Predictors of mortality in patients with bacteremia: the importance of functional status.

OBJECTIVE: To evaluate the influence of functional status on the outcome in older patients with bacteremia. DESIGN: Prospective study of all episodes of bacteremia that occurred in adults during a 27-month period (January 1991 to March 1993). SETTING: A 280-bed community hospital. PARTICIPANTS: During the study period, bacteremia was diagnosed in 242 consecutive patients (incidence of 11.2 bacteremic episodes per 1000 hospital admissions). One hundred twenty-seven of these patients were 65 years of age or older, and 115 were less than age 65. MEASUREMENTS: On identification of a positive blood culture, data on demographics, clinical findings, and a series of factors frequently cited as predisposing to infection were collected. The patient's functional status was assessed using the Barthel index (a score of < 60 identifies moderately and highly dependent patients). RESULTS: The overall mortality rate was 14.9% (36 of 242). In the univariate analysis, mortality was associated significantly with age greater than 65 years, nosocomial infection, absence of fever, shock, leukocytosis or leukopenia, inappropriate therapy, more than one underlying disease, immuno-compromised state, and limited functional status. Multiple logistic regression analysis revealed that shock (OR = 27.6, 95% CI 5.7-133), a Barthel score less than 60 (OR = 11.7, 95% CI 3.2-43), nosocomial infection (OR = 6.7, 95% CI 1.8-25.5), absence of fever (OR = 5.2, 95% CI 1.05-26), and immunocompromised state (OR = 15.6, 95% CI 2.4-101.5) were significantly associated with death attributable to bacteremia. CONCLUSION: The main prognostic factors in a patient with bacteremia were the presence of shock, impaired functional status, immunodeficiency state, acquisition of infection in the hospital, and absence of fever on admission. Age alone did not influence outcome.

Model-guided labeling of coronary structure.

Assigning anatomic labels to coronary arteries in X-ray angiograms is an important task in medical imaging, motivated by the desire to standardize the assessment of coronary artery disease and to facilitate the three-dimensional (3-D) reconstruction and visualization of the coronary vasculature. However, automatic labeling poses a number of significant challenges, including the presence of noise, artifacts, competing structures, misleading visual cues, and other difficulties associated with a dynamic and inherently complex structure. We have developed a model-guided approach that addresses these challenges and automatically labels the vascular structure in coronary angiographic images. The approach consists of two models: 1) a symbolic model, represented through a directed acyclic graph, that captures vascular tree hierarchies and branch interrelationships and 2) a generalized 3-D model that captures spatial and geometric relationships. Importantly, the approach detects ambiguities (such as vessel overlaps) that may be found in a frame of a ciné sequence, and resolves these ambiguities by considering the information derived from other (unambiguous) frames in the temporal sequence, employing dynamic programming methods to match the image features found in the different (ambiguous and unambiguous) frames. This paper presents this model-guided labeling algorithm and discusses the experimental results obtained from implementing and applying the resulting labeling system to a variety of clinical images. The results indicate the feasibility of achieving robust and consistently accurate image labeling through this model-guided, temporal disambiguation method.

Effects of lethal and sublethal concentrations of the herbicide, triclopyr butoxyethyl ester, in the diet of zebra finches.

Lethal and sublethal effects of dietary triclopyr butoxyethyl ester (TBEE) on zebra finches (Poephila guttata Gould) were determined in laboratory experiments conducted between 8 January and 1 May 1991. The 8-day median lethal dietary concentration, LC50 (95% confidence interval), of TBEE to zebra finches was 1,923 (1,627 to 2,277) mg/kg. In the sublethal effects experiment, when birds were exposed to 500 mg/kg TBEE in the diet for 29 days, food consumption and body weight were significantly depressed (P < 0.05). Similar prolonged exposures to 50 and 150 mg/kg TBEE in the diet had no significant effect on food consumption or body weight (P > 0.05). Perch-hopping activity was depressed relative to controls in the 500 mg/kg group, and elevated in the 150 mg/kg group, but neither of these differences was significantly (P > 0.05). Disappearance of TBEE residues from treated seeds over the 29 day experimental period followed an exponential decay model, with half-lives in the order of 15 to 18 days. On the basis of our observation that TBEE had no significant adverse effects at a concentration greater than the maximum expected environmental concentration, we propose that forestry applications of triclopyr at registered dosage rates pose little risk to wild songbirds.

Toxicity of a new molt-inducing insecticide (RH-5992) to aquatic macroinvertebrates.

The molt-inducing insecticide RH-5992, a potent ecdysone agonist, is being evaluated for potential use in forestry to control defoliating lepidopterans. The possible adverse effects of RH-5992 on nontarget aquatic organisms were studied in two test systems. Acute lethal effects were determined for one aquatic amphipod and 11 species of aquatic insects in laboratory flowthrough toxicity tests. Lethal and behavioral effects (drift response) on the amphipod and 8 species of stream insects were also evaluated under natural environmental conditions and more realistic exposure regimens in outdoor stream channels. There were no significant effects on drift or survival of the test species exposed to RH-5992 at the maximum test concentration of 3.5 mg/liter (100x the worst-case expected environmental concentration) in laboratory toxicity tests and stream channel treatments. Mortality of the amphipod Gammarus sp. in one toxicity test was considered an artifact, because there was no significant mortality in subsequent tests at concentrations up to 7.0 mg/liter, or in stream channels treated at 3.5 mg/liter. Yellow birch leaves were sprayed with RH-5992 at a rate of 50 g/ha and tested for residual toxic effects on two species of shredding invertebrates in the outdoor stream channels. There was no feeding inhibition or lethal effect on either test species resulting from consumption of the contaminated foliage. The candidate insecticide RH-5992 does not appear to pose undue risk of direct adverse effects to aquatic macroinvertebrates, particularly in water bodies where residues are likely to be short lived following aerial applications (e.g., lotic systems).

Necrotizing fasciitis caused by Salmonella enteritidis.

A 76-yr-old man developed necrotizing fasciitis due to Salmonella enteritidis 1 month after an episode of gastroenteritis due to the same microorganism. The fact that S. enteritidis was the only organism isolated despite adequate anaerobic cultures confirm the ability of salmonellae to produce severe monomicrobial soft tissue infections.