This study compared the effect on renal function of flucloxacillin and vancomycin
antibiotic prophylaxis for elective first-time coronary artery bypass grafting (CABG)
surgery, using both direct biochemical markers and indirect clinical outcome measures.
Recent evidence has suggested that vancomycin may be nephrotoxic in patients undergoing
A retrospective observational study of patients undergoing elective first-time CABG
was performed, covering a 13-month period. All patients received prophylactic antibiotics:
flucloxacillin 1 g pre-operatively and three 1 g doses post-operatively. Patients
who were MRSA-positive, MRSA unknown or penicillin allergic received an alternative
regimen: vancomycin 1 g pre-operatively and 1 g post-operatively. Exclusion criteria:
pre-operative creatinine >133 mmol/l, any antibiotics other than prophylaxis and haemodynamic
support except <5 μg/kg/hour dopamine.
Of 1,413 patients in the study period, 415 met the study criteria: 360 patients received
flucloxacillin and 55 patients received vancomycin. There were no significant differences
between the two groups in sex, age, BMI, euroSCORE, diabetes status, ejection fraction,
pre-operative creatinine, eGFR, sodium, or potassium. Comparing change in renal function
pre-operatively to post-operatively, there were no significant group differences in
change in: creatinine (mmol/l; VAN median 0 (IQR 11); FLU -2 (19); P = 0.22), eGFR
(ml/min; VAN 0 (14); FLU 2.4 (19.3); P = 0.22), sodium (mmol/l; VAN 1 (4); FLU 1 (4);
P = 0.28). Change in potassium differed significantly (mmol/l; VAN 0.7 (0.9); FLU
0.5 (0.7); P < 0.05). In clinical outcome measures, the groups were similar. Most
patients in both groups stayed in ITU for 1 day and there was no significant difference
in the number of patients staying for longer than 1 day (VAN 7/55 (13%); FLU 29/360
(8%); P = 0.30). There was no difference in hospital length of stay (days; VAN 7 (4);
FLU 6 (3); P = 0.19).
In elective first-time CABG patients, there is no significant difference in change
in renal function between those given vancomycin antibiotic prophylaxis and those
given flucloxacillin prophylaxis, as assessed by creatinine, eGFR and sodium levels,
and indirect clinical outcome measures. Potassium increased more in the vancomycin
group but the clinical significance of this is unclear. Our data suggest that prophylactic
vancomycin does not impair renal function relative to flucloxacillin.