Pre-operative pain and sensory function in groin hernia

TY - JOUR

T1 - Pre-operative pain and sensory function in groin hernia

AU - Aasvang, Eske K

AU - Hansen, Jeanette B

AU - Kehlet, Henrik

N1 - Keywords: Adolescent; Adult; Calibration; Groin; Hernia; Hot Temperature; Humans; Hyperalgesia; Male; Middle Aged; Pain; Pain Measurement; Pain Threshold; Physical Stimulation; Preoperative Period; Risk Factors; Sensation; Young Adult

PY - 2009

Y1 - 2009

N2 - BACKGROUND: Although persistent postherniotomy occurs in 5-10% of patients, pathogenic mechanisms remain debatable. Since pre-operative pain has been demonstrated to be a risk factor for persistent postherniotomy pain, pre-operative alterations in nociceptive function may be a potential pathogenic mechanism. AIMS: To investigate the correlation between pre-operative pain intensity and sensory functions in the groin hernia area. METHODS: Patients with unilateral groin hernia were examined preoperatively by quantitative sensory testing (thermal, mechanical, and pressure [detection and pain thresholds]) and assessments were correlated to patients' reports of intensity and frequency of spontaneous pain in the groin area. RESULTS: Forty-two patients were examined, whereof one was excluded since no hernia was found intraoperatively. Mechanical pain threshold was inversely correlated with spontaneous pain intensity (rho=-0.413, p=0.049), indicating a paradoxical association between level of mechanical pain threshold and magnitude of spontaneous pain. No other sensory modality was significantly correlated to pain intensity. New/increased pain during repetitive pinprick stimulation (wind-up) was seen in 3 patients (7%), all whom experienced no pain or pain less than weekly. Only cool detection thresholds were significantly lower between the hernia vs. contralateral side (p<0.04), but with numerically very small differences (Delta=0.4 degrees C, range 0.1-0.7 degrees C). CONCLUSION: Pre-operative groin hernia pain is not related to findings of hyperalgesia or other changes in sensory function that may support pain-induced pre-operative neuroplasticity as a pathogenic mechanism for the development of persistent postherniotomy pain.

AB - BACKGROUND: Although persistent postherniotomy occurs in 5-10% of patients, pathogenic mechanisms remain debatable. Since pre-operative pain has been demonstrated to be a risk factor for persistent postherniotomy pain, pre-operative alterations in nociceptive function may be a potential pathogenic mechanism. AIMS: To investigate the correlation between pre-operative pain intensity and sensory functions in the groin hernia area. METHODS: Patients with unilateral groin hernia were examined preoperatively by quantitative sensory testing (thermal, mechanical, and pressure [detection and pain thresholds]) and assessments were correlated to patients' reports of intensity and frequency of spontaneous pain in the groin area. RESULTS: Forty-two patients were examined, whereof one was excluded since no hernia was found intraoperatively. Mechanical pain threshold was inversely correlated with spontaneous pain intensity (rho=-0.413, p=0.049), indicating a paradoxical association between level of mechanical pain threshold and magnitude of spontaneous pain. No other sensory modality was significantly correlated to pain intensity. New/increased pain during repetitive pinprick stimulation (wind-up) was seen in 3 patients (7%), all whom experienced no pain or pain less than weekly. Only cool detection thresholds were significantly lower between the hernia vs. contralateral side (p<0.04), but with numerically very small differences (Delta=0.4 degrees C, range 0.1-0.7 degrees C). CONCLUSION: Pre-operative groin hernia pain is not related to findings of hyperalgesia or other changes in sensory function that may support pain-induced pre-operative neuroplasticity as a pathogenic mechanism for the development of persistent postherniotomy pain.

U2 - 10.1002/j.1532-2149.2011.00088.x

DO - 10.1002/j.1532-2149.2011.00088.x

M3 - Journal article

C2 - 19147380

SN - 1090-3801

VL - 13

SP - 1018

EP - 1022

JO - European Journal of Pain

JF - European Journal of Pain

IS - 10

ER -