title: Intraosseous lipid emulsion: an effective alternative to IV delivery in emergency situations.
abstract: OBJECTIVE
  To determine whether intraosseous infusion of a lipid emulsion reverses cardiac pharmacotoxicity in anaesthetized rats.
  
  
  METHODS
  Prospective, randomized animal study.
  
  
  METHODS
  Academic research laboratory.
  
  
  METHODS
  Adult, male Sprague-Dawley rats.
  
  
  METHODS
  We assigned 25 male Sprague-Dawley rats into four groups: intraosseous lipid emulsion, intraosseous saline, IV lipid emulsion, and sham/null. Rats were anesthetized with 1.5% isoflurane and 95% oxygen. The left internal carotid artery and both internal jugular veins were cannulated and a flow probe was placed on the right carotid artery. Subsequently, in animals assigned to the intraosseous groups, the greater trochanter of the left proximal femur was exposed and the intraosseous space was cannulated. After surgical recovery, bupivacaine (10 mg/kg) was injected IV over 20 seconds followed 10 seconds later by treatment with one of the following: intraosseous lipid-emulsion (10 mL/kg over 180 s), intraosseous saline (10 mL/kg over 180 s), IV lipid-emulsion (10 mL/kg over 90 s), or no treatment (sham/null).
  
  
  RESULTS
  Electrocardiogram, aortic blood pressure, and carotid blood flow were recorded continuously. Rats treated with intraosseous lipid emulsion experienced a significantly faster recovery of hemodynamic variables (return of 50% flow; median [CI]: 160 s [105-263 s]) than did rats treated with saline (471 s [283-611 s]; p < 0.05) or animals with no treatment (415 s [340-539 s], p < 0.05), but at a similar rate to animals treated with IV lipid emulsion (176 s [152-217 s], p = not significant). All groups experienced persistent negative chronotropic effects. A compensatory increase in systemic arterial pressure was observed in rats treated with lipid emulsion.
  
  
  CONCLUSIONS
  These proof-of-principle data indicate that intraosseous infusion of lipid emulsion rapidly reverses bupivacaine-induced cardiac toxicity in rats. Further studies are warranted to optimize this novel route of lipid emulsion injection in emergency situations when intravascular access is not secured.
authors.affiliation: 1Department of Anesthesiology, University of Illinois Hospital and Health Sciences System, Chicago, IL. 2Department of Bioengineering, University of Illinois at Chicago, Chicago, IL. 3Division of Research, Jesse Brown VA Medical Center, Chicago, IL. 4College of Letters and Science, University of Illinois at Chicago, Chicago, IL. 5Section of Pulmonary, Critical Care, Sleep and Allergy Medicine, Department of Medicine, University of Illinois Hospital and Health Sciences System, Chicago, IL.
authors.forename: Michael Robert
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: Douglas L
authors.initials: DL
authors.lastname: Feinstein
authors.forename: Israel
authors.initials: I
authors.lastname: Rubinstein
authors.forename: Guy
authors.initials: G
authors.lastname: Weinberg
mesh_terms: D000779:Anesthetics, Local / Q000633:toxicity*; D000818:Animals; D002045:Bupivacaine / Q000633:toxicity*; D004638:Emergency Treatment; D004655:Emulsions / Q000008:administration & dosage*; D006331:Heart Diseases / Q000139:chemically induced* / Q000628:therapy*; D017148:Infusions, Intraosseous; D008055:Lipids / Q000008:administration & dosage*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D000779:Anesthetics, Local; D004655:Emulsions; D008055:Lipids; D002045:Bupivacaine