Penetration characteristics of cefamandole into the right atrial appendage and pericardial fluid in patients undergoing open-heart surgery.

In 24 patients undergoing open-heart operation, 2 gm of cefamandole was administered intravenously by bolus technique at various time intervals prior to operation. Samples of pericardial fluid, atrial appendage tissue, and serum were obtained simultaneously in order to compare antibiotic levels in these sites as a function of time. All samples were microbiologically assayed by disc diffusion. Using linear regression analysis, the atrial appendage and serum half-lives for cefamandole were 36 and 38 minutes, respectively. At 40 minutes, peak levels of cefamandole were observed both in pericardial fluid and in atrial appendage tissue. The peak concentrations of cefamandole were 50 micrograms/gm in atrial appendage and 25 micrograms/ml for free drug content in pericardial fluid. These amounts were appreciably above the mean minimum inhibitory concentration of cefamandole for penicillin-resistant staphylococci, the usual pathogens grown in infections following implant operation.