extubation. The objective of this study was to determine whether assessment of the load relative to the capacity of respiratory muscles by measurement of the tension time index (TTI) successfully predicted extubation outcome in infants.
  
  
  METHODS
  Prospective study.
  
  
  METHODS
  Tertiary neonatal intensive care unit.
  
  
  METHODS
  Twenty ventilated infants, with a median gestational age of 31 (range 24-39) weeks, were studied at a median postnatal age of 2.5 (range 1-37) days.
  
  
  METHODS
  The diaphragm tension time index (TTdi) was derived from measurements of transdiaphragmatic pressure using a dual-pressure transducer tipped catheter. The respiratory muscle tension time index (TTmus) was derived from non-invasive airway pressure measurements. Measurements were made within the 6 h prior to extubation.
  
  
  METHODS
  Extubation failure was defined as the need for reintubation within 48 h of extubation.
  
  
  RESULTS
  Five infants failed extubation; their median TTdi (p=0.001) and TTmus (p=0.001) were significantly higher than those of the successfully extubated infants. A TTdi of >0.15 and a TTmus of >0.18 were 100% sensitive and 100% specific in predicting extubation failure
  
  
  CONCLUSIONS
  In ventilated infants, invasive and non-invasive measurements of the TTI could provide an accurate prediction of extubation outcome.
authors.affiliation: Division of Asthma, Allergy & Lung Biology, MRC-Asthma UK Centre in Allergic Mechanisms of Asthma, King’s College London, London, UK.
authors.forename: Andrew
authors.initials: A
authors.lastname: Currie
authors.forename: Deena-Shefali
authors.initials: DS
authors.lastname: Patel
authors.forename: Gerrard F
authors.initials: GF
authors.lastname: Rafferty
authors.forename: Anne
authors.initials: A
authors.lastname: Greenough
mesh_terms: D003964:Diaphragm / Q000503:physiopathology*; D005260:Female; D005865:Gestational Age; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007234:Infant, Premature; D007363:Intensive Care Units, Neonatal; D008297:Male; D011379:Prognosis; D011446:Prospective Studies; D012127:Respiratory Distress Syndrome, Newborn / Q000503:physiopathology / Q000628:therapy; D012680:Sensitivity and Specificity; D015300:Ventilator Weaning