title: Immune function, pain, and psychological stress in patients undergoing spinal surgery.
abstract: METHODS
  This study was an exploratory repeated measures design comparing patients undergoing two magnitudes of surgery in the lumbar spine: lumbar herniated disc repair and posterior lumbar fusion.
  
  
  OBJECTIVE
  The present study evaluated and compared the effect of perceived pain, perceived stress, anxiety, and mood on natural killer cell activity (NKCA) and IL-6 production among adult patients undergoing lumbar surgery.
  
  
  BACKGROUND
  Presurgical stress and anxiety can lead to detrimental patient outcomes after surgery, such as increased infection rates. It has been hypothesized that such outcomes are due to stress-immune alterations, which may be further exacerbated by the extent of surgery. However, psychologic stress, anxiety, and mood have not been previously characterized in patients undergoing spinal surgery.
  
  
  METHODS
  Pain, stress, anxiety, and mood were measured using self-report instruments at T1 (1 week before surgery), T2 (the day of surgery), T3 (the day after surgery), and T4 (6 weeks after surgery). Blood (30 mL) was collected for immune assessments at each time point.
  
  
  RESULTS
  Pain, stress, anxiety, and mood state were elevated at baseline in both surgical groups and were associated with significant reduction in NKCA compared with the nonsurgical control group. A further decrease in NKCA was observed 24 hours after surgery in both surgical groups with a significant rise in stimulated IL-6 production, regardless of the magnitude of surgery. In the recovery period, NKCA increased to or above baseline values, which correlated with decreased levels of reported pain, perceived stress, anxiety, and mood state.
  
  
  CONCLUSIONS
  This study demonstrated that patients undergoing elective spinal surgery are highly stressed and anxious, regardless of the magnitude of surgery and that such psychologic factors may mediate a reduction in NKCA.
authors.affiliation: Intercollegiate College of Nursing, Washington State University, Spokane, WA 99224, USA. astarkweather@wsu.edu
authors.forename: Angela R
authors.initials: AR
authors.lastname: Starkweather
authors.forename: Linda
authors.initials: L
authors.lastname: Witek-Janusek
authors.forename: Russ P
authors.initials: RP
authors.lastname: Nockels
authors.forename: Jonna
authors.initials: J
authors.lastname: Peterson
authors.forename: Herbert L
authors.initials: HL
authors.lastname: Mathews
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D003601:Cytotoxicity Tests, Immunologic; D005260:Female; D006801:Humans; D007111:Immunity, Cellular / Q000502:physiology*; D007405:Intervertebral Disc Displacement / Q000523:psychology / Q000601:surgery; D007694:Killer Cells, Natural / Q000276:immunology / Q000378:metabolism; D008159:Lumbar Vertebrae / Q000473:pathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D010146:Pain / Q000523:psychology*; D012647:Self-Assessment; D013128:Spinal Osteophytosis / Q000523:psychology / Q000601:surgery*; D013131:Spine / Q000601:surgery*; D013315:Stress, Psychological / Q000523:psychology*; D011795:Surveys and Questionnaires