[ASA classification : Transition in the course of time and depiction in the literature]. / ASA-Klassifikation : Wandel im Laufe der Zeit und Darstellung in der Literatur.

The American Society of Anesthesiologists classification of physical status (ASA PS) is a widely used system for categorizing the preoperative status of patients. The ASA class is a good independent predictor of perioperative morbidity and mortality. The definitions of the ASA classes have been amended several times since 1941, resulting in inconsistent and confusing usage in the current literature. Conflicting definitions of ASA PS exist, particularly for classes III, IV and V. The high variability of individual classifications by different anesthesiologist, however, can be explained by the previous lack of examples for diagnoses. In 2014, the ASA has added a catalogue of examples for a simplified definition for classification of the ASA PS. This has so far received limited attention in German-speaking countries. This article describes the transition of the ASA classification over the past 75 years und summarizes the currently valid definitions.

[Above and beyond BMI : Alternative methods of measuring body fat and muscle mass in critically ill patients and their clinical significance]. / Jenseits des BMI : Alternative Methoden zur Erfassung von Körperfett und Muskelmasse in der Intensivmedizin und deren klinischer Stellenwert.

Obesity leads to better survival in critically ill patients. Although there are several studies confirming this thesis, the "obesity paradox" is still surprising from the clinician's perspective. One explanation for the "obesity paradox" is the fact that the body mass index (BMI), which is used in almost all clinical evaluations to determine weight categories, is not an appropriate measure of fat and skeletal muscle mass and its distribution in critically ill patients. In addition, height and weight are frequently estimated rather than measured. Central obesity has been identified in many disorders as an independent risk factor for an unfavourable outcome. The first clues are to be found in intensive care. Along with obesity, an individual's entire muscle mass is a variable that has an influence on outcome. Central obesity can be measured relatively easily with an abdominal calliper, but the calculation of muscle mass is more complex. A valid and detailed measurement of this can be obtained using computed tomography (CT) images, acquired during routine care. For future clinical observation or interventional studies, single cross-sectional CT is a more sophisticated tool for measuring patients' anthropometry than a measuring tape and callipers. Patients with sarcopenic obesity, for example, who may be at a particular risk, can only be identified using imaging procedures such as single cross-sectional CT. Thus, BMI should take a back seat as an anthropometric tool, both in the clinic and in research.

Association between single-slice measurements of visceral and abdominal subcutaneous adipose tissue with volumetric measurements: the Framingham Heart Study.

OBJECTIVE: Volumetric visceral abdominal adipose tissue (VAT) and subcutaneous abdominal adipose tissue (SAT) as measured by computed tomography (CT) are associated with metabolic risk factors. We sought to identify the correlations of VAT and SAT between area-based measures at different anatomic locations with volumetric measurements to identify the optimal anatomic site, and to relate measurements at this site with metabolic risk factors. METHODS: We measured SAT and VAT volumes across the total imaging volume, whereas we measured SAT and VAT area at seven predefined anatomic landmarks in 200 participants from the Framingham Heart Study (mean age 54 years, 50% women) who underwent abdominal multi-detector CT. Correlation coefficients were used to assess the association between area measurements and volumes as well as metabolic risk factors stratified by gender. RESULTS: Area-based measurements of SAT and VAT obtained at all anatomic landmarks were strongly associated with SAT and VAT volumes (all r>0.93, P<0.0001 and r>0.87, P<0.0001, for women and men; respectively). Consistently, area-based measurements of SAT and VAT obtained at L(3/4) were most strongly associated with volumetric measured VAT and SAT independent of age (both r=0.99 in men, r=0.96 for SAT and r=0.99 for VAT in women, all P-value <0.0001) and were similarly correlated with risk factors compared with SAT and VAT volumes (all P<0.05 for fasting plasma glucose, triglycerides, high-density lipoprotein, systolic blood pressure). CONCLUSION: Among area-based measurements of SAT and VAT, those obtained at the level of L(3/4) were strongly associated with SAT and VAT volumes and cardio-metabolic risk factors in both men and women.