Ceftazidime in the treatment of nosocomial sepsis

Ceftazidime has broad antibacterial activity against many gram-positive and most clinically significant nosocomial gram-negative bacillary pathogens. Many studies have been undertaken both in this country and in western Europe to determine the clinical effectiveness of ceftazidime in seriously ill patients. Differentiating between nosocomial and community-acquired infections is difficult in many reports, but high cure rates, usually exceeding 80 percent, have been reported for documented gram-negative bacillary infections. In non-neutropenic patients, response rates have also been in a comparable range. Particularly impressive have been the high cure rates in Pseudomonas aeruginosa bacteremia complicating burns and other gram-negative bacteremias in patients with underlying diseases. In comparative studies carried out in seriously ill or neutropenic patients, the results with ceftazidime have not significantly differed from those obtained with regimens that included beta-lactam agents paired with aminoglycosides. Some problem areas persist in these studies: the interpretation of comparative studies in which a large number of cases were eliminated because of "unevaluability," superinfections due to gram-positive organisms that may require or necessitate addition of agents like vancomycin, and the emergence of resistance as seen in three groups of organisms--Pseudomonas, Serratia, and Enterobacter species. Nonetheless, summary data from cases treated in the United States indicate cure and/or improvement in 100 percent of 14 cases of Serratia bacteremia, 83 percent of 12 cases of Enterobacter sepsis, 82 percent of 22 cases of Staphylococcus aureus bacteremia, and 85 percent in 27 cases of P. aeruginosa bacteremia. Only 11 of 86 cases of bacteremia due to the organisms just cited were judged unevaluable. Three of the four failures in the treatment of Pseudomonas bacteremia occurred in neutropenic patients. More definitive information on the relative efficacy of ceftazidime in controlled trials, particularly in granulocytopenic patients, may result from more careful analysis of survivorship using methods that do not eliminate "unevaluable cases." Techniques for this type of analysis have already been implemented in some studies.