3-in-1 lumbar plexus block for muscle biopsy in malignant hyperthermia patients. Amide local anaesthetics may be used safely.

A 3-in-1 lumbar plexus block with the aid of a nerve stimulator was performed in 32 patients and a psoas compartment block was performed in five patients for muscle biopsy of the upper leg for diagnosis of malignant hyperthermia (MH) susceptibility. Twenty-two patients were found to be MH susceptible by the in vitro contracture test. Twenty patients received 40 ml prilocaine 1.5% with epinephrine 1:200,000 and two received 40 ml bupivacaine 0.5% with epinephrine 1:200,000 without any untoward reaction. The 3-in-1 block provides a high success rate and excellent analgesia for muscle biopsy of the upper leg. Amide local anaesthetics are safe in MH-susceptible patients.