Experimental subdural retrobulbar injection of anesthetic.

Sudden respiratory arrest following retrobulbar block, a complication which has gained increasing attention, is explained by an experimental study in which radiopaque dye was injected into the intraorbital subdural space, as could easily be done in a living patient, and was shown by radiography to diffuse posteriorly along the subdural space to the midbrain surrounding the respiratory center. Clinical implications are discussed.