Pre‐procedure

ActionRationale

1. 1.Show
   Introduce yourself to the patient, and explain and discuss the procedure with them. Obtain consent to proceed in all cases except in emergencies when the patient is unable to consent.
   To ensure that the patient feels at ease, understands the procedure and gives their valid consent (NMC [165], C). To minimize anxiety, which may distort analysis or exacerbate symptoms. E

   Consent may not be possible in certain clinical scenarios, such as where the patient is critically ill with rapid decompensation or has an altered level of consciousness (Danckers and Fried [41], E).
2. 2.Show
   Check the patient's identity and allergy status.
   To ensure the procedure is undertaken with the correct patient and to minimize the risk of allergic reaction (NPSA [166], C; RCN 2017a, C).
3. 3.Show
   Check the concentration of oxygen the patient is breathing and their body temperature at the time of sampling; document both on the sampling results.
   Inspired oxygen concentration and temperature parameters are required to interpret arterial blood gases (ABGs) accurately (Adam et al. [2], E).
4. 4.Show
   Check the patient's current coagulation screen, platelet count, medical history and prescription chart for anticoagulation therapy.
   To identify possible risk of bleeding and haematoma formation post‐procedure and, where appropriate, to prevent puncture until coagulation is corrected (Danckers and Fried [41], E).
5. 5.Show
   Prepare trolley and take to bedside.
   To reduce the risk of cross‐infection (DH [46], C).
6. 6.Show
   Wash hands with bactericidal soap and water or an alcohol‐based handrub.
   To reduce the risk of cross‐infection (NHS England and NHSI [155], C).

Procedure

1. 7.Show
   Assume a stable and comfortable position. If possible, sit down on a chair or stool near the patient.
   To maximize the chance of successful sampling at the first attempt, thereby minimizing patient discomfort. To prevent back strain in the practitioner and minimize the risk of a needle stick injury. E
2. 8.Show
   Inspect and assess the tissues and anatomical structures surrounding the intended sampling site.
   To identify any areas of excoriation or infection, poor perfusion or other puncture sites. If any of these are present, the site should not be used (Pagana and Pagana [177], E).
3. 9.Show
   Locate and palpate the radial artery with the middle and index fingers of the non‐dominant hand.
   To assess maximum pulsation so as to ensure the radial artery is the optimum site for successful puncture. The dominant hand will be used to perform the puncture (Pagana and Pagana [177], E; Weinstein and Plumer [253], E).
4. 10.Show
   Perform the modified Allen test (see Figure 13.11).
   To confirm patency of ulnar artery circulation and assess collateral circulation to the hand in the event of radial artery damage, for example thrombosis (Pagana and Pagana [177], E).
5. 11.Show
   Prepare the patient in a supine position: with forearm supinated at the wrist, gently extend the wrist at 40° over a rolled towel while avoiding overextension (ask for assistance if required) to bring the radial artery to a more superficial plane (Danckers and Fried [41]).
   To reduce the risk of the patient moving unexpectedly, which could result in through‐puncture (Hudson et al. [98], E; Pagana and Pagana [177], E). To flex the hand slightly to facilitate insertion. E

   Overextension of the wrist is discouraged, because interposition of flexor tendons may make the pulse difficult to detect (Danckers and Fried [41], E).
6. 12.Show
   Clean hands, open the pack and place the equipment onto it.
   To ensure all equipment required is prepared. E
7. 13.Show
   Withdraw the plunger of the ABG syringe 1–2 mL before the puncture. If using a vented sample syringe, withdraw fully.
   To reduce blood haemolysis. Arterial pressure causes a brisk pulsatile reflux of blood into the syringe (unless the patient is severely hypotensive) (Weinstein and Plumer [253], E).
8. 14.Show
   Place a sterile field under the patient's wrist and maintain aseptic technique throughout the procedure.
   To minimize the risk of infection (DH [46], C).
9. 15.Show
   Clean hands and then clean the site with chlorhexidine in 70% alcohol and allow to dry.
   To minimize the risk of infection (DH [46], C).
10. 16.Show
    Prepare and administer subcutaneous local anaesthetic. Only inject 0.5–1 mL of the anaesthetic to create a small dermal papule at the site of puncture.
    To minimize pain during the procedure. Local vasodilation effects of the local anaesthetic may reduce vasospasm, making for a successful puncture (Lipsitz [127], E).

    Using larger amounts or injecting the anaesthetic into deeper planes may distort the anatomy and hinder identification of the vessel (Danckers and Fried [41], E).
11. 17.Show
    After the skin is punctured but just before the anaesthetic is injected, the clinician should pull back the plunger to confirm that the needle is not inside a blood vessel; intravascular placement will be indicated by blood filling up the anaesthetic syringe.
    Injecting local anaesthetic directly intravascularly may cause cardiac arrhythmias (Danckers and Fried [41], E).
12. 18.Show
    Clean hands with bactericidal skin‐cleaning solution or wash with soap and water.
    To minimize the risk of infection (DH [46], C).
13. 19.Show
    Apply non‐sterile gloves. Take care not to touch the puncture site after cleaning.
    To minimize the risk of infection and prevent contamination of hands with blood (NHS England and NHSI [155], C).
14. 20.Show
    Uncap the ABG syringe, attach the 22 swg needle and hold it with two fingers of the dominant hand.
    To guide the needle into position above the radial artery and aid successful puncture. E
15. 21.Show
    Angle the needle at 30–45° for a radial artery, with the bevel of the needle up just distal to the planned puncture site. While palpating the radial pulse proximal to the planned puncture site, advance the needle slowly, aiming in the direction of the artery until a flashing pulsation is seen in the hub of the needle (see Figure 13.12).
    To minimize trauma to the artery. E

    Rapid insertion may result in a through‐puncture (Chernecky and Berger [32], E).

    Take care not to touch the puncture site after cleaning, to minimize risk of infection (DH [46], C; WHO [257], C).

    Pulsatile flow indicates access to radial artery. E

    Arterial pressure causes blood to pulsate spontaneously back into the syringe (Weinstein and Plumer [253], E).
16. 22.Show
    Slowly aspirate by gently pulling the plunger of the arterial gas syringe to a minimum of 0.6 mL of blood for the sample (check recommended amount of blood as directed by manufacturer's guidelines). If using a vented sample syringe, aspiration is not required as the syringe will fill automatically.
    To minimize vasospasm. E

    To ensure the optimal volume is obtained in order to ensure an appropriate mix of blood with heparin (Chernecky and Berger [32], E; see manufacturer's guidelines, C).
17. 23.Show
    Withdraw the needle and immediately apply pressure using a low‐linting swab.
    To prevent haematoma formation and excessive bleeding. E
18. 24.Show
    Discard the sharp into a sharps container. Promptly return the wrist to the neutral position following sampling.
    To ensure correct clinical waste management and to reduce the risk of sharps injury (DH [48], C). Prolonged hyperextension may be associated with changes in median nerve conduction (Chowet et al. [34], R).
19. 25.Show
    Apply pressure for a minimum of 5 minutes or until no signs of bleeding are observed. Ask for assistance from another nurse if necessary.
    To minimize blood loss and to ensure pressure is exerted to prevent haematoma and blood loss (Pagana and Pagana [177], E; RCN [211], C).

Post‐procedure

1. 26.Show
   Dispose of equipment safely.
   To prevent contamination of others (DH [48], C).
2. 27.Show
   Expel any air bubbles from the syringe and cap the arterial syringe.
   To keep the sample airtight and avoid inaccuracies (see manufacturer's guidelines, C).
3. 28.Show
   Label the sample with the patient's name, number, date of birth, etc. at their bedside.
   To prevent mislabelling when away from the patient. To maintain accurate records and provide accurate information for laboratory analysis (NMC [165], C; Weston [255], E).
4. 29.Show
   Immediately send the sample to an area with ABG analysis machines, such as a laboratory, intensive care unit, high‐dependency unit, theatre or A&E department.
   ABG samples can be processed immediately and usually a result can be obtained within minutes. E
5. 30.Show
   Check the puncture site and apply a clean, sterile, low‐linting gauze dressing. Secure with tape.
   To maintain pressure and prevent haematoma formation. E
6. 31.Show
   Clearly document the rationale for the procedure in the patient's notes and verbally communicate the arterial analysis findings to relevant medical and nursing teams.
   To acknowledge accountability for actions and ensure effective communication. To ensure prompt and appropriate treatment (NMC [165], C).