Sequential ventricular fluid concentrations of ceftazidime--report of three cases.

Three adult subjects, each with a ventriculostomy, received ceftazidime 2g iv q8h for three doses. Serial samples of serum and CSF ventricular fluid were obtained following the third dose; ceftazidime concentrations were measured by high pressure liquid chromatography. In one patient without inflammatory cells in the CSF, ceftazidime CSF concentrations were only approximately 0.3 micrograms/ml. In two other patients who had inflammatory cells and blood in the CSF, concentrations of ceftazidime in ventricular fluid demonstrated a slow rise and decline over an eight-hour period. Although contamination of the CSF by blood in these two patients confounds the interpretation of the concentrations achieved, it is concluded that obtaining serial samples of CSF from a ventriculostomy offers a more realistic appraisal of the dynamics of antibiotic penetration compared with the single-point method.