LIPID EMULSION THERAPY FREE

For lipid soluble beta-blockers, they provide a neutral recommendation for cardiac arrest and life-threatening toxicity and for calcium channel blockers they provide a neutral recommendation for cardiac arrest and suggest not using it as first-line therapy in life-threatening toxicity. In patients with hemodynamic instability and bupropion, or amitriptyline overdose, ILE may be considered after other conventional treatments have failed. Based on the current data available from animal models and clinical case reports, they recommend ILE in cardiac arrest from bupivacaine toxicity and suggest its use if other therapies fail in life-threatening toxicity from other local anesthetics. The Lipid Emulsion Workgroup (a collaboration of representatives from all of the major toxicology organizations) published recommendations for the use of ILE in cardiac arrest due to various medications. ILE has been successfully used to treat LAST associated with various regional anesthetic techniques and multiple local anesthetics. If a patient decompensates while receiving regional anesthesia, ILE therapy may be considered along with standard BLS/ACLS protocols. ILE therapy should be considered when there is high suspicion of LAST and hemodynamic instability, such as hypotension and/or bradycardia. Although there are various theorized mechanisms of action for ILE, the “lipid sink” seems the most compelling as it has demonstrated beneficial effects, most frequently in lipid soluble drug overdose, independent of the mechanism of toxicity. For LAST specifically, other mechanisms include active shuttling of local anesthetics away from the heart and brain, cardiotonic effects, and postconditioning cardioprotective effects. In addition to the aforementioned mechanisms, it was hypothesized that ILE activates either or both calcium and sodium channels.

LIPID EMULSION THERAPY FREE

Theoretically, by providing excess fatty acids, ILE overcomes blocked or inhibited enzymes by mass activation, facilitating myocardial free fatty acid utilization. Other proposed mechanisms include modulation of intracellular metabolism and activation of ion channels. The mechanism of action of ILE in toxicology is not clearly understood, but one of the most prevalent theories is that it acts as a “lipid sink.” According to this theory, ILE reduces the volume of distribution of the toxic agent by pulling lipid soluble drugs out of the periphery and into the intravascular compartment, effectively removing them from their site of action, reversing toxicity. The primary triglycerides include linoleic, linolenic, oleic, palmitic, and stearic acids. The 20% IV fat emulsion is made up of 20% soybean oil, 1.2% egg yolk phospholipids, 2.25% glycerin, and water for injection. Intralipid®, or intravenous fat emulsion, is the most commonly reported ILE used for drug toxicity and is composed of two types of lipids: triglycerides and phospholipids. ILE therapy has also been used in life-threatening overdose from lipophilic medications, including but not limited to, calcium channel blockers, beta-blockers, and cyclic antidepressants. Toxicity may occur after an overdose, an intravascular injection, or inadvertent systemic absorption of a local anesthetic. Systemic toxicity from local anesthetics is a rare but potentially fatal complication of regional anesthesia and occurs in approximately 1 out of every 1000 peripheral nerve blocks. ILE is commonly used as a source of calories and essential fatty acids for patients requiring parenteral nutrition and, in recent years, has gained steam for the management of LAST and various other life-threatening overdoses due to lipophilic (fat-soluble) medications. The ED physician suspects that the cardiac arrest may be due to local anesthetic systemic toxicity (LAST) and immediately requests for intravenous lipid emulsion (ILE) therapy. EMS states that the patient received an unknown amount of a local anesthetic prior to the cardiac arrest. A 33-year-old female presents to the emergency department (ED) in cardiac arrest from an outpatient cosmetic procedure.

Lipid emulsion therapy