title: Effect of age, gender, and platelet count on Sonoclot coagulation analysis in patients undergoing orthopedic operations.
abstract: OBJECTIVE
  To assess the relationship between Sonoclot coagulation variables and age, gender, or platelet count in surgical patients without coagulation disorders.
  
  
  METHODS
  This study included 136 patients undergoing orthopedic surgical procedures under spinal or epidural anesthesia. Whole blood was withdrawn preoperatively from each patient, and a Sonoclot analysis was performed within 2 minutes after the sample was obtained. The Sonoclot results were considered investigational and not used in the perioperative management of the patients. Variables from the Sonoclot graphs were analyzed statistically to determine any associations with age, gender, or platelet count.
  
  
  RESULTS
  The Sonoclot baseline height was decreased in patients with lower hemoglobin levels, older age, and female gender. The upward slope from baseline to inflection (R1) was increased in female patients and older patients. In comparison with patients who had lower platelet counts, patients with higher platelet counts exhibited a shorter time to inflection, increased upward slope from inflection to peak (R2), shorter time to peak, increased downward slope from peak to plateau (R3), decreased time to plateau, and lower plateau height (P < or = 0.01 for all relationships).
  
  
  CONCLUSIONS
  Sonoclot coagulation analysis reliably evaluates platelet count as an indicator of platelet function. Controlled studies are needed to examine the clinical usefulness of Sonoclot coagulation analysis in the diagnosis and treatment of perioperative coagulopathies and hemorrhagic complications.
authors.affiliation: Department of Anesthesiology, Mayo Clinic Rochester, Minnesota 55905, USA.
authors.forename: T T
authors.initials: TT
authors.lastname: Horlocker
authors.forename: D R
authors.initials: DR
authors.lastname: Schroeder
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D001780:Blood Coagulation Tests / Q000379:methods*; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D009985:Orthopedics; D010976:Platelet Count; D011237:Predictive Value of Tests; D012737:Sex Factors