Phlebotomy – the drawing of blood – has been practised for centuries and is still one of the most common invasive procedures in health care. Each step in the process of phlebotomy affects thequality of the specimen and is thus important for preventing laboratory error, patient injury andeven death.
Issues in Phlebotomy
If a blood sample is poorly collected, the results may be inaccurate and misleading to the clinician, and the patient may have to undergo the inconvenience of repeat testing. The three major issues resulting from errors in collection are haemolysis, contamination and inaccurate labelling.
Factors that increase the risk of haemolysis include:
• use of a needle of too small a gauge (23 or under), or too large a gauge for the vessel;
• pressing the syringe plunger to force the blood into a tube, thus increasing the shear force
on the red blood cells;
• drawing blood specimens from an intravenous or central line;
• underfilling a tube so that the ratio of anticoagulant to blood is greater than 1:9;
• reusing tubes that have been refilled by hand with inappropriate amounts of anticoagulants;
• mixing a tube too vigorously;
• failing to let alcohol or disinfectant dry;
• using too great a vacuum; for example, using too large a tube for a paediatric patient, or
using too large a syringe (10–20 ml).
Risk for Phlebotomist
Phlebotomy also poses risks for health workers. It is still common to see a phlebotomist carry out dangerous practices known to increase the risk of needle-stick injury and transmission of disease.
Dangerous practices include:
• recapping used needles using two hands;
• recapping and disassembling vacuum-containing tubes and holders;
• reusing tourniquets and vacuum-tube holders that may be contaminated with bacteria and
• working alone with confused or disoriented patients who may move unexpectedly, contributing to needle-sticks.
Phlebotomy involves the use of large, hollow needles that have been in a blood vessel. The needles can carry a large volume of blood that, in the event of an accidental puncture, may be more likely to transmit disease than other sharps. Bloodborne organisms that have been transmitted after needle-sticks include viruses such as hepatitis B and human immunodeficiency virus (HIV), bacteria such as syphilis and parasites such as malaria.
The objectives of these guidelines are to:
• improve knowledge and awareness of the risks associated with phlebotomy among all health workers involved in the practice;
• increase safe practices and reduce bloodborne virus exposure and transmission;
• improve patient confidence and comfort;
• improve the quality of laboratory tests.
Indications for blood sampling and blood collection:
The most common use of blood sampling is for laboratory tests for clinical management and health assessment. Categories that require specialist training include:
• arterial blood gases for patients on mechanical ventilation, to monitor blood oxygenation;
• neonatal and paediatric blood sampling
– heel-prick (i.e. capillary sampling);
– scalp veins in paediatrics;
• capillary sampling (i.e. finger or heel-pricks or, rarely, an ear lobe puncture) for analysis of
capillary blood specimens for all ages; examples include testing of iron levels before blood
donation, blood glucose monitoring, and rapid tests for HIV, malaria and syphilis.
Blood collection is used to obtain blood from donors for various therapeutic purposes.
Assemble equipment :
Collect all the equipment needed for the procedure and place it within safe and easy reach on a tray or trolley. Inspect the integrity of equipment.
. Butterfly set, largest bore suitable for subject’s veins
. Vacutainer holder
. Labeled vacutainer tubes per protocol
. Alcohol swabs
. Clean gloves
. 2×2 sterile gauze pads
. Squeeze ball
Identify and prepare the patient :
Where the patient is adult and conscious, follow the steps outlined below.
1. Check for signed, dated approved consent form, signed physician’s orders, and completed inclusion/exclusion criteria form.
2. Ascertain the subject’s ID, name, date of birth. Assess the subject’s understanding of the study and the procedure to done at this visit.
3. Explain procedure to Patient.
Draw Sample :
Perform venepuncture as follows.• Unless drawing blood cultures, or prepping for a blood collection, clean the site with a 70% alcohol swab for 30 seconds and allow to dry completely (30 seconds).
• DO NOT touch the cleaned site; in particular, DO NOT place a finger over the vein to guide the shaft of the exposed needle. It the site is touched, Repeat the disinfection.
• Perform hand hygiene; that is
– wash hands with soap and water, and dry with single-use towels; or
– if hands are not visibly contaminated, clean with alcohol rub – use 3 ml of alcohol rub on the palm of the hand, and rub it into fingertips, back of hands and all over the hands until dry.
• After performing hand hygiene, put on well-fitting, non-sterile gloves.
• Anchor the vein by holding the patient’s arm and placing a thumb BELOW the venepuncture site.
• Ask the patient to form a fist so the veins are more prominent.
• Enter the vein swiftly and continue to introduce the needle along the vein at the easiest angle of entry.
• Once sufficient blood has been collected, release the tourniquet BEFORE withdrawing the needle. Some guidelines suggest removing the tourniquet as soon as blood flow is established, and always before it has been in place for two minutes or more.
• Withdraw the needle gently and apply gentle pressure to the site with a clean gauze or dry cotton-wool ball. Ask the patient to hold the gauze or cotton wool in place, with the arm extended and raised. Ask the patient NOT to bend the arm, because doing so causes a haematoma.
• When obtaining multiple tubes of blood, use evacuated tubes with a needle and tube holder. This system allows the tubes to be filled directly. If this system is not available, use a syringe or winged needle set instead.
• Discard the used needle and syringe or blood sampling device into a puncture-resistant sharps container.
• Inform the patient when the procedure is over.
• Ask the patient or donor how they are feeling. Check the insertion site to verify that it is not bleeding.