Risk-prediction tool for identifying hospitalized children with a predisposition for development of venous thromboembolism: Peds-Clot clinical Decision Rule.

BACKGROUND: The prevalence of VTE is increasing in tertiary pediatric hospitals. Identification of high-risk populations using uniform criteria is required to develop evidence-based VTE prevention guidelines. OBJECTIVE: To develop a VTE risk prediction rule, the Peds-Clot clinical Decision Rule (PCDR), to identify high-risk children who were at increased risk of developing VTE. METHODS: This retrospective case-control study developed the PCDR using a derivation cohort (173 cases, 346 controls) and validated it on a separate validation cohort (100 cases, 100 controls). A uniform data collection strategy was applied to derive both the samples. Conditional logistic regression analyses were used to develop a risk-prediction model. Each significant predictor was assigned a score based on its beta coefficient and the PCDR was developed. ROC curves were derived to test the performance of the PCDR. RESULTS: Characteristics of derivation and validation cohorts were comparable. Six risk factors (positive blood stream infection, central venous catheter, direct admission to ICU/NICU, hospitalization for ≥ 7 days, immobilization for > 72 h, and use of birth control pills) formed the final risk prediction model (risk score range, 0.5-9.5). A risk score of 3 or more identified high-risk children at a sensitivity of 70% and specificity of 80% and AUC of 0.852 (95% confidence interval, 0.814-0.890). The application of a risk score to the validation sample showed sensitivity 57% and specificity 88% and an AUC of 0.875 (95% confidence interval, 0.82-0.924). CONCLUSION: Incorporation of the PCDR in routine clinical care can be an attractive strategy to identify high-risk hospitalized children with a predisposition for VTE. The clinical utility of the PCDR needs validation in prospective studies.

Observations of air composition in Brazil between the Equator and 20°s during the dry season

Field measurement programs in Brazil during the dry season months of August and September in 1979 and 1980 have demonstrated the great importance of the continental tropics in global air chemistry. Especially in the mixed layer, the air composition over land is much different from that over the ocean and the land areas are clearly longe scale sources of many inportant trace gases. During the dry season much biomass, burning takes place especially in the cerrado regions leading to substantial emission of air pollutants, such as CO, NOx, N2O, CH4 and other hydrocarbons. Ozone concentrations are alsoenhanced due to photochemical reactions. Biogenic organic emissions from tropical forests play likewise an important role in the photochemistry of the atmosphere. Carbon monoxide was found to be present in high concentrations in the boundary layer of the tropical forest, but ozone concentrations were much lower than in the cerrado.

Programa de medidas de campo no Brasil nas estações secas de 1979 e 1980, durante os meses de agosto e setembro, demonstraram a grande importância das regiões tropicais continentais na química atmosférica global. Especialmente na camada de mistura, a composição do ar sobre o continente e oceano é muito diferente e as regiões terrestres são fontes de produção em grande escala de muitos gases-traço importantes. Queimas de blomassa ocorrem durante a estação seca, especialmente nos cerrados, causando emissões substanciais de poluentes atmosféricos tais como CO, HOx, H2O, CH4, e outros hidrocarbonetos. Concentrações de ozônio são tombém aumentadas devido a reações fotoquímicas. Emissões orgânicas biogênicas de florestas tropicais tem um papel importante na fitoquímica da atmosfera. O monóxido de carbono mostrou-se presente em altas concentrações na camada limite da floresta tropical e as concentrações de ozônio foram muito inferiores no cerrado.