Pyogenic vertebral osteomyelitis of the posterior elements.

Lone pyogenic involvement of the posterior elements of the vertebrae is a rare event. We present two cases of isolated lumbar vertebral infection of the posterior elements and review 13 cases previously reported in the literature. Clinical presentation, laboratory and radiographic findings, microbiological etiology, and treatment were evaluated. Back pain, an elevated erythrocyte sedimentation rate, and computed tomography or magnetic resonance imaging were most useful in identifying the presence and extent of infection. Antibiotic therapy with or without surgical intervention was successful in all cases.

Infectious complications of hepatic cryosurgery.

Hepatic cryosurgery is a novel procedure for patients with metastatic liver disease. To date, no reviews of the infectious complications of this procedure have been published. One hundred and fifty patients underwent 158 hepatic cryosurgical procedures at Allegheny General Hospital (Pittsburgh) from November 1987 through July 1995. Gastrointestinal malignancies accounted for 93% of the underlying diagnoses. The following 12 infections were directly related to the cryosurgical procedure: hepatic abscess (six), intraperitoneal abscess (three), ascending cholangitis (two), and an intrahepatic device (Infusaid; Strato/Infusoid, Norwood, MA) infection (one). Enterococcus was the most commonly isolated organism. Seven of the 12 infections were polymicrobial. The patients who developed infections had longer hospital stays (26 days vs. 13 days) and had more days of fever (6.5 days vs. 2.3 days). than those who did not develop infections. If perioperative manipulation of the biliary tree is avoided, the infection rate in patients who undergo hepatic cryosurgery may be decreased even further. Overall, cryoablation of the liver is not related to an increased risk of infection.

A large randomized clinical trial of a silver-impregnated urinary catheter: lack of efficacy and staphylococcal superinfection.

PURPOSE: The antibacterial activity of silver-containing compounds has recently been employed in constructing medical devices, such as vascular and urinary catheters, that may be effective in blocking infection. The present study was designed to evaluate the efficacy of a silver oxide-coated urinary catheter. PATIENTS AND METHODS: A total of 1,309 hospitalized patients who required placement of an indwelling urinary catheter for 24 hours or longer were randomly assigned to receive either a silicone catheter coated externally with 5% silver oxide or a standard silicone elastomer-coated latex catheter. Daily catheter-urine specimens were collected aseptically and catheter-care violations were monitored daily for the duration of the catheterization. RESULTS: Bacteriuria developed in 85 of 745 patients (11.4%) in the silver-coated catheter group and in 73 of 564 patients (12.9%) in the control group (P = 0.45). In women who did not receive antibiotics, the rates were 29.3% and 30.4%, respectively (P = 0.98). In men who did not receive antibiotics, the rate of bacteriuria was significantly higher with the silver-coated catheter (29.4% compared to 8.3%, respectively, P = 0.02). Staphylococcal species were isolated more often from the silver-coated catheter group than from the control group (25% versus 8% of all isolates, respectively, P = 0.002). CONCLUSIONS: This study, the largest ever reported evaluating any silver-impregnated device, has not only failed to demonstrate the efficacy of silver in prevention of catheter-associated bacteriuria, as suggested in prior studies, but it has also shown a significantly increased incidence of bacteriuria in male patients and a significantly increased occurrence of staphylococcal bacteriuria. These results suggest the need for caution and for similar large-scale trials before silver-containing compounds are widely used for preventing device-associated infections, both in vascular and urinary catheters.

Surveillance cultures in bone marrow transplant recipients: worthwhile or wasteful?

A prospective study of the value of surveillance cultures was performed in a bone marrow transplant (BMT) unit among 48 consecutive patients. All patients were admitted to laminar airflow or high-efficiency particulate air (HEPA) filtered rooms, maintained on reduced microbial diets and received oral non-absorbable antibiotics. With the onset of neutropenia, all patients received imipenem/cilastatin and 17 patients received low-dose amphotericen B 0.1 mg/kg/day. Pre-transplant and weekly post-transplant cultures of the stool, throat and urine were obtained on all patients. Nasal and vaginal cultures were performed on 26 patients. Sixteen patients developed 23 documented infections. The sensitivity of surveillance cultures for all infections was 38%, specificity 25%, positive predictive value 20% and negative predictive value 44%. When stratified by organisms, the sensitivity, specificity, positive predictive value and negative value were: Gram positive infections, 33%, 36%, 11%, 70%, Gram negative infections, 17%, 88%, 17%, 88%; fungal infections 37%, 50%, 11%, 75%; and Candida albicans, 100%, 57%, 14%, 100%. These data suggest that surveillance cultures may be useful to exclude C. albicans infections but are of limited value in predicting other types of infections in recipients of BMT.

The prophylactic use of low-dose amphotericin B in bone marrow transplant patients.

PURPOSE: To evaluate the efficacy of prophylactic low-dose amphotericin B (0.1 mg/kg per day) (LDA) in preventing fungal infections in patients who have had a bone marrow transplant (BMT). MATERIALS AND METHODS: Double-blind, randomized, controlled trial in which patients undergoing bone marrow transplantation received intravenous LDA or similar-appearing placebo from the onset of neutropenia until the absolute neutrophil count remained > 0.5 x 10(9)/L, or until high-dose amphotericin B was initiated. Weekly surveillance cultures were obtained from all patients. RESULTS: Five of 18 patients (28%) randomized to placebo developed documented systemic fungal infections within the first 30 days after transplantation, compared to none of 17 patients who received LDA (P = 0.045). LDA recipients received fewer days of high-dose amphotericin B (P = 0.04) and fewer days of antibiotics (P = 0.008). There were trends towards fewer days of hospitalization (P = 0.14) and improved survival (P = 0.08); these differences were statistically significant among recipients of allogeneic BMT. No adverse effects occurred with LDA therapy. CONCLUSIONS: LDA appears to be safe and to reduce early systemic fungal infections in BMT recipients. Improved survival was observed among LDA recipients, but this was not directly attributable to the prevention of fungal infection.