IntroductionSevere hyperkalemia, with potassium (K+) levels ≥ 6.5 mEq/L, is a potentially life-threatening electrolyte imbalance. For prompt and effective treatment, it is important to know its risk factors, clinical manifestations, and predictors of mortality.MethodsAn observational cohort study was performed at 2 medical centers. A total of 923 consecutive Korean patients were analyzed. All were 19 years of age or older and were hospitalized with severe hyperkalemia between August 2007 and July 2010; the diagnosis of severe hyperkalemia was made either at the time of admission to the hospital or during the period of hospitalization. Demographic and baseline clinical characteristics at the time of hyperkalemia diagnosis were assessed, and clinical outcomes such as in-hospital mortality were reviewed, using the institutions' electronic medical record systems.ResultsChronic kidney disease (CKD) was the most common underlying medical condition, and the most common precipitating factor of hyperkalemia was metabolic acidosis. Emergent admission was indicated in 68.6% of patients, 36.7% had electrocardiogram findings typical of hyperkalemia, 24.5% had multi-organ failure (MOF) at the time of hyperkalemia diagnosis, and 20.3% were diagnosed with severe hyperkalemia at the time of cardiac arrest. The in-hospital mortality rate was 30.7%; the rate was strongly correlated with the difference between serum K+ levels at admission and at their highest point, and with severe medical conditions such as malignancy, infection, and bleeding. Furthermore, a higher in-hospital mortality rate was significantly associated with the presence of cardiac arrest and/or MOF at the time of diagnosis, emergent admission, and intensive care unit treatment during hospitalization. More importantly, acute kidney injury (AKI) in patients with normal baseline renal function was a strong predictor of mortality, compared with AKI superimposed on CKD.ConclusionsSevere hyperkalemia occurs in various medical conditions; the precipitating factors are similarly diverse. The mortality rate is especially high in patients with severe underlying disease, coexisting medical conditions, and those with normal baseline renal function.

Scattering experiments were conducted on a critical, binary mixture of polyethylene (PE) and head-to-head polypropylene (PP), and a symmetric PE−PP diblock copolymer melt. The binary mixture exhibited a liquid−liquid phase transition at 143 °C, while the block copolymer exhibited an order−disorder transition at 149 °C. Estimates of the Flory−Huggins interaction parameter between PE and PP, and the statistical segment lengths of the chains were obtained by fitting neutron scattering profiles from the PE/PP blends and the PE−PP block copolymer, in the single-phase regime, to theoretical predictions based on the random phase approximation (RPA). These estimates were used to compute the scattering profiles of multicomponent blends comprising PE, PP, and PE−PP. A phase diagram for these blends was constructed on the basis of the computed scattering profiles. In the paper that follows this one, we compare the theoretical computations with experimental data from multicomponent PE/PP/PE−PP blends.

Concentration fluctuations and phase transitions in multicomponent polymer blends comprising polyethylene (PE), head-to-head polypropylene (PP), and a symmetric PE−PP diblock copolymer were studied by a combination of light and neutron scattering. When the block copolymer concentration was below a certain threshold (12.5 vol % in our system), the blends exhibited macrophase separation. At higher block copolymer concentrations, we found stable, periodic structures that were characterized by a neutron scattering peak at finite scattering vector, q. In this regime, the block copolymer serves as a surfactant. At high block copolymer concentrations, ordered microphases that were similar to those found in pure block copolymer melts were obtained. At lower block copolymer concentrations, however, microemulsions that are periodic phases that lack long-range order were obtained. Concentration fluctuations of individual components in these multicomponent mixtures in the single-phase regime were examined by conducting neutron scattering experiments on contrast-matched systems. The formation of disordered phases and microemulsions is announced by transient, intermolecular aggregation of the homopolymers. In contrast, the formation of ordered structures is announced by both intermolecular and intramolecular signatures. Many of our results are in quantitative agreement with theoretical predictions based on the random phase approximation.

Combined aerobic and anaerobic exercise training during dialysis was found to be effective on physical health status, intradialytic hypotension, and depression in terms of mental health. Therefore, the findings of the current study may provide an appropriate guidance for encouraging exercise by nephrologists.