Validation of a clinical decision rule: chest X-ray in patients with chest pain and possible acute coronary syndrome.

Current literature suggests that a large proportion of chest X-rays (CXRs) performed in emergency department (ED) patients with chest pain and suspected acute coronary syndrome (ACS) are unnecessary. The Canadian ACS Guidelines aim to guide clinicians in the appropriate use of CXR within this patient population. This study determined the prevalence of clinically significant CXR abnormalities and assessed the utility of the guidelines in a population of ED patients with chest pain and suspected ACS. Included in the study were participants over the age of 18 who presented to an Australian metropolitan ED, over a 1-year period, with a primary complaint of chest pain and who had a CXR and troponin level ordered in the ED (N = 760). We retrospectively compared their radiographic findings with their recommendations for CXR according to the ACS Guidelines. We found that 12 % of the participants had a clinically significant chest X-ray. The guidelines had a sensitivity of 80 % (95 % CI 0.70-0.87) and specificity of 50 % (95 % CI 0.47-0.54). The positive predictive value was 18 % (95 % CI 0.15-0.22) with a 95 % negative predictive value (95 % CI 0.92-0.97). Had the ACS guidelines been applied to our patient population, the number of CXR performed would have been reduced by 47 %. This study suggests that the ACS Guidelines has the potential to reduce the numbers of unnecessary CXR performed in ED patients. However, this would come at the expense of missing a minority of significant CXR abnormalities.

Penetrating angle grinder injury to the neck causing subclavian artery injury.

Penetrating injuries to the neck present a unique challenge due to the confined space of the thoracic outlet for haemorrhage control and repair. This results in high mortality rates when the major vascular structures of the neck are transected, as well as potential neurological compromise. We present the case of a penetrating injury to the proximal subclavian artery from a broken angle grinder disc which is a unique mechanism of injury that can have fatal consequences. The patient described in this case underwent an emergent median sternotomy for proximal control of the brachiocephalic trunk and ligation of the right vertebral artery to facilitate a primary repair of the injured vessel segment. Post operatively the patient made a complete recovery with no central or peripheral neurologic deficits and requiring no further interventions. The key points from this case are that angle grinders pose a significant injury burden and early specialised medical attention should be sought, rapid control of the proximal neck vessels can be obtained via a median sternotomy and that the vertebral artery can be ligated in an emergent situation without neurological consequence.

Computed Tomography Angiography in the Assessment of Great Saphenous Vein as Conduit for Infrainguinal Bypass Surgery.

INTRODUCTION: The great saphenous vein (GSV) is commonly used as a conduit during infrainguinal bypass (IIB) and is usually well seen on computed tomography angiography (CTA) which is frequently performed for preoperative planning. In this study, we asked whether CTA could replace ultrasonography (US) as the primary mode of conduit assessment, by comparing GSV measurements for patients who underwent both CTA and US vein mapping prior to IIB. METHODS: All IIB that were completed in the six-and-a-half-year period from January 1, 2012, to July 31, 2018, at the authors' institution were examined. Great saphenous vein measurements were analyzed for patients who had undergone both CTA and US vein mapping. Correlation between the measurements was calculated with the Pearson correlation coefficient. Data were then examined using Bland-Altman plots. Then categorical analysis was used to determine the adequacy of GSV for use as a bypass conduit. RESULTS: There were 302 patients who underwent IIB, with 73 legs, in 47 patients, examined with CTA and US. Computed tomography angiography and US measurements were moderately correlated (r = 0.531) across all measurement locations. Correlation progressively reduced distally (proximal thigh r = 0.534, midthigh r = 0.536, knee r = 0.35, midcalf r = 0.185, P = .074, ankle r = 0.078, P = .485). Bland-Altman plots of the pooled location data demonstrated no systematic bias. However, the upper and lower limits of agreement were wide, between -2.02 and +2.37 mm, demonstrating a lack of agreement between CTA and US. Analysis of each location revealed similar findings. A receiver operator characteristic curve was constructed based on a minimum US GSV diameter for adequate bypass conduit of 3 mm. The CTA value that maximized the Youden index was 3.8 mm. CONCLUSION: The level of error between CTA and US measurements, demonstrated by the large limits of agreement on Bland-Altman plots, would not be clinically acceptable. However, if a larger threshold is accepted, CTA has the potential to replace preoperative US vein mapping of GSV.