Injury measurement properties of serum interleukin-6 following lumbar decompression surgery.
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.
Kumbhare
Dinesh
D
Department of Medicine, McMaster University, Hamilton, Ontario, Canada. kumbhad@mcmaster.ca
Parkinson
William
W
Dunlop
Brett
B
Richards
Carl
C
Kerr
Christine
C
Buckley
Norm
N
Adachi
Jonathan
J
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
D015415:Biomarkers; D015850:Interleukin-6; D003402:Creatine Kinase