Persistent post-surgical pain: Prevalence, risk factors and pain mechanisms

Abstract

Persistent pain is reported to be a frequent complication from surgery. Among the proposed risk factors are perioperative nerve injury and individual differences in pain sensitivity. The 6th Tromsø Study, a cross-sectional survey and medical examination, provided questionnaire data on persistent pain in general and persistent pain following surgery in particular. Participants performed tests of sensitivity to experimental pain stimuli. A sample of participants who had performed surgery 3-36 months before the survey, were re-assessed with questionnaires and quantitative assessments of sensory function 15-32 months after Tromsø 6. In accordance with previous research, we found that persistent pain after surgery was common. Moderate or severe pain in the area of surgery 3-36 months after the procedure was reported by 18.3 %. Most cases were coexistent with other chronic pain. Only in a small minority of cases did the patients themselves attribute persistent pain to surgery alone. In a general surgical sample, we could not identify specific associations between persistent post-surgical pain and sensitivity to experimental pain stimuli when comorbid pain was adjusted for. Persistent post-surgical pain was strongly associated with self-reported sensory disturbances, indicating possible nerve injury as a contributing factor. Sensory aberrations were confirmed with sensory testing in a majority of individuals with persistent pain in the surgical area. However, nerve injury does not appear sufficient for development of such pain, as signs of nerve injury, confirmed with quantitative sensory testing, were just as common among individuals without persistent post-surgical pain.