title: Respiratory mechanics in brain-damaged patients.
abstract: OBJECTIVE
  To assess respiratory mechanics on the 1st and 5th days of mechanical ventilation in a cohort of brain-damaged patients on positive end-expiratory pressure (PEEP) of 8 cmH(2)O or zero PEEP (ZEEP).
  
  
  METHODS
  Physiological study with randomized control trial design in a multidisciplinary intensive care unit of a university hospital.
  
  
  METHODS
  Twenty-one consecutive mechanically ventilated patients with severe brain damage and no acute lung injury were randomly assigned to be ventilated with ZEEP (n = 10) or with 8 cmH(2)O of PEEP (n = 11). Respiratory mechanics and arterial blood gases were assessed on days 1 and day 5 of mechanical ventilation.
  
  
  RESULTS
  In the ZEEP group on day 1 static elastance and minimal resistance were above normal limits (18.9 +/- 3.8 cmH(2)O/l and 5.6 +/- 2.2 cmH(2)O/l per second, respectively); on day 5 static elastance and iso-CO(2) minimal resistance values were higher than on day 1 (21.2 +/- 4.1 cmH(2)O/l; 7.0 +/- 1.9 cmH(2)O/l per second, respectively). In the PEEP group these parameters did not change significantly. One of the ten patients on ZEEP developed acute lung injury. On day 5 there was a significant decrease in PaO(2)/FIO(2) in both groups.
  
  
  CONCLUSIONS
  On day 1 of mechanical ventilation patients with brain damage exhibit abnormal respiratory mechanics. After 5 days of mechanical ventilation on ZEEP static elastance and minimal resistance increased significantly, perhaps reflecting "low lung volume" injury. Both could be prevented by administration of moderate levels of PEEP.
authors.affiliation: Department of Critical Care and Pulmonary Services, Evangelismos General Hospital and M Simou Laboratory, Medical School, University of Athens, Athens, Greece. koutsoukou@yahoo.gr
authors.forename: Antonia
authors.initials: A
authors.lastname: Koutsoukou
authors.forename: Helen
authors.initials: H
authors.lastname: Perraki
authors.forename: Asimina
authors.initials: A
authors.lastname: Raftopoulou
authors.forename: Nikolaos
authors.initials: N
authors.lastname: Koulouris
authors.forename: Christina
authors.initials: C
authors.lastname: Sotiropoulou
authors.forename: Anastasia
authors.initials: A
authors.lastname: Kotanidou
authors.forename: Stylianos
authors.initials: S
authors.lastname: Orfanos
authors.forename: Charis
authors.initials: C
authors.lastname: Roussos
mesh_terms: D000328:Adult; D000368:Aged; D001930:Brain Injuries / Q000628:therapy*; D005260:Female; D006801:Humans; D007362:Intensive Care Units; D007427:Intracranial Pressure; D008297:Male; D008875:Middle Aged; D011175:Positive-Pressure Respiration / Q000009:adverse effects* / Q000379:methods; D011659:Pulmonary Gas Exchange; D012128:Respiratory Distress Syndrome / Q000209:etiology*; D015656:Respiratory Mechanics; D013990:Tidal Volume