Free
Correspondence  |   January 2012
In Reply
Author Affiliations & Notes
  • Menelaos Karanikolas, M.D., M.P.H.
    *
  • *Washington University School of Medicine, St. Louis, Missouri.
Article Information
Correspondence
Correspondence   |   January 2012
In Reply
Anesthesiology 1 2012, Vol.116, 224-225. doi:10.1097/ALN.0b013e31823bdccd
Anesthesiology 1 2012, Vol.116, 224-225. doi:10.1097/ALN.0b013e31823bdccd
We would like to thank Drs. Lindsay, Pyati, Buchheit, and Shaw for their interest in our study1 and for raising the important issue of residual limb pain. As they correctly point out, our study had a small sample size and did not differentiate between subtypes of residual limb pain. However, based on data from previous studies by Bach et al  .2 and Nikolajsen et al  .,3 our clinical trial was designed to study phantom limb pain (phantom limb pain intensity at 6 months was our primary endpoint), whereas residual limb pain was only one of several secondary outcomes.
At the 6-month follow-up, our study did not show any difference between treatment and control groups with regard to residual limb pain, and in fact only one or two patients in each group (including the control group) had any residual limb pain. Therefore, we believe that even if we had looked at subclassifications of residual limb pain, we would not be able to show any significant differences because of small sample size and the need to use Bonferroni correction, to avoid spurious “significant” findings due to multiple comparisons.
Of course, we agree that residual limb pain after amputation is an important issue that deserves more study. A clinical trial designed to evaluate subtypes of residual limb pain would be very interesting and could provide answers to some important questions. However, such a study probably would need a bigger sample size and perhaps a simpler study design so that multiple comparisons and the need for Bonferroni correction would not be an issue, as was the case in our study.
References
Karanikolas M, Aretha D, Tsolakis I, Monantera G, Kiekkas P, Papadoulas S, Swarm RA, Filos KS: Optimized perioperative analgesia reduces chronic phantom limb pain intensity, prevalence, and frequency: A prospective, randomized, clinical trial. ANESTHESIOLOGY 2011; 114:1144–54
Bach S, Noreng MF, Tjéllden NU: Phantom limb pain in amputees during the first 12 months following limb amputation, after preoperative lumbar epidural blockade. Pain 1988; 33:297–301
Nikolajsen L, Ilkjaer S, Christensen JH, Krøner K, Jensen TS: Randomised trial of epidural bupivacaine and morphine in prevention of stump and phantom pain in lower-limb amputation. Lancet 1997; 350:1353–7