? Clinical Skills Venepuncture Clinical Skills and Simulation team Version 1.1 October 2015
Aims and Objectives Aims and Objectives The aim of this module is to facilitate learning regarding the purpose and procedure of venepuncture. Learning Outcomes At the end of this session the student should be able to: Explain the need for venepuncture Identify the need for care in handling blood samples Describe the process and importance of labelling blood samples Demonstrate, to a level expected of the students stage of training, a degree of competence in the procedural steps of venepuncture
Introduction Introduction Venepuncture is a common procedure, performed in order to obtain venous blood for investigative or diagnostic purposes. Results may be compared to an age appropriate range of 'normal' values and to the patient`s previous results. As all blood is potentially infective and sharps are used for this procedure, local guidelines for PPE and disposal of sharps should be followed. This module will focus on the adult patient and as such a medium sized needle (21 gauge, green) is required. This provides the required flow rate so that a moderate amount of blood may be obtained and stored in sample bottles without clotting.
Introduction Introduction There are many blood tests (too many to list here), but fortunately there are far fewer bottles than tests. Some common tests are:- urea and electrolytes full blood count clotting studies cross match (you are NOT permitted to take a blood sample for cross match until you have undergone your blood transfusion training) You must ensure the correct bottle (colour coded bottle top) is used for each test. The volume of blood required per test varies and is marked on the blood bottle itself.
Anatomy Anatomy Veins in the antecubital fossa are most commonly used for venepuncture. They are usually large Little variation in anatomy Less sensitive to pain than other regions However, there are structures in the antecubital fossa that may be damaged if care is not used, these being:- Brachial artery Median nerve
Anatomy Anatomy Brachial artery Lies on the medial side of the antecubital fossa, palpate before performing venepuncture in order to avoid inadvertent puncture. Median nerve Usually centrally located and deep to the veins, so care should be taken to avoid damage to this structure. Most appropriate venepuncture site Lateral side of the antecubital fossa. Ensure the needle is superficial at all times, damage to other structures should be easily avoided.
Anatom Anatomy - Choice of vein in order of preference 1. Median cubital Vein Most prominent vein Well anchored Surrounded by fewer nerve endings 2. Cephalic Vein Runs superficially across outer aspects of arm Lies lateral to the bicep 3. Basilic Vein Close proximity to the brachial artery and median nerve
Sites to avoid Sites to avoid In an arm with IV cannula in-situ. The blood sample will be affected by the composition of the fluids being given via the cannula. If it is unavoidable and you have to use an arm with an IV canula in-situ you may be required to stop the infusion for a short time before taking the sample Avoid using an arm with an arterio-venous fistula present. The fistula is an artificial communication between the artery and vein and provides quick access for dialysis. Damage to this structure may prevent the patient from undergoing dialysis Avoid affected arm in CVA patient (may lack sensation thus potential risk of damaging surrounding structures) Avoid affected side in mastectomy patients Inflammation Infection Ezcema Haematomas
Equipment Equipment Gather equipment including relevant blood bottles Place on clean and stable surface (e.g clean kidney bowl on trolley) Ensure sharps box is within reach Orange Sharps Box Tape Gauze Blood forms Absorbent Sheet Alcohol Gel Ideally use specifically designed tray with area for small sharps box to be attached Gloves It is recommended that blood collection bottles are arranged in the order of draw Vacutainer holder Blood Bottles Tray Vacutainer Needles Tourniquet Alcohol Wipe Butterfly Needle
Order of Blood Draw & Mixing Guide Order of Blood Draw & Mixing Guide Blood collection bottles have a variety of additives within them to allow the laboratory to undertake specific tests TRUST NAME DISPLAYED HERE The tube guide informs you of which bottle to use for each test The order of draw is the order in which the tubes must be filled. If the order is incorrect additives from one bottle can cross contaminate another bottle, subsequently test results may be inaccurate and may need repeating Check number of times the tube should be inverted after filling to ensure correct mixing of blood and tube contents The Trust you work in will be able to provide the current copy of the order of draw
Patient Communication Patient Communication I C Check Introduce yourself Give your name, clinical title and the reason why you have come to see the patient (e.g. Hello my name is.. I am a junior doctor and ) patient identification Check addressograph details on request form with the patient Ask the patient, if they are able, to tell you their: full name, date of birth & address If an in-patient check hospital ID band with request form E Explanation Explain procedure to patient, include reason for the procedure and any discomfort that may be experienced. Include benefits, risks, what will be done to minimise risks and why the benefits outweigh the risks
Patient Communication Patient Communication BENEFITS RISKS ACTION TO MINIMISE RISK Informed Consent Gain verbal informed consent Obtain sample to aid diagnosis Obtain sample for comparison with previous results to monitor progress Wash hands, apply PPE and gather equipment Infection Pain/discomfort Bruising Not being able to obtain sample Using a technique which includes good skin cleaning preparation Having a competent practitioner to perform the procedure Applying pressure and keeping a straight arm after needle withdrawal Take time in choosing site and will refer to more senior colleague if unsuccessful
Position your patient Patient should be sitting or lying down. You will need to ascertain how the patient feels about blood being taken, some may feel Faint Dizzy Or may be needle phobic If the patient has previously experienced any of the above or thinks that they may, it is advisable to lie them down. Ensure that you have adequate lighting.
Apply a disposable tourniquet to the upper arm (may be applied over clothing for comfort) a few inches above the antecubital fossa. The pressure on the arm should be between the systolic and diastolic, so that the veins in the arm distend It is usual practice to check arm preference with patient Consider using the non-dominant arm as there may be discomfort experienced following the procedure If patient has difficult veins to bleed the patient may be able to advise on the best vein to use The arm should be below the level of the heart to help the veins fill
Palpate suitable vein The vein should be easy to palpate, and should refill rapidly when compressed *SEEK SENIOR SUPPORT IF UNABLE TO LOCATE A VEIN OR UNSURE WHICH SITE TO USE* Once site selected undo tourniquet to minimise time pressure applied
Unable to Find a Vein What to do if you are unable to find a vein Check all sites and take your time Check both arms and hands if necessary. Take your time in choosing your site before needle insertion. It is better to choose the optimal site the first time to minimise the chance of having to repeat the procedure. Tap Gently tapping the area releases local histamines which leads to vasodilation and make veins more prominent. Clench hand into a fist Ask the patient to make a fist with their hand and release. Repeat a few times. This causes the muscles to contract and relax, and acts as a pump forcing blood into the veins. Be aware that fist clenching with venous occlusion can cause a false raised potassium measurement which may mask hypokalaemia in the patient. Warm If the patient is cold the veins may constrict and be more difficult to bleed. Either wait until they warm up or apply a warm compress to assist vasodilation making the veins easier to see and palpate. Hydrate If the patient is even mildly dehydrated the circulating volume will be reduced and thus veins may be harder to see and palpate.
Venepuncture Assemble equipment by removing the white cap from needle. This end attaches to the vacutainer holder and punctures the vacutainer bottles Remember that a sharp needle is under the soft grey covering. Be aware of risk of needle stick injury Insert this end into plastic vacutainer holder and screw into place. Do NOT remove needle sheath until you are ready to insert needle into patient`s vein
Venepuncture Place a pillow and absorbent sheet under patient`s arm Re-apply tourniquet Prepare skin by cleaning the area overlying the vein with an alcohol wipe. Skin should be in contact with disinfectant for 30 seconds. Use an outward spiralling motion starting from intended puncture site Allow to dry for a further 30 seconds Refrain from palpating the vein once the area has been cleaned If you do need to re-palpate you must re-clean the skin
Venepuncture Create skin traction by anchoring vein with your thumb below the proposed insertion site Insert needle with the bevel upwards, through the skin towards the vein at an angle of 35-40
A loss of resistance will be felt when the needle enters the vein Advance needle tip 1-2mm into vein, and reduce the angle with the skin Do NOT dig with your needle. You may advance and retract if you are in the incorrect position. However, if the needle is removed completely you MUST use new equipment NOTE: If you are unsuccessful at introducing the needle into the vein you need to use a new needle for a second attempt and a different site. The generally accepted rule is that each practitioner may have a maximum of 3 attempts before referring to a senior colleague. This depends on the situation, the patient`s condition and consent.
Push blood sample bottle, colour top end first into the vacutainer holder. Ensure you firmly hold the vacutainer holder so that the action of pushing on the bottle does not advance the needle further The needle will pierce the self sealing bung on the top of the bottle, and blood will suck into the bottle due to the vacuum Keep in place until blood ceases to flow. Bottles fill until they have the required amount of blood or until the blood flow stops, e.g. the needle is dislodged Carefully remove blood bottle and gently invert tube the correct number of times
Repeat with other sample bottles if required. Ensure correct order of draw Remove tourniquet from arm Remove final blood bottle from vacutainer
Withdraw needle from vein. Once fully removed press on puncture site with a gauze swab
Hold gauze swab on puncture site for 30-60 seconds. The patient can do this if they are able and happy to do so To minimise bruising keep elbow straight Patients with clotting problems, may need to press for a longer duration If patient has bled through the gauze apply a new swab. Apply tape to the gauze to secure it before leaving the patient
Dispose of sharps immediately and safely into a sharps box Dispose gloves and apron into a clinical waste bag, as per hospital policy Return unused equipment and clean your tray/trolley Wash your hands Label blood sample bottles while you are with patient Place blood bottles into clear bags of appropriate request forms, seal and send directly to laboratory
Documentation You must document the procedure in the patients medical notes. Your entry must include: Date & time Verbal consent obtained Site used Equipment used e.g vacutainer system, butterfly needle Number of attempts Type of samples obtained. As a student it is advisable to note who requested the samples Problems or complications Advice given to patient Your signature, job role and bleep/extension number. If you work in a Trust which provides staff ID stamps you must also add this
Tips Tips Once the vein is punctured keep the non-dominant hand as still as possible. Even slight movement will displace the needle from the vein. This is more of a problem if large volumes of blood are required. If you find this difficult, try using a Butterfly to aspirate the blood. This is a small needle with side flaps which give an appearance of a butterfly and it has attached tubing running from the needle. The needle can be fixed to the skin via the plastic Butterfly, which enables both hands to be freed up for attachment of the blood bottle to the vacutainer without needle displacement. For some samples (notably calcium estimates), a tourniquet should not be used during blood aspiration. Plasma calcium is largely bound to serum albumin, which concentrates in venous blood when a tourniquet is applied. This may lead to an over-estimation of the plasma calcium levels. Use the tourniquet to identify the vein, insert the needle, then release the tourniquet before aspirating the blood. You are more likely to be successful if the arm is below the level of the heart, allowing gravity to dilate the arm veins.
Other Important Things Other Important Things Four important things the WHO does not want us to do. 1. Re-sheath a used needle with two hands i.e. holding sheath in one hand and needle in the other. 2. Recap used vacutainer needles and disassemble them from the holder. 3. Re-use tourniquets and vacutainer holders. 4. Work alone with patients who may move unexpectedly and thus increase the risk of needle stick injury e.g. confused patients and paediatric patients. Important things Cardiff University wants you to remember. 1. As medical students you must practice under supervision. 2. Venepuncture is a practical skill that the GMC requires you to do competently. You must be signed off as competent in your practical skills log before graduating. 3. Performing a cross match blood sample is another practical skill that the GMC requires you to do competently before graduating. However you must successfully undertake your blood transfusion training before performing this procedure.
Video Summary Video Summary (Not available in PDF)
Checklist Checklist Introduce yourself, explain procedure to the patient and seek consent Apply tourniquet to upper arm Select vein Apply gloves and apron Clean patient s skin carefully using appropriate preparation and allow to dry Do not re-palpate vein or touch skin at puncture site Create skin traction by anchoring vein with your thumb below the proposed insertion site Insert needle smoothly at an angle of 35-40 Level off needle when puncture of the vein wall is felt If possible, advance needle a further 1-2 mm into vein Do not exert pressure on needle. Withdraw required amount of blood using Vacutainer system Release tourniquet Place sterile gauze swab over puncture point
Checklist Checklist Do not apply pressure until needle is fully removed Apply pressure until bleeding stops Invert tubes to allow adequate mixing Label bottles with relevant details Inspect puncture point before applying dressing. Check for known allergies Apply adhesive plaster or alternative dressing Discard waste in correct containers, e.g. sharps into sharps box Wash hands
References References World Health Organisation (2010) WHO guidelines on drawing blood: best practices in phlebotomy http://www.who.int/injection_safety/phleb_final_screen_ready.pdf Akunjee et al (2012) Clinical Skills Explained Cambridge: Scion Publishing Ltd