PENETRATION OF CEFTRIAXONE INTO MEDIASTIN AL AND CARDIAC TISSUES IN HUMANS

Ceftriaxone penetration into heart tissues (valves, myocardium, auricl es and pericardium) and mediastinal tissues (fat and sternal bone) was evaluated after two regimens of ceftriaxone administration, Ten patie nts were given 1,000 g intravenously of ceftriaxone 30 min. before ane sthesia. Ten other patients received the same dose and then a second 1 ,000 mg dose at the time of initiation of cardiopulmonary bypass. Simi lar and very satisfactory ceftriaxone tissue penetrations were observe d in both groups. However, for some patients in the two groups and mai nly in the sternal bone at the time of thorax closure, ceftriaxone lev els in tissues were less than the MICs for some potential pathogens (M ethicillin susceptible Staphylococcus aureus and Staphylococcus epider midis). During the different steps of the surgical procedures all pati ents in both groups had tissue levels greater than the MICs for Gram n egative aerobic bacilli, except for Pseudomonas spp.