Brain-stem anesthesia as a complication of regional anesthesia for ophthalmic surgery

Brain-stem anesthesia is a serious complication of orbital regional anesthesia that may occur when the injected local anesthetic agent gains access to the central nervous system by direct spread from the apex of the orbit via submeningeal pathways. In most studies the reported incidence rate during retrobulbar block is one case per 350 to 500 patients. Failure to recognize the condition or to treat it adequately may be life threatening. Treatment includes reassurance, intravenous administration of fluids, pharmacologic circulatory support or suppression of convulsions, and cardiopulmonary resuscitation. With proper treatment complete recovery is the rule. In all situations in which orbital block is to be done, basic cardiopulmonary resuscitation equipment and personnel familiar with its use are essential. Monitoring of the blood pressure, electrocardiography and pulse oximetry should be routine. Having the globe in primary gaze renders the optic nerve less vulnerable, and avoidance of deep penetration of the orbit is of great importance.