The use of prolonged peripheral neural blockade after lower extremity amputation: the effect on symptoms associated with phantom limb syndrome.
BACKGROUND
Phantom limb syndrome (PLS) is common after limb amputations, involving up to 90% of amputees. Although many different therapies have been evaluated, none has been found to be highly effective. Therefore, we evaluated the efficacy of a prolonged perineural infusion of a high concentration of local anesthetic solution in preventing PLS.


METHODS
A perineural catheter was placed immediately before or during surgery in 71 patients undergoing lower extremity amputation. A continuous infusion of 0.5% ropivacaine was started intraoperatively at 5 mL/h using an elastomeric (nonelectronic) pump, and continued for 4 to 83 days after surgery. PLS was evaluated on the first postoperative day and then 1, 2, 3, and 4 weeks, and 3, 6, 9, and 12 months after surgery. To evaluate the presence and severity of PLS while the patient was receiving the ropivacaine infusion, it was discontinued for 6 to 12 hours before each assessment period (i.e., until the sensation in the extremity returned). The severity of phantom limb and stump pain was assessed using a 5-point verbal rating scale (VRS), with 0 = no pain to 4 = intolerable pain, and "phantom" sensations were recorded as present or absent. If the VRS score was >1 or significant phantom sensations were present, the ropivacaine infusion was immediately restarted at 5 mL/h. If the VRS score remained at 0 to 1 and the patient had not experienced phantom sensations for 48 hours, the infusion was permanently discontinued and the catheter was removed.


RESULTS
Median duration of the local anesthetic infusion was 30 days (95% confidence interval, 25-30 days). On postoperative day 1, 73% of the patients complained of severe-to-intolerable pain (visual analog scale >2). However, the incidence of severe-to-intolerable phantom limb pain was only 3% at the end of the 12-month evaluation period. At the end of the 12-month period, the percentage of patients with VRS pain scores were 0 = 84%, 1 = 10%, 2 = 3%, 3 = 3%, and 4 = none. However, phantom limb sensations were present in 39% of patients at the end of the 12-month evaluation period. All patients were able to manage the elastomeric catheter infusion system at home.


CONCLUSIONS
Use of a prolonged postoperative perineural infusion of ropivacaine 0.5% seems to be an effective therapy for the treatment of phantom limb pain and sensations after lower extremity amputation.
Borghi
Battista
B
Department of Surgery and Anesthesiology Sciences, University of Bologna, Bologna, Italy.
D'Addabbo
Marco
M
White
Paul F
PF
Gallerani
Pina
P
Toccaceli
Letizia
L
Raffaeli
William
W
Tognù
Andrea
A
Fabbri
Nicola
N
Mercuri
Mario
M
D000293:Adolescent; D000328:Adult; D000368:Aged; D000577:Amides / Q000008:administration & dosage*; D000671:Amputation, Surgical / Q000009:adverse effects*; D016058:Analgesia, Patient-Controlled; D000701:Analgesics, Opioid / Q000008:administration & dosage; D000779:Anesthetics, Local / Q000008:administration & dosage*; D002404:Catheterization; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D006801:Humans; D007260:Infusion Pumps; D007558:Italy; D035002:Lower Extremity / Q000294:innervation / Q000601:surgery*; D008875:Middle Aged; D009020:Morphine / Q000008:administration & dosage; D009407:Nerve Block; D010147:Pain Measurement; D010149:Postoperative Pain / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control*; D017933:Peripheral Nervous System / Q000187:drug effects* / Q000503:physiopathology; D010591:Phantom Limb / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control*; D011446:Prospective Studies; D000077212:Ropivacaine; D012677:Sensation / Q000187:drug effects; D012720:Severity of Illness Index; D013577:Syndrome; D013997:Time Factors; D016896:Treatment Outcome; D055815:Young Adult
D000577:Amides; D000701:Analgesics, Opioid; D000779:Anesthetics, Local; D009020:Morphine; D000077212:Ropivacaine