Background: Percutaneous cricothyroidotomy is a lifesaving procedure for airway obstruction in trauma victims who need airway establishment and cannot be intubated or in whom intubation has failed.
Methods: The purpose of this study was to examine whether there is a training effect using Seldinger technique emergency cricothyroidotomy (group 1; Arndt Emergency Cricothyroidotomy Catheter Set; Cook Critical Care, Bloomington, IN) versus standard surgical cricothyroidotomy (group 2). Twenty emergency physicians performed five cricothyroidotomies with each method in a total of 200 human cadavers, comparing efficacy and safety (speed, success rate, and injuries).
Results: Seven attempts in group 1 and six in group 2 had to be aborted. Time intervals from the start of the procedure to location of the cricothyroid membrane were not significantly different between the groups. However, time to tracheal puncture (P < 0.01) and time to first ventilation (P < 0.001) were significantly longer in group 2. No time effect could be observed in both groups. The airway was accurately placed into the trachea through the cricothyroid membrane in 88.2% (82 of 93) of the cadavers in group 1 and in 84.0% (79 of 94) in group 2 (not significant). No injuries were observed in group 1, whereas there were six punctures of the thyroid vessels in group 2 (P < 0.05). 相似文献
We assessed whether the range of passive hip motion is reliable for predicting abnormal femoral ante-version. We measured the passive medial and lateral rotation in extension in both hips of 1, 140 children between 8 and 9 years of age. The children were divided into 3 groups: group 1: difference between lateral and medial rotation less than 10° group 2: medial rotation more than 10° greater than the lateral; group 3: lateral rotation more than 10° greater than the medial. Group 1 comprised 90% of the children, whereas 8% belonged to group 2 and 2% to group 3.
The angle of femoral neck anteversion was measured in 57 children from the first group, in 67 from the second and in 24 children from the third group, using biplane radiography. The mean anteversion angles in the 3 groups were 24°, 36° and 14°, respectively. To predict an abnormally high anteversion angle (above mean +2SD), the difference between medial and lateral rotation must be 45° or more, whereas an abnormally low anteversion angle (lower than mean -2SD) could be predicted when the lateral rotation was at least 50° higher than the medial rotation. 相似文献
In gamma-ray spectrometry, true coincidence summing correction factors for an extended sample can be calculated from full-energy-peak and total efficiencies as if the sample were a point source, if the so-called linear-to-square- (LS) curve, introduced by Blaauw and Gelsema, is known and properly applied. A method is described for obtaining the efficiencies and the corresponding LS-curve for an arbitrary cylindrical sample from calibration measurements in a reference geometry. The approach is aimed at the analysis of samples measured on p-type HPGe detectors in environmental gamma-ray spectrometry and was successfully verified against experimental data. 相似文献
Adrenocorticotrophic hormone (ACTH) is essential for developmental maturation of numerous organ systems during the fetal period and for adaptation to environmental challenges. Immunocytochemical and stereological methods were used in the present study to examine the effects of dexamethasone (Dx) administration during pregnancy on fetal rat pituitary ACTH-producing cells. Doses of 0.5, 0.5 and 1.0 mg Dx/kg body weight/day were given to the dams on 3 consecutive days starting on day 16 of gestation. Morphometric analysis of the ACTH-producing cells of fetuses at 21 days of gestation revealed significant inhibition by 24% and 27%, respectively, of cell volume and cell number after maternal Dx administration, whereas the volume of cell nuclei and volume density of ACTH-stained cells were insignificantly decreased. Immunocytochemical analysis showed reduced numbers, sizes and immunopositivity of ACTH cells of 21-day-old fetuses from Dx-treated dams as compared with the control group. Maternal Dx treatment in the period of intense differentiation of the hypothalamo-hypophyseal-adrenal system had an inhibitory effect on fetal function and proliferative activity of ACTH-producing cells at 21 days of gestation. Thus, inhibition of activity of fetal ACTH-producing cells may lead to adrenal suppression, modified activity of the hypothalamo-pituitary-adrenal axis and reduced body weight possibly causing lasting functional abnormalities. 相似文献
The effect of some solvent/nonsolvent pairs on the efficiency of the column fractionation of polystyrene was investigated. Extensive cloud point titration experiments were shown to be needed for the correct assessment of thermodynamic qualities of a solvent/nonsolvent pair used in the column fractionation of polymers. Besides the thermodynamic suitability of solvent pairs their kinetic behavior was shown to differ. Possible reasons for the observed differences were discussed. 相似文献
An indirect fluorescent-antibody test for detection and titration of antibodies to Ehrlichia canis, the causative agent of tropical canine pancytopenia, has been described. The organism propagated by an in vitro technique in canine blood monocytes served as an antigen in the test. The specificity of the test was revealed by absence of cross-reactivity between the antigen and sera from dogs infected with various common pathogens and specific sera against eight rickettsial species. The accuracy of the test was ascertained by isolation of the organism from reactor dogs located in and outside the United States. Histopathological examination of nine reactor dogs revealed plasmacytosis of meninges and kidneys in eight of them. 相似文献