Estimation of Muscle Mass in the Integrated Assessment of Patients on Hemodialysis

Assessment of muscle mass (MM) or its proxies, lean tissue mass (LTM) or fat-free mass (FFM), is an integral part of the diagnosis of protein-energy wasting (PEW) and sarcopenia in patients on hemodialysis (HD). Both sarcopenia and PEW are related to a loss of functionality and also increased morbidity and mortality in this patient population. However, loss of MM is a part of a wider spectrum, including inflammation and fluid overload. As both sarcopenia and PEW are amendable to treatment, estimation of MM regularly is therefore of major clinical relevance. Whereas, computer-assisted tomography (CT) or dual-energy X-ray absorptiometry (DXA) is considered a reference method, it is unsuitable as a method for routine clinical monitoring. In this review, different bedside methods to estimate MM or its proxies in patients on HD will be discussed, with emphasis on biochemical methods, simplified creatinine index (SCI), bioimpedance spectroscopy (BIS), and muscle ultrasound (US). Body composition parameters of all methods are related to the outcome and appear relevant in clinical practice. The US is the only parameter by which muscle dimensions are measured. BIS and SCI are also dependent on either theoretical assumptions or the use of population-specific regression equations. Potential caveats of the methods are that SCI can be influenced by residual renal function, BIS can be influenced by fluid overload, although the latter may be circumvented by the use of a three-compartment model, and that muscle US reflects regional and not whole body MM. In conclusion, both SCI and BIS as well as muscle US are all valuable methods that can be applied for bedside nutritional assessment in patients on HD and appear suitable for routine follow-up. The choice for either method depends on local preferences. However, estimation of MM or its proxies should always be part of a multidimensional assessment of the patient followed by a personalized treatment strategy.

3303Classification of patients with acute chest pain by analytical benchmarks and subsequent management recommendations - A comparison of three highly-sensitivity troponin assays in the ROMICAT trials

Background Concordance of different highly-sensitive troponin (hsTn) assays in stratifying acute chest pain (ACP) patients according to analytical benchmarks and subsequent emergency department (ED) management recommendations are unknown. Methods We included patients enrolled in the ROMICAT (Rule Out Myocardial Infarction/Ischemia Using Computer-Assisted Tomography) I and II trials (n=624; 39.1% female; 52.8±10.0 years), who presented to the ED and were referred to further non-invasive diagnostic testing. In ROMICAT I, blood was obtained at 4 hours, and in ROMICAT II at ED presentation, and at 2 and 4 hours and was tested with three state-of-the-art hsTn assays (Roche Diagnostics, Elecsys 2010; Abbott ARCHITECT i2000SR; Siemens Diagnostics, HsVista). In a per sample analysis, we compared the concordance of assays for analytic benchmarks (below the level of detection (LOD)/LOD to 99th percentile/99th percentile to myocardial infarction (<LOD], ><LOD], >MI)/above MI). In a per patient analysis of serial hsTn testing in ROMICAT II, we determined concordance of management recommendations (rule out/observe/rule in) based on 2015ESC guidelines, results of coronary CT angiography and stress myocardial perfusion, and adjudicated endpoints of ACS. Results Overall, only 34.4% (353/1027) of samples were classified into the same benchmark category by all assays (table 1). In a per patient analysis, all assays agreed on the same of management recommendation in 25.3% (49/242) patients after the 1st hsTn, mostly driven by differences in discharge (6.6%, 21.1%, and 61.2%; respectively; all p<0.001). The concordance of management recommendations improved significantly to 67.4% (163/242; p<0.001) after the 2nd hsTn measurement but the final agreement for “observe” and “rule in” remained limited (13/90 and 5/18). Among patients in whom discharge was recommended, at least 18.8% (range: 18.8–21.0% across assays) had a positive imaging/stress test and at least 2.9% (range: 2.9–3.4%) had ACS. Table 1. Classification of measurements from three hsTn assays in 1027 samples of patients with ACP according to analytical benchmarks <LOD LOD – 99th %tile* 99th %tile* – AMI** AMI**< Roche Elecsys, n (%) 578 (56.3) 328 (31.9) 95 (9.3) 26 (2.5) Abbott ARCHITECT, n (%) 176 (17.1) 788 (76.7) 14 (1.7) 49 (4.8) Siemens Vista, n (%) 96 (9.4) 861 (83.9) 33 (3.2) 37 (3.6) *Assay specific 99th percentiles; **as per ESC 2015 guidelines. Conclusion Differences in hsTn assay concordance for analytical benchmarks and subsequent ED management recommendations in patients with ACP are substantial raising concerns about the lack of uniform management. Acknowledgement/Funding Fulbright Visiting Student Researcher Grant

Virtual reality and augmented reality applications and simulation in vascular access management with three-dimensional visualization

Obtaining adequate and precise anatomical information is mandatory to prevent vascular access–related complications in dialysis patients. For this purpose, we underwent Doppler ultrasound, vascular access angiogram, and plain computer-assisted tomography scan of the arm with vascular access. With the use of computer graphics software, the anatomical structure of the vascular access can be visualized three dimensionally which is shared among the staffs for precise and better recognition. Furthermore, created object is applicable for virtual reality and/or augmented reality presentation that provides useful means for education and practical procedures in the management of vascular access.

The Use of Computed Tomography in the Diagnosis of Fatty Liver and Abdominal Fat Distribution among a Saudi Population

BACKGROUND: The pandemic of obesity is striking heavily worldwide and particularly among the affluent Gulf States where it is expected to continue to rise along with its complications.AIM: To examine the link between liver fat infiltration and abdominal fat amount using plain computer-assisted tomography (CT).METHODS: Fifty patients visiting the obesity clinic of “King Fahd Specialist Hospital” or Dr Suliman Alhabeeb Hospital between January 2015 and April 2016 were included. Liver and splenic attenuation dimensions were undertaken with three hepatic regions of interests (ROIs) and two ROIs from the spleen. The liver attenuation indices (LAIs) that were measured liver parenchymal attenuation (CTLP), liver/splenic attenuation ratio (LS ratio)and the (3) difference between liver and splenic attenuation (LS dif) and based on this LS dif The patients were grouped as LS dif greater or less than 5. Abdominal fat was evaluated utilising a 3 mm chop CT scan starting from the umbilicus; then computed by a workstation. The abdominal fat was classified as total fat (TF) and the sub-compartments of visceral adipose (fat) (VF), and subcutaneous fat (SF).RESULTS: Twenty-six of the participants were males. The mean (SD) of the age and BMI was 48 (14.9) years and 32.05 (8.3) kg/m2 respectively.The BMI and body Wt had a moderate negative correlation with the liver attenuation indices CTLP, LS ratio, LS diff (r = -0.417, -0.277, -0.312 and 0.435, -0.297, -0.0297), respectively. A very strong negative correlation between fatty liver, LS ratio and CTLP was found (-0.709, -0.575) respectively.CONCLUSION: Plain computed tomography can reliably be used as a survey device for fatty liver disease.

Exemplification of Tomographic Method to Evaluate the Quality of Welded Joints Made from EN 5754-H22 Alloy

The quality of welded joints depends on many factors. The relevant standards stipulate technical conditions of welds quality assessment, which provides the basis for stating whether the given joint is compatible with the requirements or whether it is defective. In practice, making welded joints that are totally devoid of defects is extremely difficult. To conduct the control of inner structure of the given joint a non-destructive method with the application of industrial CT scanner might be applied. This modern diagnosing method combines the x-ray examination with advanced computer technology. The basic advantage of computer-assisted tomography consists in examining objects in three dimensions and the possibility to carry out three-dimensional reconstructions. The aim of this article is to discuss the use of this method to evaluate the quality of welded joints made of aluminium alloys. Capabilities of computer-assisted tomography were depicted by the case of weld probes constructed with TIG (ang. Tungsten Inert Gas) welding by different process variables. One has made the analysis of the quality of probes showing the smallest and the biggest internal and external welding defects.