title: Influence of the ischaemic tourniquet in antibiotic prophylaxis in total knee replacement.
abstract: OBJECTIVE
  There is level iv evidence that the preoperative administration of antibiotics helps in the prevention of prosthetic infection. There is controversy on whether the ischemia applied during surgery may affect the minimum inhibitory concentration of the antibiotic in the peri-prosthetic tissues. The aim of this study is to review this phenomenon through the determination of antibiotic concentration in the synovial tissue.
  
  
  METHODS
  A prospective observational clinical study was conducted on 32 patients undergoing total knee replacement. Cefonicid 2g was administered as prophylaxis, with a tourniquet used for all patients. The antibiotic concentration was quantified by high performance liquid chromatography in samples of synovial tissue collected at the beginning and at the end of the intervention.
  
  
  RESULTS
  The mean concentration of antibiotic was 23.16 μg/g (95% CI 19.19 to 27.13) in the samples at the beginning of the intervention and 15.45 μg/g (95% CI 13.20 to 17.69) in the final samples, being higher than the minimum inhibitory concentration of cefonicid, set at 8 μg/g. These results were statistically significant for both concentrations (P<.00001).
  
  
  CONCLUSIONS
  The antibiotic concentration throughout the standard total knee prosthesis surgery performed with tourniquet gradually decreases throughout the intervention. The concentration determined at the end of the intervention was higher than the minimum inhibitory concentration required for the antibiotic studied. In conclusion, the use of a tourniquet does not increase the risk of infection.
authors: Servicio de Cirugía Ortopédica y Traumatología, Hospital Universitari Arnau de Vilanova de Lleida, Lleida, España; Facultad de Medicina, Universidad de Lleida, Lleida, España. Electronic address: pratsgispert@hotmail.com.
authors: Laura
authors: L
authors: Prats
authors: Unidad de Estadística del Institut de Recerca Biomédica de Lleida, Lleida, España; Institut de Recerca Biomédica de Lleida, Lleida, España.
authors: Joan
authors: J
authors: Valls
authors: Facultad de Medicina, Universidad de Lleida, Lleida, España; Institut de Recerca Biomédica de Lleida, Lleida, España.
authors: Joaquim
authors: J
authors: Ros
authors: Facultad de Medicina, Universidad de Lleida, Lleida, España; Institut de Recerca Biomédica de Lleida, Lleida, España; Unidad Funcional para el Control de la Infección Nosocomial, Servicio de Medicina Interna del Hospital Universitari Arnau de Vilanova de Lleida, Lleida, España.
authors: Alfredo
authors: A
authors: Jover
authors: Servicio de Cirugía Ortopédica y Traumatología, Hospital Universitari Arnau de Vilanova de Lleida, Lleida, España.
authors: Ferran
authors: F
authors: Pérez-Villar
authors: Servicio de Cirugía Ortopédica y Traumatología, Hospital Universitari Arnau de Vilanova de Lleida, Lleida, España; Facultad de Medicina, Universidad de Lleida, Lleida, España.
authors: José Juan
authors: JJ
authors: Fernández-Martínez
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000032:analysis / Q000493:pharmacokinetics* / Q000627:therapeutic use; D019072:Antibiotic Prophylaxis / Q000379:methods*; D019645:Arthroplasty, Replacement, Knee / Q000295:instrumentation / Q000379:methods; D015790:Cefonicid / Q000032:analysis / Q000493:pharmacokinetics* / Q000627:therapeutic use; D002851:Chromatography, High Pressure Liquid; D005260:Female; D006801:Humans; D007720:Knee Prosthesis / Q000009:adverse effects; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D011446:Prospective Studies; D016459:Prosthesis-Related Infections / Q000209:etiology / Q000517:prevention & control; D013583:Synovial Membrane / Q000737:chemistry*; D014111:Tourniquets / Q000009:adverse effects*
chemical_list: D000900:Anti-Bacterial Agents; D015790:Cefonicid
keywords: Antibiotic prophylaxis; Manguito de isquemia; Profilaxis antibiótica; Prótesis total de rodilla; Total knee prosthesis; Tourniquet