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AMERICAN SOCIETY OF REGIONAL AND MEDICINE

Practice Advisory on Treatment of Local Systemic Toxicity

For Patients Experiencing Signs or Symptoms of Systemic Toxicity (LAST) • Get Help • Initial Focus o : ventilate with 100% oxygen o suppression: are preferred o Basic and Advanced Cardiac Life Support (BLS/ACLS) may require prolonged effort • Infuse 20% (values in parenthesis are for a 70 kg patient) o Bolus 1.5 mL/kg (lean body mass) intravenously over 1 min (~100 mL) o Continuous infusion at 0.25 mL/kg/min (~18 mL/min; adjust by roller clamp) o Repeat bolus once or twice for persistent cardiovascular collapse o Double the infusion rate to 0.5 mL/kg per minute if pressure remains low o Continue infusion for at least 10 mins after attaining circulatory stability o Recommended upper limit: approximately 10 mL/kg lipid emulsion over the first 30 mins • Avoid vasopressin, calcium channel blockers, β-blockers, or local anesthetic • Alert the nearest facility having cardiopulmonary bypass capability • Avoid in patients having signs of cardiovascular instability • Post LAST events at www.lipidrescue.org and report use of lipid to www.lipidregistry.org

© 2010 American Society of Regional Anesthesia and Pain Medicine ASRA hereby grants practitioners the right to reproduce this document as a tool for the care of patients who receive potentially toxic doses of LAs. Publication of these recommendations requires permission from ASRA. The ASRA Practice Advisory on Local Anesthetic Toxicity is published in the society’s official publication Regional Anesthesia and Pain Medicine, and can be downloaded from the journal Web site at www.rapm.org. Neal JM, Weinberg GL, Bernards CM, et al. ASRA practice advisory on local anesthetic systemic toxicity. Reg Anesth Pain Med 2010;35:152-161.

Continued on reverse… BE PREPARED o Depression (drowsiness, obtundation, • We strongly advise that those using local , apnea) (LAs) in doses sufficient o Nonspecific (metallic taste, circumoral to produce systemic toxicity (LAST) numbness, diplopia, , establish a plan for managing this dizziness) complication. Making a local anesthetic • Cardiovascular signs (often the only toxicity kit and posting instructions for its manifestation of severe LAST) use are encouraged. • Initially may be hyperdynamic (, tachycardia, ventricular ), RISK REDUCTION (BE SENSIBLE) then • Use the least dose of LA necessary to o Progressive achieve the desired extent and duration of o Conduction block, bradycardia, or block. asystole • Local anesthetic blood levels are o Ventricular (ventricular influenced by site of and dose. tachycardia, torsades de pointes, Factors that can increase the likelihood of ventricular fibrillation) LAST include: advanced age, • reduce seizure failure, ischemic heart disease, conduction risk, but even light may abolish abnormalities, metabolic (eg, mitochondrial) the patient’s ability to recognize or report disease, disease, low plasma protein symptoms of rising LA concentrations. concentration, metabolic or respiratory acidosis, and that inhibit channels. Patients with severe TREATMENT cardiac dysfunction, particularly very low • Timing of lipid infusion in LAST is ejection fraction, are more sensitive to controversial. The most conservative LAST and also more prone to receive approach, waiting until after ACLS has ‘stacked’ injections (with resulting proven unsuccessful, is unreasonable elevated LA tissue concentrations) because early treatment can prevent because of slowed circulation time. cardiovascular collapse. Infusing lipid • Consider using a pharmacologic marker at the earliest sign of LAST can result in and/or test dose, for example, epinephrine unnecessary treatment because only a 5 μg/mL of LA. Know the expected response, fraction of patients will progress to onset, duration, and limitations of a “test severe toxicity. The most reasonable dose” in identifying intravascular injection. approach is to implement lipid therapy on • Aspirate the syringe prior to each injection the basis of clinical severity and rate of while observing for blood. progression of LAST. • Inject incrementally, observing for signs • There is laboratory evidence that epinephrine and querying frequently for symptoms of can impair resuscitation from LAST and toxicity between each injection. reduce the efficacy of lipid rescue. Therefore it is recommended to avoid DETECTION (BE VIGILANT) high doses of epinephrine and use smaller • Use standard American Society of doses, for example, 1 μg/kg, for treating Anesthesiologists (ASA) monitors. hypotension. • Monitor the patient during and after • Propofol should not be used when there completing the injection, as clinical are signs of cardiovascular instability. toxicity can be delayed up to 30 mins (or Propofol is a cardiovascular longer after tumescent procedures). with lipid content too low to provide • Consider LAST in any patient with benefit. Its use is discouraged when there altered mental status, neurologic symptoms, is a risk of progression to cardiovascular or cardiovascular instability following a collapse. regional anesthetic. • Prolonged (> 12 hrs) is • Central signs (may be recommended after any signs of cardiac subtle or absent) toxicity because cardiovascular depression o Excitation (agitation, confusion, due to LAs can persist or recur after muscle twitching, seizure) treatment.