ABSTRACT
PURPOSE: Pancreatic enzymes are routinely measured during reception of trauma patients to assess for pancreatic injury despite conflicting evidence on their utility. The aim of this study was to investigate the utility of routine initial serum lipase measurement for the diagnosis of acute pancreatic trauma. MATERIALS AND METHODS: Lipase measurements were introduced as part of the trauma pathology panel and requested on all patients who presented to an adult major trauma service and met trauma call-out criteria. Clinical records of these patients were extracted from the trauma registry and retrospectively reviewed. The performance of an initial serum lipase level measured on presentation to detect pancreatic trauma was determined. RESULTS: There were 2,580 patients included in the study, with 17 patients diagnosed with pancreatic trauma. An elevated lipase was recorded in 390 patients. Statistically significant associations were observed for elevated lipase in patients with pancreatic trauma, head injury, acute alcohol ingestion and massive blood transfusion. As a test for pancreatic trauma, an abnormal serum lipase result had a specificity of 85.3 % (95 % CI 83.8-86.6), sensitivity of 76.5 % (95 % CI 49.8-92.2), positive predictive value of 3.3 % (95 % CI 1.8-5.8) and negative predictive value of 99.8 % (95 % CI 99.4-99.9). Higher cut-offs of serum lipase did not result in better performance. CONCLUSIONS: A normal serum lipase result can be a useful adjunct to exclude pancreatic injury. A positive lipase result, regardless of the cut-off used, was not reliably associated with pancreatic trauma, and should not be used to guide further assessment.
ABSTRACT
A magnetic inverse solution that uses a single current dipole in a homogeneous volume conductor with realistic torso shape was tested numerically to establish the effect of magnetic noise, number of measurement points, and torso size on the localization accuracy. Seven different sites of cardiological interest were selected as locations for the source dipole. The three components of the magnetic field were calculated as if measured by second order gradiometers, Gaussian noise was added, and Monte Carlo tests performed for inverse solutions using a single field component, or all three combined. It was found that for any of the single component solutions, and a signal-to-noise ratio of 100, 25 measuring points are sufficient for good accuracy; just 12 points are needed if all three components are used together. If, however, the torso size of the inverse solution is different from that of the field data by 10 or 20%, a larger error occurs, even for 56 measurement points and no noise. In this case, the field component orthogonal to the measurement grid, Bz, yields better results than the other two components, or even all three combined. We conclude that a multichannel system measuring the z component of the magnetic field in about 30 locations would be the best choice to locate a dipolar source, provided the torso of the field data is closely matched by the model used in the inverse solution. To this effect, scaling of the torso model can easily be included in the computation. Imaging techniques could be used to accommodate different torso shapes.
Subject(s)
Heart/physiology , Magnetics , Models, Anatomic , Thorax/anatomy & histology , Bias , Computer Simulation , Evaluation Studies as Topic , Humans , Monte Carlo Method , Normal DistributionABSTRACT
Non-beta-cell adenoma of the islet apparatus in the pancreas was described. The tumor measured 8 X 4 X 4 cm. Histological examination revealed its mixed structure. The tumor was composed of trabecular and solid structures, adenoma-like rosettes, and pericytial muffs. APUD-amyloid was found in its stroma. Application of a specific immunoperoxidase technique and electron microscopy provided good evidence for the fact that the tumor consisted of gastrin-producing cells. In view of clinical features, the tumor was regarded as gastrinoma.