Venipuncture angle

The angle of venipuncture is mainly determined by the patient's physical condition and environment to determine whether the surgery is suitable. In addition, the vein under the skin should be selected to expose the blood vessel before venipuncture can be performed. The angle of venous puncture requires you to use your thumb and index finger to pinch the upper and lower sides of the needle handle respectively. The general angle is about 45 degrees, which can reduce the pain caused by venous puncture.

1. Correctly assess the patient and the environment. To assess whether the patient cooperates with the treatment, first give them a warm welcome and provide complete explanations; assess whether the environment is quiet, the light is bright, etc., and reduce the presence of irrelevant personnel. When selecting a vein, be careful to stay away from joints and bony protrusions, and try to avoid skin scars, papules and other skin lesions. The veins in the hands and feet of the elderly, weak people, and patients with chronic diseases are smaller and more superficial, with less subcutaneous fat and poor elasticity, and the blood vessels lack tissue support and are more mobile. Children should pay attention to distinguishing between arteries and veins, and make the distinction based on the appearance of the blood vessels and the presence or absence of pulsation when touched with the fingers. The blood vessels are not clearly displayed, so the veins should be searched patiently and carefully according to the distribution and direction of the blood vessels. Gently massage the local skin to expose the blood vessels. Patting is generally not recommended, especially after the compression cuff is put in place, as patting the local skin may increase the patient's pain. Choose the appropriate infusion set and needle according to the thickness of the blood vessels and treatment needs.

2. There are two ways to hold the needle handle: one is to pinch the upper and lower sides of the needle handle with the thumb and index finger respectively; the other is to hold the front and back edges of the needle handle with the thumb and index finger respectively. Choose according to personal habits. Some people report that the former has a higher puncture success rate.

3. Needle insertion angle: For thick, straight and elastic veins, choose a 40-45° angle to directly enter the skin and blood vessels to relieve pain. When puncturing the radial cephalic vein at the wrist, be careful to reduce the angle to avoid puncturing the nerve. Because the deep surface of the cephalic vein runs along with the radial nerve, if the puncture angle is too large, the nerve can be easily injured. In clinical practice, examples of nerve damage due to venous puncture are common, causing numbness or electric shock-like sensations. The needle should be removed immediately and the drug should be re-injected. It is not advisable to continue inserting the needle or even release the regulator to infuse the drug, as this will cause long-term nerve damage and leave sequelae. For those with poor blood vessel filling, insert the needle into the skin first and then into the blood vessels. Be cautious when there is a feeling of emptiness and no blood return, and consider the movement of small bubbles at the connection between the scalp needle and the hose. If small bubbles move, it proves that they have entered the blood vessel; if they do not move, you can gently squeeze the hose and see the returning blood push a little along the blood vessel. It is common in clinical practice that the access blood vessel is too shallow and the bevel is not fully inserted, resulting in fluid leakage and the need for re-puncture. It has been reported [1] that loosening the fist has no comparable effect on the chance of a needle drawing blood compared to clenching the fist tightly, but loosening the fist can reduce the pain caused by puncture. According to my personal clinical practice, the success rate of Songquan is higher and the pain level is significantly lower. When clenching a fist, the blood vessels are poorly filled and the tension of muscles and skin increases, so the pain increases and the success rate is low. The subcutaneous fat of the elderly is thin, so the needle insertion angle should be reduced; the needle insertion angle should also be small during scalp vein puncture in children, generally around 15~20°, not exceeding 30°. For example, for the median frontal vein, the needle is inserted at a 15° angle to the skin; for the temporal vein, the needle is inserted at a 20° angle to the skin; for the deep scalp veins, the needle is inserted at a 30° angle to the skin. The skin of the elderly is loose, so when tightening the skin, pay attention to the pulling force up, down, left and right, and generally use comprehensive force. Push to the left and right and pull down, with an assistant helping to tighten the skin if necessary. Needle insertion should be quick, steady, accurate, and shallow rather than deep to avoid vasoconstriction due to pain, which may reduce the success rate of puncture. Before inserting the needle, compare the length of the needle body and the blood vessel to determine the length of the needle, and make sure the entire bevel is placed in the blood vessel.

4. Fixing method : In summer, due to the high temperature, the skin is prone to sweating, which affects the viscosity of the tape. If the adhesive tape has good viscosity, it is advisable to fix two horizontal ones and one oblique one, using the principle that a triangle is the most stable. The end of the tape should not be close to the skin to avoid increasing the difficulty of needle removal and reduce pain. If the adhesive tape has poor viscosity, you can also stick it around like a bandage to avoid the needle being displaced due to loose tape. The hose can also be taped with a strip of tape a few centimeters above the puncture. After the pediatric scalp vein puncture is successful, fix the needle handle with your hand or thumb; if the child moves violently, hold the needle with a soft tube. For some elderly patients, in order to prevent the needle from penetrating the subcutaneous tissue and causing fluid leakage due to excessive hand movement on the puncture side, cardboard (both the syringe packaging box and the medicine box can be used) can be used to fix the local area, which is more effective.

5. Needle removal method: Press the needle handle while tearing off the adhesive tape to avoid pulling the needle tip and causing pain. Tear off the tape along the direction of hair growth, and the hair on the back of your hand will grow from the inside to the outside. Therefore, tearing from the inside to the outside can reduce the pain.

pain. After the child's scalp intravenous infusion is completed, the tape should be torn in the direction of hair growth after the needle is removed to reduce the child's crying. After the needle is removed, the cotton end of the cotton swab should be broken off and taped horizontally with a short piece of tape [3]. Press for a while and instruct the child to tear it off after returning home. Avoid prolonged pressure.

In addition, you should also pay attention to the following: keep a positive mood at work, be confident when operating, and complete the work in one go.