Evaluation of VITEK 2 for analysis of Enterobacteriaceae using the Advanced Expert System (AES) versus interpretive susceptibility guidelines used at Dynacare Kasper Medical Laboratories, Edmonton, Alberta.

OBJECTIVE: To evaluate the applicability and adaptability of the bioMérieux VITEK 2 Advanced Expert System (AES) to the customized interpretive susceptibility guidelines used at Dynacare Kasper Medical Laboratories (DKML). METHODS: Three hundred isolates of Enterobacteriaceae (not more than 30% Escherichia coli) were tested on the VITEK 2 system and the API 20E for identification. Susceptibility testing for these isolates was performed on the VITEK 2 system and the Pasco broth microdilution panels. Minimal inhibitory concentrations (MICs) and interpreted results according to the AES and DKML antimicrobial susceptibility guidelines were compared. RESULTS: Of 300 isolates tested for susceptibility, 13 did not give AES interpretations. Of the remaining 287 isolates, interpretations between AES and DKML guidelines were compared for 10 antibiotics. The overall correlation between the AES and DKML interpretations was 96.2%. CONCLUSION: This study demonstrated the benefits and limitations of the bioMérieux AES. Automated knowledge-based systems provide a useful laboratory tool for the interpretation of susceptibility results.

Pneumocystis carinii pneumonia complicating methotrexate treatment of primary sclerosing cholangitis.

The etiology of primary sclerosing cholangitis, a chronic progressive cholestatic liver disease, is poorly understood. Treatment with oral methotrexate may improve patient symptoms, liver biochemistry, and hepatic histology. This report describes a severe life-threatening complication of methotrexate therapy in primary sclerosing cholangitis--the development of Pneumocystis carinii pneumonia. The reported cases of methotrexate-associated P. carinii pneumonia in the literature are reviewed. With the increasing use of methotrexate in chronic inflammatory disorders, physicians should be aware of this potentially lethal complication.

Treatment of the chronic fatigue syndrome. A review and practical guide.

The chronic fatigue syndrome (CFS) was formally defined in 1988 to describe a syndrome of severe and disabling fatigue of uncertain aetiology associated with a variable number of somatic and/or psychological symptoms. CFS has been reported in most industrialised countries and is most prevalent in women aged between 20 and 50 years. Despite occasional claims to the contrary, the aetiology of CFS remains elusive. Although abnormalities in tests of immune function and cerebral imaging have been described in variable numbers of CFS patients, such findings have been inconsistent and cannot be relied upon, either to establish or exclude the diagnosis. Thus, diagnosis rests on fulfillment of the Centers for Disease Control case definition which was revised in 1992. This case definition remains somewhat controversial, largely due to its subjectiveness. The mainstay of treatment is establishing the diagnosis and educating the patient about the illness. An empathetic clinician can stop further consultations elsewhere ('doctor shopping') and subsequent excessive investigations, which frequently occur in such patients. Most patients should undertake a trial of antidepressant therapy, even if major depression is not present. The choice of antidepressant drug should tailor the tolerability profile to relief of particular CFS symptoms, such as insomnia or hypersomnia. Failure to improve within 12 weeks warrants an alternative antidepressant agent of another class. Many other drugs have been reported anecdotally to be beneficial, but no therapy has been demonstrated to be reproducibly useful in double-blind, placebo-controlled clinical trials with an adequate duration of follow-up.

Containing cefoxitin costs through a program to curtail use in surgical prophylaxis.

OBJECTIVE: To reduce drug costs attributable to anti-anaerobic cephalosporins - specifically to reduce cefoxitin use in surgical prophylaxis. DESIGN: Before and after intervention cefoxitin use comparison. SETTING: Tertiary care hospital. PARTICIPANTS: Hospitalized patients. INTERVENTIONS: Chart review of patients identified through pharmacy records as cefoxitin recipients was carried out to determine which physicians were the principal users of cefoxitin and the purpose for such use. These data were used to direct cost containment strategies. MAIN OUTCOME MEASURES: Hospital quarterly pharmacy acquisition costs and grams of cefoxitin used. RESULTS: The departments of surgery (49%) and obstetrics/gynecology (37%) were the principal users of cefoxitin, and surgical prophylaxis was found to be the principal indication for use (63%). These departments were invited by the Antibiotic Utilization Subcommittee of the hospital's Pharmacy and Therapeutics Committee to draft surgical prophylaxis guidelines in keeping with published recommendations. Such guidelines were written and distributed to medical staff and substituted cefazolin for most forms of prophylaxis, gentamicin/metronidazole for colorectal prophylaxis and cefoxitin only for appendectomies. Over the following 21 months, hospital-wide cefoxitin use fell from 6093 g, $70,076 per quarter, to 1316 g, $11,515 per quarter (partially offset by a 2595 g, $9,131 per quarter increase in cefazolin use). CONCLUSION: As a first step in reducing hospital costs of anti-anaerobic cephalosporins, rationalization of cefoxitin use may be preferable to formulary interchange with alternatives such as ceftizoxime or cefotetan.

The pregnant antithrombin III deficient patient: management without antithrombin III concentrate.

Pregnant patients with antithrombin III (AT III) deficiency have an unacceptably high risk of venous thromboembolism (VTE). Antithrombotic therapy is therefore recommended. The reported clinical experience of such prophylaxis is limited. Some authors have recommended the use of AT III concentrate in addition to heparin in the management of these patients. We report successful management with heparin alone during pregnancy and the postpartum period in two patients with AT III deficiency. Both patients had experienced VTE during a prior pregnancy; one also experienced VTE during the reported pregnancy. Both patients were therefore at particularly high risk of further VTE. Based on the good results in these two patients, and a review of previously reported cases, we propose that heparin alone, in a dose to maintain the APTT in a therapeutic range, provides adequate prophylaxis and treatment for VTE during pregnancy and delivery in many AT III deficient subjects.