What are the factors to be considered in good venipuncture?

What is venipuncture?

It is the collection of blood from veins. It is most often performed for the purpose of laboratory testing. It is done with a needle, and typically performed by a phlebotomist. Venipuncture may also be performed in order to remove extra red blood cells from the blood, to treat various blood disorders.

There are many factors at play during a procedure. For example, “Order of Draw” is a vital concept to understand, for the purpose of avoiding cross-contamination of additives between tubes. Venipuncture is actually one of the most routinely performed invasive procedures. There are five primary reasons for performing a venipuncture:

1. Obtaining blood for diagnostic purposes
2. Monitoring levels of blood components
3. Administering therapeutic treatments (medications, nutrition, chemotherapy)
4. Removing blood due to excess levels of iron or erythrocytes (red blood cells)
5. Collecting blood for later uses (transfusion in the donor)

Steps in the venipuncture process

Here is our master list of steps to practicing venipuncture successfully. In a phlebotomy course, these steps will be broken down and taught with hands-on training by professional educators.

1. Review the order of draw

2. Gather the supply tray and cart

3. Approach, identify, and prepare the patient for the process

4. Maintain proper hand-hygiene

5. Apply the tourniquet, ask the patient to make a fist, and assess the antecubital space

6. Select a vein, release the tourniquet, and ask the patient to relax their fist

7. Cleanse the site thoroughly

8. Put on clean gloves and prepare your equipment

9. Reapply the tourniquet, have the patient make a fist, and uncap the needle

10. Properly anchor the vein and insert the needle

11. Establish blood flow and have the patient open his or her fist, then release the tourniquet

12. Fill tubes using the correct order of draw and mix tubes

13. Place gauze, remove the needle, and apply appropriate pressure to the site

14. Discard the collection unit

15. Label the tubes

16. Implement special handling techniques

17. Check and inspect the patient’s arm, then apply a bandage

18. Dispose of the materials and clean up

19. Remove your gloves, perform hand hygiene techniques, and thank the patient

20. Securely transport specimens to the lab for testing

Equipment

The equipment used during a blood test can vary, but the following are most commonly used:

• Collection tubes
• Needles
• Tourniquet
• Wipes/Swabs
• Gauze
• Bandages
• Gloves
• Disposal unit

Venipuncture Sites

PhlebotomyU offers venipuncture courses

• General precautions for venepuncture
• Preliminary checks
• Patient reassurance
• Patient identification / request forms
• Selection of venepuncture site
• Preparation before venepuncture
• Venepuncture procedure
• Care of venepuncture site and disposal of the needle
• Labelling blood samples
• Patient aftercare

General Precautions For Venepuncture

It is recommended that protective clothing and disposable gloves be worn when performing venepuncture. Hands should be washed after wearing gloves. Any cut or abrasion on the hand must be covered with a waterproof dressing or plaster.

Appropriate precautions to prevent injuries from needles used during venepuncture should be taken. Used needles should never be recapped and the entire unit of hub and needles should be disposed of into a designated sharps bin. The yellow sharps bins should be filled to the line only and be accessible during venepuncture. Never overfill as this can lead to injuries when attempting to close the lid. Sharps bins should always be stored upright to prevent contaminated needles falling out.

Preliminary Checks

Some blood tests such as Lipids, Glucose or Glucose Tolerance Test (GTT) require the patient to fast overnight. Check before performing venepuncture that the patient has not eaten or drank anything but water since the night before. If the patient has fasted ensure the fasted box is ticked on the request form so the correct tests will be ordered. If the patient has not fasted but the test required them to do so, venepuncture should not be undertaken and the patient should be advised to re-attend when they have fasted.
Samples for tests related to a drug regime are dependent on correct timing of collection. Ensure all relevant information regarding dosage is included on the request form.

Tests for Basildon site only  
Certain tests must only be performed at Basildon, as they need to be received in the laboratories within a specified timescale. Details are available on the Test Directory section of this handbook or contact Clinical Biochemistry if in doubt. 

Groups of patients needing special treatment
Some patients will either not be able to be bled or need to be bled in an alternative area due to their clinical condition or situation. The following group of hospital patients should not be bled under any circumstances unless the issue is completely rectified to your satisfaction and following Trust policies:

• Patients without a wristband
• Patients where the information on form and wristband does not match
• Patient receiving a blood transfusion at the time of venepuncture

There are patient groups that require special consideration before venepuncture but this should not stop them from being bled: –

• Blood should never be collected from a vein proximal to an infusion site i.e. on a drip. Blood can be collected from the opposing arm as long as this does not also contain a drip.
• Patients who have an indwelling fistula should have blood taken from the opposing arm and never from the fistula arm as this can damage the area.
• Patients who have had mastectomies will need blood taken from the opposing arm. If patients have double mastectomies seek the advice of your supervisor before venepuncture. There are rare occasions when bleeding from the foot is acceptable but this must never be performed by inexperienced staff.

Patient Reassurance

Staff should gain the patient’s confidence and generally reassure the patient at all times, as venepuncture can be a frightening procedure.
Phlebotomists must assume that informed consent will have been obtained by the requesting source for any tests ordered. If a patient questions what tests have been requested they should be referred back to their doctor. Phlebotomists should never attempt to give advice about tests requested, as this is not their role.
If the patient refuses a blood test their wishes must be respected and the procedure terminated. Under no circumstances proceed once a refusal has been given as this could constitute an assault.
Only two attempts at venepuncture should be made on adults, and only one attempt on a child by one phlebotomist. A more experienced member of staff must always be called if difficulties arise, and patients from GP surgeries may be forwarded to the hospital phlebotomy sites for venepuncture.

Confidentiality
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Patient Identification /Request Forms

Correct patient identification is essential to ensure that the specimens collected are from the patient named on the request form. Ask directly “What is your name” and NOT indirectly “Are you X”. The Date of Birth (DOB) should be ascertained in the same way.
Certain information must be present on the request form before venepuncture is performed.
If insufficient information has been supplied, the patient must be asked to supply any additional information required and the phlebotomist is allowed to write this on the form.
The minimum amount of information acceptable on the Request form is as follows: –

Hospital In-patients and Out-patients must provide the patient’s surname plus two of the following:

• First name
• Hospital number
• NHS number
• A&E number
• Date of Birth

GP request forms must provide patient’s surname and first name plus one of the following: –

• Hospital number
• NHS number
• Date of Birth

This information should be checked with the patient verbally. For patients on the ward the wristband must also match the request form before venepuncture can proceed. Any discrepancies should be highlighted with ward staff and the patient must not be bled until corrected.
If the request is from a GP but the GP information is missing, the patient may be asked to supply this information and the phlebotomist may write it on the form.  

Blood Transfusion Identification
Blood Transfusion forms must be correctly completed with full patients name, DOB, hospital number plus location of request, consultant and reason for test. The doctor making the request must sign them.
It is acceptable for the phlebotomists to verbally verify this information with the patient in an OPD setting and a corresponding letter does not need to be produced. This is because not all patients are given admission letters for sensitive reasons and asking for the letter can be upsetting for the patient.
On the wards the blood transfusion request form needs to be checked against the wristband. Any discrepancies should be highlighted with ward staff and the patient must not be bled until corrected.

Selection of Venepuncture Site

The availability of patient’s veins may be of paramount importance to the ongoing care of the patient, especially in cases where repeated transfusions, infusions and/or injections of therapeutic agents are indicated. Great care should be taken, therefore, to avoid injury by poor technique.
Any outer clothing over the arm should be removed; the sleeve of the inner clothing should be folded up over the elbow if required. Care should be taken to ensure there is no tightness above the elbow, as this will restrict blood flow. The patient should be seated with their arm outstretched and elbow supported to prevent bending.
The patient should have nothing in the mouth (except dentures) during venepuncture.
Any special considerations should be noted i.e. drips, fistulas or mastectomies.
As a preliminary step potential sites should be inspected by asking the patient to clench the fist or the arm on which venepuncture is intended to be made. This will cause the veins of the arm to become more prominent. The veins should be felt; the best ones are not always visible.

Factors to consider during site selection
Areas of inflammation, infection or extensive scarring, such as healed burns should be avoided.
Blood specimens should not be taken from an area with a haematoma as erroneous results might ensue.
Blood must not be taken from drip arms, arms with indwelling fistulas or canulas or on patients undergoing blood transfusion.
A tourniquet should never be applied for more than one minute prior to venous blood collection, as haemoconcentration will occur and may adversely affect the test results.
The chosen vein should be palpitated and its path traced.

Preparation Before Venepuncture

Before attempting venepuncture all consumables required should be available, including any special blood bottles. The needle should be inserted into the hub in preparation to bleed the patient.

Cleansing the venepuncture site
After selecting the vein, the skin around the site is cleansed with an Isopropyl swab (Steret) and allowed to dry for a few seconds before proceeding.

Venepuncture

The patient’s arm should be held straight with the wrist extended. Suitable support should be placed behind the elbow to keep it steady during insertion of the needle.
To make it easier to pierce the skin draw it tight below the chosen site of puncture. This will also help the vein from moving.
The needle and hub assembly should be held at an angle of 15º to the patient’s arm as the vein is punctured.
It is necessary to push the needle about 1cm through the skin to ensure that its beveled point is completely inside the vein. If the needle is pushed further than this there is a risk that it will perforate the opposite wall of the vein. Once inserted the blood bottles can be inserted in turn into the hub and will be filled automatically by vacuum.

The order of draw is important and should be as follows: –

• Blood culture bottles (if required)
• Tubes with no additives (Red or Yellow topped tubes)
• Coagulation tubes
• Other tubes with additives

Coagulation tubes must be mixed immediately by thorough but gentle inversion.

Blood culture collection

• Cleanse puncture site thoroughly with a Steret
• Assemble the holder and open the Safety-Lok™ butterfly.
• Perform venepuncture and secure the needle with tape.
• Press adapter down over the aerobic bottle first and fill with 10ml blood using the 5ml scale on the bottle label as a guide.
• Repeat for anaerobic bottle.
• If further blood samples are required insert the adaptor into the holder and collect blood as normal.
• Once finished hold the yellow safety shield on the butterfly and pull the tubing taut to advance the shield to cover the needle.
• Dispose of all the equipment into a burn bin.
• Remove the bar code stickers from the blood culture bottles and fix to request form.
• Label the samples

Care of The Venepuncture Site And disposal of The Needle

Before removing the needle from the vein, check that the tourniquet is released and that the fist is unclenched.
The site of the needle entry is covered with a fresh dry sterile dressing.
Firm pressure is applied to the dressing by the patient (where possible) until the bleeding stops. Bending of the elbow should be discouraged.
The dressing should be secured with microtape before the patient leaves the area.

Immediately after extraction from the arm the needle and hub unit should be placed carefully into a burn bin.

Labelling Blood Samples

All blood containers should be labelled with the patient information immediately after the blood sample has been collected and only by the person who collected the sample.
The only exception is for barrier-nursed patients where the blood bottles can be pre labelled before venepuncture.

Samples with inadequate information will normally be discarded and the patient will require a re-bleed.

Routine samples
On all samples other than Blood Transfusion the minimum acceptable labelling is listed below.

Hospital In-patients and Out-patients must provide the patient’s surname plus two of the following:

• First name
• Hospital number
• NHS number
• A&E number
• Date of Birth

In addition the date must be written on the sample. The form must be dated, time sample taken written in the box and, when indicated, the phlebotomy number written in the space provided.

GP request forms must provide patient’s surname and first name plus one of the following: –

• NHS number
• Date of Birth

Blood transfusion samples
Blood transfusion samples must always have the following information written on them to be acceptable to the laboratory.

• Patient’s surname
• Patient’s forename
• Date of Birth
• Patient identification number (not NHS number)
• Hospital ward or department
• Date and time of specimen collection
• Phlebotomy number or signature of person collecting blood

The form must also be signed to confirm a positive identification of the patient was performed.
All samples once completed should be placed in the appropriate rack or bag for transport to the central reception area of Pathology for processing.  

Patient Aftercare

After venepuncture the site should checked to ensure bleeding has stopped. The dressing should be secured with a piece of tape. Patients should be advised to keep the area covered for at least thirty minutes and not to exert pressure on the area. This could lead to bruising.

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