Increased osmotic pressure of extracellular fluid

Introduction Increased extracellular fluid osmotic pressure is a clinical manifestation of hypertonic dehydration. Hypertonic dehydration refers to the simultaneous loss of water and sodium, but the lack of water is more than the lack of sodium, so the serum sodium is higher than the normal range, and the extracellular fluid is hyperosmotic. When the lack of water is more than the lack of sodium, the extracellular fluid osmotic pressure increases, the secretion of antidiuretic hormone increases, the reabsorption of water by the renal tubules increases, and the amount of urine decreases. Aldosterone secretion increases, and sodium and water reabsorption increases to maintain blood volume. If the water shortage continues, the extracellular fluid osmotic pressure is further increased, and the intracellular fluid is moved to the outside of the cell, and finally the degree of water shortage in the cell exceeds the degree of water shortage in the extracellular fluid. Water shortage in brain cells will cause brain dysfunction.

Cause

The main causes are:

a. Insufficient intake of water, such as trauma, coma, difficulty in swallowing esophageal diseases, can not eat, critically ill patients with insufficient water supply, nasal feeding hypertonic diet or infusion of a large amount of hypertonic saline solution.

b. Excessive water loss, not timely replenishment, such as high fever, excessive sweating, extensive burns, tracheotomy, prolonged visceral exposure during thoracoabdominal surgery, and diabetes coma.

an examination

Related inspection

Plasma osmotic pressure (POP)

Urine test

The urine has a high specific gravity.

2. Serological examination

The increase of serum sodium was more than 150mmol/L; the red blood cell count, hemoglobin and hematocrit were slightly increased.

Differential diagnosis

Differential diagnosis of extracellular fluid osmotic pressure:

Dehydration of brain cells: Increased osmotic pressure of extracellular fluid can cause a series of symptoms of central nervous system dysfunction, including lethargy, muscle twitching, coma, and even death. It belongs to hypertonic dehydration. When the brain volume is significantly reduced due to dehydration, the vascular tension between the skull and the cerebral cortex increases, which can lead to rupture of the vein and local intracerebral hemorrhage and subarachnoid hemorrhage.

Diagnosis: According to different symptoms, hyperosmotic water deficiency is generally three degrees:

Mild water shortage: Except for thirst, there are no other symptoms. The amount of water shortage is 2% to 4% of body weight.

Moderate water shortage: extreme thirst, with fatigue, low urine, and high urine weight. Dry lips, poor skin elasticity, eye sockets, often irritated. The water shortage is 4% to 6% of body weight.

Severe water shortage: In addition to the above symptoms, there are symptoms of brain dysfunction such as mania, hallucinations, slang, and even coma. The amount of water shortage is more than 6% of body weight.

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