What are the techniques for drawing blood gas?

Drawing blood gas is done by piercing the skin with a needle, causing the skin to bleed and then extracting blood. Blood tests can be used to diagnose some physical diseases or whether the body is healthy. Drawing blood gas also requires mastering some skills. When drawing blood gas, a syringe can be used to puncture the inside of the skin, and then blood is gently drawn. After the needle is pulled out, it must be disinfected immediately.

What are the techniques for blood gas extraction ?

Methods: 1. Blood collection methods from radial artery, brachial artery and femoral artery: (radial artery and femoral artery are commonly used, brachial artery and dorsal artery of hand and foot are not commonly used). (1) Draw out 0.2 ml of 6250 U/ml heparin sodium with a syringe, rotate the needle plug to make the heparin evenly adhere to the entire syringe, and push the needle tip upward to push out excess liquid and residual bubbles in the syringe. You can also use a BD arterial blood gas puncture needle to directly draw out.

(2) Select the arterial puncture site, touch the most obvious part of the arterial pulsation, and use iodine cotton swab to disinfect the puncture site (5 cm) and the operator's left index and middle fingers.

(3) Use the index finger and thumb of your left hand to fix the artery (it varies from person to person), hold the syringe in your right hand and puncture the skin at a 40-60 degree angle. If you are taking blood from the femoral artery, insert the needle vertically. If the puncture is successful, the blood will automatically flow into the needle tube and the color will be bright red. 1-2 ml of blood is sufficient.

(4) After drawing blood, remove the needle immediately and insert the bevel of the needle into the rubber stopper to prevent air from entering and affecting the results. If there are bubbles in the syringe, they should be expelled as soon as possible. Gently rotate the syringe and rub it with your hands for 1 minute to fully mix the blood and heparin to prevent blood clotting. Use a sterile dry cotton swab to press the puncture point. The pressure should be such that you can no longer feel the arterial pulse. Press for 10-15 minutes.

2. Take peripheral arterial blood:

(1) Location: The earlobe, fingers and heel arterial blood are commonly used.

(2) Apply local hot compress for 5 minutes before blood collection to make the area slightly congested.

(3) Disinfect the area with 75% alcohol, and quickly pierce the skin about 3 mm with a three-point needle. Do not squeeze the blood with your hands to prevent it from overflowing. Immediately connect a heparinized capillary glass tube, and after the blood is fully absorbed, seal both ends with plasticine. At the same time, press the puncture site with a cotton ball.

Several key points of blood gas analysis test report

For respiratory acidosis and respiratory alkali poisoning, just look at CO2, because CO2 is a gas.

So, is it an acidic or alkaline gas?

We learned in junior high school chemistry that CO2 produces carbonic acid, so it is an acidic gas.

So, the more of it there is, the more acidic it becomes, which is acidosis. The less it is, the less acid there is, which means alkali poisoning.

Its normal value is 40+-5, which is 35~45 mmol/L.

PaCO2>45 is acidosis [excessive acidosis]

HCO3- ion represents metabolic acidosis and metabolic alkali poisoning. It is the opposite of CO2 and is alkaline.

The more HCO3- there is, the more alkaline it is, which is alkali poisoning; the less HCO3- there is, the more acidic it is, which is acidosis.

Its normal value is 22~27mmol/L.

HCO3- >27 is alkali [alkali-rich]