title: Influence of cardiopulmonary bypass on cefuroxime plasma concentration and pharmacokinetics in patients undergoing coronary surgery.
abstract: OBJECTIVE
  The aims of this study were to evaluate the influence of cardiopulmonary bypass (CPB) on the plasma concentrations and pharmacokinetics of cefuroxime and to assess whether the cefuroxime dose regimen (a 1.5 g dose, followed by 750 mg every 6 h for 24 h) is adequate for cardiac surgery antibiotic prophylaxis.
  
  
  METHODS
  A prospective, controlled, observational study compared patients undergoing coronary surgery with CPB (CPB group, n = 10) or off-pump surgery (off-pump group, n = 9). After each cefuroxime dose, blood samples were sequentially collected and analysed using high-efficiency chromatography. For demographic data and pharmacokinetic parameters, the authors used Fisher's exact test for nominal variables and Student's t-test and the Mann-Whitney U-test for parametric and non-parametric variables, respectively. Plasma concentrations were compared using ANOVA, and the percentage of patients with a remaining plasma concentration of >16 mg/l within 6 h after each bolus was quantified in tabular form.
  
  
  RESULTS
  After each cefuroxime bolus was administered, both groups presented a significant decrease in plasma concentration over time (P < 0.001), without differences between the groups. The mean CPB time of 59.7 ± 21.1 min did not change cefuroxime plasma concentrations or pharmacokinetics. The mean clearance ± SD (ml/kg/min) and median elimination half-life (h) of the CPB group versus the off-pump group were 1.7 ± 0.7 versus 1.6 ± 0.6 (P = 0.67), respectively, and 2.2 versus 2.3 (P = 0.49), respectively. Up to 3 h following the first bolus of 1.5 g, but not after 6 h, all patients had plasma concentrations >16 mg/l (CPB group = 20% and off-pump group = 44%). However, after all 750 mg boluses were administered, concentrations <16 mg/dl were reached within 3 h.
  
  
  CONCLUSIONS
  CPB does not influence cefuroxime plasma concentrations. The dosing regimen is adequate for the intraoperative period, but in the immediate postoperative period, it requires further review.
authors.affiliation: Discipline of Anaesthesiology, Heart Institute of the University of São Paulo Medical School, São Paulo, Brazil. fabianabosco@hotmail.com
authors.forename: Fabiana
authors.initials: F
authors.lastname: Ferreira
authors.forename: Silvia
authors.initials: S
authors.lastname: Santos
authors.forename: Jorge
authors.initials: J
authors.lastname: Nascimento
authors.forename: Tânia
authors.initials: T
authors.lastname: Strabelli
authors.forename: Maria
authors.initials: M
authors.lastname: Carmona
mesh_terms: D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000097:blood* / Q000493:pharmacokinetics; D019072:Antibiotic Prophylaxis; D006348:Cardiac Surgical Procedures / Q000379:methods*; D002315:Cardiopulmonary Bypass / Q000379:methods*; D016022:Case-Control Studies; D002444:Cefuroxime / Q000008:administration & dosage / Q000097:blood* / Q000493:pharmacokinetics; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D013530:Surgical Wound Infection / Q000517:prevention & control
chemical_list: D000900:Anti-Bacterial Agents; D002444:Cefuroxime