SLR - March 2011 - Karen Shum
Reference: Borghi Battista MD, D'Addabbo Marco MD, White Paul F. MD, PhD, Gallerani Pina Toccaceli Letizia MD, Raffaeli William MD, Tognù Andrea MD, Fabbri, Nicola MD, Mercuri Mario MD. The Use of Prolonged Peripheral Neural Blockage After Lower Extremity Amputation: The Effect on Symptoms Associated with Phantom Limp Syndrome. Anesthesia and Analgesia. Volume 111(5), November 2010, 1308-1315.
Scientific Literature Review
Reviewed by: Karen Shum, DPM
Residency Program: Cedars-Sinai Medical Center
Podiatric Relevance:
There is a high prevalence of stump pain, phantom limb pain, or phantom limb sensation with patients who have had lower extremity amputations. This phenomenon is called phantom limb syndrome. The incidence of phantom limb syndrome can be as high as 90% of patients who undergo lower limb amputation. The article evaluates the use of prolonged perineural infusion with a high concentration local anesthetic to manage phantom limb syndrome.
Method:
This is a prospective observational study that started with 71 patients who were underwent a lower extremity amputation. Patients were given a sciatic nerve perineural block with catheter placement pre- or intra-operatively depending on the level of lower extremity amputation. They were started on a continuous infusion of 0.5% ropivicaine at a rate of 5 ml/h and this was continued after surgery. Phantom limb syndrome was assessed at set time intervals following the surgery and for up to 12 months. Before each assessment interval, the infusion was discontinued for 6-12 hours. The phantom limb and stump pain was then evaluated using the 5 point verbal rating scale (VRS). The anesthetic infusion was discontinued if the VRS was 0 to 1 and if the patient did not experience phantom limb syndrome for 48 hours.
Results:
The median duration of perineural infusion in lower extremity amputees was 30 days, and ranged from 4 to 83 days. The first post-operative day was when 73% of the patients related of severe to intolerable pain. After 12 months of patient evaluation, the incidence of severe to intolerable pain had decreased to 3% following amputation. 84% of the amputees had complete resolution of phantom limb pain and reported of VRS pain score of 0 at the end of 12 months. For 39% of the patients, phantom limb syndrome was present at the end 12 months.
Conclusion:
The peripheral nerve blockade has an effect in thwarting the transmission of pain signals to the sensory nerve endings that have been transected. This study showed that by administering a prolonged peripheral nerve blockade, relief of phantom limb pain can be adequately achieved in lower extremity amputees.