title: Cardiac depression after experimental air embolism in pigs: role of addition of a surface-active agent.
abstract: OBJECTIVE
  Air bubbles entering the coronary artery may have harmful effects on cardiac function. From the physical point of view it is the relatively high surface tension of the blood-air interface which causes bubbles to trap in small vessels. The aim of the present study was to reduce depression of myocardial function from air embolism by lowering the surface tension of air bubbles.
  
  
  METHODS
  The effect of using antifoam as a surface-tension-reducing agent on air bubble entrapment and cardiac function was investigated in 6 anesthetized pigs (27 +/- 1 kg) and analyzed using a two-compartment diffusion model. Air bubbles with a diameter of 150 microns were selectively injected into the left anterior descending coronary artery (LADCA) in a carrying fluid in the presence or absence of antifoam. Myocardial systolic segment shortening in the LADCA region (SS-LADCA) was measured by sonomicrometry. Presence of emboli was detected by measuring the amount of reverberation of ultrasound scattered by trapped air bubbles.
  
  
  RESULTS
  SS-LADCA transiently decreased after injections of air bubbles in both the absence and presence of antifoam. However, in the presence of antifoam the regional depression recovered to normal sooner, the average depth of the depression was reduced, and bubbles from the embolized area cleared faster. These observations can be explained by a model derived from Laplace's law.
authors.affiliation: Thoraxcenter, Erasmus University Rotterdam, Netherlands. van.blankenstein@grabowsky.nl
authors.forename: J H
authors.initials: JH
authors.lastname: van Blankenstein
authors.forename: C J
authors.initials: CJ
authors.lastname: Slager
authors.forename: L K
authors.initials: LK
authors.lastname: Soei
authors.forename: H
authors.initials: H
authors.lastname: Boersma
authors.forename: T
authors.initials: T
authors.lastname: Stijnen
authors.forename: J C
authors.initials: JC
authors.lastname: Schuurbiers
authors.forename: R
authors.initials: R
authors.lastname: Krams
authors.forename: B
authors.initials: B
authors.lastname: Lachmann
authors.forename: P D
authors.initials: PD
authors.lastname: Verdouw
mesh_terms: D000818:Animals; D000934:Antifoaming Agents / Q000008:administration & dosage*; D003331:Coronary Vessels; D004618:Embolism, Air / Q000503:physiopathology / Q000628:therapy*; D005260:Female; D006321:Heart / Q000503:physiopathology*; D008297:Male; D013500:Surface Tension; D013552:Swine; D014463:Ultrasonography
chemical_list: D000934:Antifoaming Agents