TY - JOUR

T1 - Late sensory function after intraoperative capsaicin wound instillation

AU - Aasvang, E K

AU - Hansen, J B

AU - Kehlet, H

AU - Aasvang, E K

AU - Hansen, J B

AU - Kehlet, H

N1 - Keywords: Adolescent; Adult; Aged; Analgesics; Capsaicin; Double-Blind Method; Follow-Up Studies; Hernia, Inguinal; Humans; Hyperalgesia; Instillation, Drug; Intraoperative Care; Male; Middle Aged; Nerve Fibers; Pain Measurement; Pain Threshold; Pain, Postoperative; Placebos; Pressure; Sensation; Sensory System Agents; Sensory Thresholds; Surgical Mesh; Temperature Sense; Touch; Treatment Outcome; Young Adult

PY - 2010/2/1

Y1 - 2010/2/1

N2 - BACKGROUND: Intense capsaicin-induced C-fiber stimulation results in reversible lysis of the nerve soma, thereby making capsaicin wound instillation of potential interest for the treatment of post-operative pain. Clinical histological and short-term sensory studies suggest that the C-fiber function is partly re-established after skin injection of capsaicin. However, no study has evaluated the long-term effects of wound instillation of purified capsaicin on sensory functions. METHODS: Patients included in a double-blind placebo-controlled randomized study of the analgesic effect of capsaicin after groin hernia repair were examined by quantitative sensory testing before, 1 week and 2 years post-operatively. The primary endpoint was occurrence of hyperalgesia/allodynia. The secondary endpoints were acute and late sensory changes between the two patient groups. Patients were blinded to the allocated treatment. RESULTS: Twenty (100%) capsaicin and 16 (76%) placebo-treated patients were seen at the 2 1/2 year follow-up. Hyperalgesia was seen in five capsaicin- vs. one placebo-treated patient (P=0.2). The mechanical detection threshold was significantly increased on the operated side in the capsaicin vs. placebo group at the 1-week follow-up (P<0.05), but was not different at the 2 1/2 year follow-up (P=0.3). There were no other significant differences in sensory function on the operated side between groups at the pre-operative, 1-week or 2 1/2 year post-operative follow-up (P>0.05). The sensory function on the contralateral side was comparable between groups throughout the study (P>0.1). CONCLUSION: This small-volume study calls for further long-term safety studies of wound capsaicin instillation.

AB - BACKGROUND: Intense capsaicin-induced C-fiber stimulation results in reversible lysis of the nerve soma, thereby making capsaicin wound instillation of potential interest for the treatment of post-operative pain. Clinical histological and short-term sensory studies suggest that the C-fiber function is partly re-established after skin injection of capsaicin. However, no study has evaluated the long-term effects of wound instillation of purified capsaicin on sensory functions. METHODS: Patients included in a double-blind placebo-controlled randomized study of the analgesic effect of capsaicin after groin hernia repair were examined by quantitative sensory testing before, 1 week and 2 years post-operatively. The primary endpoint was occurrence of hyperalgesia/allodynia. The secondary endpoints were acute and late sensory changes between the two patient groups. Patients were blinded to the allocated treatment. RESULTS: Twenty (100%) capsaicin and 16 (76%) placebo-treated patients were seen at the 2 1/2 year follow-up. Hyperalgesia was seen in five capsaicin- vs. one placebo-treated patient (P=0.2). The mechanical detection threshold was significantly increased on the operated side in the capsaicin vs. placebo group at the 1-week follow-up (P<0.05), but was not different at the 2 1/2 year follow-up (P=0.3). There were no other significant differences in sensory function on the operated side between groups at the pre-operative, 1-week or 2 1/2 year post-operative follow-up (P>0.05). The sensory function on the contralateral side was comparable between groups throughout the study (P>0.1). CONCLUSION: This small-volume study calls for further long-term safety studies of wound capsaicin instillation.

U2 - 10.1111/j.1399-6576.2009.02068.x

DO - 10.1111/j.1399-6576.2009.02068.x

M3 - Journal article

C2 - 19681784

VL - 54

SP - 224

EP - 231

JO - Acta Anaesthesiologica Scandinavica

JF - Acta Anaesthesiologica Scandinavica

SN - 0001-5172

IS - 2

ER -