title: Echocardiographic detection of transpulmonary bubble transit during acute respiratory distress syndrome.
abstract: BACKGROUND
  Transpulmonary bubble transit (TPBT) detected with contrast echocardiography is reported as a sign of intrapulmonary shunt during cirrhosis or exercise in healthy humans. However, its physiological meaning is not clear during acute respiratory distress syndrome (ARDS). Our aim was to determine the prevalence, significance, and prognosis of TPBT detection during ARDS.
  
  
  METHODS
  This was a prospective observational study in an academic medical intensive care unit in France. Two hundred and sixteen consecutive patients with moderate-to-severe ARDS underwent transesophageal echocardiography with modified gelatine contrast. Moderate-to-large TPBT was defined as right-to-left passage of at least ten bubbles through a pulmonary vein more than three cardiac cycles after complete opacification of the right atrium. Patients with intra-cardiac shunt through patent foramen ovale were excluded.
  
  
  RESULTS
  The prevalence of moderate-to-large TPBT was 26% (including 42 patients with moderate and 15 with large TPBT). Patients with moderate-to-large TPBT had higher values of cardiac index and heart rate as compared to those without TPBT. There was no significant difference in PaO2/FIO2 ratio between groups, and TPBT was not influenced by end-expiratory positive pressure level in 93% of tested patients. Prevalence of septic shock was higher in the group with moderate-to-large TPBT. Patients with moderate-to-large TPBT had fewer ventilator-free days and intensive care unit-free days within the first 28 days, and higher in-hospital mortality as compared to others.
  
  
  CONCLUSIONS
  Moderate-to-large TPBT was detected with contrast echocardiography in 26% of patients with ARDS. This finding was associated with a hyperdynamic and septic state, but did not influence oxygenation.
authors: AP-HP, Hôpital Henri Mondor, DHU A-TVB, Service de Réanimation Médicale, Groupe de recherche CARMAS, 51 Av Mal de Lattre de Tassigny, Créteil, 94010 France ; INSERM, Unité U955 (IMRB), 8 rue du Général Sarrail, Créteil, 94010 France ; Faculté de Médecine, Université Paris Est Créteil, 8, rue du Général Sarrail, Créteil, 94010 France.
authors: Florence
authors: F
authors: Boissier
authors: AP-HP, Hôpital Henri Mondor, DHU A-TVB, Service de Réanimation Médicale, Groupe de recherche CARMAS, 51 Av Mal de Lattre de Tassigny, Créteil, 94010 France.
authors: Keyvan
authors: K
authors: Razazi
authors: AP-HP, Hôpital Henri Mondor, DHU A-TVB, Service de Réanimation Médicale, Groupe de recherche CARMAS, 51 Av Mal de Lattre de Tassigny, Créteil, 94010 France ; CHU de Poitiers, Réanimation médicale, Poitiers, France; INSERM CIC 1402 (équipe 5 ALIVE), Université de Poitiers, 2 Rue de la Milétrie, 86021 Poitiers, France.
authors: Arnaud W
authors: AW
authors: Thille
authors: AP-HP, Hôpital Henri Mondor, DHU A-TVB, Service de Réanimation Médicale, Groupe de recherche CARMAS, 51 Av Mal de Lattre de Tassigny, Créteil, 94010 France ; Servei de Medicina Intensiva, Hospital Verge de la Cinta, Carrer de les Esplanetes, 14, 43500 Tortosa, Tarragona Spain.
authors: Ferran
authors: F
authors: Roche-Campo
authors: AP-HP, Hôpital Henri Mondor, DHU A-TVB, Service de Réanimation Médicale, Groupe de recherche CARMAS, 51 Av Mal de Lattre de Tassigny, Créteil, 94010 France ; Centre Hospitalier Intercommunal de Créteil, Réanimation polyvalente, 40 avenue de Verdun, 94010 Créteil, France.
authors: Rusel
authors: R
authors: Leon
authors: AP-HP, Hôpital Henri Mondor, DHU A-TVB, Service de Réanimation Médicale, Groupe de recherche CARMAS, 51 Av Mal de Lattre de Tassigny, Créteil, 94010 France ; Centre Hospitalier Saint Luc Saint Joseph, Réanimation Polyvalente, 20, quai Claude Bernard, 69007 Lyon, France.
authors: Emmanuel
authors: E
authors: Vivier
authors: Saint Michael's Hospital, 30 Bond Street, ON M5B 1 W8 Toronto, Canada.
authors: Laurent
authors: L
authors: Brochard
authors: AP-HP, Hôpital Henri Mondor, DHU A-TVB, Service de Réanimation Médicale, Groupe de recherche CARMAS, 51 Av Mal de Lattre de Tassigny, Créteil, 94010 France ; INSERM, Unité U955 (IMRB), 8 rue du Général Sarrail, Créteil, 94010 France ; Faculté de Médecine, Université Paris Est Créteil, 8, rue du Général Sarrail, Créteil, 94010 France.
authors: Christian
authors: C
authors: Brun-Buisson
authors: AP-HP, Hôpital Henri Mondor, DHU A-TVB, Service de Réanimation Médicale, Groupe de recherche CARMAS, 51 Av Mal de Lattre de Tassigny, Créteil, 94010 France ; INSERM, Unité U955 (IMRB), 8 rue du Général Sarrail, Créteil, 94010 France ; Faculté de Médecine, Université Paris Est Créteil, 8, rue du Général Sarrail, Créteil, 94010 France.
authors: Armand
authors: A
authors: Mekontso Dessap
keywords: Acute respiratory distress syndrome; Echocardiography; Shunt