Human dehydration refers to the phenomenon that the human body loses a large amount of water and Na, causing a serious reduction in extracellular fluid. When dehydrating, clinical dehydration is often divided into three types according to the level of serum sodium concentration: isotonic dehydration, hypotonic dehydration and hypertonic dehydration.
1. Hypertonic dehydration is also called water-deficiency dehydration, that is, more water is lost than salt is lost. This situation is mostly caused by high temperature, excessive sweating or high fever, which leads to a large amount of water loss and failure to replenish it in time. Because the osmotic pressure of extracellular fluid increases and the secretion of antidiuretic hormone increases, patients have obvious symptoms such as thirst and oliguria. Patients with milder hypertonic dehydration can be relieved if they drink water early. In severe cases, the patient can be treated by instilling a glucose solution with a mass fraction of 5.
2. Hypotonic dehydration is also called salt-deficient dehydration, which means that the salt loss is more than the water loss. This situation is mostly caused by severe vomiting, diarrhea, massive bleeding or extensive burns, etc., resulting in a large loss of water and salt and failure to replenish it in time. As the osmotic pressure of extracellular fluid decreases and the secretion of antidiuretic hormone decreases, the patient's urine output increases and there is no thirst, which easily creates the illusion that there is no dehydration. This condition can be treated by infusing the patient with saline.
3. Isotonic dehydration is also called mixed dehydration, that is, the degree of water loss and salt loss is almost the same. This type of dehydration is the most common clinically. For example, dehydration caused by vomiting and diarrhea mostly falls into this category. This situation can be treated by injecting normal saline and a glucose solution with a mass fraction of 5 into the patient.