Venipuncture, also called venepuncture or venopuncture, is the process of drawing blood via intravenous access. Venipuncture is one of the most common invasive medical procedures. It is carried out for two reasons, to get blood for a medical diagnosis or to monitor blood component levels. Blood analysis is an extremely important diagnostic tool in clinical healthcare. The data of such blood samples is relied upon to interpret a range of clinical signs and symptoms. So a good Phelobotomist must develop excellent venipuncture skills to facilitate in the timely treatment of patients.
Common Venipuncture Techniques
- In patients who are obese or have dark skin, it may be very difficult to see or feel for the presence of a vein. You should use a penlight next to the skin. Under that intense light, the vein should show up in red.
- When searching for the vein, make sure to clearly identify whether it has a pulse. If it has a pulse, then it is an artery and not a vein and you should avoid it. You should also avoid veins with valves as this complicates the blood extraction process.
- For young patients, Lidocaine Iontophoresis is an effective method for reducing pain and alleviating distress during venipuncture. However you must still make every effort to relax and calm the children such that they are not unduly frightened by the needle and harm themselves during the extraction process.
- Avoid performing Venipuncture on an arm with an IV attached. Also avoid the arm on the side of the body which has recently received a mastectomy.
Common Venipuncture Extraction Tools
- For patients with normal veins, you should use the Evacuated Tube method of blood collection. The tubes in which blood is transported back to the laboratory contain a variety of additives or none at all. It is important to know which tube the individual laboratory requires for which test as reagents vary between laboratories and may be affected by different additives.
- Some health care workers use the syringe-needle technique for drawing blood. This is a preferred technique for overweight patients, elderly patients, badly burnt patients, oncology patients, and patients with fragile veins. Since the syringes are operated by hand, it is relatively easy to control the amount of suction applied. This is very useful for patients with small veins that cannot hold up to the suction power of an evacuated tube.
- A butterfly needle is used to draw blood from some patients with small or fragile veins. A butterfly needle is inserted into the vein until blood returns, then it’s small plastic wings are taped down while the blood is drawn out via a small plastic tube. This method can be less painful than both the Evacuated Tube and Syringe-Needle methods.
Common Venipuncture Complications
- Bruising is a very common Venipuncture Complication. When drawing blood from the vein, a small amount of blood is leaked into the surrounding tissues. This causes some temporary discoloration and usually resolves itself within a few days.
- Sometimes, the inserted needle hits a nerve. This causes the patient to experience a painful burning sensation. You should quickly withdraw the needle and find another location. The painful sensations would usually subside within several minutes.
- Some patients may have an extreme phobia to the needle. You should carefully review the patient’s past venipuncture history and cautiously proceed to draw blood in a manner that is relatively calm and relaxing to the patient.
- Patients with fragile veins may experience a vein blow. This occurs when you draw blood from a fragile vein, and it leaks a large amount of blood. This can cause significant bruising and swelling of the extraction site. You should quickly remove the needle, disinfect and treat the site. Then you should proceed to find another extraction location.
