title: Postoperative pain patterns in chronic pain patients: a pilot study.
abstract: OBJECTIVE
  This exploratory investigation compared patterns of postoperative pain over 6 days in normal patients recovering from surgery with those of patients using opioid medications for chronic pain. It tested the following hypotheses: 1) Chronic pain patients have a different pattern of postoperative pain than normals; 2) Women have a different pattern of postoperative pain resolution than men.
  
  
  METHODS
  Normal (N = 96) and chronic pain (N = 42) patients undergoing surgery served as subjects.
  
  
  METHODS
  The study employed a linear mixed effects model to compare repeated measures of pain in the two patient groups.
  
  
  METHODS
  Patients rated pain daily following surgery over 6 days. Each patient's pain pattern is a linear trend having an intercept (initial pain level) and a slope (rate of pain change over days).
  
  
  RESULTS
  The chronic pain patients initially reported a higher mean pain level, and they differed from normal patients in their average postoperative pain patterns (P < 0.001), as did men and women (P = 0.039). Whereas normals decreased in pain report over the 6 days of recovery at an average rate of -0.35 units per day, chronic pain patients changed at an average rate of only -0.06 units per day (P < 0.001). Women began at day 0 with greater average pain than men (6.15 vs 5.16, P = 0.029) but resolved their pain more rapidly (-0.291 points per day vs -0.118 points per day, P = 0.017).
  
  
  CONCLUSIONS
  Surgical patients who have chronic pain and use opioid medications for that pain have more postoperative pain than normals and resolve that pain more slowly.
authors.affiliation: Department of Anesthesiology, School of Medicine, University of Utah, Salt Lake City, Utah, USA. crc20@utah.edu
authors.forename: C Richard
authors.initials: CR
authors.lastname: Chapman
authors.forename: Gary
authors.initials: G
authors.lastname: Donaldson
authors.forename: Jennifer
authors.initials: J
authors.lastname: Davis
authors.forename: Donald
authors.initials: D
authors.lastname: Ericson
authors.forename: John
authors.initials: J
authors.lastname: Billharz
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000701:Analgesics, Opioid / Q000627:therapeutic use; D002908:Chronic Disease; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010146:Pain / Q000188:drug therapy / Q000503:physiopathology*; D010147:Pain Measurement; D010149:Postoperative Pain / Q000188:drug therapy / Q000453:epidemiology*; D010865:Pilot Projects; D011183:Postoperative Complications / Q000453:epidemiology*; D012737:Sex Factors; D013514:Surgical Procedures, Operative / Q000009:adverse effects*
chemical_list: D000701:Analgesics, Opioid