What Is an Electrolyte Imbalance?

The main cations in human plasma are Na, K, Ca, and Mg, which play a decisive role in maintaining the osmotic pressure of extracellular fluid, the distribution and transfer of body fluids; the main anions in extracellular fluid are mainly Cl ^- and HCO _3- In addition to maintaining the tension of body fluids, the two have an important role in maintaining acid-base balance. In general, the total number of anions in the body fluid is equal to the total number of cations and remains electrically neutral. When any amount of electrolyte changes, it will lead to different body damage, that is, electrolyte disorders.

Basic Information

English name

electrolytedisturbance

Visiting department

Internal medicine

Common causes

Disturbance of sodium metabolism, disturbance of potassium metabolism, disturbance of calcium metabolism, abnormal metabolism of magnesium ions

Common symptoms

Hypernatremia, hyponatremia, hyperkalemia, hypokalemia, hypercalcemia, hypocalcemia, hypomagnesemia, hypermagnesemia

Causes of electrolyte disorders

1. Disorders of sodium metabolism

Decreased plasma sodium concentration, less than 130mmol / L is called hyponatremia. Hyponatremia can be seen in low intake (rare), high loss, absolute or relative increase in water. It is a complex water and electrolyte disorder. There are many reasons, which can be divided into two categories of renal and non-renal causes. Hyponatremia caused by impaired renal function is caused by osmotic diuresis, hypoadrenal function, and acute and chronic renal failure. Non-renal factors such as vomiting, diarrhea, intestinal fistula, massive sweating and burns In addition, there is pseudohyponatremia: due to an increase in some insoluble and soluble substances in the plasma. Reduce the water content per unit volume, reduce the blood sodium concentration (sodium is only dissolved in water), and cause hyponatremia. The former is found in hyperlipoproteinemia (blood lipid> 10g / L), hyperglobulinemia (total protein> 100g / L (such as multiple myeloma, macroglobulinemia, Sjogren's syndrome); the latter is seen after intravenous hypertonic glucose or intravenous mannitol. Hypernatremia: An increase in blood sodium concentration, greater than 150mmol / L, is called hypernatremia. Mainly seen in reduced water intake (primary hypernatremia due to thalamus damage), excessive drainage (diabetes insipidus), retention of sodium (primary aldosteronism, Cushing syndrome).

2. Disorders of potassium metabolism

(1) Hypokalemia Serum potassium below 3.5mmol / L is called hypokalemia. Common clinical causes are: insufficient potassium intake: such as chronic inadequate eating (such as chronic wasting disease) or fasting (such as fasting for a long time after surgery); potassium loss or increased excretion: common in severe diarrhea, vomiting, Gastrointestinal decompression and intestinal fistula; Adrenocortical hormone can promote potassium excretion and sodium retention. When used for a long time, it can cause hypokalemia; Heart failure, liver cirrhosis patients, long-term use of diuretics Increased potassium loss due to large amounts of urination. Extracellular potassium enters the cell: If excessive glucose is input intravenously, especially when insulin is added, it promotes the utilization of glucose and then synthesizes glycogen, all K ⁺ enters the cell, which easily causes hypokalemia; metabolic alkali Poisoning or importing too much alkaline drugs, acute alkalemia is formed, H ⁺ enters from the cell to the outside of the cell, and extracellular K ⁺ enters the cell, causing hypokalemia. In addition, plasma dilution can also cause hypokalemia.

(2) Hyperkalemia Serum potassium is higher than 5.5mmol / L, which is called hyperkalemia. Common clinical causes are: excessive potassium input, which is more common when the potassium solution is input too fast or too large, especially with renal insufficiency, decreased urine output, and the potassium solution is likely to cause hyperkalemia. Potassium excretion disorder: oliguria or anuria caused by various reasons such as acute renal failure; intracellular potassium is transferred to the outside of the cell, such as large area burns, a large number of tissue cells are destroyed, and intracellular potassium is released into human blood in large quantities; Metabolic acidosis, the transfer of plasma hydrogen ions into the cell, and intracellular potassium transfer to the outside of the cell. At the same time, renal tubular epithelial cells increase H ⁺ secretion and K ⁺ secretion decrease, leaving potassium in the body.

3. Disorders of calcium metabolism

In addition to the effect of phosphorus, the concentration of blood calcium is also related to protein concentration, vitamin D, and parathyroid hormone. Calcium is mainly involved in osteogenesis and regulating the excitability of neuromuscular muscles. It can increase the nerve excitement threshold and slow the nerve conduction speed. Serum calcium concentration L is hypocalcemia, and serum calcium concentration> 2.75mmol / L is hypercalcemia.

4. Abnormal magnesium ion metabolism

Magnesium ion is one of the main elements in the body. It is related to the secretion of acetylcholine in the nerve gap and sympathetic ganglia, and it has inhibitory and sedative effects on nerves and muscles. Neuromuscular excitability abnormality occurs when magnesium ion is lacking. Serum magnesium concentration L is hypomagnesemia, while serum magnesium concentration> 1.25mmol / L is hypermagnesemia. Generally due to insufficient magnesium intake, renal tubular reabsorption disorders, endocrine disorders, long-term fasting, malabsorption, chronic alcoholism, pancreatitis, hypoparathyroidism, hyperaldosteronism, diabetic coma, long-term use of diuretics , Blood purple disease and so on. Hypomagnesemia is often accompanied by hypercalcemia.

Clinical manifestations of electrolyte disorders

Hypernatremia

Clinical manifestations are atypical and weakness can occur. Dry lips, skin loss of elasticity, irritability, and even mania, hallucinations, delirium and coma. Cerebral atrophy caused by hypernatremia can be secondary to cerebral hemorrhage, subarachnoid hemorrhage, and even death.

2. Hyponatremia

Mild hyponatremia (serum sodium concentration 120-135mmol / L) can lead to taste loss and muscle soreness; moderate (serum sodium concentration 115-120mmol / L) headache, personality changes, nausea, vomiting, etc .; severe (serum Sodium concentration <115mmol / L) can appear coma, and the reflection disappears.

3. Hyperkalemia

It is manifested in three aspects: Physical symptoms Severe bradycardia, atrioventricular block and even sinus arrest. The electrocardiogram showed a sharp T wave, and in severe cases, the PR interval prolonged, P wave disappeared, QRS wave widened, and finally cardiac arrest, mild blood pressure increased early, blood pressure decreased in the later period, irregular breathing, and arrhythmia. Neuromuscular symptoms Early manifestations of muscle pain and weakness, respiratory muscle paralysis may occur when the extremities are significantly severe. Symptoms in the early stage are indifferent expression, slow response to the outside world, excitement, emotional instability, restlessness, etc., and severe consciousness disturbance, lethargy, and coma.

4. Hypokalemia

It is not only related to the concentration of serum potassium, but also to the rate of hypokalemia. Therefore, although patients with slow onset have severe hypokalemia, the clinical symptoms may not be obvious. Severe, but the clinical symptoms can be significant: physical symptoms of lack of appetite, abdominal distension, thirst, nausea, vomiting, chest tightness, palpitations, severe myocardial involvement can lead to heart failure, T wave is low or disappears early in the ECG, and U appears In severe cases, ventricular tachycardia, ventricular fibrillation, or sudden death occurs. Neuromuscular symptoms are the most prominent symptoms of hypokalemia, the most important manifestations of which are limb weakness, weakness, and flaccid paralysis and periodic paralysis. Psychiatric symptoms in the early stages are fatigue, apathy, memory loss, depression, and stiffness may also appear. In severe cases, there is a disturbance of consciousness, lethargy, delirium, and coma.

5. Hypercalcemia

Unresponsiveness, indifference to the outside world, indifferent emotions, and memory disorders; may also have symptoms such as hallucinations, delusions, depression; severe cases may have consciousness disorders such as drowsiness and coma.

6. Hypocalcemia

Common neuropsychiatric symptoms include hand and foot convulsions, seizure-like seizures, paresthesia, increased muscle tone, hypertonic reflexes, muscle tenderness, and disturbance of consciousness. Bronchial spasm, laryngeal spasm, and respiratory failure can also occur.

7. Hypomagnesemia

Clinical manifestations of dizziness, muscle weakness, tremor, cramps, auditory allergies, nystagmus, dyskinesia, hand and foot movements, coma and other symptoms, irritability, depression or excitement, hallucinations, disorientation, forgetfulness-delirium Syndrome.

8. Hypermagnesemia

It often occurs during renal insufficiency, before treatment of diabetic acidosis, and myxedema. The neurological symptoms are mainly inhibitory. The central or peripheral nerves are inhibited, and paralysis and respiratory paralysis occur. Dumb tendon reflexes or disappearance are often important indicators of early hypermagnesemia.

Diagnosis of electrolyte disorders

1. Meet the laboratory positive test results of water and electrolyte disorders.

2. Auxiliary inspection changes in compliance with water and electrolyte disorders.

Electrolyte Disorders Treatment

The key to treatment is to promptly and thoroughly treat the electrolyte disorders according to the cause, such as correcting the acid-base balance and electrolyte disorders, and to remove the causes of hypokalemia when treating hypokalemia, and prevent hyperkalemia during the potassium supplement process. Generally with potassium supplementation, clinical symptoms also recover, such as convulsions should pay attention to whether there are other electrolyte changes, especially the regulation of blood calcium. Use antipsychotics with caution to prevent unconsciousness. In the case of hyperkalemia, in addition to the cause of the disease, the principle of treatment is to combat potassium poisoning, promote the excretion of potassium ions, and protect myocardial function. Hyponatremia should focus on sodium supplementation, while hypernatremia should be monitored for calculated water supplementation.

Maintain the function of the cardiovascular system, give a lot of vitamins and neurotrophic substances to promote the recovery of brain cell functions, such as glutamic acid, adenosine triphosphate (adenosine triphosphate), coenzyme A, niacin and so on. Mental disorders generally have no special treatment. If necessary, anti-anxiety and antidepressant drugs can be used symptomatically. The use of psychotropic substances should be cautious. Care must be taken to avoid further damage to related organs, deepen the disturbance of consciousness or damage other organ functions.