-Case Reports-

Subarachnoid Block-Induced Deafferentation Pain Successfully Treated with Pentazocine

Hiroaki Kishikawa¹, Zen'ichiro Wajima², Toshiro Shitara³, Toru Shimizu⁴, Hitoshi Adachi⁵ and Atsuhiro Sakamoto¹

¹Department of Anesthesiology, Nippon Medical School, Tokyo, Japan
²Department of Anesthesiology, Tokyo Medical University Hachioji Medical Center, Tokyo, Japan
³Department of Anesthesiology, Seirei Sakura Citizen Hospital, Chiba, Japan
⁴Seseragi Home Clinic Tsukuba, Ibaraki, Japan
⁵Department of Anesthesiology, Zama General Hospital, Kanagawa, Japan

Deafferentation pain induced by subarachnoid block (SAB) is rare, but it can appear in the form of recurrent phantom lower limb pain, new acute-onset stump pain in amputees, lower limb pain in patients with tabes dorsalis, and neuropathic pain. We have previously reported that thiopental is an effective treatment for deafferentation pain induced by therapeutic SAB applied to treat neuropathic pain of central origin. Here, we report the case of an amputee who developed new stump pain in his lower limb immediately after subarachnoid tetracaine was administered prior to appendectomy. A 51-year-old man who had previously undergone right below-knee amputation for acute arterial thrombosis, and who had not previously experienced chronic phantom limb or stump pain, was scheduled for emergency open appendectomy. For anesthesia, we induced SAB with a hyperbaric tetracaine solution. No paresthesia occurred during administration. However, the patient immediately complained of severe, lightning-bolt pain in the right lower limb stump after the SAB was established. He was given intravenous pentazocine, which promptly resolved the pain. Appendectomy was then performed under sedation using intravenous midazolam. The patient did not experience further deafferentation pain during his hospital stay and has reported no stump pain since discharge from the hospital. This case report suggests that SAB induces deafferentation pain in some patients and that this unusual pain can be treated with pentazocine.

J Nippon Med Sch 2017; 84: 183-185

Keywords
deafferentation pain, subarachnoid block, pentazocine

Correspondence to
Hiroaki Kishikawa, Department of Anesthesiology, Nippon Medical School, 1-1-5 Sendagi, Bunkyo-ku, Tokyo 113-8603, Japan
h-k@nms.ac.jp

Received, November 19, 2016
Accepted, March 23, 2017