Serum Antibiotic Concentrations Pre- and Postcardiopulmonary Bypass

Abstract

Serum concentrations of cephalothin or kanamycin, or both, were determined in 53 patients undergoing cardiopulmonary bypass. Conventional doses of these antibiotics did not provide serum levels above the accepted minimum inhibitory concentrations in children. Adults had adequate serum antibiotic concentrations only when the antimicrobials were administered within 4 h of beginning cardiopulmonary bypass. The impact of these variations upon the occurrence of infectious endocarditis could not be appraised since no cases of infective endocarditis were seen during a 4-month postoperative period.

Cephalothin kinetics: Before, during, and after cardiopulmonary bypass surgery

“…26 The fall has been postulated to be due to the dilutional effect of the pump priming volume at the start of bypass. 9 A decrease in serum protein binding, which could increase the volume of drug distribution, could also contribute to this fall. 5 The plateau period or occ.asional increase may be due to further inhibition of drug elimination brought about by extracorporeal circulation and hypothermia in combination with redistribution and elimination of the priming fluid.…”

“…The metabolite deacetylcephalothin was rapidly formed on all 3 days and its kinetic behavior paralleled that of the parent drug.Organ perfusion can alter drug absorption, distribution, metabolism, and excretion. Cardiopulmonary bypass (CPB) surgery alters organ perfusion, particularly renal blood flow.n ' 13, 16, 19 Previous studies of drug elimination during bypass surgery have indicated that drug disposition is altered by extracorporeal circulation, but data are insufficient to identify or quantitate all the causative factors,2, 3,9,18,26…”

Comparison of Cephalothin and Cefamandole Prophylaxis During Insertion of Prosthetic Heart Valves

“…Plasma or serum levels of antibiotics administered "on call" or "on the morning of surgery" may be very low or undetectable during surgery, and thus contaminating organisms may gain access to and persist in tissues. Kluge et al (11) measured <1 ,ug of CP per ml in plasma during surgery in 69% of patients who were begun on CPB more than 5 h after the last dose of CP. As a possible consequence of low antibiotic levels, contaminating organisms, particularly S. epidermidis and diphtheroids, were recovered from cardiac tissue in 71% of these patients (12).…”