The Preventive Value of Epidural Calcitonin in Patients with Lower Limb Amputation

Abstract Background. Postamputation pain is highly prevalent after limb amputation with neuropathic nature; calcitonin may effectively relieve many neuropathic pain states. Design. Double-blind randomized multicenter study. Setting. Our study hypothesis is to evaluate the preventive value of epidural calcitonin on postoperative pain, grade of phantom pain, and the development of allodynia and hyperalgesia in patients undergoing lower limb amputation. Patients. A cohort of 60 diabetic patients of both genders suffering from vascular insufficiency of one or both lower limbs underwent minor or major lower limb amputation. Patients were divided randomly into two equal groups: an epidural bupivacaine-calcitonin-fentanyl (BCF) group and a bupivacaine-fentanyl (BF) group. Methods. Patients were instructed about the use of a 10 cm visual analog scale (VAS). Phantom limb pain was graded using a four-grade scale. Pin-prick hyperalgesia and allodynia were evaluated at one week, one month, three months, and six months after surgery. Results. There were no significant differences between groups regarding patients' characteristics. There was no significant difference in the VAS scale between groups. There was statically significant improvement in the grade of phantom pain in the BCF group at six and 12 months after surgery (P = 0.033 and 0.001, respectively). A significantly higher number of patients developed allodynia in the BF group at six (P = 0.039) and 12 (P = 0.013) months and hyperalgesia at 12 months (P = 0.025). Conclusion. The preventive use of epidural calcitonin improved the grade of phantom pain and reduced the incidence of allodynia and hyperalgesia in patients undergoing lower limb amputation under combined spinal-epidural anesthesia during one year of follow-up.