It's this stuff, Intralipid:
It's a fat (hence "lipid'") solution that can be given intravenously. Certain chemicals (some medications, some poisons, some intoxicants) are fat-soluble, which basically means they can be absorbed by or dissolved into fat, but generally do not interact with water the same way.
This property makes it very difficult to get them out of patients' bodies, because the substances we use to flush toxins out of patients (like most IV fluids) tend to be water-based. Treating a patient with Intralipid would give the dangerous medication, poison, or intoxicant a place to go other than the patient's own fat cells, allowing that substance to be flushed from the patient more easily. Among those dangerous substances are THC (the active ingredient in marijuana), synthetic marijuana (a.k.a. Spice), baclofen (a powerful human muscle relaxant), and pesticides like bromethalin, permethrin, and pyrethrin.
We haven't had a very effective way to treat ingestion of these substances in the past, so we are really excited to have access to this treatment!