The American Society of Regional Anesthesia and Pain Medicine Practice Advisory on Local Anesthetic Systemic Toxicity assimilates and summarizes current knowledge regarding the prevention, diagnosis, and treatment of this potentially fatal complication. It offers evidence-based and/or expert opinion-based recommendations for all physicians and advanced practitioners who routinely administer local anesthetics in potentially toxic doses. The advisory does not address issues related to local anesthetic-related neurotoxicity, allergy, or methemoglobinemia. Recommendations are based primarily on animal and human experimental trials, case series, and case reports. When objective evidence is lacking or incomplete, recommendations are supplemented by expert opinion from the Practice Advisory Panel plus input from other experts, medical specialty groups, and open forum. Specific recommendations are offered for the prevention, diagnosis, and treatment of local anesthetic systemic toxicity.

For ambulatory patients at our institution, the time to achievement of discharge criteria was significantly reduced with CP 40 vs. lidocaine 60 mg. There have been no reports of perioperative neurologic injury with the introduction of CP as a spinal anesthetic at our institution.

Although new drugs and techniques may improve outcomes when unintended high blood levels of local anesthetics occur, the primary focus of daily practice should remain the prevention of such events. Although adoption of no single "safety step" will reliably prevent systemic toxicity, the combination of several procedures seems to have reduced the frequency of systemic toxicity since 1981. These include the use of minimum effective doses, careful aspiration, and incremental injection, coupled with the use of intravascular markers when large doses are used. Epinephrine remains the most widely used and studied marker, but its reliability is impaired in the face of beta-blockade, anesthesia, advanced age, and active labor. As an alternative, the use of subtoxic doses of local anesthetics themselves can produce subjective symptoms in unpremedicated patients. Fentanyl has also been confirmed to produce sedation in pregnant women when used as an alternative. The use of ultrasound observation of needle placement and injection may be useful, but has also been reported as not completely reliable. Constant vigilance and suspicion are still needed along with a combination of as many of these safety steps as practical.

This is the first study to examine the relationship between concentration and density for custom drug concentrations commonly used in implanted intrathecal pumps. We calculated an equation that defines the relationship between concentration and density for each drug. Using these equations, clinicians can calculate the density of any solution made from the drugs studied here.

Epinephrine test-dose administration in nonsedated, chronically β-blocked patients cannot distinguish intravenous injection at the classic threshold increase of 20 bpm. The response in individuals is varied, and thresholds for a positive test need revising for this population of patients on therapeutic β-blockers.