What is the osmotic pressure of plasma crystals in mmHg

The normal range of plasma crystal osmotic pressure is 280-310 mmHg, mainly influenced by the concentration of solutes such as electrolytes, glucose, and urea in the plasma.

1. Electrolyte concentration:

Sodium ions are the most important electrolyte for maintaining plasma crystal osmotic pressure, with a normal concentration of 135-145 mmol/L. For every 10mmol/L increase in blood sodium, the osmotic pressure increases by approximately 20mmHg. Potassium, calcium, and chloride ions also participate in regulation, but their impact is relatively small. When dehydration and adrenal cortex dysfunction occur, electrolyte imbalance can lead to abnormal osmotic pressure.

2. Glucose levels:

For every 5.6mmol/L increase in blood glucose, osmotic pressure increases by approximately 1.6mmHg. When blood sugar in diabetes patients increases significantly, hyperosmolar state may be triggered. It is necessary to distinguish the effect of stress hyperglycemia and diabetes hyperglycemia on the results.

3. Urea nitrogen content:

Urea, as a small molecule metabolite, can freely pass through the cell membrane. Although it is included in the calculation of osmotic pressure, its effect on the pressure difference inside and outside the cell is limited. Urea accumulation during renal insufficiency can increase the measured osmotic pressure, but the effective osmotic pressure may be normal.

4. Other solute effects: In abnormal situations such as methanol poisoning, infusion of mannitol, etc., exogenous small molecule substances can significantly increase osmotic pressure. Abnormal protein increase in patients with multiple myeloma may also lead to abnormal osmotic pressure measurements, which should be combined with clinical judgment.

5. Osmotic gap: If the difference between the measured value and the calculated value exceeds 10mOsm/kg, it indicates the presence of unmeasured solutes, which is common in poisoning cases. The increase in osmotic pressure gap is an important clue for diagnosing alcohol poisoning and ketoacidosis, which needs to be comprehensively evaluated in combination with blood gas analysis.

Maintaining normal plasma osmotic pressure requires a daily intake of 1500-2000ml of water, and timely supplementation of electrolyte containing beverages after exercise. Individuals with abnormal heart and kidney function should adjust their water intake plan under the guidance of a doctor to avoid blind water restriction or excessive drinking. Regular physical examination shall be carried out to monitor electrolyte, renal function and other indicators. In case of abnormalities, timely medical treatment shall be conducted to check metabolic diseases such as diabetes and diabetes insipidus. It is recommended that workers in high-temperature environments supplement 200ml of diluted saline water every 2 hours to prevent dehydration and osmotic pressure imbalance.