Using principal component analysis to aid bayesian network development for prediction of critical care patient outcomes.

BACKGROUND: Predicting an intensive care unit patient's outcome is highly desirable. An end goal is for computational techniques to provide updated, accurate predictions about changing patient condition using a manageable number of physiologic parameters. METHODS: Principal component analysis was used to select input parameters for critical care patient outcome models. Vital signs and laboratory values from each patient's hospital stay along with outcomes ("Discharged" vs. "Deceased") were collected retrospectively at a Level I Trauma-Military Medical Center in the southwest; intensive care unit patients were included if they had been admitted for burn, infection, or hypovolemia during a 5-year period ending October 2007. Principal component analysis was used to determine which of the 24 parameters would serve as inputs in a bayesian network developed for outcome prediction. RESULTS: Data for 581 patients were collected. Pulse pressure, heart rate, temperature, respiratory rate, sodium, and chloride were found to have statistically significant differences between Discharged and Deceased groups for "Hypovolemia" patients. For "Burn" patients, pulse pressure, hemoglobin, hematocrit, and potassium were found to have statistically significant differences. For a "Combined" group, heart rate, temperature, respiratory rate, sodium, and chloride had statistically significant differences. A bayesian network based on these results, developed for the Combined group, achieved an accuracy of 75% when predicting patient outcome. CONCLUSIONS: Outcome prediction for critical care patients is possible. Future work should explore model development using additional temporal data and should include prospective validation. Such technology could serve as the basis of real-time intelligent monitoring systems for critical patients.

Historical contamination of the Anacostia River, Washington, D.C.

The tidal Anacostia River in Washington DC has long been impacted by various sources of chemical pollution over the past 200 years. To explore more recent inputs of various chemicals, six sediment cores were collected for dating and chemical analysis in the downstream section of the tidal Anacostia River. Profiles of contaminants in sediment cores can be useful in determining management direction and effectiveness of pollution controls over time. There were two main objectives for this investigation: (1) determine current sediment contaminant levels; (2) determine a historical perspective of the sediment changes in contamination using (137)Cs and (210)Pb dating. The determination of an age-depth relationship using (210)Pb and (137)Cs dating gave somewhat different results, suggesting that the assumptions of (210)Pb dating were not met. Using the (137)Cs horizon allowed an assignment of approximate sediment accumulation rates and hence an age-depth relationship to contaminant events in the upper portions of the cores. Total PAHs showed higher concentrations at depth and lower surface concentrations. In the upper sections, PAHs were a mixture of combustion and petrogenic sources, while at depth the signature appeared to be of natural origins. Total PCBs, DDTs and chlordane concentrations showed a maximum in recent sediments, decreasing towards the surface. PCBs had lower molecular weight congeners near the surface and higher molecular weights at depth. A phthalate ester, DEHP, appeared in the mid 1940-1950s, and decreased towards the surface. Trace elements fell roughly into three groups. Fe, Mn, and As were in approximately constant proportion to Al, except in some deeper, sandy sediments, where they showed enrichments linked to redox conditions. Ag, Cd, Cu, Hg, Pb, and Zn had low concentrations in the deepest sediments, high concentrations at mid-depths, and declines to intermediate levels at the surface. Ni and Cr followed neither of these patterns closely. We observed that many contaminants appeared in the Anacostia sediments at various times, and reached relatively high concentrations in the past, but are now showing declines in loadings. In some cases, such as PCBs, DDT, chlordane, and Pb from leaded gasoline, these declines can be clearly linked to the discontinuation of their use for environmental reasons. For other contaminants (e.g., PAHs, DEHP, selected metals) these declines are more likely the result of changes in production, usage and waste control.

Implementing a unit-level intervention to reduce the probability of ventilator-associated pneumonia.

BACKGROUND: Ventilator-associated pneumonia (VAP) is the second most common hospital-acquired infection and is associated with high morbidity and mortality rates for mechanically ventilated patients in the intensive care unit. Routine nursing interventions have been shown to reduce VAP rates. OBJECTIVES: The purpose of this study was to evaluate the effectiveness of a unit-specific education intervention that emphasized hand hygiene, head-of-the-bed elevation, and oral care. The goals were to improve staff compliance with hand washing, head-of-the-bed elevation, and oral care; to decrease VAP rates, and to decrease number of ventilator days. METHODS: Two-hour observations were conducted on a convenience sample of 100 ventilated patients not diagnosed with VAP and the clinical staff that interacted with them. Instrumentation included a compliance checklist, a demographic patient survey, and the Acute Physiology and Chronic Health Evaluation AEIV tool. Unit-specific educational interventions were designed and implemented on each participating unit. RESULTS: : The VAP and the ventilator day rates did not improve significantly. There were no significant changes in clinician adherence to hand hygiene, provision of oral care, or patient positioning. DISCUSSION: Despite implementation of both structured and creative education, team-based approach, and frequent staff reminders, patient outcomes and staff compliance did not improve significantly. Unit-based education interventions may not be the best strategy to facilitate change. Organizations with frequent changes in personnel and leadership may not have the unit-level infrastructure necessary to attain and sustain change.

Using the Sediment Quality Triad to characterize baseline conditions in the Anacostia River, Washington, DC, USA.

The Sediment Quality Triad (SQT) consists of complementary measures of sediment chemistry, benthic community structure, and sediment toxicity. We applied the SQT at 20 stations in the tidal portion of the Anacostia River from Bladensburg, MD to Washington, DC to establish a baseline of conditions to evaluate the effects of management actions. Sediment toxicity was assessed using 10-day survival and growth tests with the freshwater amphipod, Hyalella azteca and the midge, Chironomus dilutus. Triplicate grabs were taken at each station for benthic community analysis and the Benthic Index of Biotic Integrity (B-IBI) was used to interpret the data. Only one station, #92, exhibited toxicity related to sediment contamination. Sediments from this station significantly inhibited growth of both test species, had the highest concentrations of contaminants, and had a degraded benthic community, indicated by a B-IBI of less than 3. Additional sediment from this station was tested and sediment toxicity identification evaluation (TIE) procedures tentatively characterized organic compounds as the cause of toxicity. Overall, forty percent of the stations were classified as degraded by the B-IBI. However, qualitative and quantitative comparisons with sediment quality benchmarks indicated no clear relationship between benthic community health and contaminant concentrations. This study provides a baseline for assessing the effectiveness of management actions in the Anacostia River.

Poverty reduction and Millennium Development Goals: recognizing population, health, and environment linkages in rural Madagascar.

The Millennium Development Goals (MDGs), committed to by all 191 United Nations member states, are rooted in the concept of sustainable development. Although 2007 (midway) reports indicated that programs are under way, unfortunately many countries are unlikely to reach their goals by 2015 due to high levels of poverty. Madagascar is one such example, although some gains are being made. Attempts of this island nation to achieve its MDGs, expressed most recently in the form of a Madagascar Action Plan, are notable in their emphasis on (1) conserving the country's natural resource base, (2) the effect of demographic trends on development, and (3) the importance of health as a prerequisite for development. Leadership in the country's struggle for economic growth comes from the president of the Republic, in part, through his "Madagascar Naturally" vision as well as his commitment to universal access to family planning, among other health and development interventions. However, for resource-limited countries, such as Madagascar, to get or stay "on track" to achieving the MDGs will require support from many sides. "Madagascar cannot do it alone and should not do it alone." This position is inherent in the eighth MDG: "Develop a global partnership for development." Apparently, it takes a village after all - a global one.

A 34-year-old man with Darier-White disease: a case report and review of the literature.

Darier-White disease is an uncommon genodermatosis that is commonly under-recognized and is characteristically refractory to treatment. It is most frequently due to an autosomal dominant mutation in an intracellular calcium pump. It can be associated with severe cutaneous infections requiring hospitalization as well as neurologic and psychiatric comorbid disease. There are many treatment modalities described in the literature and systemic retinoids are the most effective. An increased clinical suspicion could possibly lead to a decreased delay in the diagnosis of this disease and an increased quality of life for these patients. We report a case of a man with Darier-White disease followed by a review of the current literature on the pathogenesis, clinical features, diagnosis, and treatment of this cutaneous malady.

A comparison of congeneric PCB patterns in American eels and striped bass from the Hudson and Delaware River estuaries.

The Hudson River estuary has enormous spatial variation in polychlorinated biphenyl (PCB) contamination due in large part to historical point source discharges above Troy Dam. The Delaware River estuary has accumulated significant levels of PCBs through decades of industrial, municipal, and non-point source inputs. The overall goal of this research was to use existing data sets to compare and contrast the patterns of accumulated PCB congeners in sub-populations of American eels and striped bass inhabiting these two estuaries and surrounding coastal waters. Using principal component analysis and analysis of covariance (ANCOVA), inter- and intra-estuarine differences in accumulated congeneric patterns were denoted for both species. Results from our study support the idea that migratory behaviors of striped bass hamper the use of accumulated congener-specific PCB patterns in providing information on localized contamination, although major regional differences were seen between upriver Hudson River fish, downriver Hudson River fish and fish from other areas within this study. This study provides additional evidence for the use of the American eel as a biomonitoring tool, since its limited home range provides finer resolution of regional contamination.

Children's daily exposure to polychlorinated biphenyls from dietary supplements containing fish oils.

In children, omega-3 polyunsaturated fatty acids (PUFAs) may elicit a suite of health benefits including enhancement of cognitive development. Subsequently, dietary supplements containing omega-3 PUFAs have become increasingly popular. Often, the largest source of beneficial PUFAs in these supplements is fish oil, which may contain significant levels of contaminants such as polychlorinated biphenyls (PCBs). The objectives of this study were to evaluate congener-specific PCB concentrations in 13 over-the-counter children's dietary supplements containing fish oils/powders and assess potential PCB exposures through ingestion of these products on a daily basis. Every supplement analysed contained PCBs, with a mean concentration of 9 ± 8 ng PCBs/g supplement. When following serving size suggestions, mean daily exposure values ranged from 2.5 to 50.3 ng PCBs/day. Daily exposures for children's supplements were significantly lower than those previously reported for adult supplements and may be explained, in part, by the variability in the amount of fish oil (and PUFA content) in a serving size. Based on this study, factors such as fish oil purification methods (e.g., molecular distillation) and the trophic level of the fish species used to make the fish oil cannot be used as indicators of PCB levels within children's supplements. Fish supplements may decrease or increase daily PCB exposure compared with ingestion of fresh fish. However, eating fish high in omega-3 PUFAs and low in PCBs may reduce PCB exposure compared with daily supplementation with fish oils for some products studied.

Bacterial community profiles from sediments of the Anacostia River using metabolic and molecular analyses.

UNLABELLED: BACKGROUND AIM AND SCOPE: Though the tidal Anacostia River, a highly polluted riverine system, has been well characterized with regard to contaminants, its overall resident bacterial populations have remained largely unknown. Improving the health of this system will rely upon enhanced understanding of the diversity and functions of these communities. Bacterial DNA was extracted from archived (AR, year 2000) and fresh sediments (RE, year 2006) collected from various locations within the Anacostia River. Using a combination of metabolic and molecular techniques, community snapshots of sediment bacterial diversity and activity were produced. RESULTS: Employing Biolog EcoPlates, metabolic analysis of RE sediments from July revealed similar utilization of amines, amino acids, carbohydrates, carboxylic acids, and polymers at all sites. Normalized optical density measurements demonstrated that for most compounds, utilizations were similar though when differences did occur, the downstream site was enhanced compared to one or both of the upstream sites. Using denaturing gradient gel electrophoresis, bacterial diversity fingerprints of operational taxonomic units (OTUs) were obtained. Dendograms of the banding patterns revealed qualitative relationships as well as differences between replicate samples from similar sites. Replicates from the AR sites shared several common OTUs, while RE sites were more varied. Species richness and Shannon diversity indices generally increased with increasingly downstream locations, and were significant for the AR sediments (analysis of variance, P < 0.0001). Carbon and nitrogen content and concentration of fine grain sediment (<63 µm) were positively correlated with OTU richness (r (2) = 0.37, P = 0.0008; r (2) = 0.45, P < 0.0001; r (2) = 0.48, P = 0.001, respectively). CONCLUSIONS: This study demonstrated that the bacterial communities from all regions sampled were not only metabolically active with the capacity to utilize several different compounds as energy sources but also were genetically diverse. This study is the first to focus on the overall bacterial community, providing insight into this vital component of stream ecosystems. Understanding the bacterial components of aquatic systems such as the Anacostia River will increase our knowledge of the overall structure and function of the ecological communities in polluted systems, subsequently enhancing our ability to improve the health of this important tidal river.

Contaminants in fish of the Hackensack Meadowlands, New Jersey: size, sex, and seasonal relationships as related to health risks.

The trace metal content and related safety (health risk) of Hackensack River fish were assessed within the Hackensack Meadowlands of New Jersey, USA. Eight elements were analyzed in the edible portion (i.e., muscle) of species commonly taken by anglers in the area. The white perch collection (Morone americana) was large enough (n = 168) to enable statistically significant inferences, but there were too few brown bullheads and carp to reach definite conclusions. Of the eight elements analyzed, the one that accumulates to the point of being a health risk in white perch is mercury (Hg). Relationships between mercury concentrations and size and with collection season were observed; correlation with lipid content, total polychlorinated biphenyl (PCB) content, or collection site were very weak. Only 18% of the Hg was methylated in October (n = 8), whereas June and July fish (n = 12) had 100% methylation of Hg. White perch should not be considered edible because the Hg level exceeded the "one meal per month" action level of 0.47 microg/g wet weight (ppm) in 32% of our catch and 2.5% exceeded the "no consumption at all" level of 1 microg/g. The larger fish represent greater risk for Hg. Furthermore, the warmer months, when more recreational fishing takes place, might present greater risk. A more significant reason for avoiding white perch is the PCB contamination because 40% of these fish exceeded the US Food and Drug Administration (FDA) action level of 2000 ng/g for PCBs and all white perch exceeded the US Environmental Protection Agency cancer/health guideline (49 ng/g) of no more than one meal/month. In fact, nearly all were 10 times that advisory level. There were differences between male and female white perch PCB levels, with nearly all of those above the US FDA action level being male. Forage fish (mummichogs and Atlantic silversides) were similarly analyzed, but no correlations were found with any other parameters. The relationship of collection site to contaminants cannot be demonstrated because sufficient numbers of game fish could not be collected at many sites at all seasons.

The effects of small dam removal on the distribution of sedimentary contaminants.

With increasing concern over degradation of aquatic resources, issues of liability, and maintenance costs, removal of small dams has become increasing popular. Although the benefits of removal seem to outweigh the drawbacks, there is a relative paucity of studies documenting the extent and magnitude of biological and chemical changes associated with dam removal, especially those evaluating potential changes in contaminant inventories. In August and November of 2000, a run-of-the-river dam on Manatawny Creek (southeast Pennsylvania) was removed in a two-stage process. To assess the effects of dam removal on the contaminant redistribution within the creek, sedimentary concentrations of polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), and trace metals (Cd, Cr, Cu, Ni, Pb, Zn) were evaluated prior to and several months after removal. Pre- and post-removal analyses revealed elevated and spatially variable concentrations of total PAHs (ranging from approximately 200 to 81,000 ng(g dry weight) and low to moderate concentrations of trace metals and PCBs. The concentrations of these sedimentary contaminants pre- versus post-removal were not significantly different. Additionally, though the impoundment received storm water run-off and associated contaminants from the adjacent city of Pottstown, the total inventory of fine-grain sediments in the impoundment prior to removal was very low. The removal of the low-level Manatawny Creek dam did not significantly redistribute contaminants downstream. However, each dam removal should be assessed on a case by case basis where the potential of sedimentary contaminant redistribution upon dam removal exists.

Outcomes of adoption: measuring evidence uptake by individuals and organizations.

BACKGROUND: The translation and diffusion of findings into health care validate the potential of evidence-based innovation to improve clinical practice and affirm the benefits of society's investment in advancing science. AIMS: This article briefly reviews key concepts in the knowledge use process, considers theoretical implications for measuring outcomes and uptake of innovation, discusses issues to consider in planning for measurement of adoption, and provides an example of confronting those challenges from a project now in progress. THEORETICAL PERSPECTIVES AND TRANSLATION OUTCOMES: Four principal conceptual frameworks related to translational science, Lewin, Rogers, Havelock, and Promoting Action on Research Implementation in Health Services (PARIHS), explicate a process that catalyzes new knowledge adoption and use by individuals and systems to solve problems. Each conceptual perspective suggests that translation is not complete until the extent and impact of use is examined and understood. Most perspectives support evaluation of impact of evidence-based practice using process measures that integrate clinician knowledge, actual performance of the practice, and patient/clinician outcomes. Based on the Agency for Healthcare Research and Quality (AHRQ) framework, additional measures might include changes in patterns of care and changes in policies, procedures, or protocols. CASE EXAMPLE: A description of process and outcome measures used in an in-progress quality improvement demonstration project, California Nursing Outcomes Coalition (CalNOC) Partners in Quality Translating Research into Practice to Reduce Patient Falls Project, is presented. IMPLICATION(S) FOR PRACTICE, RESEARCH, AND POLICY: Since the adoption of evidence-based innovation is a process that is often described along a continuum, investigators seeking to measure the impact of an evidence-based innovation must gather evidence that uptake of the innovation has occurred. The theoretical perspective and practical measurement issues of a given project will drive selection of process and outcome measures. CONCLUSIONS: Efforts to change practice in order to enhance evidence-based patient care must integrate monitoring and evaluation of specific target outcomes of adoption as the basis for validating the impact of the change.