Patients with Chronic Pain After Abdominal Surgery Show Less Preoperative Endogenous Pain Inhibition and More Postoperative Hyperalgesia: A Pilot Study

• Published in: Journal of pain & palliative care pharmacotherapy 2010-05, Vol.24 (2), p.119-128
• Main Authors: Wilder-Smith, Oliver Hamilton, Schreyer, Tobias, Scheffer, Gert Jan, Arendt-Nielsen, Lars
• Format: Article
• Language: English
• Subjects: Abdomen - surgery; Chronic Disease; chronic pain; cold pressor task; Cold Temperature; diffuse noxious inhibitory controls (DNIC); Electric Stimulation; Female; Follow-Up Studies; Humans; hyperalgesia; Hyperalgesia - etiology; Male; Middle Aged; Pain - etiology; Pain Measurement - methods; Pain Threshold; Pain, Postoperative; Pilot Projects; postoperative pain; Prospective Studies; quantitative sensory testing; surgery; Time Factors
• ISSN: 1536-0288; 1536-0539
• DOI: 10.3109/15360281003706069

ABSTRACT Chronic pain is common and undesirable after surgery. Progression from acute to chronic pain involves altered pain processing. The authors studied relationships between presence of chronic pain versus preoperative descending pain control (diffuse noxious inhibitory controls; DNICs) and postoperative persistence and spread of skin and deep tissue hyperalgesia (change in electric/pressure pain tolerance thresholds; ePTT/pPTT) up to 6 months postoperatively. In 20 patients undergoing elective major abdominal surgery under standardized anesthesia, we determined ePTT/pPTT (close to [abdomen] and distant from [leg] incision), eDNIC/pDNIC (change in ePTT/pPTT with cold pressor pain task; only preoperatively), and a 100 mm long pain visual analogue scale (VAS) (0 mm = no pain, 100 mm = worst pain imaginable), both at rest and on movement preoperatively, and 1 day and 1, 3, and 6 months postoperatively. Patients reporting chronic pain 6 months postoperatively had more abdominal and leg skin hyperalgesia over the postoperative period. More inhibitory preoperative eDNIC was associated with less late postoperative pain, without affecting skin hyperalgesia. More inhibitory pDNIC was linked to less postoperative leg deep tissue hyperalgesia, without affecting pain VAS. This pilot study for the first time links chronic pain after surgery, poorer preoperative inhibitory pain modulation (DNIC), and greater postoperative degree, persistence, and spread of hyperalgesia. If confirmed, these results support the potential clinical utility of perioperative pain processing testing.