Successful Therapy Of Phantom Pain In The Upper Limb By Blocking The Brachial Plexus

Abstract

Early treatment of phantom limb pain in patients after amputation reduces the incidence of chronic pain sensations from 60 85 % to 10 20 % [1]. A 33 year old patient with osteosarcoma of proximal humerus developed a burning pain VAS 7-8 (Visual analog scale 0-10) of the left hand and fingers three days after amputation of the left arm in the shoulder joint. Treatment with calcitonin, amitriptyline, naproxen, piritramide and carbamazepine did not influence the pain. On the seventh day an interscalene block was done with the use of a nerve stimulator. After a bolus of 30 ml ropivacaine 0.2 % was infused with a rate of 6 ml/h for ten days. Within a time period of ten minutes the phantom limb pain was relieved (VAS 0). After four hours phantom limb sensations developed, but were not classified as pain by the patient. With the option of a patient controlled bolus of 5 ml (2x /h) it was possible to reduce the additional pain therapy to carbamazepine and amitriptyline. During the ropivacaine treatment no motor blockade or other side effects were observed. After ten days the catheter site showed minor signs of inflammation and the catheter was removed. In an early follow-up (5 month) the patient reported mild phantom limb sensations and infrequent phantom pain (VAS 1-2), no analgesic medication was necessary. Interscalene block provided comfortable and safe analgesia for this patient and helped to avoid development of chronic phantom limb pain. A comparable therapy using bupivacaine would have led to toxic plasma concentrations. Ropivacaine is not only less toxic (16), it also provides the advantage of a less intensive motor blockade (17), limiting the danger of phrenic nerve block.