title: Injury measurement properties of serum interleukin-6 following lumbar decompression surgery.
abstract: BACKGROUND
  Circulating interleukin-6 (IL-6) is frequently used to study surgical injury and inflammation. Measurement properties of serum IL-6 were examined following lumbar decompression surgery (LDS), including time course, sensitivity, and validity for detecting muscle trauma in comparison to the muscle cytoplasmic protein creatine kinase (CK).
  
  
  METHODS
  Seven women and seven men had serial blood samples taken in the preoperative waiting areas, immediately after surgery, at 6, 12, 24, 48 h, 4 d, and at 6 to 7 d. Lumbar surgeries were single level, decompression, with laminotomy.
  
  
  RESULTS
  Time to peak serum IL-6 varied across individuals (range 6 to 48 h). However, the higher of two samples drawn within the sensitive time window (6 to 24 h) had a strong correlation with peak IL-6 (r = 0.99, P < 0.001). There was a moderate correlation between the rise in serum IL-6 and rise in serum CK, r = 0.56, P < 0.05. T-tests revealed that group mean IL-6 was significantly elevated at only one serial time point (6 h), whereas group mean CK was significantly elevated at three serial time points (6, 12, 24 h) and approached significant elevation as late as 48 h (P = 0.07). Women had lower CK concentrations at 6 and 24 h but gender differences on IL-6 were not statistically significant.
  
  
  CONCLUSIONS
  The serum IL-6 response to LDS injury can be captured in a practical manner, despite individual variability in time course. Inclusion of CK measurement may improve sensitivity to the muscle trauma component of an overall injury.
authors.affiliation: Department of Medicine, McMaster University, Hamilton, Ontario, Canada. kumbhad@mcmaster.ca
authors.forename: Dinesh
authors.initials: D
authors.lastname: Kumbhare
authors.forename: William
authors.initials: W
authors.lastname: Parkinson
authors.forename: Brett
authors.initials: B
authors.lastname: Dunlop
authors.forename: Carl
authors.initials: C
authors.lastname: Richards
authors.forename: Christine
authors.initials: C
authors.lastname: Kerr
authors.forename: Norm
authors.initials: N
authors.lastname: Buckley
authors.forename: Jonathan
authors.initials: J
authors.lastname: Adachi
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D003402:Creatine Kinase / Q000097:blood; D019299:Decompression, Surgical / Q000009:adverse effects*; D005260:Female; D006801:Humans; D015850:Interleukin-6 / Q000097:blood*; D008159:Lumbar Vertebrae / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000293:injuries* / Q000378:metabolism; D012189:Retrospective Studies; D013997:Time Factors
chemical_list: D015415:Biomarkers; D015850:Interleukin-6; D003402:Creatine Kinase