Severe Respiratory Depression and Intracranial Air after Epidural Morphine -Subdural or Epidural Injection?-

Massive extradural spread, distinguished from subarachnoid injection that sometimes follows the introduction of small amounts of local anesthetics or narcotics during attempted epidural anesthesia or analgesia, has been attributed to subdural injection. A 64-year-old woman was admitted for partial radical hysterectomy under general anesthesia after insertion of lumbar epidural cathter by loss of resistance technique with 5 ml of air. In this case, we experienced severe respiratory depression and loss of consciousness after administration of 4 mg of morphine for postoperative pain control. We confirmed air shadows at right silvian and suprasella cisterna region by CT scanning. Patients was recovered without sequele after 2 days, As this case resembles a "massive epidural", it is suggested that subdural injection rather than epidural injection may explain the phenomenon.