Local Anesthetic Systemic Toxicity: Are You Prepared?

Vigilance and meticulous preparation are critical, both in providing high quality anesthesia care with the best possible outcomes, and in enabling the practicing anesthesiologist to avoid medico-legal complications. Perhaps in no other anesthesia-related situation is this truer than in the all too common and potentially deadly complication of local anesthetic systemic toxicity (LAST). Estimated to have an occurrence as frequent as 1/1000 with countless closed claims examples, this dreaded complication of the use of local anesthetics results often in CNS and/or cardiac collapse that is particularly resistant to treatment with resuscitations, sometimes lasting more than an hour and with the use of cardiopulmonary bypass occasionally required.

The one bit of good news regarding this costly complication has been the discovery of the specific use of 20% Lipid Emulsion to treat and possibly even prevent such prolonged resuscitation needs. There are numerous review articles detailing the successful use of Lipid Emulsion 20% in the treatment of LAST, and each one emphasizes the importance of early recognition and quick treatment. With every minute that goes by in such an arrest, increasing acidosis and hypercarbia aggravate and accelerate the toxic effects in the CNS and cardiovascular system. Time wasted sending someone to find Lipid Emulsion, or large syringes, or IV tubing, is time the patient cannot afford to lose.

For this reason, it is recommended by many sources to have a LAST Rescue Kit available at the bedside whenever a peripheral block is performed and also one easily available in the general operating room for use if a surgeon inadvertently gives a toxic dose of local anesthetic. Such LAST Rescue Kits can be customized by individual groups, but the basic components should include:

• Basic airway management tools:
  • laryngoscopes, endotracheal tubes, LMA's, airways
• Benzodiazepine for seizure suppression
• Lipid Emulsion 20% 1000 ml
• Macro-drip tubing
• #3 50-60 ml syringes
• 3-way stopcock so that boluses can be obtained and administered via macro-drip tubing.
• Large bore IV access equipment
• Telephone number for nearest facility having cardiopulmonary bypass capability

Most importantly, each LAST Rescue Kit should include the "Checklist for Treatment of Local Anesthetic Systemic Toxicity," which is available on the Regional Anesthesia and Pain Medicine website (www.rapm.org) under search-term "LAST checklist."

Last, but not least, in enabling vigilance and preparation to benefit our patients in the potentially catastrophic occurrence of LAST, is proper education and familiarity with such kits, not only within our own departments of Anesthesia but also among our Surgical and Emergency Medicine colleagues whose practices may bring them face-to-face with this dreaded complication.