What Is Arterial Blood? Why Does Blood Gas Analysis Usually Use Arterial Blood?

At present, patients with severe patients not only clinically not only are more complicated and serious, but also require frequent blood test analysis for the purpose of treatment. Because each test item has its own standards for the collection of blood, blood gas analysis (BG) can understand the human body's respiratory function and acid -base balance by determining the Hconcentration of human blood and the gas dissolved in the blood by determining the Hconcentration of human blood (mainly referring to CO2, O2) A means of state can directly reflect the function of lung air replacement and its acid -base balance. The specimens adopted are often arterial blood. So, what is arterial blood? Why does blood gas analysis usually use arterial blood?

The difference between arterial blood and vein blood is mainly the concentration of oxygen and carbon dioxide. The color of arterial blood with rich oxygen is bright red and contains more carbon dioxide. The venous blood color is dark red, and ordinary testing venous blood can be used as test indicators. However, due to the deeper position of the arteries, there are many abundant nerve fiber distribution on the blood vessel wall, the pain nerve is more sensitive, it is easy to damage the arterial blood vessels when collecting blood, and it is also easy to use it to use the venous blood. Arterial vascular injury has certain bleeding risk.

The main difference between blood and blood gas analysis is oxygen pressure and oxygen saturation. The arterial blood PAO2 of normal people is between 80 and 100 mmHg, SAO2> 95%; the venous blood PVO2 of normal people is between 35 and 45 mmHg, and SVO2 is about 75%. When the circulation function is not good, the difference between PH, PCO2, HCO3-difference between arteries and central veins will increase, and the prognosis is not good. However, intravenous blood gas analysis can only be used to judge acid -base imbalances and cannot be used to judge respiratory function.

So what preparations should patients make before the analysis of arterial blood gas analysis?

The patient's breathing state should be stable: the patient should be in a stable state before the sampling, keep the patient's calm breathing state, and the ventilation state should also be stable. Tell the patient's sampling steps to avoid unnecessary tension. Patient's tension can cause excessive breathing. Excessive ventilation is one of the main causes of blood errors. It can increase the amount of alveolar ventilation, cause PCO2 to decrease, increase pO2, and increase PO2.