title: Preliminary results of a new test for rapid diagnosis of septic arthritis with use of leukocyte esterase and glucose reagent strips.
abstract: BACKGROUND
  Most currently used tools to diagnose septic arthritis are either not readily available or fail to provide real-time results. Reagent strip tests have identified infections in various body fluids. We hypothesized that combined leukocyte esterase and glucose strip tests can aid in diagnosing septic arthritis in native synovial fluid because (1) leukocyte esterase concentrations would be elevated at the infection site because of secretion by recruited neutrophils, and (2) glucose concentrations would be reduced because of bacterial metabolism.
  
  
  METHODS
  We prospectively investigated synovial fluid from consecutive patients with an atraumatic joint effusion who underwent arthrocentesis in our emergency department during a one-year period. Leukocyte esterase and glucose strip tests were performed on the synovial fluid. Synovial fluid leukocyte count, crystal analysis, Gram staining, culture, and glucose concentration results were also assessed.
  
  
  RESULTS
  Nineteen fluids were classified as septic and 127 as aseptic. Considering septic arthritis to be present when the leukocyte esterase reading was positive (++ or +++) and the glucose reading was negative (-) yielded a sensitivity of 89.5% (95% confidence interval [CI], 66.9% to 98.7%), specificity of 99.2% (95% CI, 95.7% to 99.9%), positive predictive value of 94.4% (95% CI, 72.7% to 99.9%), negative predictive value of 98.4% (95% CI, 94.5% to 99.8%), positive likelihood ratio of 114, and negative likelihood ratio of 0.11. The synovial leukocyte counts and polymorphonuclear cell percentages were consistent with the semiquantitative readings on the leukocyte esterase strip tests, and the glucose concentrations were consistent with the glucose strip test results.
  
  
  CONCLUSIONS
  Combined leukocyte esterase and glucose strip tests can be a useful additional tool to help confirm or rule out a diagnosis of septic arthritis.
authors.affiliation: Trauma Department (M.O., M.E., M.R., M.P., D.G., E.M.S., M.J., and C.K) and Institute of Clinical Chemistry (R.L.), Hannover Medical School, Carl-Neuberg-Straße 1, 30625 Hannover, Germany. E-mail address for M. Omar: omar.mohamed@mh-hannover.de.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Omar
authors.affiliation: Trauma Department (M.O., M.E., M.R., M.P., D.G., E.M.S., M.J., and C.K) and Institute of Clinical Chemistry (R.L.), Hannover Medical School, Carl-Neuberg-Straße 1, 30625 Hannover, Germany. E-mail address for M. Omar: omar.mohamed@mh-hannover.de.
authors.forename: Max
authors.initials: M
authors.lastname: Ettinger
authors.affiliation: Trauma Department (M.O., M.E., M.R., M.P., D.G., E.M.S., M.J., and C.K) and Institute of Clinical Chemistry (R.L.), Hannover Medical School, Carl-Neuberg-Straße 1, 30625 Hannover, Germany. E-mail address for M. Omar: omar.mohamed@mh-hannover.de.
authors.forename: Moritz
authors.initials: M
authors.lastname: Reichling
authors.affiliation: Trauma Department (M.O., M.E., M.R., M.P., D.G., E.M.S., M.J., and C.K) and Institute of Clinical Chemistry (R.L.), Hannover Medical School, Carl-Neuberg-Straße 1, 30625 Hannover, Germany. E-mail address for M. Omar: omar.mohamed@mh-hannover.de.
authors.forename: Maximilian
authors.initials: M
authors.lastname: Petri
authors.affiliation: Trauma Department (M.O., M.E., M.R., M.P., D.G., E.M.S., M.J., and C.K) and Institute of Clinical Chemistry (R.L.), Hannover Medical School, Carl-Neuberg-Straße 1, 30625 Hannover, Germany. E-mail address for M. Omar: omar.mohamed@mh-hannover.de.
authors.forename: Ralf
authors.initials: R
authors.lastname: Lichtinghagen
authors.affiliation: Trauma Department (M.O., M.E., M.R., M.P., D.G., E.M.S., M.J., and C.K) and Institute of Clinical Chemistry (R.L.), Hannover Medical School, Carl-Neuberg-Straße 1, 30625 Hannover, Germany. E-mail address for M. Omar: omar.mohamed@mh-hannover.de.
authors.forename: Daniel
authors.initials: D
authors.lastname: Guenther
authors.affiliation: Trauma Department (M.O., M.E., M.R., M.P., D.G., E.M.S., M.J., and C.K) and Institute of Clinical Chemistry (R.L.), Hannover Medical School, Carl-Neuberg-Straße 1, 30625 Hannover, Germany. E-mail address for M. Omar: omar.mohamed@mh-hannover.de.
authors.forename: Eduardo M
authors.initials: EM
authors.lastname: Suero
authors.affiliation: Trauma Department (M.O., M.E., M.R., M.P., D.G., E.M.S., M.J., and C.K) and Institute of Clinical Chemistry (R.L.), Hannover Medical School, Carl-Neuberg-Straße 1, 30625 Hannover, Germany. E-mail address for M. Omar: omar.mohamed@mh-hannover.de.
authors.forename: Michael
authors.initials: M
authors.lastname: Jagodzinski
authors.affiliation: Trauma Department (M.O., M.E., M.R., M.P., D.G., E.M.S., M.J., and C.K) and Institute of Clinical Chemistry (R.L.), Hannover Medical School, Carl-Neuberg-Straße 1, 30625 Hannover, Germany. E-mail address for M. Omar: omar.mohamed@mh-hannover.de.
authors.forename: Christian
authors.initials: C
authors.lastname: Krettek
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001170:Arthritis, Infectious / Q000175:diagnosis*; D002265:Carboxylic Ester Hydrolases / Q000032:analysis*; D005260:Female; D005947:Glucose / Q000032:analysis*; D006801:Humans; D008297:Male; D008875:Middle Aged; D013582:Synovial Fluid / Q000737:chemistry*; D055815:Young Adult
chemical_list: C021443:leukocyte esterase; D002265:Carboxylic Ester Hydrolases; D005947:Glucose