Therapy limitation in octogenarians in German intensive care units is associated with a longer length of stay and increased 30 days mortality: A prospective multicenter study.

PURPOSE: The approach to limit therapy in very old intensive care unit patients (VIPs) significantly differs between regions. The focus of this multicenter analysis is to illuminate, whether the Clinical Frailty Scale (CFS) is a suitable tool for risk stratification in VIPs admitted to intensive care units (ICUs) in Germany. Furthermore, this investigation elucidates the impact of therapeutic limitation on the length of stay and mortality in this setting. METHODS: German cohorts' data from two multinational studies (VIP-1, VIP-2) were combined. Univariate and multivariate logistic regression were used to evaluate associations with mortality. RESULTS: 415 acute VIPs were included. Frail VIPs (CFS > 4) were older (85 [IQR 82-88] vs. 83 [IQR 81-86] years p < .001) and suffered from an increased 30-day-mortality (43.4% versus 23.9%, p < .0001). CFS was an independent predictor of 30-day-mortality in a multivariate logistic regression model (aOR 1.23 95%CI 1.04-1.46 p = .02). Patients with any limitation of life-sustaining therapy had a significantly increased 30-day mortality (86% versus 16%, p < .001) and length of stay (144 [IQR 72-293] versus 96 [IQR 47.25-231.5] hours, p = .026). CONCLUSION: In German ICUs, any limitation of life-sustaining therapy in VIPs is associated with a significantly increased ICU length of stay and mortality. CFS reliably predicts the outcome.

Nitric oxide synthase in human skeletal muscles related to defined fibre types.

Skeletal muscle functions regulated by NO are now firmly established. However, the knowledge about the NO synthase (NOS) expression related to a defined fibre type in human skeletal muscles necessitates further clarification. To address this issue, we examined localization of NOS isoforms I, II and III, in human skeletal muscles employing immunocytochemical labeling with tyramide signal amplification complemented with enzyme histochemistry and Western blotting. The NOS immunoreactivity was related to fibre types of different classification systems: physiological classification into slow and fast, ATPase classification into I, IIA, IIAX, IIX, and physiological-metabolic classification into slow-oxidative (SO), fast-oxidative glycolytic (FOG) and fast-glycolytic (FG). We found a correlation of NOS I-III immunoreactivity to metabolic defined fibre types with strong expression in FOG fibres. This implies that NO as modulator of muscle function is involved in oxidative metabolism in connection with fast force development, which only occurs in FOG fibres. The NOS expression showed no correlation to ATPase fibre subtypes due to the metabolic heterogeneity of ATPase fibre types. Healthy and affected vastus medialis muscles after anterior cruciate ligament rupture revealed similar NOS expression level as shown by Western blotting with, however, different expression patterns related to the fibre types in affected muscles. This suggests an altered modulation of force development in the fibres of diseased muscles.

Nitric oxide synthase is up-regulated in muscle fibers in muscular dystrophy.

Nitric oxide (NO) mediates fundamental physiological actions on skeletal muscle. The neuronal NO synthase isoform (NOS1) was reported to be located exclusively in the sarcolemma. Its loss from the sarcolemma was associated with development of Duchenne muscular dystrophy (DMD). However, new studies evidence that all three NOS isoforms-NOS1, NOS2, and NOS3-are co-expressed in the sarcoplasm both in normal and in DMD skeletal muscles. To address this controversy, we assayed NOS expression in DMD myofibers in situ cytophotometrically and found NOS expression in DMD myofibers up-regulated. These results support the hypothesis that NO deficiency with consequent muscle degeneration in DMD results from NO scavenging by superoxides rather than from reduced NOS expression.