title: Rapid cardiotonic effects of lipid emulsion infusion*.
abstract: OBJECTIVE
  Bolus infusion of lipid emulsion can reverse cardiac pharmacotoxicity caused by local anesthetics and other lipophilic drugs. The mechanisms of this effect are not completely elucidated. The authors test the hypothesis that lipid emulsion infusion exerts direct, positive inotropic effects.
  
  
  METHODS
  Prospective, randomized animal study.
  
  
  METHODS
  University research laboratory.
  
  
  METHODS
  Adult male Sprague-Dawley rats.
  
  
  METHODS
  Rats anesthetized with isoflurane were given intravenous infusions (9 mL/kg over 1 min) of either 20% soybean oil-based emulsion or saline.
  
  
  RESULTS
  Arterial pressure and aortic flow were measured continuously in intact animals. Lipid infusion increased aortic flow and arterial pressure faster and to a greater degree than did the same volume of saline infusion. Isolated rat hearts were studied using an isovolumetric, constant flow, nonrecirculating system. Left ventricular pressure was monitored. The infusion of lipid emulsion in the isolated heart dose-dependently increased rate pressure product, dP/dt, -dP/dt, and myocardial oxygen demand.
  
  
  CONCLUSIONS
  Lipid emulsion exerts rapid, positive inotropic and positive lusitropic effects in both intact animal and isolated heart models. We hypothesize that this inotropy and the resulting increase in tissue blood flow contribute to the phenomenon of lipid reversal of cardiac toxicity caused by drug overdose.
authors.affiliation: University of Illinois College of Medicine, Chicago, IL, USA. mfetti3@uic.edu
authors.forename: Michael R
authors.initials: MR
authors.lastname: Fettiplace
authors.forename: Richard
authors.initials: R
authors.lastname: Ripper
authors.forename: Kinga
authors.initials: K
authors.lastname: Lis
authors.forename: Bocheng
authors.initials: B
authors.lastname: Lin
authors.forename: Jason
authors.initials: J
authors.lastname: Lang
authors.forename: Brian
authors.initials: B
authors.lastname: Zider
authors.forename: Jing
authors.initials: J
authors.lastname: Wang
authors.forename: Israel
authors.initials: I
authors.lastname: Rubinstein
authors.forename: Guy
authors.initials: G
authors.lastname: Weinberg
mesh_terms: D000818:Animals; D001012:Aorta, Abdominal / Q000502:physiology*; D001783:Blood Flow Velocity / Q000502:physiology; D001794:Blood Pressure / Q000187:drug effects* / Q000502:physiology; D004655:Emulsions / Q000494:pharmacology; D005217:Fat Emulsions, Intravenous / Q000494:pharmacology*; D006339:Heart Rate / Q000187:drug effects / Q000502:physiology; D008297:Male; D023421:Models, Animal; D010101:Oxygen Consumption / Q000187:drug effects / Q000502:physiology; D010743:Phospholipids / Q000494:pharmacology*; D011446:Prospective Studies; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D012039:Regional Blood Flow / Q000187:drug effects* / Q000502:physiology; D013024:Soybean Oil / Q000494:pharmacology*; D014655:Vascular Resistance / Q000187:drug effects / Q000502:physiology
chemical_list: D004655:Emulsions; D005217:Fat Emulsions, Intravenous; D010743:Phospholipids; C545823:soybean oil, phospholipid emulsion; D013024:Soybean Oil