Magnesium excess
Introduction
Introduction to Magnesium Magnesium hypertrophy is a rare biochemical abnormality, and renal damage is the most important cause of high blood magnesium. However, most of the symptoms of magnesium deficiency are related to the use of magnesium-containing drugs. Mainly in patients with renal insufficiency, urinary magnesium excretion is reduced, causing hypermagnesemia. Occasionally, in the treatment of eclampsia with magnesium sulfate, high blood magnesium can occur in mothers and children. Early burns, extensive injury or surgical stress response, severe extracellular fluid deficiency, and severe acidosis can also cause elevated serum magnesium. basic knowledge The proportion of sickness: 0.002% - 0.006% Susceptible people: no special people Mode of infection: non-infectious Complications: constipation, urinary retention, chronic heart failure, cardiogenic shock
Cause
Cause of magnesium hyperactivity
Acute or chronic renal failure is more common, but in general, patients with renal failure have hypercalcemia of magnesium, which can still maintain normal or normal high levels, and no symptoms caused by hypermagnesemia. If excessive intake (such as the use of antacids) or excessive access to the body through other means (such as intramuscular injection of magnesium sulfate, etc.), there may be significant hypermagnesemia and symptoms. In addition, thyroxine can inhibit renal magnesium reabsorption and promote urinary magnesium excretion, so some patients with mucinous edema can develop hypermagnesemia. Aldosterone also inhibits renal tubular magnesium reabsorption and promotes urinary magnesium excretion, so patients with Addison may have hypermagnesemia.
Prevention
Magnesium prevention
When using magnesium-containing drugs, the serum magnesium concentration should be checked regularly to avoid magnesium deficiency. After the diagnosis of hypermagnesemia is established, the cause should be actively sought, if it is caused by iatrogenic factors. The application of magnesium-containing drugs or preparations should be stopped immediately.
Complication
Hypermagnesia complications Complications constipation urinary retention chronic heart failure cardiogenic shock
Common complications of this disease:
1, the reflection disappears
2, cardiac conduction dysfunction
3, respiratory depression
4, cardiac arrest
Hypermagnesemia can inhibit myocardial contractility, leading to cardiac insufficiency or cardiogenic shock. High concentrations of magnesium can inhibit conduction in the atrioventricular and intraventricular, and reduce myocardial excitability, which can cause conduction block and bradycardia. The prolongation of the PR interval and the widening of the QRS complex wave can be seen on the electrocardiogram.
5. Effect on smooth muscle Magnesium also inhibits smooth muscle. Inhibition of vascular smooth muscle during hypermagnesemia can dilate small arteries, arterioles, etc., resulting in decreased peripheral resistance and decreased arterial blood pressure. Inhibition of visceral smooth muscle can cause symptoms such as hernia, vomiting, constipation, and urinary retention.
Symptom
Symptoms of Magnesium Hyperactivity Common symptoms Drowsiness, reflexes, disappearance, coma, respiratory depression, hyperkalemia
When the serum magnesium concentration is >2mmol/L, symptoms and signs of magnesium excess will occur, mainly including fatigue, fatigue, loss of tendon reflex and blood pressure drop. When serum magnesium is further increased, cardiac conduction function is impaired, and ECG shows PR. Prolonged period, QRS broadening and T wave elevation, similar to ECG changes in hyperkalemia, respiratory depression, lethargy and coma, and even cardiac arrest in the advanced stage.
Examine
Magnesium hyperactivity check
Laboratory inspection:
1. Increased serum magnesium concentration (sera magnesium > 1.25mmol / L) can directly diagnose hypermagnesemia.
2.24h urinary magnesium elimination is of great help in diagnosing the cause. If the amount of loss is reduced, it is caused by renal factors, endocrine factors, and metabolic factors, otherwise it is caused by increased intake or abnormal distribution.
Other auxiliary inspections:
1. Electrocardiogram examination showed conduction block and bradycardia. The electrocardiogram of hypermagnesemia showed prolongation of PR interval, QRS broadening and prolongation of QT interval. Because high blood magnesium is often accompanied by high blood potassium, high-point T waves can occur.
2. B-ultrasound early detection of renal organic changes.
Diagnosis
Diagnostic identification of magnesium deficiency
Judgment can be made based on medical history, clinical performance and laboratory data.
Mild hypermagnesemia, symptoms and signs are often absent, easy to be ignored, for patients with magnesium, especially with renal insufficiency should pay attention to monitoring blood magnesium concentration, combined with uranium determination, primary basis Diagnosis and differential diagnosis of the disease. Slightly elevated serum magnesium, non-specific symptoms such as loss of appetite, nausea, skin flushing, headache, etc., are easily ignored. Once serum [Mg2+]>2mmol/L, it may cause respiratory depression and cardiac arrest.
This disease should be differentiated from hyperkalemia.
