Pseudomembranous colitis: how useful is endoscopy?

Clostridium difficile colitis may be diagnosed either by endoscopy or by laboratory tests. To determine the role of endoscopy, we reviewed 59 cases of confirmed C. difficile colitis. In all patients, the etiology was confirmed by stool tests. Twenty-nine underwent lower gastrointestinal endoscopy. In 16 (55%) there was endoscopic confirmation of pseudomembranes while 4 (14%) had only nonspecific colitis. There was no apparent difference in the rate of detection of pseudomembranes between rigid sigmoidoscopy (57%), flexible sigmoidoscopy (50%), and colonoscopy (50%). Vancomycin and metronidazole were equally effective therapy but treatment with vancomycin cost more than 250 times that for metronidazole. There were no patients in whom the diagnosis was made by endoscopy alone. Endoscopy was costly and insensitive, while noninvasive stool tests were cheap and accurate. We conclude that endoscopy should be relegated to a secondary role in the workup of antibiotic-associated diarrhea.

Penetration of eight beta-lactam antibiotics into the peritoneal fluid. A pharmacokinetic investigation.

Serial serum and peritoneal fluid samples were taken after intravenous injection of cefuroxime sodium, cefoxitin sodium, cefotaxime sodium, cefoperazone sodium, ceftazidime, moxalactam disodium, mezlocillin sodium, and piperacillin sodium. Time-concentration curves were obtained for both pharmacokinetic compartments. The geometric mean of peritoneal fluid concentrations from eight to ten patients was used to define the time-concentrations curve for each substance. Serum pharmacokinetic values were calculated using an open two-compartment model. The concentrations (Cps) were calculated from peritoneal fluid concentrations by quadratic interpolation. The time for which one fourth of the Cp (Cp1/4) is maintained within the peritoneal cavity varied according to the substance and can be used to estimate dosage intervals. The Cp1/4 was compared with the minimal inhibitory concentrations for 1,344 pathogens encountered in 415 intra-abdominal infections from 31 studies.

Ticarcillin therapy of risk patients with infections due to Pseudomonas aeruginosa.

The implication of nosocomial infection due to Pseudomonas aeruginosa is demonstrated by comparing the bacteriological findings with the clinical picture of ten patients in a surgical intensive care unit. The occurrence of this organism and its resistance to beta-lactam-antibiotics and aminoglycosides is demonstrated. Ticarcillin was administered to ten patients following bacteriological and clinical evidence of infections due to P. aeruginosa. The pathogenicity of P. aeruginosa as an organism complicating the course of severely injured patients is discussed. Therapeutic consequences in regard to possible combination with other antibiotics are suggested.