Intravenous Bupivacaine in Children

To the Editor I question the methodology of a recent study by Polaner et al.1 and the ethics related to injecting bupivacaine (0.1 mL/kg) and epinephrine 1:200,000 IV into 17 healthy children anesthetized with propofol and remifentanil. All other studies quoted in the article’s introduction as the basis for the chosen methodology were, in fact, performed using a test dose of lidocaine with epinephrine, or epinephrine alone.2–5 None used IV bupivacaine. Although the authors used a dose approximately one-tenth (0.25 mg/kg up to maximum of 7.5 mg) of the widely accepted maximum dose (2–2.5 mg/kg), this latter dose pertains to tissue infiltration or regional anesthesia, not an IV bolus. Animal studies indicate central nervous system toxicity in dogs at doses of 5 mg/kg6 and death in sheep at 3.7 mg/kg7 after IV injection. A landmark human volunteer study of bupivacaine infusions in adults revealed symptoms of central nervous system toxicity in all volunteers, and at doses as low as 0.84 mg/kg.8 In the absence of toxicity data on IV bupivacaine boluses in anesthetized children, the study raises several questions. Were parents fully informed of the potential of IV bupivacaine to cause seizures and/or cardiac arrest? Was it really necessary to use bupivacaine instead of lidocaine, or plain epinephrine, given the toxicity of IV bupivacaine? How did the local IRB approve a study with no immediate benefit to enrolled minors while exposing them to the possibility of serious adverse events?9 Kirk Lalwani, MD, FRCA, MCR Department of Anesthesiology and Perioperative Medicine Oregon Health and Science University Portland, Oregon [email protected]