This case conference reports two cases of epidural anesthesia in which air
was used to identify the epidural space during a loss-of-resistance placeme
nt technique. Both patients subsequently complained of severe pain and subd
ural air was demonstrated in case 1 by computed tomography and in case 2 by
magnetic resonance imaging. The possible causes of the pain syndrome exper
ienced by both patients are discussed. (C) 2001 by Elsevier Science Inc.