Lipid Emulsion
Intravenous lipid emulsions (ILE) are sterile, non-pyrogenic fat emulsions used primarily for **parenteral nutrition** to provide a dense source of calories and essential fatty acids. In emergency veterinary medicine, they are increasingly utilized as an **antidote** for lipophilic drug toxicities (e.g., avermectins, local anesthetics like bupivacaine). > **Clinical Warning:** Use with extreme caution in patients with insulin resistance (e.g., diabetes mellitus) or those at risk of pancreatitis. Strict aseptic technique is mandatory as the emulsion strongly supports microbial growth. **Clinical Pearl:** The use of ILE for toxicosis is often referred to as 'Lipid Rescue' therapy.
Mechanism: As a nutritional supplement, lipid emulsions provide **triglycerides** which are hydrolyzed by **lipoprotein lipase** into free fatty acids and glycerol, entering cellular metabolism via **beta-oxidation** to produce ATP. As an antidote, the primary mechanism is the **'lipid sink' theory**: the infusion creates an expanded intravascular lipid phase that sequesters highly lipophilic toxins (e.g., bupivacaine, ivermectin) away from target organs (brain, heart) → reducing clinical toxicity.
Dosing by species
- Parenteral nutrition · Supply 30% (partial peripheral) to 40-60% of energy requirements · IV · continuous · As required · Amount governed by physiological status
- Treatment of lipid-soluble toxicosis (e.g., ivermectin, moxidectin) · 1.5-5 ml/kg of 20% lipid solution as bolus, followed by 0.25-0.50 ml/kg/min infusion. Boluses of 1.5 ml/kg can be repeated. · IV · bolus followed by continuous infusion · Infusion for 30-60 min (maximum 24 hours) · Infusions of 0.5 ml/kg/min can be administered for a maximum of 24 hours.
- Parenteral nutrition · Supply 40-60% of energy requirements · IV · continuous · As required · Generally used as an energy source in a nutrient admixture for infusion through central venous access (total parenteral nutrition).
- Treatment of lipid-soluble toxicosis (e.g., ivermectin, moxidectin) · 1.5-5 ml/kg of 20% lipid solution as bolus, followed by 0.25-0.50 ml/kg/min infusion. Boluses of 1.5 ml/kg can be repeated. · IV · bolus followed by continuous infusion · Infusion for 30-60 min (maximum 24 hours) · Infusions of 0.5 ml/kg/min can be administered for a maximum of 24 hours.
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Routes of administration
Contraindications
- Insulin resistance (e.g., diabetes mellitus)
- Hyperlipidaemia
- Disrupted fat metabolism
Adverse effects
- Febrile episodes (mainly with 20% emulsions)
- Vasculitis
- Thrombosis
- Anaphylaxis (rare)
- Hepatic failure (with prolonged treatment)
- Pancreatitis (with prolonged treatment)
- Cardiac arrest (with prolonged treatment)
- Thrombocytopenia (with prolonged treatment)
Drug interactions
- Other IV medications · Physical incompatibility; requires dedicated IV line for parenteral feeding · major
- Biochemical assays · Lipaemia interferes with blood gas and calcium measurements if samples are taken before fat is cleared · moderate
Monitoring
- Plasma clearance (visual lipaemia or serum triglycerides daily)
- Blood glucose
- Pancreatic enzymes
- Coagulation profile (if prolonged use)
Overdose
Overdosage or failure to clear lipids can lead to **fat overload syndrome**, characterized by hyperlipidaemia, fever, jaundice, hepatosplenomegaly, and coagulopathy. Treatment involves immediate cessation of the infusion and supportive care.
VetSheet drug reference is intended for licensed veterinary professionals as a clinical decision-support aid, not a substitute for professional judgement or the manufacturer’s current label.