Intralipid – myth or miracle?

Intralipid is one of the most exciting recent developments in clinical toxicology (right up there with high-dose insulin euglycemic therapy, aka HIET). We are rightly skeptical of any new therapy, especially one that promises so much. Nevertheless, many of the animal studies and published case reports are quite dramatic.

For instance, this video shows the left ventricular pressure and electrocardiogram tracings of an intact, anesthetized rat during acute bupivacaine cardiotoxicity and successful recovery with a lipid emulsion infusion.

WARNING: you may develop optokinetic nystagmus watching this!

The Poison Review recently commented on the first published case describing the clinical use of intralipid in reversing propanolol toxicity. Importantly, some of the caveats in interpreting this type of report are highlighted. Nevertheless, it’s well worth remembering intralipid as a last-ditch measure for the resuscitation of a patients with cardiotoxicity induced by a lipophilic drug.

You can find out more about intralipid from its major proponents at lipidrescue.org. They suggest the use of intralipid when standard resuscitation methods fail to re-establish sufficient circulatory stability. Their suggested treatment protocol (with my comments in brackets) is as follows:

20% Intralipid

• 1.5 mL/kg as an initial bolus
  (e.g. about 100 mL in a 70kg adult)
  followed by
• 0.25 mL/kg/min for 30-60 minutes
  (e.g. about 600 mL over 30 minutes in a 70kg adult)
• Bolus could be repeated 1-2 times for persistent asystole
  (e.g. at 5 minute intervals)
• Infusion rate could be increased if blood pressure declines
  (e.g. double the infusion rate)

Most importantly, however, we must remember to do the basics right — maintain effective CPR throughout — and don’t give up! Good neurological outcomes can be achieved even with hours of CPR in the setting of cardiotoxic poisoning.

References

• Cave G, Harvey M. Intravenous lipid emulsion as antidote beyond local anesthetic toxicity: a systematic review. Acad Emerg Med. 2009 Sep;16(9):815-24. PMID: 19845549.
• Leskiw U, Weinberg GL. Lipid resuscitation for local anesthetic toxicity: is it really lifesaving? Curr Opin Anaesthesiol. 2009 Oct;22(5):667-71.  PMID: 19581805.
• Sirianni AJ, Osterhoudt KC, Calello DP, Muller AA, Waterhouse MR, Goodkin MB, Weinberg GL, Henretig FM. Use of lipid emulsion in the resuscitation of a patient with prolonged cardiovascular collapse after overdose of bupropion and lamotrigine. Ann Emerg Med. 2008 Apr;51(4):412-5, 415.e1. Epub 2007 Sep 4. PMID: 17766009.