Use of an Agitation Measure to Screen for Suicide and Self-Harm Risk Among Emergency Department Patients.

BACKGROUND: Suicidality alone is insensitive to suicide risk among emergency department (ED) patients. OBJECTIVE: We describe the performance of adding an objective assessment of agitation to a suicide screening instrument for predicting suicide and self-harm after an ED encounter. METHODS: We tested the performance of a novel screener combining the presence of suicidality or agitation for predicting suicide within 90 days or a repeat ED visit for self-harm within 30 days using retrospective data from all patients seen in an urban safety net ED over 27 months. Patients were assessed for suicidality using the Columbia-Suicide Severity Rating Scale-Clinical Practice Screener and for agitation using either the Behavioral Activity Rating Scale or Richmond Agitation Sedation Scale. We hypothesized that a screener based on the presence of either suicidality or agitation would be more sensitive to suicide risk than the Columbia-Suicide Severity Rating Scale-Clinical Practice Screener alone. The screener's performance is described, and multivariable regression evaluates the correlations between screening and outcomes. RESULTS: The sample comprised 16,467 patients seen in the ED who had available suicide screening and agitation data. Thirteen patients (0.08%) died by suicide within 90 days after ED discharge. The sensitivity and specificity of the screener combining suicidality and agitation for predicting suicide was 0.69 (95% confidence interval, 0.44-0.94) and 0.74 (0.44-0.94), respectively. The sensitivity and specificity for agitation combined with positive suicide screening for self-harm within 30 days were 0.95 (0.89-1.00) and 0.73 (0.73-0.74). For both outcomes, augmenting the Columbia-Suicide Severity Rating Scale-Clinical Practice Screener with a measure of agitation improved both sensitivity and overall performance compared to historical performance of the Columbia-Suicide Severity Rating Scale-Clinical Practice Screener alone. CONCLUSIONS: Combining a brief objective measure of agitation with a common suicide screening instrument improved sensitivity and predictive performance for suicide and self-harm risk after ED discharge. These findings speak to the importance of assessing agitation not only for imminent safety risk during the patient encounter but also for reducing the likelihood of future adverse events. This work can improve the detection and management of suicide risk in emergency settings.

Universal Pediatric Suicide Risk Screening in a Health Care System: 90,000 Patient Encounters.

BACKGROUND: Suicidal behavior is increasing among US youths. Contact with the health care system is common in the months before suicide. OBJECTIVE: To assess the characteristics of suicide risk among youths presenting for health care, universal screening results from a large hospital system were analyzed. METHODS: A retrospective analysis of the Ask Suicide-Screening Questions tool administered to patients aged 10-17 years in a hospital system including an emergency department, inpatient medical units, and primary care clinics was conducted. Demographic and clinical data from 3 years of encounters were analyzed. RESULTS: The sample consisted of 91,580 pediatric encounters, predominantly white Hispanic and women, with one third speaking Spanish. Across health care settings, 2.9% of encounters produced positive suicide risk screens, with the highest rate in the emergency department (8.5%). Acute positive screens, indicating imminent risk for suicidal behavior, accounted for 0.3% of all encounters. Approximately one-fourth (27.6%) of encounters for psychiatric presenting problems screened positive compared with 2.3% for nonpsychiatric encounters. Higher rates of positive screens were present among encounters for psychiatric presenting problems across all settings. Positive screens were less common among preteen (1.8%) than adolescent (3.1%) encounters (χ2 = 65.50, P < 0.001). CONCLUSIONS: Universal screening detected suicide risk in approximately 3% of pediatric health care encounters. Screening identified risk in encounters among preteen and adolescent patients, with a higher prevalence of positive screens in encounters for youths presenting with psychiatric problems and for emergency department visits. Acute positive screens were rare, occurring in less than half of 1 percent of encounters.

Suicide and Self-Harm Outcomes Among Psychiatric Emergency Service Patients Diagnosed As Malingering.

BACKGROUND: Malingering is a common and challenging clinical presentation in emergency departments (EDs). OBJECTIVE: This study describes characteristics and outcomes among patients diagnosed as malingering in a psychiatric emergency service. METHODS: Index psychiatric ED encounters were identified for all adult patients seen during a 27-month period. Mortality data were obtained for patients from the state public health authority, and repeat ED visits for self-harm were obtained from the state hospital association. Patients with a diagnosis of malingering were compared with those without a malingering diagnosis using correlative statistics and multivariable analyses. RESULTS: Of 4710 encounters analyzed, 236 (5%) had a malingering diagnosis. No patients diagnosed as malingering died of suicide within 365 days of discharge, compared with 16 (0.4%) nonmalingering patients. Self-harm outcomes were available for 2689 encounters; 129 (5%) had a malingering diagnosis. Malingering was significantly associated with a repeat ED visit for self-harm within 365 days in multivariable analyses (adjusted odds ratio 2.52; 95% confidence interval 1.35-4.70); p < 0.01). CONCLUSIONS: No psychiatric emergency service patients diagnosed as malingering died by suicide after discharge. New clinical approaches must balance malingering patients' apparent low suicide risk with their other substantial comorbidities and risk for self-harm.

Neurological effects of inorganic arsenic exposure: altered cysteine/glutamate transport, NMDA expression and spatial memory impairment.

Inorganic arsenic (iAs) is an important natural pollutant. Millions of individuals worldwide drink water with high levels of iAs. Chronic exposure to iAs has been associated with lower IQ and learning disabilities as well as memory impairment. iAs is methylated in tissues such as the brain generating mono and dimethylated species. iAs methylation requires cellular glutathione (GSH), which is the main antioxidant in the central nervous system (CNS). In humans, As species cross the placenta and are found in cord blood. A CD1 mouse model was used to investigate effects of gestational iAs exposure which can lead to oxidative damage, disrupted cysteine/glutamate transport and its putative impact in learning and memory. On postnatal days (PNDs) 1, 15 and 90, the expression of membrane transporters related to GSH synthesis and glutamate transport and toxicity, such as xCT, EAAC1, GLAST and GLT1, as well as LAT1, were analyzed. Also, the expression of the glutamate receptor N-methyl-D-aspartate (NMDAR) subunits NR2A and B as well as the presence of As species in cortex and hippocampus were investigated. On PND 90, an object location task was performed to associate exposure with memory impairment. Gestational exposure to iAs affected the expression of cysteine/glutamate transporters in cortex and hippocampus and induced a negative modulation of NMDAR NR2B subunit in the hippocampus. Behavioral tasks showed significant spatial memory impairment in males while the effect was marginal in females.

Adulteration of diesel/biodiesel blends by vegetable oil as determined by Fourier transform (FT) near infrared spectrometry and FT-Raman spectroscopy.

In this work it has been shown that the routine ASTM methods (ASTM 4052, ASTM D 445, ASTM D 4737, ASTM D 93, and ASTM D 86) recommended by the ANP (the Brazilian National Agency for Petroleum, Natural Gas and Biofuels) to determine the quality of diesel/biodiesel blends are not suitable to prevent the adulteration of B2 or B5 blends with vegetable oils. Considering the previous and actual problems with fuel adulterations in Brazil, we have investigated the application of vibrational spectroscopy (Fourier transform (FT) near infrared spectrometry and FT-Raman) to identify adulterations of B2 and B5 blends with vegetable oils. Partial least square regression (PLS), principal component regression (PCR), and artificial neural network (ANN) calibration models were designed and their relative performances were evaluated by external validation using the F-test. The PCR, PLS, and ANN calibration models based on the Fourier transform (FT) near infrared spectrometry and FT-Raman spectroscopy were designed using 120 samples. Other 62 samples were used in the validation and external validation, for a total of 182 samples. The results have shown that among the designed calibration models, the ANN/FT-Raman presented the best accuracy (0.028%, w/w) for samples used in the external validation.

Aggregation and disaggregation of microbial food webs.

Models of the microbial food web have generally used compartments aggregated by general body size and gross taxonomy. It has been assumed that these also reflect guilds or holons. Generally, results of simulation or analysis based on this structure have been reasonably well validated. Herein I summarize why the aggregations may be justified and what may be learned from disaggregation.

Synergism between research and simulation models of estuarine microbial food webs.

Construction of mathematical simulation models helps to organize current information and extend inferences from available data. During the past two decades, microbial ecology has undergone rapid developments in both quantity and quality of available data. In particular, considerable advances have been made in our knowledge of microbial food web dynamics in the Duplin River watershed at Sapelo Island, Georgia. Here we provide examples of how modeling and microbial ecology have interfaced. In the early 1970s, construction of a 14-compartment model of carbon flow through a salt marsh ecosystem aided in directing method development and field experiments on the sediment microbial community. In turn, the results of field experiments corroborated the model's postulated controls on the community. Also, during the past 12 years we have developed a series of simulation models reflecting the growing information on the aquatic microbial food web. Early models provided evidence for the microbial loop but illustrated the paucity of knowledge concerning controls for bacterial growth on detritus. Results from newer methods in microbial ecology and studies from the Duplin River have allowed us to construct a model which provides realistic simulations but is also highly sensitive to certain parameter value changes (e.g., in organic matter availability and grazing by protozoans). Thus improvements in model structure and corroboration of the models with extant data have been closely tied to methodological and conceptual advances in microbial ecology. The relationship is viewed as synergistic, as needs for model parameter values and equation forms have directed further development of methods, experimentation, and field observations.

Bacteriological quality of fabrics washed at lower-than-standard temperatures in a hospital laundry facility.

We determined whether the bacteriological quality of fabrics cleaned in a hospital laundry could be maintained at wash temperatures lower than 75 degrees C by the use of economically reasonable formulas and wash conditions. Three groups of bacteria were examined to determine bacteriological quality: aerobic, nonexacting chemoorganotrophs, staphylococci, and total coliforms. The distribution of bacteria on soiled fabric was patchy, with staphylococci and total coliforms ranging from less than 0.1 to greater than 4 X 10(3) CFU/cm2 and chemoorganotrophs ranging from less than 0.1 to greater than 5 X 10(5) CFU/cm2. The washing process routinely produced fabric containing less than 1 CFU/cm2. Low-temperature (47.8 to 60.0 degrees C) wash procedures eliminated all bacterial groups at least as effectively as did high-temperature procedures. The effectiveness of bacterial density reduction at low temperature was augmented by increased concentrations of bleach. Successful low-temperature washing such as that shown here may save both energy and money for hospitals.

Frequency distribution of coliforms in water distribution systems.

Nine small water distribution systems were sampled intensively to determine the patterns of dispersion of coliforms. The frequency distributions of confirmed coliform counts were compatible with either the negative-binomial or the lognormal distribution. They were not compatible with either the Poisson or Poisson-plus-added zeroes distribution. The implications of the use of the lognormal distributional model were further evaluated because of its previous use in water quality studies. The geometric means from 14 data sets ranged from 10(-6) to 0.2 coliforms per 100 ml, and the geometric standard deviations were between 10 and 100, with one exception. If the lognormal model is representative of the coliform distribution; the arithmetic mean sample count is a poor estimator of the true mean coliform density, and the probability of water in a distribution system containing small patches with large coliform densities without detection by routine monitoring is finite. These conclusions have direct bearing on the interpretation of microbiological quality standards for drinking water.

Comparison of methods for measurement of bacterial growth rates in mixed batch cultures.

Eight methods of assessing growth rate constants of bacteria were compared in batch cultures of 3-micrometers-filtered estuarine water from the Skidaway River in Ga. Mixed assemblages of bacteria were grown under four nutrient regimes of added yeast extract ranging from 0 to 100 mg/liter. Linear and exponential growth rate constants were computed from changes in cell densities, biovolumes, and ATP concentrations. Exponential growth rate constants were obtained from the frequency of dividing cells and RNA synthesis as measured by [3H]adenine uptake. Rate constants obtained during lag, exponential, and stationary growth phases depended largely on the method used. Constants calculated from changes in cell densities, frequency of dividing cells, and adenine uptake correlated most closely with each other, whereas constants calculated from changes in ATP concentrations and biovolumes correlated best with each other. Estimates of in situ bacterial productivity and growth vary depending on the method used and the assumptions made regarding the growth state of bacteria.

Frequency of dividing cells as an estimator of bacterial productivity.

It has recently been proposed that the frequency of dividing bacterial cells (FDC) can be used to predict growth rates of natural aquatic bacterial assemblages. We have examined the relationship between FDC and growth rate in bacteria from southern-temperate, coastal marine waters by using incubation under conditions of manipulated nutrient availability and exclusion of bacterivores. The regression of the natural logarithm of bacterial instantaneous growth rate (mu) on FDC resulted in a better fit than regression of untransformed mu on FDC. The regression equation was ln mu = 0.299FDC - 4.961. The coefficient of variation for predicted ln mu at mean FDC was 7%. The range of FDC-estimated bacterial instantaneous generation times for coastal Georgia waters was 12 to 68 h, and range of calculated bacterial production rates was 0.6 to 17.6 mg of C.m. h. Unresolved problems of and suggested improvements on the FDC method of predicting growth rate are discussed.