Lipid Resuscitation： Update on the Mechanism, Administration Protocol and Side Effects

Abstract

Scavenging and non-scavenging（direct）effects are suggested as mechanisms for treatment of local anesthetic systemic toxicity by lipid emulsion. Scavenging effect was formerly called lipid sink, where lipid emulsion uptakes local anesthetics, reduces their concentration in the brain and in the heart, and transports them to the liver for facilitating elimination from the circulating blood. Direct effects include volume effect, an increase in energy supply to the heart, protective effect of mitochondria, and improvement of insulin signaling. The American Society of Regional Anesthesia revised the“Checklist for treatment of local anesthetics systemic toxicity”in 2017. Although the administration regimen of lipid emulsion has not changed for patients ≤ 70 kg, bolus 100 mL over 2−3 min, followed by 200−250 mL of 20％ lipid emulsion over 15−20 min is recommended for patients ≥ 70 kg. The maximum dose is 12 mL/kg. Lung injury and pancreatitis are typical complications by lipid emulsion, although their incidence is low. Blood tests to examine serum amylase and lipase are recommended after administration of lipid emulsion for resuscitation.