Metabolic alkalosis in the elderly
Introduction
Introduction to metabolic alkalosis in the elderly Metabolic alkalosis (alkali) is caused by a decrease in non-volatile acids or an increase in alkali in extracellular fluid. Its main feature is an increase in plasma HCO3- concentration and a compensatory increase in PaCO2. It can be present alone or in combination with respiratory acidosis. The main compensatory mechanisms are respiratory CO2 retention and renal excretion of bicarbonate and retention of H+. basic knowledge The proportion of illness: 0.001%, (more than 50 years old middle-aged and older people are more common) Susceptible people: the elderly Mode of infection: non-infectious Complications: coma, arrhythmia, hypokalemia
Cause
The cause of metabolic alkalosis in the elderly
Extracellular fluid volume (35%):
Excessive acid loss in the body or excessive in vitro alkali, excessive amount of extracellular fluid, low potassium and low chlorine, hypercapnia or decreased blood pH, can lead to increased HCO3-resorption, according to the response to chlorine treatment Alkali can be divided into chlorine-sensitive alkali and chlorine-resistant alkali, and endocrine disorders are often caused by chlorine-resistant alkali.
Drug, endocrine (25%):
Long-term use of a large number of absorbable alkaline drugs or infusion of sodium lactate, sodium citrate or potassium citrate, such as infusion of blood. Endocrine disorders, such as Cushing syndrome, primary aldosteronism, Bartter syndrome, etc.
Loss of stomach contents, application of diuretics (21%):
Loss of stomach contents, such as persistent vomiting due to pyloric obstruction or continuous drainage of the gastric tube. The application of diuretics is mainly thiazide and loop diuretics.
Prevention
Prevention of metabolic alkalosis in the elderly
When arginine is applied, it can cause severe hyperkalemia, because the organic cation arginine enters the cell, causing K+ to be caused by intracellular and extracellular migration, and attention should be paid to hyperchloremia.
Complication
Complications of metabolic alkalosis in the elderly Complications, coma, arrhythmia, hypokalemia
Alkali can be complicated by numbness, convulsions, coma, arrhythmia, hypokalemia and so on.
Symptom
Symptoms of metabolic alkalosis in the elderly Common symptoms Metabolic alkalosis, dizziness, polydipsia, urinary convulsions, weakness, confusion, arrhythmia, slow response
Symptoms of alkaloids include numbness, tingling, brachiopod and arrhythmia, but often covered by the primary disease, with low calcium, hand and foot convulsions; with low potassium, polyuria, polydipsia and paralysis With low volume, postural dizziness and muscle weakness may occur. In severe cases, confusion may occur, slow response, and even paralysis.
Examine
Examination of metabolic alkalosis in the elderly
1, blood gas analysis helps the diagnosis of metabolic alkalosis, plasma HCO3- primary increase, resulting in increased SB, AB, BB, BE positive value, pH increase at the time of compensation, plasma PCO2 has a certain degree of generation Increased repayment.
2, metabolic alkalosis, renal secretion H + reduced HCO3-excretion increased, urine is alkaline, but in the absence of potassium alkalosis, renal tubular secretion H + increased, urine is acidic.
3. The concentration of Cl- in urine in patients with metabolic alkalosis helps to analyze the etiology of metabolic alkalosis.
4, clinical manifestations of hypokalemia, ECG icon: lower wave low level, U wave, severe ST segment decline and T wave inversion.
Diagnosis
Diagnosis and differential diagnosis of metabolic alkalosis in the elderly
Diagnostic criteria
The diagnosis is mainly based on blood gas analysis and hematuria electrolyte results. According to the medical history, plasma pH and PCO2, it is not difficult to identify with respiratory acidosis. When alkali is used, HCO3- increases by 10mmol, and PCO2 increases by 0.8kPa (6mmHg). The PCO2 is outside this range, suggesting that there may be a combination of respiratory acidosis.
Once diagnosed as alkaloids, it should be determined according to the concentration of urinary chlorine (Cl-) to determine whether it is a chlorine-sensitive base or a chlorine-resistant base. Chlorine-sensitive alkali chloride concentration is often significantly reduced, generally below 25mmol/L ( Except for diuretics, the concentration of chlorine-resistant alkali chloride is more than 40mmol/L. If it is chlorine-resistant alkali, it is necessary to determine plasma renin activity and aldosterone level to determine the cause, renin activity and The highest level of aldosterone, suggesting renal artery stenosis, renin or malignant hypertension; low are those suggesting Cushing disease, taking mineralocorticoids; renin activity is significantly reduced and aldosterone levels are significantly elevated, should consider the primary Hyperaldosteronism.
Differential diagnosis
It is not difficult to identify metabolic alkalosis and other types of simple acid-base balance disorder by blood gas analysis, but the existence of mixed acid-base balance disorder such as metabolic alkalosis combined with metabolic acidosis, metabolic alkalosis combined with respiratory alkali Poisoning, metabolic alkalosis combined with respiratory acidosis, must pay attention to identification, such as chronic hypercapnia patients often complicated by metabolic alkalosis, HCO3-increased in chronic hypercapnia is the body's compensation, metabolic alkalosis When the increase of PaCO2 is also the compensation of the body, the patient is metabolic alkalosis or metabolic alkalosis with chronic hypercapnia. The simplest identification method is to treat metabolic alkalosis, then review PaCO2, if PaCO2 continues Increased, suggesting that patients with hypercapnia or respiratory acidosis, in addition, the calculation of (Aa) oxygen gradient is also helpful in diagnosis (normal value of 0.67 ~ 2.00 kPa; 5 ~ 15mmHg), due to chronic respiratory acidosis patients ( Aa) The oxygen gradient is often elevated. Calculating the (Aa) oxygen gradient value, if normal, indicates primary metabolic alkalosis, but the (Aa) oxygen gradient is not increased. It is definitely chronic hypercapnia or respiratory acidosis, because many acute and chronic lung diseases can have (Aa) increased oxygen gradient without carbon dioxide retention without hypercapnia, hypercapnia The degree is also helpful in determining whether patients are accompanied by chronic respiratory acidosis. In general, metabolic alkalosis is not more than 7.33 to 8.00 kPa (55-60 mmHg) in the absence of hypercapnia, ie, respiratory acidosis. rare.
