title: Prevalence and prognosis of shunting across patent foramen ovale during acute respiratory distress syndrome.
abstract: OBJECTIVE
  Right-to-left shunting across a patent foramen ovale may occur in acute respiratory distress syndrome as a result of pulmonary hypertension and positive-pressure mechanical ventilation. The shunt may worsen the hypoxemia. The objective of our study was to determine the prevalence, clinical implications, and prognosis of patent foramen ovale shunting during acute respiratory distress syndrome.
  
  
  METHODS
  Prospective study.
  
  
  METHODS
  Medical intensive care unit of a university hospital in Créteil, France.
  
  
  METHODS
  Two hundred three consecutive patients with acute respiratory distress syndrome.
  
  
  METHODS
  Patent foramen ovale shunting was detected by using transesophageal echocardiography with modified gelatin contrast. Moderate-to-large shunting was defined as right-to-left passage of at least 10 bubbles through a valve-like structure within three cardiac cycles after complete opacification of the right atrium. In 85 patients without and 31 with shunting, the influence of the positive end-expiratory pressure level on shunting was studied.
  
  
  RESULTS
  The prevalence of moderate-to-large patent foramen ovale shunting was 19.2% (39 patients). Compared to those in the group without shunting, the patients in group with shunting had larger right ventricle dimensions, higher pulmonary artery systolic pressure, and a higher prevalence of cor pulmonale. Compared to patients without shunting, patients with shunting had a poorer Pa(O(2))/Fi(O(2)) ratio response to positive end-expiratory pressure, more often required prone positioning and nitric oxide as adjunctive interventions, and had fewer ventilator-free and intensive care unit-free days within the first 28 days.
  
  
  CONCLUSIONS
  Moderate-to-large patent foramen ovale shunting occurred in 19.2% of patients with acute respiratory distress syndrome, in keeping with findings from autopsy studies. Patent foramen ovale was associated with a poor oxygenation response to positive end-expiratory pressure, greater use of adjunctive interventions, and a longer intensive care unit stay.
authors.affiliation: AP-HP, Groupe Henri-Mondor Albert-Chenevier, Service de Réanimation Médicale, Créteil, France. armand.dessap@hmn.aphp.fr
authors.forename: Armand
authors.initials: A
authors.lastname: Mekontso Dessap
authors.forename: Florence
authors.initials: F
authors.lastname: Boissier
authors.forename: Rusel
authors.initials: R
authors.lastname: Leon
authors.forename: Serge
authors.initials: S
authors.lastname: Carreira
authors.forename: Ferran Roche
authors.initials: FR
authors.lastname: Campo
authors.forename: François
authors.initials: F
authors.lastname: Lemaire
authors.forename: Laurent
authors.initials: L
authors.lastname: Brochard
mesh_terms: D000368:Aged; D017548:Echocardiography, Transesophageal; D005260:Female; D054092:Foramen Ovale, Patent / Q000150:complications*; D006344:Heart Septal Defects, Atrial / Q000150:complications*; D006801:Humans; D006976:Hypertension, Pulmonary / Q000150:complications; D008297:Male; D008875:Middle Aged; D009569:Nitric Oxide / Q000008:administration & dosage; D011175:Positive-Pressure Respiration / Q000009:adverse effects; D015995:Prevalence; D011379:Prognosis; D011446:Prospective Studies; D012128:Respiratory Distress Syndrome / Q000150:complications*
chemical_list: D009569:Nitric Oxide