title: Gastric capnometry with air-automated tonometry predicts outcome in critically ill patients.
abstract: BACKGROUND
  Contrary to tonometer gastric intramucosal pH, there is currently no validated threshold prognostic value for Pco2 gap (tonometer gastric mucosal Pco2 minus arterial Pco2) in the critically ill patient.
  
  
  OBJECTIVE
  To demonstrate a relationship between Pco2 gap and mortality in mechanically ventilated patients.
  
  
  METHODS
  Inception cohort study from a 9-month prospective survey of 95 consecutively ventilated critically ill patients in a teaching hospital.
  
  
  METHODS
  All the ventilated patients of the intensive care unit were included at their admission.
  
  
  RESULTS
  Gastric Pco2 using regional capnometry with air-automated tonometry, arterial gas, lactate, and organ system failure score were measured at admission and after 6, 12, 24, 48, 72, 96, and 120 hrs. For the entire population, the 28-day mortality was 44%. In multivariate analysis, independent predictors of death were organ system failure score (odds ratio, 2.12; 95% confidence interval, 1.02-3.14), 24-hr Pco2 gap (odds ratio, 1.57; 95% confidence interval, 1.10-2.24), and 24-hr lactate (odds ratio, 1.48; 95% confidence interval, 1.06-2.05). We found a threshold value of 20 mm Hg for Pco2 gap and 2.5 mmol/L for lactate, which was associated with a sensitivity of 0.70 and 0.72, respectively, and a specificity of 0.72 and 0.73, respectively.
  
  
  CONCLUSIONS
  The Pco2 gap is a marker of mortality in ventilated patients in the intensive care unit.
authors.affiliation: Réanimation Médicale, Hôpital Central, Nancy, France.
authors.forename: Bruno
authors.initials: B
authors.lastname: Levy
authors.forename: Pascale
authors.initials: P
authors.lastname: Gawalkiewicz
authors.forename: Benoit
authors.initials: B
authors.lastname: Vallet
authors.forename: Serge
authors.initials: S
authors.lastname: Briancon
authors.forename: Lionel
authors.initials: L
authors.lastname: Nace
authors.forename: Pierre-Edouard
authors.initials: PE
authors.lastname: Bollaert
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000388:Air; D001784:Blood Gas Analysis / Q000379:methods*; D002245:Carbon Dioxide / Q000097:blood*; D015331:Cohort Studies; D016638:Critical Illness / Q000401:mortality / Q000628:therapy*; D005753:Gastric Mucosa; D006801:Humans; D008365:Manometry; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D015996:Survival Rate; D016896:Treatment Outcome
chemical_list: D002245:Carbon Dioxide