Unintentional Epinephrine Auto-Injector Maxillofacial Injury in a Pediatric Patient.

CASE PRESENTATION: A four-year-old female patient presented to the emergency department with an epinephrine auto-injector that had unintentionally discharged into her mandible. There was difficulty removing the auto-injector at bedside. Images we acquired noted needle curvature not present in an off-the-shelf model. She was sedated, and the auto-injector was removed by retracing the angle of discharge, with care taken not to inject epinephrine into the patient. DISCUSSION: Epinephrine auto-injector accidental discharges are an unusual injury pattern, but the incidence of such events is increasing in the United States. The emergency clinician should be cognizant of complicating factors with discharges, such as bent needles. Here we discuss a case of discharge into the maxillofacial region (lower jaw), with approaches to treatment.

Fractionated Ablative Carbon Dioxide Laser Therapy Decreases Ultrasound Thickness of Hypertrophic Burn Scar: A Prospective Process Improvement Initiative.

INTRODUCTION: Carbon dioxide (CO2) laser treatment is routinely used to treat hypertrophic burn scars (HBS). Although prior research has documented subjective improvement in HBS after treatment, there is little data evaluating objective changes in scar characteristics after therapy. The aim of our process improvement project was to evaluate changes to scar thickness (ST) using high-frequency ultrasound in patients with HBS undergoing CO2 laser therapy. METHODS: Ultrasound measurements of ST were obtained from patients with HBS before initial and at each subsequent treatment. ST, reduction in ST per treatment, and percentage reduction in ST from baseline were tabulated. Post hoc analyses examining the effect of initial ST and scar maturity on outcome were performed. First, patients were grouped by baseline ST into thicker (group 1, initial ST ≥ median value) and thinner (group 2, initial ST < median value) scar groups. Second, patients were divided into quartiles based on time from injury to treatment. Outcomes at each time point were compared with either Mann-Whitney U or Kruskal-Wallis tests, with Bonferonni corrections performed for post hoc subgroup analyses. Significance was set at P < 0.05. RESULTS: Twenty-one consecutive patients with HBS treated with CO2 laser were included. All patients completed 1 or more treatment, 48% completed 2 or more treatments, and 28% completed 3 treatments. Median initial ST was 0.71 cm (0.44-0.98 cm), and median scar maturity was 7.5 months (4.9-9.8 months). Overall, ST decreased over the treatment course (P < 0.001), with post hoc analysis demonstrating that 2 treatments were required to achieve a significant ST reduction (P < 0.01). On subgroup analysis comparing initial ST, ST decreased significantly in group 1 (thicker scars) overall (P < 0.001) but not in group 2 (P = 0.109). ST reduction was greatest after 1 treatment in group 1 (P = 0.022) and group 2 (P = 0.061). Percent reduction was greater in group 1 relative to group 2 after 1 treatment (P = 0.016). On subgroup analysis of scar maturity, there were no significant differences in either baseline ST or ST at any subsequent visit. CONCLUSIONS: Fractionated ablative CO2 laser treatment improved ST after 1 to 2 treatments. Patients with thicker scars demonstrated greater ST reduction than those with thinner scars. Ultrasound adequately assessed treatment response.

Gas Turbine Engine Nonvolatile Particulate Matter Mass Emissions: Correlation with Smoke Number for Conventional and Alternative Fuel Blends.

This study evaluates the relationship between the emissions parameters of smoke number (SN) and mass concentration of nonvolatile particulate matter (nvPM) in the exhaust of a gas turbine engine for a conventional Jet A-1 and a number of alternative fuel blends. The data demonstrate the significant impact of fuel composition on the emissions and highlight the magnitude of the fuel-induced uncertainty for both SN within the Emissions Data Bank as well as nvPM mass within the new regulatory standard under development. Notwithstanding these substantial differences, the data show that correlation between SN and nvPM mass concentration still adheres to the first order approximation (FOA3), and this agreement is maintained over a wide range of fuel compositions. Hence, the data support the supposition that the FOA3 is applicable to engines burning both conventional and alternative fuel blends without adaptation or modification. The chemical composition of the fuel is shown to impact mass and number concentration as well as geometric mean diameter of the emitted nvPM; however, the data do not support assertions that the emissions of black carbon with small mean diameter will result in significant deviations from FOA3.

Impact of alternative fuels on emissions characteristics of a gas turbine engine - part 1: gaseous and particulate matter emissions.

Growing concern over emissions from increased airport operations has resulted in a need to assess the impact of aviation related activities on local air quality in and around airports, and to develop strategies to mitigate these effects. One such strategy being investigated is the use of alternative fuels in aircraft engines and auxiliary power units (APUs) as a means to diversify fuel supplies and reduce emissions. This paper summarizes the results of a study to characterize the emissions of an APU, a small gas turbine engine, burning conventional Jet A-1, a fully synthetic jet fuel, and other alternative fuels with varying compositions. Gas phase emissions were measured at the engine exit plane while PM emissions were recorded at the exit plane as well as 10 m downstream of the engine. Five percent reduction in NO(x) emissions and 5-10% reduction in CO emissions were observed for the alternative fuels. Significant reductions in PM emissions at the engine exit plane were achieved with the alternative fuels. However, as the exhaust plume expanded and cooled, organic species were found to condense on the PM. This increase in organic PM elevated the PM mass but had little impact on PM number.

Impact of alternative fuels on emissions characteristics of a gas turbine engine - part 2: volatile and semivolatile particulate matter emissions.

The work characterizes the changes in volatile and semivolatile PM emissions from a gas turbine engine resulting from burning alternative fuels, specifically gas-to-liquid (GTL), coal-to-liquid (CTL), a blend of Jet A-1 and GTL, biodiesel, and diesel, to the standard Jet A-1. The data presented here, compares the mass spectral fingerprints of the different fuels as measured by the Aerodyne high resolution time-of-flight aerosol mass spectrometer. There were three sample points, two at the exhaust exit plane with dilution added at different locations and another probe located 10 m downstream. For emissions measured at the downstream probe when the engine was operating at high power, all fuels produced chemically similar organic PM, dominated by C(x)H(y) fragments, suggesting the presence of long chain alkanes. The second largest contribution came from C(x)H(y)O(z) fragments, possibly from carbonyls or alcohols. For the nondiesel fuels, the highest loadings of organic PM were from the downstream probe at high power. Conversely, the diesel based fuels produced more organic material at low power from one of the exit plane probes. Differences in the composition of the PM for certain fuels were observed as the engine power decreased to idle and the measurements were made closer to the exit plane.

Polycyclic aromatic hydrocarbon emissions from the combustion of alternative fuels in a gas turbine engine.

We report on the particulate-bound polycyclic aromatic hydrocarbons (PAH) in the exhaust of a test-bed gas turbine engine when powered by Jet A-1 aviation fuel and a number of alternative fuels: Sasol fully synthetic jet fuel (FSJF), Shell gas-to-liquid (GTL) kerosene, and Jet A-1/GTL 50:50 blended kerosene. The concentration of PAH compounds in the exhaust emissions vary greatly between fuels. Combustion of FSJF produces the greatest total concentration of PAH compounds while combustion of GTL produces the least. However, when PAHs in the exhaust sample are measured in terms of the regulatory marker compound benzo[a]pyrene, then all of the alternative fuels emit a lower concentration of PAH in comparison to Jet A-1. Emissions from the combustion of Jet A-1/GTL blended kerosene were found to have a disproportionately low concentration of PAHs and appear to inherit a greater proportion of the GTL emission characteristics than would be expected from volume fraction alone. The data imply the presence of a nonlinear relation between fuel blend composition and the emission of PAH compounds. For each of the fuels, the speciation of PAH compounds present in the exhaust emissions were found to be remarkably similar (R(2) = 0.94-0.62), and the results do provide evidence to support the premise that PAH speciation is to some extent indicative of the emission source. In contrast, no correlation was found between the PAH species present in the fuel with those subsequently emitted in the exhaust. The results strongly suggests that local air quality measured in terms of the particulate-bound PAH burden could be significantly improved by the use of GTL kerosene either blended with or in place of Jet A-1 kerosene.

Evaluation of methods for measuring particulate matter emissions from gas turbines.

The project SAMPLE evaluated methods for measuring particle properties in the exhaust of aircraft engines with respect to the development of standardized operation procedures for particulate matter measurement in aviation industry. Filter-based off-line mass methods included gravimetry and chemical analysis of carbonaceous species by combustion methods. Online mass methods were based on light absorption measurement or used size distribution measurements obtained from an electrical mobility analyzer approach. Number concentrations were determined using different condensation particle counters (CPC). Total mass from filter-based methods balanced gravimetric mass within 8% error. Carbonaceous matter accounted for 70% of gravimetric mass while the remaining 30% were attributed to hydrated sulfate and noncarbonaceous organic matter fractions. Online methods were closely correlated over the entire range of emission levels studied in the tests. Elemental carbon from combustion methods and black carbon from optical methods deviated by maximum 5% with respect to mass for low to medium emission levels, whereas for high emission levels a systematic deviation between online methods and filter based methods was found which is attributed to sampling effects. CPC based instruments proved highly reproducible for number concentration measurements with a maximum interinstrument standard deviation of 7.5%.