Hypokalemia is clinically called hypokalemia.
Its severity is closely related to the difference of intracellular and extracellular potassium concentration, and also depends on the speed, duration and etiology of hypokalemia. The hypokalemia caused by long-term use of diuretics gradually formed, so the clinical manifestations were not serious. Low potassium in a short time can cause sudden death. Blood pH and other blood electrolyte concentrations are also related to the severity of symptoms. When severe hypokalemia is accompanied by acidosis, the symptoms of hypokalemia can be alleviated because the potassium in the cell moves to the outside of the cell, such as diabetes acidosis. However, with the correction of acidosis, the symptoms of potassium deficiency can be rapidly aggravated.
1. neuromuscular system: When blood potassium is as low as 2.5mmol/L, neuromuscular symptoms are obvious. Muscle weakness is often the earliest and most prominent symptom, and the whole body muscles are weak or even paralyzed. In severe cases, tendon reflex disappears and respiratory muscles are paralyzed. Symptoms of central nervous system include depression, lethargy, disorientation and mental disorder.
2. Digestive system: intestinal peristalsis is weakened. When potassium deficiency is mild, there are only mild abdominal distension, nausea and constipation. Intestinal paralysis and even paralytic intestinal obstruction may occur when severe hypokalemia occurs. Collection and arrangement of medical teaching and education network
3. Cardiovascular system: sinus tachycardia, atrial premature contraction or ventricular premature contraction are common in patients with mild hypokalemia. Severe hypokalemia can cause supraventricular or ventricular tachycardia, ventricular fibrillation and even sudden death. Due to the weakening of myocardial contractility and the decrease of vascular tension, there are dull heart sounds, enlarged heart, cardiac insufficiency and hypotension. The ECG changes were T wave low and then inverted, U wave appeared or fused with T wave, S-T segment decreased, Q-T(Q-U) prolonged and atrioventricular block.
4. Kidney: Persistent low specific gravity urine and even renal diabetes insipidus appear due to the decrease of glomerular filtration rate and renal blood flow, which may be related to the damage of epithelial cells of distal convoluted tubules and the decrease of anti-diuretic hormone response.
5. Metabolic alkalosis: Due to the decrease of blood potassium, potassium ions in cells are transferred to the outside of cells, and hydrogen ions in extracellular fluid enter the cells, so that the concentration of extracellular hydrogen ions decreases and alkalosis occurs. Due to the decrease of intracellular potassium, the secretion of potassium ions by renal tubules decreased, and Na
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-K
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Exchange decreases and Na
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-H
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With the increase of exchange, the excretion of hydrogen ions in urine increases, which aggravates alkalosis. Due to the increase of hydrogen ions in urine, urine is acidic.