Circulation - Venepuncture
Indications
Venous blood sampling
Contraindications (absolute in bold)
Ipsilateral fistula
Ipsilateral radical mastectomy
Overlying infection
Phlebitis or thrombosis
Burns
Sclerosis
Alternatives
Blood test not required
Arterial sampling
Informed consent
Verbal consent
Less complex non-emergency procedure with low risk of complications
Potential complications
Pain
Vasovagal reaction on insertion (syncope)
Failure (to obtain sample, haemolysis, incorrect filling of vacutainers)
Vessel injury (haematoma, haemorrhage, thrombophlebitis)
Nerve injury
Thrombosis
Infection
Procedural hygiene
Standard precautions
Aseptic non-touch technique
PPE: non-sterile gloves
Area
Any clinical space
Staff
Procedural clinician
Equipment
Kidney dish
Tourniquet (single patient use)
Blood sampling device (e.g. multi-sample needle or butterfly needle)
Vacuum extraction blood tubes
Sterile gauze or cotton wool
Tape
Sharps container
Positioning
Sitting or supine, non-dominant forearm preferred
Inspect forearm starting distally and locate stable, well filled veins away from underlying structures
The preferred site if the cubital fossa, but other sites can be used
Veins of the lower extremities can be used as a last resort or in an emergency
Medication
2ml lignocaine 1% (if local anaesthetic used)
Sequence
Place a tourniquet 5-10cm proximal to venepuncture site
Stroke or tap the vein with your fingers to dilate vein (before skin disinfection)
Consider hanging the arm over the side of the bed or applying a warm compress (if no identified vein)
Using the thumb of the non-dominant hand stretch the skin distally to steady the vein
Insert needle with bevel up at approximately 15 degrees to skin (for superficial veins)
Obtain flashback, flatten the needle and advance slightly into vein
Insert the blood tube (according to the order of draw listed below) with the other hand
Release tourniquet as blood begins to fill the tube (within 1 minute of tourniquet application)
Maintain constant, forward pressure on each blood tube until blood stops flowing (vacuum exhausted)
Cover the venepuncture site with cotton wool or gauze withdraw the needle and apply direct pressure
Post-procedure care
Mix and label blood tubes, and transport for assessment
Apply point pressure to the site of venepuncture for two minutes to minimise bruising (patient may perform)
Advise patient to notify staff of bleeding, pain or swelling
Document insertion
Tips
Dedicate time to optimising patient position and vein palpation to maximise success
Do not touch the planned insertion site after decontamination
Release and reapply tourniquet if applied for more than 1 minute (minimise sampling error)
Inexperienced clinicians should make no more than two attempts at venepuncture except in an emergency
Ultrasound machines and other devices can be useful to assist identifying peripheral veins
Discussion
Blood vacutainers should be drawn in a specific order to minimise sampling error and contamination, the general order is:
Blood cultures
Coagulation (blue)
UEC, LFT, clinical chemistry (yellow then green)
Haematology (pink)
Cross match and group (pink)
Local anaesthetics reduce the pain of insertion and may reduce patient movement, however it can also distort anatomy and itself causes pain. Generally, it is not used for venepuncture, but can be considered on a case by case basis.
Where a patient has a continuous intravenous infusion, blood should be collected from the opposite arm where possible. If the patient has intravenous infusions in both arms, or the other arm cannot be used, blood should be drawn from a vein distal to the infusion, with the tourniquet placed between the IV infusion and the venepuncture site. Accurate basic electrolytes and haematologic values can be drawn from peripheral IV lines when infusions are shut off at least two minutes, at least 5ml of blood is discarded, and tubes are filled to the top to avoid inaccurate bicarbonate readings. Avoid excessive suction on the cannula, which can cause haemolysis.
Peer review
This guideline has been reviewed and approved by the following expert groups:
Emergency Care Institute
Please direct feedback for this procedure to ACI-ECIs@health.nsw.gov.au.
References
World Health Organization. World Health Organization guidelines on drawing blood: best practices in phlebotomy. 2010. 125pp. Available from: https://www.who.int/infection-prevention/publications/drawing_blood_best/en/
Roberts JR, Custalow CB, Thomsen TW. Roberts and Hedges’ clinical procedures in emergency medicine and acute care. 7th ed. Philadelphia, PA: Elsevier; 2019.
Dunn RJ, Borland M, O’Brien D (eds.). The emergency medicine manual. Online ed. Tennyson, SA: Venom Publishing; 2019.
Frank RL. Peripheral venous access in adults. In: UpToDate. Waltham (MA): UpToDate. Accessed June 2019. Available from: https://www.uptodate.com/contents/peripheral-venous-access-in-adults
Nickson, C. Peripheral venous cannulation. Life in the fast lane. 2019. Available from https://litfl.com/peripheral-intravenous-cannula/