Stream biomonitoring using macroinvertebrates around the globe: a comparison of large-scale programs.

Water quality agencies and scientists are increasingly adopting standardized sampling methodologies because of the challenges associated with interpreting data derived from dissimilar protocols. Here, we compare 13 protocols for monitoring streams from different regions and countries around the globe. Despite the spatially diverse range of countries assessed, many aspects of bioassessment structure and protocols were similar, thereby providing evidence of key characteristics that might be incorporated in a global sampling methodology. Similarities were found regarding sampler type, mesh size, sampling period, subsampling methods, and taxonomic resolution. Consistent field and laboratory methods are essential for merging data sets collected by multiple institutions to enable large-scale comparisons. We discuss the similarities and differences among protocols and present current trends and future recommendations for monitoring programs, especially for regions where large-scale protocols do not yet exist. We summarize the current state in one of these regions, Latin America, and comment on the possible development path for these techniques in this region. We conclude that several aspects of stream biomonitoring need additional performance evaluation (accuracy, precision, discriminatory power, relative costs), particularly when comparing targeted habitat (only the commonest habitat type) versus site-wide sampling (multiple habitat types), appropriate levels of sampling and processing effort, and standardized indicators to resolve dissimilarities among biomonitoring methods. Global issues such as climate change are creating an environment where there is an increasing need to have universally consistent data collection, processing and storage to enable large-scale trend analysis. Biomonitoring programs following standardized methods could aid international data sharing and interpretation.

Late HIV diagnosis is a major risk factor for intensive care unit admission in HIV-positive patients: a single centre observational cohort study.

BACKGROUND: HIV positive patients are at risk of infectious and non-infectious complications that may necessitate intensive care unit (ICU) admission. While the characteristics of patients requiring ICU admission have been described previously, these studies did not include information on the denominator population from which these cases arose. METHODS: We conducted an observational cohort study of ICU admissions among 2751 HIV positive patients attending King's College Hospital, South London, UK. Poisson regression models were used to identify factors associated with ICU admission. RESULTS: The overall incidence rate of ICU admission was 1.0 [95% CI 0.8, 1.2] per 100 person-years of follow up, and particularly high early (during the first 3 months) following HIV diagnosis (12.4 [8.7, 17.3] per 100 person-years compared to 0.37 [0.27, 0.50] per 100 person-years thereafter; incidence rate ratio 33.5 [23.4, 48.1], p < 0.001). In time-updated analyses, AIDS and current CD4 cell counts of less than 200 cells/mm3 were associated with an increased incidence of ICU admission while receipt of combination antiretroviral therapy (cART) was associated with a reduced incidence of ICU admission. Late HIV diagnosis (initial CD4 cell count <350 or AIDS within 3 months of HIV diagnosis) applied to 81% of patients who were first diagnosed HIV positive during the study period and who required ICU admission. Late HIV diagnosis was significantly associated with ICU admission in the first 3 months following HIV diagnosis (adjusted incidence rate ratio 8.72, 95% CI 2.76, 27.5). CONCLUSIONS: Late HIV diagnosis was a major risk factor for early ICU admission in our cohort. Earlier HIV diagnosis allowing cART initiation at CD4 cell counts of 350 cells/mm3 is likely to have a significant impact on the need for ICU care.

Management of severe dehydration.

The presented case is one of severe dehydration and acute kidney injury with significant resultant complications that required considerable fluid and electrolyte replacement. Approaches to fluid resuscitation in the context of hypernatraemia and the hyperosmolar state were considered and then judiciously combined to manage a complex case with a successful outcome. Conflicting guidance in this domain is discussed with recommendations for a future management strategy that is tailored to individual patients.