title: Clinical Relevance of Fluid Challenge in Patients Evaluated for Pulmonary Hypertension.
abstract: BACKGROUND
  Fluid challenge may help in the differential diagnosis between pre- and postcapillary pulmonary hypertension (PH). However, the test is still in need of standardization and better defined clinical relevance.
  
  
  METHODS
  Two hundred twelve patients referred for PH underwent a right-sided heart catheterization with measurements before and after rapid infusion of 7 mL/kg of saline. PH was defined as mean pulmonary artery pressure ≥ 25 mm Hg, and postcapillary PH was defined as pulmonary artery wedge pressure (PAWP) > 15 mm Hg. An increase in PAWP ≥ 18 mm Hg was considered diagnostic for postcapillary PH. At baseline, 66 patients received a diagnosis of no PH; 22, of postcapillary PH; and 124, of precapillary PH (mostly pulmonary arterial hypertension).
  
  
  RESULTS
  After fluid challenge, five of 66 patients with no PH (8%) and eight of 124 with precapillary PH (6%) had the diagnosis reclassified as postcapillary PH. Fluid challenge was associated with an increase in PAWP by 7 ± 2 mm Hg in postcapillary PH and 3 ± 1 mm Hg in both precapillary PH and no-PH groups. Between-group differences were significant, but there was overlap. There were no adverse events related to fluid challenge. Prediction bands calculated from quadratic fits of the PAWP responses in pooled control subjects with no PH and patients with precapillary PH helped confirm 18 mm Hg as the cutoff for diagnosing postcapillary PH.
  
  
  CONCLUSIONS
  Fluid challenge with 7 mL/kg saline increases PAWP, more in postcapillary than in precapillary PH or in control subjects with no PH. A cutoff value of 18 mm Hg allows reclassification of 6% to 8% of patients with precapillary PH or normal hemodynamic characteristics at baseline.
authors: Department of Cardiology, Second University of Naples, Naples, Italy. Electronic address: mic.dalto@tin.it.
authors: Michele
authors: M
authors: D'Alto
authors: Department of Cardiology, Second University of Naples, Naples, Italy.
authors: Emanuele
authors: E
authors: Romeo
authors: Department of Cardiology, Second University of Naples, Naples, Italy.
authors: Paola
authors: P
authors: Argiento
authors: Department of Pathophysiology, Free University of Brussels, Brussels, Belgium.
authors: Yoshiki
authors: Y
authors: Motoji
authors: Department of Cardiology, Second University of Naples, Naples, Italy.
authors: Anna
authors: A
authors: Correra
authors: Department of Cardiology, Second University of Naples, Naples, Italy.
authors: Giovanni Maria
authors: GM
authors: Di Marco
authors: Department of Cardiology, Second University of Naples, Naples, Italy.
authors: Agostino Mattera
authors: AM
authors: Iacono
authors: Department of Cardiology, Second University of Naples, Naples, Italy.
authors: Rosaria
authors: R
authors: Barracano
authors: Department of Cardiology, Second University of Naples, Naples, Italy.
authors: Antonello
authors: A
authors: D'Andrea
authors: Department of Radiology, Monaldi Hospital, Naples, Italy.
authors: Gaetano
authors: G
authors: Rea
authors: Department of Cardiology, Second University of Naples, Naples, Italy.
authors: Berardo
authors: B
authors: Sarubbi
authors: Department of Cardiology, Second University of Naples, Naples, Italy.
authors: Maria Giovanna
authors: MG
authors: Russo
authors: Department of Pathophysiology, Free University of Brussels, Brussels, Belgium.
authors: Robert
authors: R
authors: Naeije
mesh_terms: D000328:Adult; D000368:Aged; D006328:Cardiac Catheterization / Q000379:methods; D005260:Female; D018495:Fluid Shifts; D006801:Humans; D006976:Hypertension, Pulmonary / Q000175:diagnosis / Q000503:physiopathology; D007262:Infusions, Intravenous / Q000379:methods; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011652:Pulmonary Circulation; D011669:Pulmonary Wedge Pressure; D015203:Reproducibility of Results; D012965:Sodium Chloride / Q000494:pharmacology*; D014655:Vascular Resistance
chemical_list: D012965:Sodium Chloride
keywords: fluid challenge; heart catheterization; heart failure; pulmonary hypertension