The Royal Marsden Hospital Manual of Clinical Nursing Procedures - Lisa Dougherty [410]
Nurses must be aware of the physical and psychological comfort of the patient (Hoeltke 2006). They must appreciate the value of adequate explanation and simple measures to prevent the complications of venepuncture, such as haematoma formation, when it is neither a natural nor acceptable consequence of the procedure (Hoeltke 2006).
The number of litigation cases within the healthcare environment has increased in recent years (Garza and Becan-McBride 2010). It is therefore vital that nurses receive accredited and appropriate training, supervision and assessment by an experienced member of staff (RCN 2010). The nurse is then accountable and responsible for ensuring that skills and competence are maintained and knowledge is kept up to date, in order to fulfil the criteria set out in the The Code (NMC 2008a).
Preprocedural considerations
Safety of the practitioner
It is recommended that well-fitting gloves are worn during any procedure that involves handling blood and body fluids, particularly venepuncture and cannulation (ICNA 2003, NHS Employers 2007, RCN 2010). This is to prevent contamination of the practitioner from potential blood spills. Whilst it is recognized that gloves will not prevent a needlestick injury, the wiping effect of a glove on a needle may reduce the volume of blood to which the hand is exposed, thereby reducing the volume inoculated and the risk of infection (ICNA 2003, Mitchell Higgs 2002, NAO 2003). However, there is no substitute for good technique and practitioners must always work carefully when performing venepuncture.
A range of safety devices are now available for venepuncture which can reduce the risk of occupational percutaneous injuries amongst healthcare workers, in particular vacuum blood collection systems (Centers for Disease Control and Prevention 1997). Used needles should always be discarded directly into an approved sharps container, without being resheathed (Garza and Becan-McBride 2010, RCN 2010). Specimens from patients with known or suspected infections such as hepatitis or human immunodeficiency virus (HIV) should have a biohazard label attached. The accompanying request forms should be kept separately from the specimen to avoid contamination (HSE 2003). All other non-sharp disposables should be placed in a universal clinical waste bag.
Equipment
Tourniquets
There are several types of tourniquet available. A good-quality, buckle closure, single hand release type is most effective but the choice will depend on availability and operator. Consideration should be given to the type of material and the ability to decontaminate the tourniquet (Golder et al. 2000, RCN 2010). Disposable tourniquets are available for single use and should be discarded immediately after use (Warekois et al. 2007).
Needles
The intravenous devices commonly used to perform a venepuncture for blood sampling are a straight steel needle and a steel winged infusion device. The optimum gauge to use is 21 swg (standard wire gauge), which measures internal diameter: the smaller the gauge size, the larger the diameter. Standard wire gauge measurement is determined by how many cannulas fit into a tube with an inner diameter of 1 inch (2.5 cm), and uses consecutive numbers from 13 to 24. This enables blood to be withdrawn at a reasonable speed without undue discomfort to the patient or possible damage to the blood cells.
Vacuum systems
A vacuum system consists of a plastic holder which contains or is attached to a double-ended needle or adaptor. It is important to use the correct Luer adaptor to ensure a good connection and avoid blood leakage (Garza and Becan-McBride 2010). The blood tube is vacuumed in order to ensure that the exact amount of blood required is withdrawn when the tube is pushed into the holder. Filling ceases once the tube is full, which removes the need for decanting blood and also reduces blood