Successful use of higher-than-recommended dosage of imipenem in Pseudomonas aeruginosa endocarditis.

OBJECTIVE: To report a case of Pseudomonas aeruginosa endocarditis that was successfully treated with high-dose imipenem/cilastatin and to discuss dosage modification based on individual pharmacokinetic parameters. DATA SOURCES: Clinical studies, review articles, and relevant laboratory and pharmacokinetic information. CASE SUMMARY: A 27-year-old man with right-sided P. aeruginosa endocarditis was successfully treated with long-term imipenem/cilastatin and tobramycin. The imipenem dose required to achieve therapeutic serum concentrations and cidal activity was 6 g/d. The manufacturer's recommended maximum dose is 4.0 g/d or 50 mg/kg/d. Because of the patient's large apparent volume of distribution, low serum imipenem concentrations, and lack of serum cidal activity, the clinical decision was made to increase the dose to 6 g/d or 54 mg/kg/d. Treatment was tolerated for seven weeks without any adverse effects. The patient remains free of symptoms 24 months after the diagnosis. CONCLUSIONS: Careful and discriminate use of larger-than-recommended doses of imipenem may be indicated in certain clinical situations. Dosage may need to be adjusted to body size in order to obtain optimal serum concentrations and activity.

Hematoma infected with Mycoplasma hominis.

Although mycoplasmas are commonly isolated in the genitourinary and upper respiratory tracts, they are rarely isolated from other sites. We describe a case of a young woman with trauma to her pelvis and genitourinary tract who had a thigh hematoma infected with Mycoplasma hominis. The patient had persistent systemic symptoms that resolved with appropriate antibiotics and surgical drainage. This case as well as other cases of Mycoplasma-infected hematomas point out the need to consider mycoplasma infection in patients with persistent fever unresponsive to conventional antibiotic therapy.

Meningitis caused by Oerskovia xanthineolytica.

In summary, we describe a case of central nervous system infection with O. xanthineolytica in which the infecting microbe probably was engrafted on a ventricular shunt. The bacteria caused a smoldering meningitis that did not respond to penicillin and rifampin despite in vitro sensitivity, presumably because of inadequate cerebrospinal fluid penetration of the penicillin and the recognized difficulty of eradicating bacteria from contaminated shunts. Removal of the shunt and continued treatment with penicillin and rifampin resulted in cure.

A computer-assisted image-analysis system for analyzing polymorphonuclear leukocyte chemotaxis in patients with diabetes mellitus.

A computer-assisted image-analysis system that precisely tracks the cell movements of up to 50 polymorphonuclear leukocytes (PMNLs) was developed and used to quantitatively measure cellular chemokinesis and chemotaxis in normal individuals and in diabetic patients with hyperglycemia. The PMNLs were tested in Zigmond chambers with or without a gradient of 10(-7) M n-formylmethionylleucylphenylalanine (f-Met-Leu-Phe). Cellular movement was recorded on videotape by using a videocamera mounted on the microscope. The videotapes were analyzed by computer programs to calculate the speed and direction of each PMNL at 10-sec intervals. Average rates of chemokinesis were 19.6 microns/min without and 25.3 microns/min with f-Met-Leu-Phe. McCutcheon indices, which measure chemotaxis, were 0.01 without and 0.48 with f-Met-Leu-Phe. Similar values were observed in diabetic patients after fasting (average glucose, 217 mg/100 ml) and 2 hr after glucose challenge (average glucose, 309 mg/100 ml). These values demonstrate that PMNLs from diabetic patients with hyperglycemia move at normal rates and respond appropriately to f-Met-Leu-Phe.