A Case of Brainstem Anesthesia after Retrobulbar Block for Globe Rupture Repair.

Abstract

Purpose: To present a rare case of brainstem anesthesia from retrobulbar block and discuss evidence-based methods for reducing the incidence of this complication.

Case: A 72-year-old female, was given a retrobulbar block of 5 mL of bupivacaine 0.5% for postoperative pain management, after a globe rupture repair under general anesthesia. Prior to injection, the patient was breathing spontaneously via the anesthesia machine circuit and had not received any additional narcotics/muscle relaxants for 2.5 hr (with full recovery of neuromuscular blocking agent after anesthetic reversal). Over 7 min, however, there was a steady increase in ETCO₂ and the patient became apneic, consistent with brainstem anesthesia. She remained intubated and was transported to the postanesthesia care unit for prolonged monitoring, with eventual extubation. Discussion. Brainstem anesthesia is an important complication to recognize as it can lead to apnea and death. The judicious use of anesthetic volume, shorter needle tips, and mixed formulations can help reduce the chance of brainstem anesthesia. Observation of the contralateral eye 5-10 minutes after injection for pupillary dilation, and prior to surgical draping, can help identify early CNS involvement.