Intralipid

Intralipid is a brand name for the first safe fat emulsion for human use, approved in 1962 and invented by Professor Arvid Wretlind, Sweden. It is given intravenously to patients who are unable to get enough fat in their diet. It is an emulsion of soy bean oil and egg phospholipids. Some preparations of the anaesthetic drugs propofol and etomidate are supplied using Intralipid as a vehicle.

Weinberg et al have published data indicating Intralipid is effective in treating experimental models of severe cardiotoxicity secondary to intravenous overdose of local anaesthetic drugs such as bupivacaine (Picard & Meek 2006, Weinberg et al 1998, 2003 and 2004). Recent case reports have been published of the successful use of lipid emulsion in this way (Rosenblatt 2006, Litz 2006, Foxall 2007) to save patients who were unresponsive to the usual resuscitation methods. All patients recovered completely shortly after intravenous injections of lipid.

Intralipid is also widely used in optical experiments to simulate the scattering properties of biological tissues (Driver et al. 1989). Solutions of appropriate concentrations of intralipid can be prepared that closely mimic the response of human or animal tissue to light at wavelengths in the red and infrared ranges where tissue is highly scattering but has a rather low absorption coefficient.

References

*Driver I, Feather J W, King P R, Dawson J B. The optical properties of aqueous suspensions of Intralipid, a fat emulsion. Physics in Medicine and Biology 1989, Vol.34 No. 12, 1927–1930.
*Foxall G, McCahon R, Lamb J, Hardman JG, Bedforth NM. Levobupivacaine-induced seizures and cardiovascular collapse treated with Intralipid. Anaesthesia 2007 62:5, 516-518.
*Litz, RJ, Popp M, Stehr S N, Koch T. Successful resuscitation of a patient with ropivacaine-induced asystole after axillary plexus block using lipid infusion. Anaesthesia 2006;61:800-1.
*Picard J, Meek T. Lipid emulsion to treat overdose of local anaesthetic: the gift of the glob (editorial). Anaesthesia 2006;61:107-9.
*Rosenblatt MA, Abel M, Fischer GW, Itzkovich CJ, Eisenkraft JB. Successful Use of a 20% Lipid Emulsion to Resuscitate a Patient after a Presumed Bupivacaine-related Cardiac Arrest. Anesthesiology 2006;105:217-8.
*Weinberg GL, VadeBoncouer T, Ramaraju GA, Garcia-Amaro MF, Cwik MJ. Pretreatment or resuscitation with a lipid infusion shifts the dose-response to bupivacaine-induced asystole in rats. Anesthesiology 1998; 88: 1071-5.
*Weinberg G, Ripper R, Feinstein DL, Hoffman W. Lipid emulsion infusion rescues dogs from bupivacaine-induced cardiac toxicity. Regional Anesthesia and Pain Medicine 2003; 28: 198-202.
*Weinberg G. Reply to Drs. Goor, Groban and Butterworth – Lipid rescue: Caveats and recommendations for the “silver bullet” (letter). Regional Anesthesia and Pain Medicine 2004; 29: 74.

External links

* [http://www.lipidrescue.org Lipid rescue] (intralipid as antidote)