by marie on March 24, 2017 - 3:26pm
There are several medical analysis that can be carried out to diagnose diseases, to assess the function of the organs in the body and to check whether the drugs are therapeutic or not. One of the most common methods is venipuncture. Venipuncture is a medical technique which consists of withdrawing samples of blood from a vein. The technique can be carried out by following several steps. This techniques can be done by any professional who has received the training. To obtain blood samples, requires a good and a proper preparation of the materials and the patient.
Preparation of Materials and Patient
To begin, the health professional needs to clean their hands and to together the following materials:
Needles that fit into the vacuum tube holder
Vacuum tube holder
Tourniquet- strip of elastic to make vein palpable
Alcohol pad for disinfection
Once all the materials are ready, the professional must identify the proper patient for the blood withdrawal. He must introduce himself, explain the technique and make the patient feel at ease for good collaboration. The patient can de positioned in a sitting or lying position. Venipuncture is done from the vein of the arm. The patient should have has breast surgery on the side of the chosen arm. Also no scars should be present on the site of the insertion of the needle. Then after an arm is chosen, it is placed on the armrest or on the bed in a straight position. The tourniquet is placed 10 cm above the elbow to make the vein more visible or palpable. After locating a prominent vein, the tourniquet is loosened so as not to cause blood cell destruction.
Steps of Venipuncture
To continue the health care professional wears his gloves ad follows the steps below:
• The puncture site is cleaned using the alcohol pads. The cleaning is done in a circular motion from the center to the periphery and is allowed to dry for 30 seconds.
• While the cleaning site is drying, the needle, the vacuum tube holder and the collecting tube are assembled.
• The tourniquet is tightened so as to make the insertion of the needle easier.
• After the site is dried, the tourniquet is tightened and the needle is ready, the skin is drawn tight by placing the thumb 5-7 cm below the venipuncture site. This allows the stabilisation of the vein.
• The needle is inserted with the beveled side up at an angle of 30 degree into the vein
• After insertion the blood will start filling the tube, at the sight of the blood, the tourniquet should be loosened.
• Once the tubes are filled, a sterile pad is placed over the venipuncture site. Slowly, the needle is removed and is discarded immediately in the biohazard container.
• A bandage is applied on the sterile pad and the patient can be asked to continue applying a mild pressure to prevent bleeding.
• Then, the blood samples are mixed gently by gently inverting the collection tubes.
• Finally, the collection tubes are properly labelled and are sent to the laboratory.
Sometimes, it can be difficult to obtain a prominent vein. In this case, the patient can be asked to make a fist. This allows accumulation of blood in the veins. Otherwise, a warm towel can be placed on the site so as to dilate the vein. Other difficulty that can be encountered is that even if the needle is well-inserted into the vein, the blood does not flow in the tube. This can be due to the needle which is not deep enough in the vein or too deep into the vein. If it is too deep, we just need to pull and if it is not deep enough we need to push some more. Probing should be avoided.
In conclusion, venipuncture is a technique in which blood samples are collected from a vein by healthcare professional for analysis on the functioning of the body. The technique requires proper materials and patient preparation. It is done by following several steps. It is important to clean the sites so as to have valid samples. If it is difficult to have blood flowing into the tube, pulling or pushing the needle slightly can be the solution. If this is successful, remove the needle, apply a sterile pad and bandage and start again by looking for another vein.