The duration of spinal anesthesia with 5% lidocaine in chronic opium abusers compared with nonabusers.

Abstract

It has been demonstrated that chronic opium abusers have lower thresholds for pain. In this study we sought to determine whether chronic opium abuse has any effect on the duration of spinal block by local anesthetics. In a case-controlled study, 50 opium abusers and 50 nonabusers undergoing lower abdomen operations were selected from among the patients admitted to a university hospital for elective surgery. All patients received 100 mg hyperbaric preservative-free 5% lidocaine in dextrose, intrathecally. The duration of anesthesia was much shorter in the opium abusers (60 +/- 7 min) than in the nonabusers (83 +/- 10 min) (P < 0.0001). The study documents a shortened duration of spinal block in opium abusers.