How To Draw Blood With Butterfly

This venepuncture guide provides a pace-by-step approach to performing venepuncture in an OSCE setting, with an included video sit-in. The guide discusses venepuncture using vacutainer bottles, and then steps may differ if you are using dissimilar equipment (e.g. a needle and syringe).

Download the venepuncture PDF OSCE checklist, or use our interactive OSCE checklist.

Gather equipment

Collect all equipment needed for the procedure and place information technology inside reach on a tray or trolley, ensuring that all the items are conspicuously visible:

Clean procedure tray
Not-sterile gloves
Tourniquet
Blood sampling device (e.g. butterfly needle and butt): the size should be appropriate to the vein and sample requirements.
Blood specimen bottles
Sharps container
Alcohol swab (2% chlorhexidine gluconate in seventy% isopropyl)
Gauze or cotton wool
Sterile plaster
Laboratory forms, labels and transportation bag

Introduction

Launder your hands using alcohol gel. If your hands are visibly soiled, wash them with soap and water.

Don PPE if appropriate.

Introduce yourself to the patient including your proper name and function.

Confirm the patient's name and date of birth.

Briefly explicate what the procedure will involve using patient-friendly language: "Today I need to take a claret sample, which involves inserting a small needle into your vein. You may briefly experience a precipitous scratch every bit the needle is inserted."

Gain consent to go on with venepuncture.

Check if the patient has any allergies (e.g. latex).

Fairly expose the patient's arms for the procedure.

Position the patient so that they are sitting comfortably. If a bed is available, the patient tin can lay down for the procedure (this is sometimes preferable, especially if the patient is prone to vasovagal syncope).

Inquire the patient if they accept whatever pain before continuing with the clinical procedure.

You might also be interested in our OSCE Flashcard Drove which contains over 2000 flashcards that comprehend clinical exam, procedures, communication skills and data interpretation.

Choosing an arm

1. Choose an arm to perform venepuncture on:

You should inquire the patient if they have a preference.
Pre-existing medical conditions may prevent particular limbs from being used (e.thousand. arterio-venous fistula, lymphoedema, a stroke affecting the movement of a limb).
Exercise not perform venepuncture on an arm that has an intravenous infusion in progress as this may alter blood exam results.

2. Identify a pillow nether the relevant arm.

Choosing a vein

i. Inspect the patient'south arm for an appropriate venepuncture site:

The median cubital vein in the antecubital fossa is commonly used for venepuncture.
Areas of cleaved, bruised or erythematous peel should be avoided.
Areas in which ii veins join should be avoided where possible, as valves are often present.

2. Position the patient'southward arm in a comfortable extended position that provides adequate access to the planned venepuncture site.

3. Apply the tourniquet approximately 4-5 finger-widths above the planned venepuncture site.

4. Palpate the vein you have identified to assess if it is suitable:

Tapping the vein and request the patient to repeatedly clamp their fist tin make the vein easier to visualise and palpate.
An platonic vein feels 'springy'. A vein that feels difficult is likely sclerosed, thrombosed or phlebitic (inflamed) and should exist avoided.

5. Once yous accept identified a suitable vein you may need to temporarily release the tourniquet, every bit it should not be left on for more than than 1-two minutes at a time.

half-dozen. Wash your easily again.

vii. Don gloves (gloves don't need to be worn for cleaning the site, but they should ever exist donned prior to performing venepuncture itself).

8. Clean the site with an alcohol swab for 30 seconds and and so allow to dry completely for 30 seconds:

You should kickoff cleaning from the center of the venepuncture site and work outwards to cover an area of 5cm or more.
DO NOT bear upon the cleaned site afterward at any bespeak, otherwise, the cleaning procedure volition need to be repeated prior to venepuncture.

Insertion of the needle

one. Re-apply the tourniquet if removed previously.

two. Adhere the needle to the barrel (some blood collection systems come up pre-assembled, such every bit the butterfly needle with barrel shown in the video).

3. Unsheathe the needle.

four. Anchor the vein from below with your non-dominant hand by gently pulling on the skin distal to the insertion site.

5. Warn the patient that they will experience a sharp scratch.

vi. Insert the needle through the skin at a thirty-caste angle or less, with the bevel facing upwardly. You should see flashback into the needle'southward bedchamber and feel a sudden decrease in resistance as the needle enters the vein.

seven. Advance the needle a farther 1-2 mm into the vein later flashback is noted to ensure you are within the lumen.

8. Lower and anchor the needle to the patient's pare using the wings of the butterfly needle.

9.Attach each blood bottle, in the correct order of draw, to the barrel and permit them to fill to the advisable level. Brand sure to continue to anchor the needle to the peel as you remove each bottle from the barrel by gently pulling and twisting. If no blood begins to flow into the bottles, endeavor slightly withdrawing or adjusting the angle of the needle.

ten. Release the tourniquet.

11. Withdraw the needle and then apply gentle pressure to the site with some gauze or cotton wool.

12. Ask the patient to hold the gauze or cotton fiber wool in place whilst yous dispose of the needle into a sharps container.

13. Utilize a dressing to the patient's arm (e.thousand. cotton wool, gauze, plaster).

14.Invert each of the blood bottles the suggested number of times based on its colour.

15. Discard the used equipment into the appropriate clinical waste bin.

Number of times to invert blood bottles

Inversion aids the mixing of a blood sample with the claret bottle'due south additives. The recommended number of times a blood bottle should be inverted differs depending on the claret bottle colour:

Light blue: 3-4 inversions
Gold/yellow: 5-half-dozen inversions
Regal: 8-x inversions
Pink: 8-10 inversions
Grey: eight-10 inversions

Blood tests and order of draw

Dissimilar blood tests crave different types of blood bottles to be used. In addition, blood bottles need to be filled in a specific order to both reduce the take chances of sample contamination and improve the accuracy of results.

Below is a list of the mutual blood bottle types and the associated blood tests, organised by the recommended society of draw:

Blood culture: these bottles should always be attached first, with the aerobic sample preceding the anaerobic i.
Low-cal blue: coagulation screen, INR and D-dimer.*
Golden/yellow: U&Es, CRP, LFTs, amylase, calcium, phosphate, magnesium, TFTs, lipid contour and troponins.
Purple: FBC, claret film, ESR and HbA1c.
Pink: grouping and save assuasive for crossmatching.
Greyness: glucose and lactate.

*If your start bottle is light blue and you are using a butterfly needle you will likely demand to utilise two of these claret bottles to obtain a full sample. This is because when y'all adhere the showtime bottle it will draw in air from the tubing, resulting in a sample that is unable to fill with plenty blood to reach the required level. To avoid this, you tin can initially attach a light blue blood bottle to remove the air (i.e. fill the tubing with claret), so disassemble this and fill a second blood bottle to the required level.

If you desire to learn more than, check out our claret bottles guide.

To consummate the process…

Explain to the patient that the procedure is at present completeand that they should seek review if the venepuncture site becomes painful or inflamed.

Thank the patient for their time.

Document the patient's details on the blood sample bottles at the bedside (using either pre-printed or handwritten labels).

Dispose of PPE appropriately and launder your hands.

Send the blood samples to the lab for analysis in an appropriate plastic leak-proof pocketbook with the completed laboratory request form.

Reviewer

Graham Bone

Senior Clinical Lecturer in Medical Education

References

WHO guidelines on drawing blood: best practices in phlebotomy. Published in 2022. Available from: [LINK].
WHO Guidelines on Hand Hygiene in Healthcare: a Summary. Published in 2009. Bachelor from: [LINK].