Unit 2: Anatomy for Phlebotomy

• Topic 01

  Vascular Anatomy — Veins, Arteries, and Capillaries

  15 questions
• Topic 02

  The Antecubital Fossa — Median Cubital, Cephalic, and Basilic Veins

  15 questions
• Topic 03

  Alternative Venepuncture Sites — Hand, Wrist, and Ankle Veins

  36 questions
• Topic 04

  Arterial Blood Gas (ABG) Collection Sites — Radial, Brachial, and Femoral

  15 questions
• Topic 05

  Capillary Bed Anatomy — Fingertips and Heels

  15 questions

A few questions from this unit, with the answer and a full explanation. The complete bank is available when you start practising.

1. A patient develops pain, redness, and a warm, cord-like vein at the ankle draw site two days after venepuncture. Which complication has most likely occurred and what was the primary risk factor?

   • A
     Phlebitis only, with no thrombotic component, due to the needle size used
   • B
     Thrombophlebitis, promoted by the high venous pressure and reduced lymphatic drainage of the lower extremity
     Correct answer
   • C
     Allergic reaction to the antiseptic used, causing localised vein inflammation
   • D
     Deep vein thrombosis in the femoral vein, unrelated to the ankle draw
   Explanation

   The classic signs — localised pain, redness, warmth, and a palpable cord — describe thrombophlebitis (inflammation of the vein with associated thrombus). Lower-extremity venepuncture is known to increase this risk due to elevated hydrostatic venous pressure and impaired lymphatic drainage, both of which are inherent to the lower limbs at rest. This is a key reason ankle sites are reserved as a last resort. Key takeaway: thrombophlebitis after ankle venepuncture is driven by the physiological properties of lower-extremity venous circulation.

2. A phlebotomist accesses the basilic vein and blood fills the tube rapidly with brighter red colour than expected. The patient complains of intense, shooting pain up the arm. What is the most likely explanation and the correct immediate action?

   • A
     The tourniquet is too tight, causing venous back-pressure; loosen the tourniquet while maintaining needle position
   • B
     The patient is anxious, causing vasovagal response; ask the patient to breathe deeply and continue the draw
   • C
     Inadvertent arterial puncture of the brachial artery and/or median nerve stimulation; remove the needle immediately and apply firm continuous pressure for at least 5 minutes
     Correct answer
   • D
     The tube vacuum is drawing blood too fast; switch to a smaller vacuum tube and complete the draw
   Explanation

   Bright red blood filling rapidly and without resistance strongly suggests arterial entry (brachial artery), while shooting arm pain indicates median nerve stimulation. Both require immediate needle withdrawal. Firm pressure for at least 5 minutes (longer in anticoagulated patients) is needed to prevent haematoma formation from arterial pressure. The incident must be documented and the patient assessed for vascular and neurological status. Key takeaway: bright red rapidly filling blood plus shooting pain during basilic vein access = likely brachial artery/nerve entry — withdraw immediately and apply firm sustained pressure.

3. When the antecubital fossa is unavailable, which site is considered the primary alternative for venepuncture?

   • A
     Finger veins
   • B
     Jugular vein
   • C
     Femoral vein
   • D
     Dorsal hand veins
     Correct answer
   Explanation

   According to CLSI GP41-A7 and standard phlebotomy practice, when the antecubital fossa is unavailable the preferred alternative is the dorsal hand veins. The site preference order is: antecubital fossa → dorsal hand → wrist (with caution) → ankle (last resort, requires physician order). Ankle and femoral veins carry substantially higher risk and require authorisation. Key takeaway: dorsal hand veins are the first-line alternative when the antecubital fossa cannot be used.