ObjectiveTo evaluate if imaging studies such as CT pulmonary angiography (CTPA) or ventilation–perfusion (V/Q) scan are ordered according to the current guidelines for the diagnosis of pulmonary embolism (PE).MethodsWe performed a retrospective observational cohort study in all adult patients who presented to the Sparrow Hospital Emergency Department from January 2014 to December 2016 and underwent CTPA or V/Q scan. We calculated the Wells’ score retrospectively, and d-dimer values were used to determine if the imaging study was justified.ResultsA total of 8449 patients underwent CTPA (93%) or V/Q scan (7%), among which 142 (1.7%) patients were diagnosed with PE. The Wells’ criteria showed low probabilities for PE in 96 % and intermediate or high probabilities in 4 % of total patients. Modified Wells’ criteria demonstrated PE unlikely in 99.6 % and PE likely in 0.4 % of total patients. D-dimer was obtained in only 37 % of patients who were unlikely to have a PE or had a low score on Wells’ criteria. Despite a low or unlikely Wells’ criteria score and normal d-dimer levels, 260 patients underwent imaging studies, and none were diagnosed with PE.ConclusionMore than 99 % of CTPA or V/Q scans were negative in our study. This suggests extraordinary overutilisation of the imaging methods. D-dimer, recommended in patients with low to moderate risk, was ordered in only one-third of patients. Much greater emphasis of current guidelines is needed to avoid inappropriate utilisation of resources without missing diagnosis of PE.

PTFE tubes, which are thought to be lipophilic, were associated with more measurable lipids from the tear film than glass microcapillaries. There was no difference between collection methods in lipid profiles when used with meibum.

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Purpose: Lipid mediators of inflammation are a group of signaling molecules produced by various cells under physiological conditions and modulate the inflammatory process during various pathologic conditions. Although eicosanoids and F2-isoprostanes are recognized lipid mediators of inflammation, there is no consensus yet on the extraction and mass spectrometry method for their analysis in individual human tear samples. Thus, the aim of this study was to develop an optimal method for extraction of lipid mediators of inflammation in the tear film and evaluate mass spectrometry (MS) techniques for their analysis.Methods: Basal tears were collected from each eye of 19 subjects using glass microcapillaries. Lipid extraction was done using either varying concentrations of acidified methanol, a modified Folch method or solid phase extraction. Initially an untargeted analysis of the extracts was done using SCIEX TripleTOF 5600 mass spectrometer to identify any lipid mediators of inflammation (eicosanoids) and later a targeted analysis was done using the SCIEX 6500 Qtrap to identify and quantify prostaglandins and isoprostanes. Mass spectra and chromatograms were analyzed using Peakview, XCMS, and Multiquant software.Results: Prostaglandins and isoprostanes were observed and quantified using the Qtrap mass spectrometer under MRM mode after solid phase extraction. Extraction with acidified methanol along with the Folch method produced cleaner spectra during mass spectrometry with the Triple TOF mass spectrometer. Lipid mediators of inflammation were not observed in any of the tear samples using the Triple TOF mass spectrometer.Conclusions: Solid phase extracti on may be the method of choice for extraction of prostaglandins and isoprostanes in low volumes of tears. The SCIEX Qtrap 6500 in MRM mode may be suitable to identify and quantify similar lipid mediators of inflammation.