title: Accuracy and limits of transpulmonary dilution methods in estimating extravascular lung water after pneumonectomy.
abstract: OBJECTIVE
  The measurement of extravascular lung water index by double indicator (EVLWIdi) or the measurement of extravascular lung water index by transpulmonary thermodilution (EVLWItt) could be useful after pneumonectomy. Since pulmonary blood flow and volume are altered after pneumonectomy, the validity of these methods is uncertain. This study has compared measurements of EVLWIdi and EVLWItt with measurement of extravascular lung water index by gravimetry (EVLWIg) in a porcine model of pulmonary edema induced after right pneumonectomy.
  
  
  METHODS
  Randomized laboratory study.
  
  
  METHODS
  Animal research laboratory.
  
  
  METHODS
  Twenty-seven female pigs; mean weight, 35 +/- 5 kg (+/- SD).
  
  
  METHODS
  The pigs were anesthetized, placed on mechanical ventilation, and allocated to a two-lung group (n = 10) or a right pneumonectomy group (n = 17). EVLWIdi and EVLWItt were measured at baseline, 60 min after pneumonectomy, and 60 min after IV injection of oleic acid (OA).
  
  
  RESULTS
  There was a good correlation between EVLWIg and EVLWIdi values (r = 0.96, p < 0.0001 in the two-lung group; and r = 0.81, p = 0.02 in the pneumonectomy group). EVLWIdi underestimated EVLWIg in the two-lung group (- 3 mL/kg; 95% confidence interval [CI], - 7 to + 2 mL/kg) and in the pneumonectomy group (- 0.9 mL/kg; 95% CI, - 3.3 to + 1.5 mL/kg). After pneumonectomy, EVLWItt decreased in mean by 27% and increased in mean by 70% after OA acid. There was a good correlation between EVLWIg and EVLWItt values (r = 0.96, p < 0.0001 in the two-lung group; and r = 0.90, p < 0.0001 after pneumonectomy). EVLWItt slightly overestimated gravimetric value in the two-lung group (+ 1.5 mL/kg; 95% CI, - 1.5 to + 4.2 mL/kg) and largely overestimated gravimetric value after pneumonectomy (+ 5 mL/kg; 95% CI, + 3.4 to + 6.8 mL/kg).
  
  
  CONCLUSIONS
  Double-indicator and transpulmonary thermodilution methods could be useful in monitoring extravascular lung water index (EVLWI) after pneumonectomy, but transpulmonary thermodilution largely overestimates EVLWI.
authors.affiliation: Service de Réanimation Polyvalente, Hôpitaux Sud. Antoine.Roch@mail.ap-hm.fr
authors.forename: Antoine
authors.initials: A
authors.lastname: Roch
authors.forename: Pierre
authors.initials: P
authors.lastname: Michelet
authors.forename: Benoit
authors.initials: B
authors.lastname: D'journo
authors.forename: Denis
authors.initials: D
authors.lastname: Brousse
authors.forename: Dorothee
authors.initials: D
authors.lastname: Blayac
authors.forename: Dominique
authors.initials: D
authors.lastname: Lambert
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Auffray
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D015633:Extravascular Lung Water; D011013:Pneumonectomy / Q000009:adverse effects*; D011654:Pulmonary Edema / Q000175:diagnosis* / Q000209:etiology*; D015203:Reproducibility of Results; D013552:Swine; D013815:Thermodilution / Q000379:methods