To prevent an arterial puncture, careful assessment of vein selection is necessary. The nurse should palpate the vessel prior to needle insertion to confirm the absence of a pulse; the angle of insertion should be less than 30° and in the event of a missed vein, blind probing should be avoided (McCall and Tankersley [138]).

An arterial puncture can be identified by bright red blood, rapid blood flow and pain. The needle should be removed immediately and pressure applied for 5 minutes by the nurse. A pressure dressing should be applied and the patient should receive verbal and written advice to follow in the event of increased pain, swelling or loss of sensation. No tourniquet or blood pressure cuff should be reapplied to the arm for 24 hours. The incident should be documented in the patient's notes (NMC [165], WHO [257], [260]).

Careful vein selection and needle insertion should minimize the risk of nerve injury. The angle of insertion should be less than 30° and blind probing should be avoided (Hoeltke [88]). In the event of a nerve injury, the patient may complain of a sharp shooting pain, burning or electric shock sensation that radiates down the arm and they may experience numbness or tingling in their fingers. The needle should be removed immediately to prevent further nerve damage (Garza and Becan‐McBride [66]). The patient should receive verbal and written advice to follow if the pain or numbness continues for more than a few hours. The incident should be documented in the patient's notes.

Haematoma formation is the most common complication of venepuncture (McCall and Tankersley [138]). A haematoma develops when blood leaks from the vein into the surrounding tissues. It may be caused by the needle penetrating completely through the vein wall, the needle only being partially inserted or insufficient pressure being placed on the site when the needle is removed. If a haematoma develops, the needle should be removed immediately and pressure applied. In the event of a large haematoma developing, the nurse can apply an ice pack to relieve pain and swelling. The application of a topical cream that is used for the treatment of superficial thrombophlebitis, bruising and/or haematoma may be beneficial (BNF [16]).

The patient should receive verbal and written advice as a haematoma may lead to a compression injury to the nerve (Hoeltke [88]). The incident should be documented in the patient's notes (NMC [165], WHO [260]).

Fainting may occur during or immediately following venepuncture. The patient may complain of feeling light‐headed and appear pale and sweaty. Loss of consciousness may occur suddenly so the nurse should be vigilant throughout the procedure and routinely confirm with the patient that they do not feel unwell or faint. In the event of the patient feeling faint, the nurse should remove the device immediately, apply pressure to the site and encourage the patient to lower their head from upright or lie down and breathe deeply. The application of a cold compress to the forehead and increased ventilation (open a window if clinically acceptable) may help to make the patient more comfortable. If the patient suffers a loss of consciousness, the nurse should call for assistance and ensure the patient's safety until they recover. The patient should not be allowed to leave the department until fully recovered and should be advised not to drive for at least 30 minutes (McCall and Tankersley [138]). The incident should be documented in the patient's notes and the patient should be advised to inform staff on future occasions.

Infection at the venepuncture site is a rare occurrence and should be reported to a doctor or non‐medical prescriber (McCall and Tankersley [138]). Aseptic technique should be maintained with careful attention to hand washing and skin preparation. The venepuncture site should not be repalpated after cleaning and the site should be covered for 15–20 minutes after the procedure.