title: PEEP-induced tricuspid regurgitation.
abstract: OBJECTIVE
  To determine the presence of tricuspid regurgitation (TR) in patients affected by acute lung injury (ALI) and the adult respiratory distress syndrome (ARDS) during mechanical ventilation with positive end-expiratory pressure (PEEP).
  
  
  METHODS
  A prospective clinical study.
  
  
  METHODS
  10-bed general intensive care unit in a University Hospital.
  
  
  METHODS
  7 consecutive patients an age 44.7 +/- 8.6 years with a diagnosis of ALI or ARDS were studied. All were on mechanical ventilation with PEEP.
  
  
  METHODS
  PEEP was increased in steps of 5 cm H2O until the appearance of TR or up to a limit of 20 cm H2O.
  
  
  RESULTS
  Right atrial pressure, pulmonary artery pressure, and wedge pressure were measured and cardiac output was determined by thermodilution. TR was graded from 0 to 3. Standard 2D echocardiographic and pulsed-wave images were obtained at each level of PEEP. PEEP was increased from 4 +/- 3 to 17 +/- 2 cm H2O. Mean PAP increased from 27.7 +/- 2.9 to 36.7 +/- 3.5 mm Hg (p < 0.02) when PEEP was increased. Five patients had competent valves and two had mild TR at baseline. In six out of the seven, TR either developed or increased when PEEP was increased.
  
  
  CONCLUSIONS
  Our study demonstrated the development of TR after the use of PEEP in patients with ALI and ARDS as a consequence of pulmonary hypertension and right ventricular overloading. Since TR may randomly affect cardiac output values and derived parameters, the assessment of cardiac performance by some techniques such as thermodilution should be used with caution.
authors.affiliation: Intensive Care Department, Hospital de Clinicas (University Hospital), Universidad de la Republica, Montevideo, Uruguay.
authors.forename: H
authors.initials: H
authors.lastname: Artucio
authors.forename: J
authors.initials: J
authors.lastname: Hurtado
authors.forename: L
authors.initials: L
authors.lastname: Zimet
authors.forename: J
authors.initials: J
authors.lastname: de Paula
authors.forename: M
authors.initials: M
authors.lastname: Beron
mesh_terms: D000328:Adult; D000368:Aged; D002303:Cardiac Output, Low / Q000175:diagnosis* / Q000209:etiology; D018619:Echocardiography, Doppler, Pulsed; D005260:Female; D006439:Hemodynamics; D006801:Humans; D006976:Hypertension, Pulmonary / Q000150:complications; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D011175:Positive-Pressure Respiration / Q000009:adverse effects*; D011446:Prospective Studies; D012128:Respiratory Distress Syndrome / Q000150:complications / Q000628:therapy; D013815:Thermodilution; D014262:Tricuspid Valve Insufficiency / Q000000981:diagnostic imaging / Q000209:etiology* / Q000503:physiopathology; D018497:Ventricular Dysfunction, Right / Q000150:complications