Frailty is associated with long-term outcome in patients with sepsis who are over 80 years old: results from an observational study in 241 European ICUs

BACKGROUND

Sepsis is one of the most frequent reasons for acute intensive care unit (ICU) admission of very old patients and mortality rates are high. However, the impact of pre-existing physical and cognitive function on long-term outcome of ICU patients ≥ 80 years old (very old intensive care patients (VIPs)) with sepsis is unclear.

OBJECTIVE

To investigate both the short- and long-term mortality of VIPs admitted with sepsis and assess the relation of mortality with pre-existing physical and cognitive function.

DESIGN

Prospective cohort study.

SETTING

241 ICUs from 22 European countries in a six-month period between May 2018 and May 2019.

SUBJECTS

Acutely admitted ICU patients aged ≥80 years with sequential organ failure assessment (SOFA) score ≥ 2.

METHODS

Sepsis was defined according to the sepsis 3.0 criteria. Patients with sepsis as an admission diagnosis were compared with other acutely admitted patients. In addition to patients' characteristics, disease severity, information about comorbidity and polypharmacy and pre-existing physical and cognitive function were collected.

RESULTS

Out of 3,596 acutely admitted VIPs with SOFA score ≥ 2, a group of 532 patients with sepsis were compared to other admissions. Predictors for 6-month mortality were age (per 5 years): Hazard ratio (HR, 1.16 (95% confidence interval (CI), 1.09-1.25, P < 0.0001), SOFA (per one-point): HR, 1.16 (95% CI, 1.14-1.17, P < 0.0001) and frailty (CFS > 4): HR, 1.34 (95% CI, 1.18-1.51, P < 0.0001).

CONCLUSIONS

There is substantial long-term mortality in VIPs admitted with sepsis. Frailty, age and disease severity were identified as predictors of long-term mortality in VIPs admitted with sepsis.

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.

Metabolic profile and nitric oxide synthase expression of skeletal muscle fibers are altered in patients with type 1 diabetes

We investigate muscle fiber composition, fiber-specific glycolytic and oxidative enzyme capacity and nitric oxide synthase (NOS) expression in skeletal muscle of patients with type 1 diabetes (T1D) compared to individuals with normal glucose tolerance (NGT). Vastus lateralis muscle was obtained by percutaneous biopsy from 7 T1D patients and 10 healthy controls with similar characteristics. Using cytophotometry, muscle fiber composition and fiber type-specific glycolytic and oxidative enzyme activities were measured in slow oxidative (SO), fast oxidative glycolytic (FOG) and fast glycolytic (FG) fibers. In addition, NOS 1-3 protein expression was mea-sured. The glycolytic fiber fraction was 1.4 fold higher, whereas FOG and SO fiber fractions were significantly reduced by 13.5% and 6.2% in skeletal muscle from T1D patients. Glycolytic enzyme activities and fiber-specific ratio of glycolytic relative to oxidative enzyme activity were significantly higher in all fiber types of T1D patients and correlated with HbA (1c). Expression of NOS1-3 isoforms was reduced in skeletal muscle of T1D subjects. Increased glycolytic enzyme activity in muscle of T1D patients is most likely due to both a higher number of fast glycolytic fibers and a shift towards increased glycolytic metabolism in all fiber types. Alterations in muscle fiber distribution and enzyme activities seem to be due to impaired long-term glycemic control.

Fibre-related nitric oxide synthase (NOS) in Duchenne muscular dystrophy

Nitric oxide (NO) mediates fundamental physiological actions on skeletal muscle. The loss of NO synthase (NOS) from the sarcolemma was assumed to be associated with development of Duchenne muscular dystrophy (DMD). We have, however, recently reported that, in contrast to the commonly accepted view, NOS expression in DMD myofibres is up-regulated. This poses the question of the fibre type-specific NOS expression in DMD muscles and how the NOS expression is related to the regeneration or degeneration status. To address this issue, we examined localization of NOS isoforms I, II and III in skeletal muscles of DMD patients employing immunohistochemical labelling with tyramide signal amplification complemented with enzyme histochemistry. We found that NOS immunolabelling as well as metabolic enzyme activity in DMD muscles were heterogeneously distributed along the fibre length of DMD muscle fibres revealing regenerating and degenerate (hypercontracted) fibres as well as normal segments. Like in normal muscles, positive NOS immunoreactivity was found to be associated with fast-oxidative glycolytic (FOG) phenotype. The regeneration status of NOS-positive segments was deduced from the presence of neonatal and developmental myosin heavy chains. High NOS expression in regenerating DMD muscle fibres can be well reconciled with reports about the protective role of endogenous NO in inflammatory diseases and in muscle repair.

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.

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.