Systolic blood pressure and short-term mortality in the emergency department and prehospital setting: a hospital-based cohort study.

INTRODUCTION: Systolic blood pressure is a widely used tool to assess circulatory function in acutely ill patients. The systolic blood pressure limit where a given patient should be considered hypotensive is the subject of debate and recent studies have advocated higher systolic blood pressure thresholds than the traditional 90 mmHg. The aim of this study was to identify the best performing systolic blood pressure thresholds with regards to predicting 7-day mortality and to evaluate the applicability of these in the emergency department as well as in the prehospital setting. METHODS: A retrospective, hospital-based cohort study was performed at Odense University Hospital that included all adult patients in the emergency department between 1995 and 2011, all patients transported to the emergency department in ambulances in the period 2012 to 2013, and all patients serviced by the physician-staffed mobile emergency care unit (MECU) in Odense between 2007 and 2013. We used the first recorded systolic blood pressure and the main outcome was 7-day mortality. Best performing thresholds were identified with methods based on receiver operating characteristics (ROC) and multivariate regression. The performance of systolic blood pressure thresholds was evaluated with standard summary statistics for diagnostic tests. RESULTS: Seven-day mortality rates varied from 1.8% (95% CI (1.7, 1.9)) of 112,727 patients in the emergency department to 2.2% (95% CI (2.0, 2.5)) of 15,862 patients in the ambulance and 5.7% (95% CI (5.3, 6.2)) of 12,270 patients in the mobile emergency care units. Best performing thresholds ranged from 95 to 119 mmHg in the emergency department, 103 to 120 mmHg in the ambulance, and 101 to 115 mmHg in the MECU but area under the ROC curve indicated poor overall discriminatory performance of SBP thresholds in all cohorts. CONCLUSIONS: Systolic blood pressure alone is not sufficient to identify patients at risk regardless of the defined threshold for hypotension. If, however, a threshold is to be defined, a systolic blood pressure threshold of 100 to 110 mmHg is probably more relevant than the traditional 90 mmHg.

A review of mercury exposure among artisanal small-scale gold miners in developing countries.

PURPOSE: Extraction of gold using mercury has been a way out of poverty for millions of people in developing countries. Artisanal small-scale gold mining (ASGM) has expanded during the last decades and is often carried out under primitive conditions. Thus, workers in this industry may be exposed to high levels of mercury and suffer from toxic effects from mercury exposure. The objective of this review was to provide an outline of the studies available on elemental mercury exposure among artisanal small-scale gold miners. METHODS: Searching the PubMed and Embase databases, 26 studies with a total of 3,005 exposed subjects and 442 controls across 14 different developing countries were found. Urine mercury levels were used as biomarkers of exposure. RESULTS: In general, the urine mercury levels were elevated and a considerable proportion of workers had urine mercury levels above existing guidelines. Exposed subjects were stratified into residents, miners, millers, smelters, and refiners, who by work task content were expected to be increasingly exposed to mercury. This group order did show a clear trend of increasing mercury levels. Mercury levels differed substantially between studies. Possible explanations include dissimilarities in gold extraction methods, use of protective devices, and selection of participants. CONCLUSIONS: This review provides evidence that artisanal gold miners and residents of the mining sites are exposed to mercury vapour to an extent where acute and long-term toxic effects of mercury are likely. Interventions aimed at reducing exposure and emission of mercury from ASGM are needed.