In this episode, I’ll discuss the dosing of lipid rescue therapy for LAST vs enteral drug toxicity.
Intravenous lipid emulsion (ILE) or “lipid rescue” therapy is used in local anesthetic systemic toxicity (LAST) and enteral drug toxicity. Anesthesia, toxicology, and ACLS guidelines recommend intravenous fat emulsion with various levels of evidence.
Ever since the American College of Medical Toxicology published a position statement in 2016, the recommended dosing of lipid emulsion has been different for local anesthetic systemic toxicity (LAST) vs enteral drug toxicity.
For both indications, a bolus dose of 1.5 mL/kg 20% ILE is recommended.
For LAST, this is followed by an infusion of 0.25 mL/kg/min.
For enteral drug toxicity, after 3 minutes at 0.25 mL/kg/min the rate of ILE infusion is reduced by 90% to 0.025 mL/kg/min.
The ACMT position statement recommends this maintenance dose decrease due to concerns for adverse effects from extremely high cumulative rates of lipid infusion, and a desire to be able to monitor the impact of initial therapy in a dynamic enteral overdose situation. The idea is that this lower infusion rate should be enough to maintain the positive effects of lipids while avoiding lipid overload.
Because this intervention is rarely used and is only called for in stressful cardiac arrest or impending cardiac arrest situations, pharmacists can improve the likelihood of dosing lipid emulsion for enteral drug toxicity according to the ACMT recommendations by preparing in advance and educating relevant clinical staff who are involved in the ordering and administering of lipid rescue therapy.
While this difference in dosing is not relevant to perioperative units that are likely only going to be using lipid emulsion for LAST, ED and ICU areas should be aware of this lower dosing. Ideally, copies of the American College of Medical Toxicology recommendations for the use of IV fat emulsion in enteral drug toxicity would be made available with lipid emulsion either in automated dispensing cabinets or with dispensing from the central pharmacy.
In patients who weigh over 70 kg, especially obese patients, doses of ILE to treat LAST would get quite large if based on actual body weight. For this reason, the American Society of Regional Anesthesia (ASRA) recommends capping the bolus for patients over 70 kg to 100 mL of 20% ILE, and making the follow-on infusion 250 mL over 15-20 minutes which is 750-999 mL/hr on an infusion pump. A maximum suggested dose by ASRA of 20% ILE is 12 mL/kg.
Keep in mind that when treating a patient with LAST, one 250 mL bag will not be enough for a complete course of therapy for most patients. To address this shortfall, you could stage more than 1 bag of ILE in areas likely to treat LAST, or as soon as the bolus is given and the infusion is started, educate providers to request that additional ILE be brought to the bedside immediately.
Members of my Hospital Pharmacy Academy have access to my complete Lipid Rescue training that covers the background of ILE therapy in-depth for both LAST and enteral drug toxicity. You can get immediate access to this and hundreds of other trainings and resources to help in your practice at pharmacyjoe.com/academy.
If you like this post, check out my book – A Pharmacist’s Guide to Inpatient Medical Emergencies: How to respond to code blue, rapid response calls, and other medical emergencies.
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