High-dose aprotinin with gentamicin-vancomycin antibiotic prophylaxis increases blood concentrations of creatinine and cystatin C in patients undergoing coronary artery bypass grafting

Both aprotinin and gentamicin-vancomycin antibiotic prophylaxis have been u sed widely in cardiac surgery to prevent bleeding and infections, respectiv ely. As the drugs are excreted almost entirely by glomerular filtration, we investigated their action on renal function when administered either separ ately or together. To increase consistency, we measured serum concentration s of creatinine and cystatin C, a new marker of glomerular filtration rate, that many recent studies have shown to be more sensitive than serum creati nine. One hundred patients undergoing coronary artery bypass surgery were a llocated randomly to one of four groups: group A received antibiotic prophy laxis with cefamandole and no aprotinin; group B received cefamandole and h igh-dose aprotinin; group C received antibiotic prophylaxis with gentamicin and vancomycin, but no aprotinin; and group D received both high-dose apro tinin and gentamicin-vancomycin antibiotic prophylaxis. Data from 84 patien ts, for whom data collection was complete, were analysed. In the first week after operative, mean serum concentrations of cystatin C and creatinine ei ther remained constant or decreased slowly in all groups, except for group D. In group D, both markers increased gradually from postoperative day 2 on wards. The increase in cystatin C was significant on postoperative day 5 (f rom mean 1.02 (SD 0.11) mg litre(-1) before operation to 1.35 (0.32) mg lit re(-1); P < 0.05), reaching a peak on postoperative day 7 (1.45 (0.35) mg l itre(-1); P < 0.05), while the increase in creatinine concentration was sig nificant on postoperative day 6 (from 1.05 (0.16) mg dl(-1) before operatio n to 1.29 (0.34) mg dl(-1); P < 0.05). We conclude that simultaneous admini stration of high-dose aprotinin and prophylactic use of gentamicin with van comycin increased serum concentrations of cystatin C and creatinine in the first postoperative week in patients undergoing cardiac surgery.