A symptom of hyperkalemia is a sign of a disease in which the amount of potassium in the blood serum rises to more than 5 mmol / l. In the human body, potassium is mainly concentrated in cells, providing DNA and protein synthesis, cell growth, normal enzyme function, etc. Only 2% of potassium is in the extracellular fluid. Renal and extrarenal mechanisms support potassium homeostasis, the former are responsible for the elimination of potassium from the body, and the latter ensures the transition of potassium into cells from the extracellular fluid.
The action of potassium is to ensure the electrical potential of cell membranes. A symptom of mild hyperkalemia is a decrease in the resting potential of the membranes of nerve and muscle cells, which affects an increase in the excitability of cells. If the concentration of potassium in the blood rises to 7.5 mmol / L, the cells lose their excitability completely.
Hyperkalemia: symptoms of the disease
Hyperkalemia is accompanied by depolarization of cells and a decrease in their excitability, which causes muscle weakness, paresis and respiratory failure. The cardiotonic effect of potassium is manifested by high pointed T waves on the electrocardiogram. In some cases, the disease affects the lengthening of the PQ interval and the expansion of the QRS complex, as well as the slowdown of AV conduction and the loss of the P wave. All these manifestations lead to ventricular fibrillation and asystole.
Symptom of hyperkalemia: causes
In healthy individuals, potassium intake in high doses rarely causes the disease. The main cause of the disease with normal kidney function is adrenal insufficiency. In contrast, oliguric acute renal failure raises the level of potassium in the blood in a short time without increased potassium load. In a number of patients with chronic renal failure, the degree of hyperkalemia is affected by aldosterone deficiency, which is responsible for potassium secretion. This condition is usually observed in diabetic nephropathy, tubulointerstitial
kidney disease, and damage to the
juxtaglomerular apparatus.Diagnosis
Hyperkalemia is detected in a laboratory study of blood serum on the level of potassium and electrocardiographic examination.
Hyperkalemia treatment
The first signs of hyperkalemia should not be ignored. An acute onset, which threatens the patient’s life, is treated by intravenous administration of a solution of calcium gluconate every 2-3 hours.
An increase in blood calcium reduces the threshold potential and increases the difference between
the action and resting
potential , decreasing the excitability of cells. Intravenous administration of sodium bicarbonate promotes the transition of potassium from the extracellular fluid directly into the cells. And to prevent hypokalemia, insulin is injected intravenously, which increases the activity of the sodium-potassium pump and, thereby, potassium enters the cells. To reduce the concentration of potassium in serum, an ion-exchange sodium-phosphate cellulose resin is prescribed, often combining it with sorbitol. The purpose of the resin is advisable for the prevention of disease in acute renal failure. The symptom of hyperkalemia in the developed stage is removed by hemodialysis or
peritoneal dialysis with potassium-free solution.