The mechanism of action of a single dose of methylprednisolone on acute inflammation in vivo.

A model system for the study of inflammation in vivo has been developed using the 16-h polyvinyl sponge implant in the rat. This system allows for simultaneous measurement of in vivo chemotaxis, volume of fluid influx, and fluid concentrations of lysosomal and lactic dehydrogenase (LDH) enzymes. In addition, the enzyme content of inflammatory fluid neutrophils may also be determined. A parallel time course of neutrophil and lysosomal enzyme influx into sponge implants was observed. This was characterized by an initial lag phase and a rapid increase between 5 and 16 h. The origin of supernatant LDH and lysosomal enzymes was studied with anti-neutrophil serum to produce agranulocytic rats. Inflammatory fluid in these rats was almost acellular and contained decreased concentrations of beta glucuronidase (-96%) and LDH (-74%). In control rats all of the supernatant beta glucuronidase could be accounted for by cell death and lysis, as estimated from measurements of soluble DNA. Only 15-20% of the LDH activity could be accounted for on the basis of cell lysis. The remainder was derived from neutrophil-mediated injury to connective tissue cells. Large intravascular doses of methylprednisolone markedly inhibited neutrophil influx into sponges and adjacent connective tissue. Secondary to decreased neutrophil influx, fewer neutrophils were available for lysis, and lysosomal enzyme levels in inflammatory fluid decreased. No evidence for intracellular or extracellular stabilization of neutrophil lysosomal granules by methylprenisolone was found.

Central catheter infections: single- versus triple-lumen catheters. Influence of guide wires on infection rates when used for replacement of catheters.

A prospective study was conducted over six months to determine if triple-lumen catheters were associated with a higher rate of infection than single-lumen catheters. A total of 502 central intravascular catheters were prospectively collected from 362 consecutive patients in the adult intensive care units. Semiquantitative and broth cultures were performed on distal and proximal catheter segments, with peripheral blood culture specimens drawn in febrile patients. The overall infection rate for the 502 catheters was 11.8 percent or 2.2 infections per 100 days at risk. The infection rates were: single-lumen lines, 8 percent; triple-lumen lines, 32 percent; and triple-lumen pulmonary artery catheters, 12 percent. When corrected for time at risk, the triple-lumen lines and the triple-lumen pulmonary artery catheters had the same rate of infection, which was three times greater than that of the single-lumen catheters. After correction for confounding variables such as the presence of diabetes mellitus, the use of hyperalimentation, the degree of illness, dialysis, or ultrafiltration, and the use of a guide wire to place a replacement line over a pre-existing one, the risk of infection remained significantly higher for triple-lumen than for single-lumen catheters. The use of a guide wire to place a new line over an old one also was associated with a trend towards an increased risk of infection.

Is the use of boxed gloves in an intensive care unit safe?

PURPOSE: To identify the type, rate, burden, and pattern of contamination of boxed, clean but nonsterile gloves in our intensive care unit (ICU). MATERIALS AND METHODS: The fingertips of the first, middle, and last two pairs of gloves in 29 boxes in routine service in our ICU were cultured. The first of each of these three sets were removed aseptically, the second in a routine fashion. RESULTS: We found 16 of 29 (55%) first pairs removed aseptically to be contaminated with a mean bioburden of 1.8 colony-forming units (CFU). The percentage contamination and bioburden did not change significantly with position in the box. Use of routine compared with strict aseptic technique increased the rate of contamination by only 11% (95% confidence interval [CI] -0.05 to +0.27 percentage points) and bioburden by only a mean of 3.4 colonies per pair (CI -0.51 to +4.90 CFU). The length of the time the boxes were open and in use was unrelated to whether the final aseptically removed pair was sterile or contaminated. The predominant organisms were coagulase-negative staphylococci. CONCLUSIONS: One half the pairs of latex examination gloves in our ICU were sterile despite repeated barehanded access to the boxes. Those contaminated exhibited a small bioburden of low pathogenic potential. No pattern of contamination or unsafe duration of box use were observed. The use of boxed, clean, nonsterile gloves appears safe for routine use in an ICU.

Broncholithiasis due to Histoplasma capsulatum subsequently infected by actinomycetes.

A case of broncholithiasis in which both Histoplasma and actinomycotic organisms were demonstrated is presented. The etiology of broncholithiasis is discussed, with particular emphasis on the relationship between the organisms identified.

Nosocomial urinary-tract infections in a skilled nursing facility.

Fifty-five documented infections reported from an admission unit of a large skilled nursing facility (SNF) during a five-month period were analyzed. Of these, 45 (82 percent) were urinary-tract infections (UTIs), chiefly asymptomatic bacteriuria. Sixty-three percent of the UTIs were acquired in the SNF, and the remainder were acquired during the preceding stay in a general hospital. Statistically, Proteus species infections were more common among the SNF-acquired UTIs, whereas Pseudomonas aeruginosa infections were the most common among the hospital-acquired UTIs. The following recommendations are made: 1) for previously hospitalized elderly patients in whom urinary-tract sepsis develops soon after admission to an SNF, treatment should start with an antibiotic active against Pseudomonas aeruginosa while the results of cultures are pending; 2) symptomatic lower urinary-tract infections caused by SNF-acquired Proteus species should be treated with nalidixic acid or trimethoprimsulfamethoxazole; 3) the term "nosocomial infection" should be broadened to include infections acquired in long-term care institutions; and 4) infection surveillance should be started in selected long-term care institutions for the elderly as part of an expanded National Nosocomial Infections Survey.

Vancomycin-resistant Enterococcus faecium in hospitalized children.

OBJECTIVE: Determine the epidemiology and risk factors for colonization with vancomycin-resistant Enterococcus faecium. DESIGN: Survey; case-control study. SETTING: Children's hospital. PATIENTS: Pediatric oncology patients. INTERVENTION: Contact isolation, restriction of vancomycin prescribing. RESULTS: There was a high prevalence of colonization with vancomycin-resistant enterococci among pediatric oncology patients. The length of hospitalization and the administration of vancomycin and other intravenous antibiotics was associated with colonization. Prevention of colonization was associated with restriction of vancomycin use and contact isolation. CONCLUSIONS: Vancomycin use may predispose to colonization with vancomycin-resistant E faecium. Vancomycin-resistant E faecium may be nosocomially spread. Contact isolation and restriction of vancomycin use may prevent spread of vancomycin-resistant E faecium.

Primary osteomyelitis due to an anaerobic microorganism.

Primary osteomyelitis in a teen-aged boy that mimicked Ewing's tumor radiologically showed small Gram-negative rods on the original smear. The organism isolated was an obligately anaerobic bacterium, finally identified as Clostridium sphenoides. This finding underlines the need for microbiologic analysis of orthopedic lesions.

Epidemiology and control of vancomycin-resistant enterococci in an adult and children's hospital.

BACKGROUND: The incidence of vancomycin-resistant enterococci (VRE) has reached endemic proportions in many medical centers. To initiate an effective infection control program, an understanding of the epidemiologic attributes of the genus in medical facilities is imperative. METHODS: We studied 138 consecutive cases of VRE from April through December 1995. We created a database to analyze the risk factors for patients in both an adult hospital and a children's hospital and screened all specimens, submitted for routine microbiologic analysis, for VRE. RESULTS: One hundred twenty-three cases (89%) occurred in the adult acute care hospital, and 15 (11%) occurred in the children's hospital. Eighty patients (58%) were colonized with VRE, and 58 (42%) had an infection with VRE. Eighty-three percent of all the cases of VRE were nosocomially acquired. The majority of cases occurred in the medical service. Urine was the most important clinical specimen infected or colonized. Prior use of an antibiotic, other than vancomycin, was the most important risk factor for all nosocomial cases, followed by prior vancomycin use for surgical patients and residence in a unit with other patients infected with VRE for the medical service. Direct admission from another hospital was the most important risk factor for community-acquired cases. Special microbiologic screening of cultures yielded 48% of all VRE identified. Enterococcus faecium was the predominant resistant isolate recovered. CONCLUSIONS: The control of VRE in the hospital setting is difficult for several reasons. Almost half of all patients carrying VRE would not have been identified without special microbiologic screening efforts, as would patients, admitted from the community, who are already colonized with VRE. Controlling antibiotic use both in the hospital and the community is basic for controlling these organisms. Continuous education of all staff about VRE and other nosocomially significant organisms is the key to controlling the spread of these bacteria.

The challenge of vancomycin-resistant enterococci: a clinical and epidemiologic study.

BACKGROUND: Vancomycin-resistant enterococci have been recovered with increasing frequency from hospitalized patients. Risk factors, mode of nosocomial transmission, extent of colonization in hospitalized patients, and treatment options for these organisms have not been completely delineated. METHODS: We studied 53 patients (group A) with vancomycin-resistant enterococci isolated from various clinical specimens and also surveyed for vancomycin-resistant enterococci in stool specimens submitted for Clostridium difficile toxin assays (group B). Stool specimens submitted for identification of bacterial pathogens and stool specimens from hospital employees were also analyzed for vancomycin-resistant enterococci. RESULTS: Seventy-six isolates of vancomycin-resistant enterococci were recovered in group A. Five of these patients harbored vancomycin-resistant enterococci on admission. Fifty-three of 289 group B stool specimens submitted for C. difficile toxin assays yielded vancomycin-resistant enterococci. Cephalosporins and vancomycin were the most common antimicrobial agents received by both groups of patients. Enterococcus faecium isolates were more resistant than Enterococcus faecalis isolates to antimicrobial agents. All isolates exhibited high-level aminoglycoside resistance and were not beta-lactamase producers. There were at least 15 different molecular clones of E. faecium and three of E. faecalis. Vancomycin-resistant enterococcal bacteremia was associated with a 100% in-hospital mortality rate. CONCLUSIONS: Multidrug-resistant and vancomycin-resistant enterococci have become important nosocomial pathogens that are difficult to treat. Vancomycin-resistant enterococcal bacteremia was associated with a poor prognosis. We found a high rate of colonization in patients with suspected C. difficile toxin colitis. Judicious use of vancomycin and broad-spectrum antibiotics is recommended, and strict infection control measures must be implemented to prevent nosocomial transmission of these organisms.

Acute hematogenous osteomyelitis: an experimental model.

The injection of barium sulphate (micropaque) contaminated with Staphylococcus aureus into the nutrient artery of the canine tibia produced typical inflammatory bone changes. This alteration, similar to those observed in human hematogenous osteomyelitis, consisted of medullary destruction, spontaneous fractures, and intense periosteal new bone formation. This system seems to mimic the characteristics of some clinical bone infections and may provide a model for therapeutic trials.