What is Water Intoxication?

When the total amount of water ingested by the body greatly exceeds the amount of discharged water, so that water is retained in the body, causing a decrease in plasma osmotic pressure and an increase in circulating blood volume, it is called water intoxication, also known as dilute hyponatremia. Occurs less clinically. Its symptoms depend on the rate and extent of water excess, and can be divided into two categories, acute water poisoning and chronic water poisoning. To a lesser degree, stop the intake of water and remove excess water from the body, and then you can correct it. In severe cases, you can cause permanent damage to the nervous system or death.

Basic Information

English name: water intoxication
Visiting department: Emergency Department

Common causes: Excessive antidiuretic hormone (ADH) secretion, renal dysfunction, disturbance of water and sodium metabolism, insufficient drainage, hypotonic dehydration
Common symptoms: Dizziness, vomiting, weakness, and rapid heartbeat

Causes of water poisoning

1. Excessive secretion of antidiuretic hormone (ADH)

Excessive secretion of antidiuretic hormone caused by various reasons can be seen in fear, blood loss, shock, acute infections (such as pneumonia, toxic dysentery, etc.), application of analgesics (such as morphine, pethidine), or pain, surgery, etc. Stimulate. The increase in ADH secretion after surgery usually lasts 12 to 36 hours, or longer. In this case, excessive input of a solution containing no electrolyte such as glucose may cause water poisoning. In addition, patients with hypothyroid dysfunction who develop late-stage fluid edema can also increase ADH secretion through the stimulation of baroreceptors, and abnormal release of ADH can also occur during adrenal insufficiency.

2. Renal dysfunction

During the oliguria and anuria phases of acute renal failure, the dilution and concentration functions of the kidneys are impaired. At this time, too much water is taken in and prone to water poisoning. In addition, for any reason, the renal blood flow is insufficient or the amount of glomerular blood perfusion is severely reduced. Excessive water cannot be discharged. In the case of hypotonicity, water poisoning is prone to occur.

3. Too much water

The body intakes too much water, such as the primary polydipsia in patients with chronic mental illness. Certain iatrogenic factors such as excessive intravenous fluids, the use of oxytocin or posterior pituitary. At this time, the amount of extracellular fluid increased significantly, the serum sodium concentration decreased, and the osmotic pressure also decreased, causing too much water to enter the cells.

Clinical manifestations of water poisoning

Acute water poisoning

Acute onset, due to increased intracellular and extracellular fluid, inelasticity of the cranial cavity and spinal canal, and brain cell edema causing symptoms of increased intracranial pressure, such as headache, aphasia, insanity, disorientation, lethargy, restlessness, delirium, and even coma, further development There is a possibility of cerebral hernia, which may cause breathing and cardiac arrest. Severe cases include congestive heart failure, shortness of breath (when pulmonary edema occurs), pleural effusion, congestive hepatomegaly, jugular vein distension, increased pulmonary and central venous pressure, and edema at the crotch or extremities. If the blood sodium drops rapidly below 108mmol / L within 48 hours, it can cause permanent damage to the nervous system or death.

2. Chronic water poisoning

Symptoms are generally not obvious and are often covered by the symptoms of the primary disease. They may be weak, nausea, vomiting, drowsiness, etc., weight gain, pale and moist skin. When the plasma osmotic pressure drops to 240-250mOsm / L (blood sodium 115-120mmol / L), neuropsychiatric symptoms such as headache, drowsiness, confusion, delirium, etc. will occur. When the plasma osmotic pressure drops to 230mOsm / L (blood sodium 110mmol / L), convulsions or coma can be found.

Water poisoning check

1. Plasma osmotic pressure and blood sodium concentration

The most important laboratory indicators of water poisoning are reduced plasma osmotic pressure and reduced dilution of serum sodium. Because the cation that maintains plasma osmotic pressure is primarily sodium, the changes in the two are often consistent. For the onset of water poisoning, the rate of decrease in plasma osmotic pressure and serum sodium concentration is more important than the value of decrease. For example, the serum sodium concentration of patients with acute water poisoning decreased rapidly from 140mmol / L to 120mmol / L within 1-2 days, and the degree of water poisoning was much more severe than that of chronic water poisoning patients whose serum sodium was maintained at 115mmol / L for a long time. Severe hyponatremia can be reduced below 110mmol / L, but if the blood sodium concentration is rapidly reduced by 30mmol / L, death can result.

Blood routine

Due to excess water in extracellular fluid and blood during water poisoning, its hemoglobin, average red blood cell hemoglobin concentration (MCHC) can be reduced, and hematocrit is reduced. When a large amount of water is transferred into the cells, the average red blood cell volume (MCV) can increase.

Water poisoning diagnosis

Based on the medical history and clinical manifestations combined with the necessary laboratory tests, the diagnosis can generally be confirmed. The focus is to determine the cause and extent of water poisoning, as well as the heart, lung, and kidney function status. Should be distinguished from hyponatremia.

Water poisoning treatment

Once water poisoning is diagnosed, water intake should be stopped immediately and the primary disease should be actively treated.

1. Minor limit water intake

Record the amount of water in and out for 24 hours so that the amount of water is less than the amount of urine. Or appropriately add diuretics, preferably diuretics such as inic acid (diuretic acid) and furosemide.

2. Acute and severe excess water and water poisoning

Treatment should aim at protecting heart and brain functions, and aim at dehydration and / or correction of hypotonicity.

(1) Those with high volume syndrome are predominantly dehydrated to reduce heart load. Diuretics such as furosemide or itanilic acid are preferred. For patients with insufficient effective circulating blood volume, pay attention to supplementing effective blood volume. Critical cases can be treated with ultrafiltration. It is clear that those with excessive secretion of antidiuretic hormones can be treated with lithium carbonate and diuretics in addition to etiological treatment. To protect the heart and reduce heart load, vasodilators such as sodium nitroprusside and nitroglycerin can be used.

(2) Patients with hypotonicemia (especially those with neuropsychiatric symptoms) should quickly correct the hypotonic state in the cells. In addition to water restriction and diuresis, 3% to 5% sodium chloride solution should be used to closely observe cardiopulmonary function, etc. Condition changes, dose adjustment and speed adjustment, generally divided supply is appropriate. Diuretics can be used together to reduce blood volume. Pay attention to correct potassium metabolism disorders and acidosis.