Respiratory depression following retrobulbar bupivacaine: three case reports and literature review.

Retrobulbar bupivacaine (0.75%) administration has been implicated as a causative factor in respiratory distress, cardiovascular dysfunction, and various central nervous system disturbances. The three cases here demonstrate two separate occurrences of respiratory and central nervous system (CNS) complications following retrobulbar bupivacaine (Marcaine) injection. It is thought that the immediate and delayed occurrences result from inadvertent injection at either of two sites: intravascularly or directly into the membranous sheath surrounding the optic nerve.