title: Surfactant deactivation in a pediatric model induces hypovolemia and fluid shift to the extravascular lung compartment.
abstract: BACKGROUND
  Surfactant deficiency is the pivotal abnormality in Neonatal and Acute Respiratory Distress Syndrome. Surfactant deactivation can produce hypoxemia, loss of lung compliance, and pulmonary edema, but its circulatory consequences are less understood.
  
  
  OBJECTIVE
  To describe the sequential hemodynamic changes and pulmonary edema formation after surfactant deactivation in piglets.
  
  
  METHODS
  Surfactant deactivation was induced by tracheal instillation of polysorbate 20 in 15 anesthetized and mechanically ventilated Large White piglets. The hemodynamic consequences of surfactant deactivation were assessed at 30, 120, and 240 min by transpulmonary thermodilution and traditional methods.
  
  
  RESULTS
  Surfactant deactivation caused hypoxemia, reduced lung compliance, and progressively increased lung water content (P < 0.01). Early hypovolemia was observed, with reductions of the global end-diastolic volume and stroke volume (P < 0.05). Reduced cardiac output was observed at the end of the study (P < 0.05). Standard monitoring was unable to detect these early preload alterations. Surprisingly, the bronchoalveolar protein content was greatly increased at the end of the study compared with baseline levels (P < 0.01). This finding was inconsistent with the notion that the pulmonary edema induced by surfactant deactivation was exclusively caused by high surface tension.
  
  
  CONCLUSIONS
  Hypovolemia develops early after surfactant deactivation, in part due to the resulting fluid shift from the intravascular compartment to the lungs.
authors.affiliation: Área de Cuidados Críticos, Hospital Padre Hurtado, Santiago, Chile.
authors.forename: Franco
authors.initials: F
authors.lastname: Díaz
authors.forename: Benjamín
authors.initials: B
authors.lastname: Erranz
authors.forename: Alejandro
authors.initials: A
authors.lastname: Donoso
authors.forename: Cristóbal
authors.initials: C
authors.lastname: Carvajal
authors.forename: Tatiana
authors.initials: T
authors.lastname: Salomón
authors.forename: María
authors.initials: M
authors.lastname: Torres
authors.forename: Pablo
authors.initials: P
authors.lastname: Cruces
mesh_terms: D000758:Anesthesia; D000818:Animals; D001784:Blood Gas Analysis; D001992:Bronchoalveolar Lavage Fluid; D005079:Excipients; D015633:Extravascular Lung Water / Q000502:physiology*; D018495:Fluid Shifts / Q000502:physiology*; D006439:Hemodynamics / Q000502:physiology; D020896:Hypovolemia / Q000139:chemically induced / Q000503:physiopathology*; D008170:Lung Compliance / Q000502:physiology; D011136:Polysorbates; D011175:Positive-Pressure Respiration; D011654:Pulmonary Edema / Q000473:pathology; D011663:Pulmonary Surfactants; D012121:Respiration, Artificial; D013552:Swine; D013815:Thermodilution
chemical_list: D005079:Excipients; D011136:Polysorbates; D011663:Pulmonary Surfactants