title: Elevated static compliance of the total respiratory system: early predictor of weaning unsuccess in severed COPD patients mechanically ventilated.
abstract: OBJECTIVE
  To assess in a group of COPD patients mechanically ventilated for an episode of acute respiratory failure the respiratory mechanics with a simple and non invasive method at the bedside in order to evaluate if these parameters may be predictive of weaning failure or success.
  
  
  METHODS
  A prospective study.
  
  
  METHODS
  Intensive care and intermediate intensive care units.
  
  
  METHODS
  23 COPD patients ventilated for acute respiratory failure and studied within 24 hours from intubation.
  
  
  METHODS
  Using end-expiratory and end-inspiratory airway occlusion technique, we measured PEEPi, static compliance of the respiratory system (Crs, st) maximum respiratory resistance (Rrsmax) and minimum respiratory resistance (Rrsmin).
  
  
  RESULTS
  The weaned group (A) and the not weaned group (B) were not different regarding to static PEEPi (group A 8.5 +/- 4.0 vs group B 8.9 +/- 2.6 cmH2O), TO Rrsmax (22.4 +/- 5.3 versus 22.2 +/- 9.0 cmH2O/1/s) and to Rrsmin (17.6 +/- 5.5 versus 17.9 +/- 8.0 cmH2O/1/s), while a significant difference (p < 0.001) has been found in Cst, rs (62.7 +/- 17.% versus 111.6 +/- 18.0 ml/cm H2O). The threshold value of 88.5 ml/cmH2O was identified by discriminant analysis and provided the best separation between the two groups, with a sensitivity of 0.85 and a specificity of 0.87.
  
  
  CONCLUSIONS
  Cst, rs measured non invasively in the first 24 h from intubation, provided a good separation between the patients who were successfully weaned and those who failed.
authors.affiliation: Division of Pneumology, Fondazione Clinica del Lavoro IRCCS, Montescano (PV), Italy.
authors.forename: E
authors.initials: E
authors.lastname: Zanotti
authors.forename: F
authors.initials: F
authors.lastname: Rubini
authors.forename: G
authors.initials: G
authors.lastname: Iotti
authors.forename: A
authors.initials: A
authors.lastname: Braschi
authors.forename: A
authors.initials: A
authors.lastname: Palo
authors.forename: C
authors.initials: C
authors.lastname: Bruschi
authors.forename: C
authors.initials: C
authors.lastname: Fracchia
authors.forename: S
authors.initials: S
authors.lastname: Nava
mesh_terms: D000208:Acute Disease; D000368:Aged; D000403:Airway Resistance; D016002:Discriminant Analysis; D005260:Female; D006801:Humans; D008170:Lung Compliance; D008173:Lung Diseases, Obstructive / Q000150:complications*; D008297:Male; D008875:Middle Aged; D018467:Positive-Pressure Respiration, Intrinsic / Q000175:diagnosis; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012131:Respiratory Insufficiency / Q000209:etiology / Q000503:physiopathology / Q000628:therapy*; D017211:Treatment Failure; D015300:Ventilator Weaning