Classification and three stages of perioperative hypothermia
We are very clear about the hazards of perioperative hypothermia. In this article, we will learn about the classification and three stages of perioperative hypothermia.
Perioperative hypothermia is graded as follows:
1. Mild hypothermia: the core temperature is 34℃~35℃, and the patient feels uncomfortable. When the chills appear, the oxygen consumption is accelerated, which makes the patient's condition unstable and enters a dangerous state;
2. Moderate hypothermia: The core temperature is 32°C~34°C, and the patient's physiological function declines. However, within a few hours in the early stage, the body temperature can be recovered by some intervention measures;
3. Severe hypothermia: When the core body temperature is less than 32°C, the body will seriously lose its ability to regulate body temperature and can only passively accept or lose heat, presenting a state that is extremely life-threatening.
The perioperative hypothermia can be divided into three stages: initial rapid cooling, slow linear cooling, and plateau.
1. Initial rapid cooling: It is actually the redistribution of heat. During the first hour of general anesthesia surgery, the core body temperature began to drop. At this time, the thermal balance between peripheral body temperature and core body temperature was broken, and the core body temperature was redistributed to reduce the core body temperature, but the average body temperature and body heat did not change much;
2. Slow linear decline: This stage lasts for 2 to 3 hours. The body temperature declines because the heat loss is greater than the generation, and 90% of the heat is lost through the convection and radiation of the skin;
3. Plateau period: The core temperature stops dropping after 3~5 hours. In fact, the core temperature and the peripheral temperature begin to reach thermal equilibrium. Even if the temperature is kept constant, the body heat content continues to decrease.
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