In acute aortic dissection (AAD), timely diagnosis is challenging. However, dedicated studies of the entity and determinants of delay are currently lacking. We surveyed pre-/in-hospital time to diagnosis and explored risk factors for diagnostic delay. We analyzed the dedicated database of a metropolitan AAD network (161 patients diagnosed since 1996; 115 Stanford type A) in terms of hospital arrival times (from pain to presentation at any hospital) and in-hospital diagnostic times (presentation to final diagnosis). Median (interquartile range) in-hospital diagnostic times were approximately twofold greater than hospital arrival times (177 minutes, 644, vs 75 minutes, 124, p = 0.0001, Wilcoxon test). Median annual in-hospital diagnostic times were most often approximately 3 hours (spread was wide, but decreased after 2001; rho = -0.94, p = 0.005). Risk factors (univariate analysis) for in-hospital diagnostic time >75th percentile (12 hours) included pleural effusion (odds ratio 3.96, 95% confidence interval 1.80 to 8.69), dyspneic presentation (odds ratio 3.33, 95% confidence interval 1.93 to 8.59), and age <70 years (odds ratio 2.34, 95% confidence interval 1.03 to 5.36). Systolic arterial pressure < or =105 mm Hg decreased the likelihood of lengthy diagnosis (odds ratio 0.08, 95% confidence interval 0.01 to 0.59). In patients (n = 82) with routine values (since 2000), troponin positivity (odds ratio 3.63, 95% confidence interval 1.12 to 11.84) and an acute coronary syndrome-like electrocardiogram (odds ratio 2.88, 95% confidence interval 1.01 to 8.17) were also risk factors. In conclusion, in a metropolitan setting, most of the diagnostic delay may occur in hospital. At presentation, pleural effusion, troponin positivity, acute coronary syndrome-like electrocardiogram, and dyspnea are possible "clinical confounders" associated with particularly long in-hospital diagnostic times.
[Show abstract][Hide abstract] ABSTRACT: Background: Aortic dissection is a potentially fatal condition that primarily affects the older population. Rapid diagnosis of dissection is crucial for a favorable outcome and the only effective strategy to improve outcome is high clini-cal suspicion and prompt treatment. Objective: We present a case that demonstrates a timely diagnosis of a serious and life-threatening condition by an emer-gency bedside ultrasound (EBU). Case Report: We report a case of a 36-year-old male with prior history of cholelithiasis and frequent ED visits for biliary colic that presented with abdominal pain. An emergency bedside ultrasound showed gallstones and an aortic dissection in the abdominal aorta. Emergent surgical consultation was obtained based on the ultrasound finding, and subsequently fol-lowed with confirmatory imaging and surgical intervention. Conclusion: This case report highlights the utility of emergency bedside ultrasound, which made a timely diagnosis and saved a life.
[Show abstract][Hide abstract] ABSTRACT: To accomplish multichannel access on vehicular radio systems, it is necessary to provide a signaling system to initiate communications. This signaling function may be accomplished on a dedicated signaling channel or may be distributed over all of the communications channels. A summary of the considerations involved in specifying this system characteristic is presented. It is concluded that the dedicated signaling channel results in a fixed partition between signaling and talking capacity. If the loading of a common signaling channel would be sufficiently light so that it does not limit the talking capacity of the system, then probably the signaling function can also be distributed on the talking channels, still providing all necessary functions. With distributed signaling, the partitioning of capacity between signaling and talking can adapt to the traffic presented.
[Show abstract][Hide abstract] ABSTRACT: This paper reports infrared spectroscopy studies on oxygen related
defects in Czochralsky grown neutron irradiated Silicon material
subsequently submitted to heat treatment. The sequential formation of
various VO<sub>n</sub> (n=1,2,3,4) defects according to the reaction
is investigated. We argue that on increasing the annealing temperature
different sites for the addition of oxygen atoms become available,
triggering for n>2 two parallel formation sequencies in relation with
VO<sub>3</sub> and VO<sub>4</sub> defects. Thus in the first sequence
the oxygen atoms are added in adjacent sites to VO<sub>2</sub> defect
although in the second sequence the oxygen atoms are added in the same
vacant site of VO<sub>2</sub> defect
Semiconductor Conference, 1997. CAS '97 Proceedings., 1997 International; 11/1997
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