title: Cardiorespiratory effects of venous lipid micro embolization in an experimental model of mediastinal shed blood reinfusion.
abstract: BACKGROUND
  Retransfusion of the patient's own blood during surgery is used to reduce the need for allogenic blood transfusion. It has however been found that this blood contains lipid particles, which form emboli in different organs if the blood is retransfused on the arterial side. In this study, we tested whether retransfusion of blood containing lipid micro-particles on the venous side in a porcine model will give hemodynamic effects.
  
  
  METHODS
  Seven adult pigs were used. A shed blood surrogate containing 400 ml diluted blood and 5 ml radioactive triolein was produced to generate a lipid embolic load. The shed blood surrogate was rapidly (<2 minutes) retransfused from a transfusion bag to the right atrium under general anesthesia. The animals' arterial, pulmonary, right and left atrial pressure were monitored, together with cardiac output and deadspace. At the end of the experiment, an increase in cardiac output and pulmonary pressure was pharmacologically induced to try to flush out lipid particles from the lungs.
  
  
  RESULTS
  A more than 30-fold increase in pulmonary vascular resistance was observed, with subsequent increase in pulmonary artery pressure, and decrease in cardiac output and arterial pressure. This response was transient, but was followed by a smaller, persistent increase in pulmonary vascular resistance. Only a small portion of the infused triolein passed the lungs, and only a small fraction could be recirculated by increasing cardiac output and pulmonary pressure.
  
  
  CONCLUSIONS
  Infusion of blood containing lipid micro-emboli on the venous side leads to acute, severe hemodynamic responses that can be life threatening. Lipid particles will be trapped in the lungs, leading to persistent effects on the pulmonary vascular resistance.
authors.affiliation: Department of Cardiothoracic Surgery, Department of Clinical Sciences, Lund University, Sweden. atli.eyjolfsson@skane.se
authors.forename: Atli
authors.initials: A
authors.lastname: Eyjolfsson
authors.forename: Ignacio
authors.initials: I
authors.lastname: Plaza
authors.forename: Björn
authors.initials: B
authors.lastname: Brondén
authors.forename: Per
authors.initials: P
authors.lastname: Johnsson
authors.forename: Magnus
authors.initials: M
authors.lastname: Dencker
authors.forename: Henrik
authors.initials: H
authors.lastname: Bjursten
mesh_terms: D000818:Animals; D001794:Blood Pressure / Q000502:physiology*; D001804:Blood Transfusion, Autologous / Q000009:adverse effects*; D002302:Cardiac Output / Q000502:physiology*; D002985:Clinical Protocols; D004620:Embolism, Fat / Q000209:etiology / Q000503:physiopathology*; D007262:Infusions, Intravenous; D023421:Models, Animal; D011651:Pulmonary Artery / Q000503:physiopathology; D011655:Pulmonary Embolism / Q000209:etiology / Q000503:physiopathology*; D013552:Swine; D016896:Treatment Outcome; D014655:Vascular Resistance / Q000502:physiology*