Hypokalemia

The study investigators are interested in learning more about how drugs, that are given to children by their health care provider, act in the bodies of children and young adults in hopes to find the most safe and effective dose for children. The primary objective of this study is to evaluate the PK of understudied drugs currently being administered to children per SOC as prescribed by their treating provider.

The study aims to provide quantitative facts on the pathophysiological changes in tissue Na+ content during Na+/K+ redistribution disorders in patients with PA in response to standard therapy. The investigators hypothesize that patients with primary aldosteronism have excessive Na+ storage in the muscle, which can now be quantified non-invasively using 23NaMRI. In analogy to the role of HbA1c as a metabolic long-term marker in diabetes, the quantifiable changes in muscle Na+ content may deliver the data evidence necessary to justify and conduct randomized diagnostic endpoint outcome trials in the future, with the ultimate aim to improve PA detection rate and treatment.

The management of serum potassium in maintenance hemodialysis（MHD ）patients is one of the hot topics at present. In order to control hyperkalemia in dialysis patients, the use of hypokalemic dialysate is the most important measure to reduce potassium. This measure effectively reduces serum potassium, but increases the risk of hypokalemia after dialysis, which increases the risk of all-cause death in patients. Hyperkalemia and hypokalemia during and at the end of dialysis are important factors for arrhythmia and death in MHD patients. Due to the intermittent nature of hemodialysis treatment, MHD patients often experience frequent fluctuations in serum potassium, which is a potential risk factor for poor prognosis of MHD patients. Serum potassium variability can better reflect the potassium homeostasis in MHD patients. In addition to hyperkalemia and hypokalemia, serum potassium variability is a potential risk factor affecting the prognosis of MHD patients. At present, there are few studies on the effect of improving serum potassium variability on cardiovascular complications, especially multi-center randomized controlled trials. In this study, sodium zirconium cyclosilicate was used to control hyperkalemia before dialysis and increase potassium concentration in dialysate, so as to reduce the risk of hypokalemia after dialysis, and to verify whether improving serum potassium variability can reduce myocardial injury in hemodialysis patients.