SIMULATED PERIBULBAR INJECTION OF ANESTHETIC

To evaluate whether intracranial spreading of a local anesthetic might occur after a peribulbar injection, we did simulated peribulbar anesthetic injections with radiopaque dye into two cadaver heads. Using a standard and modified peribulbar injection with a 25-gauge needle, the four orbits were injected with 8mL of dye. Computed tomography revealed that the dye spread intraconally and intracranially. In one case the dye was seen tracking along the optic nerve sheath. Since intracranial spreading of a local anesthesic may be associated with adverse sequelae (i.e., brainstem anesthesia), we urge caution and vigilance after both peribulbar and retrobulbar anesthetic injections to prevent cardiopulmonary compromise.