Venepuncture in adults

Venepuncture is a vital procedure that is routinely used in the care and management of patients, and it is one of the most commonly performed invasive procedure (Boyd, 2013). It enables health professionals to obtain a sample of blood for analysis by the puncture of a vein with a hollow-bore needle, vacuum system or butterfly infusion system (Thomas, 2015).

These investigations typically include biochemical testing to analyse certain parameters, such as potassium and sodium levels, haematology tests to determine blood measurements (for example, full blood count (FBC)), and microbiology tests to determine the presence of pathogens (Gallagher, 2015). As this is a procedure that nurses may be asked to perform as part of their role, it is essential that they are adequately trained, competent in using the correct technique and aware of any advances or changes in the underpinning evidence (Nursing and Midwifery Council (NMC), 2018).

Informed consent and patient

Choosing the correct site and vein

Although the arm is the most commonly used site for venepuncture, it is important to assess the most appropriate site for an individual patient. Factors that influence the decision include patient preference, past medical history, age, current comorbidities, skin condition, vein suitability and accessibility and reasons for use (Infusion Nurses Society, 2016). Additionally, it is essential to consider which arm or limb to use, which vein to select within that limb and then which particular site on the skin (Table 1).

There is a wide variety of hollow-bore needles and vacuum systems available for venepuncture; therefore, it is imperative that you familiarise yourself with the equipment that is used by your trust. Box 1 gives an example list of the equipment required.

Box 1. Equipment

• Gloves
• Apron
• Alcohol gel
• Procedural tray
• Disposable tourniquet
• Alcohol-based cleansing product
• Needle
• Tube holder
• Vacuum collection tubes
• Sterile gauze
• Dressing or adhesive tape
• Sharps disposal bin
• Request forms (signed, dated and labelled)
• Pillow (Dougherty and Lister, 2015)

Vacuum collection tubes and order of draw

Traditionally, blood samples were obtained by needle and syringe, but advancements in technology and medical devices have led to this being superseded by vacuum collection tube systems (Blann and Ahmed, 2014). These glass or plastic tubes have a partial vacuum, which encourages the movement of blood from the vein into the tube, and the level of vacuum will determine the amount of

Site preparation

The latest guidelines from the Infusion Nurses Society (2016) state that skin antisepsis should be performed prior to all venepuncture procedures to prevent the risk of infection.

The site can be prepared with a cleansing agent that is alcohol based, such as 70% isopropyl alcohol or 2% chlorhexidine in 70% alcohol (Loveday et al, 2014). The skin should be prepared in accordance with the manufacturers' instructions, which will be specific to the product being used.

Procedure for venepuncture

As health professionals, it is important to work within guidelines and policies, and use evidence-based practice (NMC, 2018). The use of standard aseptic non-touch technique (ANTT) for preparation and performance of the procedure can minimise the risk of contamination and risk of infection (Loveday et al, 2014).

The first step is to communicate with the patient, gain informed consent and ascertain preferences, allergies and fears. Following this, the step-by-step procedure

Some of the common problems encountered when undertaking venepuncture, and steps that can be taken to address these are outlined in Box 2.

Box 2. Common errors and how to correct them

• Missed vein: ensure you use your fingers to anchor the vein. This will stop it from moving and will also stretch the skin for better visibility. If you also choose one of the largest veins, then the likelihood of missing it will be reduced
• Blood spray: ensure you advance the needle tip far enough into the vein, if the tip has entered before the rest [of the needle] has advanced under the skin, you have achieved only partial needle insertion, and leakage may occur. Avoid superficial veins to help reduce the chances of this occurring
• Blood stops flowing: this is probably due to the angle of insertion, or if the tip of the needle has made contact with

Conclusion

Venepuncture to obtain a blood sample is a common invasive procedure undertaken by nurses. Nurses have a responsibility and a duty of care to undertake this in a safe, competent, professional manner and to provide reassurance for patients.

References

Blann A, Ahmed N. Blood science: principles and pathology. Chichester: Wiley; 2014 

Boyd C. Clinical skills for nurses. Chichester: Wiley; 2013 

Brooks N. Venepuncture and cannulation: a practical guide. (2nd edn). Keswick: M&K Update; 2017 

Chinn A. Specimen collection. In Perry AGPotter PAOstendorf WR, eds. Clinical nursing skills and techniques. (8th edn). St Louis (MI): Mosby/Elsevier; 2014: 1052–1098 

Dougherty L, Lister S. The Royal Marsden Hospital manual of clinical nursing procedures. (9th edn). Chichester: Wiley; 2015 

Gallagher R. Aseptic technique and specimen collection. In: Delves-Yates C, ed. Essentials of nursing practice. London: Sage; 2015: 403–422 

Higgins C. Understanding laboratory investigations: a guide for nurse, midwives and healthcare professionals. (3rd edn). Chichester: Wiley; 2013 

Infusion Nurses Society. Infusion Therapy: Standards of Practice. Journal of Infusion Nursing. 2016; 39(Suppl 1): S1-S169 

Loveday HP, Wilson JA, Pratt RJ et al.. epic3: national evidence-based guidelines for preventing healthcare-associated infections in NHS hospitals in England. J Hosp Infect. 2014; 86(Suppl 1):S1–S70. https://doi.org/10.1016/S0195-6701(13)60012-2 

McCall RE,