# Phlebotomy and venepuncture, the knowledge half

*Anatomy, order of draw, and the errors that ruin a sample or injure a patient.*

## Production summary

- Modules to record: 2
- Total script: 1120 words, about 7 minutes of finished audio
- Voices: Amara (host) and Nadia (practice educator)
- Level: Level 3, healthcare assistants, nursing associates and nurses new to the task

## Accreditation wording that must appear in the description

- **The CPD Certification Service** (planned): Application scheduled.
- **WHO guidelines on drawing blood, 2010** (aligned): Written against the WHO best practices in phlebotomy. Alignment is our own mapping and implies no endorsement.
- **Health and Safety (Sharp Instruments in Healthcare) Regulations 2013** (aligned): The sharps safety content reflects the 2013 regulations. Alignment is our own mapping.

> Do not upgrade any of these words in a description or a thumbnail. Aligned is not accredited, and planned is not approved.


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## Anatomy, identification and choosing the vein

**Runtime** about 4 minutes. **Words** 565. **Starts at** 00:00 in the full course recording.

### Learning outcomes to state on camera

- Name the veins of the antecubital fossa and rank them for safety
- Explain why the median cubital vein is chosen first
- Carry out positive patient identification to laboratory standard
- Recognise the arm and sites that must not be used

### Script


`[CUE 1]` *Antecubital fossa diagram: median cubital, cephalic and basilic labelled, with the brachial artery and median nerve shown beneath the basilic.*

**AMARA**  [00:00]
Start me at the beginning. Patient sits down. What is the first thing that actually matters?

**NADIA**  [00:06]
Identification. And I want to be blunt about why, because people treat it as the boring bit before the real task. It is the real task. A beautifully taken sample with the wrong name on it is more dangerous than a failed draw, because a failed draw gets repeated and a wrong name gets acted on.

**AMARA**  [00:28]
So I ask them to confirm their name.


`[CUE 2]` *Open question identification sequence beside a crossed out leading question.*

**NADIA**  [00:32]
No. You ask them to state their name. There is a real difference. If you say, are you Mrs Ahmed, a patient who is anxious, hard of hearing or confused will say yes, because saying yes is what people do. Ask open: what is your name, your date of birth, the first line of your address. Then check it against the form and the wristband.

**AMARA**  [00:58]
Fine. Now I want a vein. Where am I looking?

**NADIA**  [01:02]
The antecubital fossa, the hollow at the front of the elbow. Three veins in play. Median cubital in the middle, cephalic on the thumb side, basilic on the little finger side.


`[CUE 3]` *Palpation comparison: bouncy vein, cord like thrombosed vein, firm tendon, pulsing artery.*

**AMARA**  [01:14]
And I want the biggest one I can see, presumably.

**NADIA**  [01:18]
That is exactly the instinct that causes injuries. You want the safest one you can palpate, and that is the median cubital: central, usually well anchored so it does not roll away from the needle, and with the fewest important structures underneath it.

**AMARA**  [01:35]
What is underneath the others?


`[CUE 4]` *Tourniquet timer showing haemoconcentration beginning after one minute.*

**NADIA**  [01:37]
Under the basilic, medially, sit the brachial artery and the median nerve. That is why the basilic is a last resort. Almost every serious phlebotomy injury you will read about involves a needle placed on the medial side, angled deep, and pushed on in hope.

**AMARA**  [01:55]
You said palpate, not look. Why?

**NADIA**  [01:58]
Because sight tells you where a vein is and touch tells you what it is. A good vein is bouncy and refills when you press it. A thrombosed vein is hard and cord like. A tendon is firm and does not refill at all, and people do stick tendons. An artery pulses, and if you feel a pulse, stop and choose elsewhere.


`[CUE 5]` *Excluded arms panel: fistula, mastectomy side, infusion running, damaged skin.*

**AMARA**  [02:22]
How long do I leave the tourniquet on while I hunt around?

**NADIA**  [02:27]
Under a minute. Ideally you apply it, find your vein, and release it before you draw or as the blood starts flowing. Leave it on longer and you get haemoconcentration: fluid leaves the vessel, cells stay, and your potassium and your haematocrit come back falsely high. The clinician then treats a number your tourniquet invented.

**AMARA**  [02:49]
That is a genuinely unsettling thought.


`[CUE 6]` *Bedside labelling sequence, with pre labelling crossed out.*

**NADIA**  [02:52]
It should be. Most of what makes phlebotomy skilled is not the needle. It is understanding that every shortcut you take shows up as a number somebody else trusts.

**AMARA**  [03:03]
Any arm I should refuse outright?

**NADIA**  [03:06]
A fistula arm, always, no exceptions, that is the patient's dialysis access and damaging it is a serious harm. The side of a mastectomy where nodes were cleared. An arm with a drip running, because your sample is diluted with whatever is in the bag. And obviously not through infection, burns or heavy bruising.

**AMARA**  [03:27]
And if the only arm available is one of those?

**NADIA**  [03:31]
Then it is not your decision alone. Escalate. The person who chose the line or the surgeon who cleared the nodes gets to weigh that risk, not the phlebotomist under time pressure with a full list.

### Sources for the on screen credit

- WHO guidelines on drawing blood: best practices in phlebotomy, World Health Organization
- Right patient, right blood: patient identification, NHS England
- Standards for infusion therapy, Royal College of Nursing

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## Order of draw, sample quality and when it goes wrong

**Runtime** about 4 minutes. **Words** 555. **Starts at** 03:46 in the full course recording.

### Learning outcomes to state on camera

- Apply the order of draw and explain the carryover it prevents
- Identify the causes of haemolysis and prevent them
- Respond correctly to nerve pain, arterial puncture and haematoma
- Follow the sharps and needlestick injury procedure without delay

### Script


`[CUE 1]` *Order of draw as six numbered tubes with the additive carryover arrow between them.*

**AMARA**  [03:46]
Order of draw. Be honest with me, is this real or is it laboratory fussiness?

**NADIA**  [03:52]
It is real and I can prove it in one example. The EDTA tube, the purple one for a full blood count, contains potassium as part of its additive. Draw it before the tube for urea and electrolytes and a trace carries over on the needle.

**AMARA**  [04:10]
And that shows up?


`[CUE 2]` *Potassium carryover demonstration: EDTA drawn before chemistry, resulting false high result.*

**NADIA**  [04:12]
As a high potassium. Which is a number clinicians take extremely seriously, because a genuinely high potassium can stop a heart. So the patient may get treated, or at minimum gets recalled, re bled and frightened. All because two tubes went on the needle in the wrong sequence.

**AMARA**  [04:31]
Give me the order then.

**NADIA**  [04:33]
Blood cultures first, because they must stay sterile. Then citrate, the coagulation tube. Then serum. Then heparin. Then EDTA. Then fluoride oxalate for glucose last.


`[CUE 3]` *Underfilled citrate tube beside a correctly filled one, with the ratio shown.*

**AMARA**  [04:43]
You said the coagulation tube has to be full.

**NADIA**  [04:46]
Completely full, and this one catches people out. Citrate works on a fixed ratio of blood to additive. Underfill it and the ratio is wrong, so the clotting time is wrong, and somebody may be adjusting a warfarin dose on it. The laboratory rejects underfilled coagulation tubes and they are right to.

**AMARA**  [05:07]
Now tell me about haemolysis, because I hear that word constantly.


`[CUE 4]` *Haemolysis causes: fine needle, forced plunger, shaken tube, wet alcohol.*

**NADIA**  [05:12]
Red cells bursting and leaking their contents into the plasma. And the reason it matters is the same reason as before: potassium lives inside red cells. Burst them and you get a high potassium that belongs to your technique, not to the patient.

**AMARA**  [05:29]
Can I see it happening?

**NADIA**  [05:31]
No. That is exactly what makes it dangerous. It is invisible to you and obvious to the laboratory. Which means the only defence is technique: do not use a needle finer than the job needs, do not yank a syringe plunger, let the vacuum tube fill at its own pace, and invert tubes gently rather than shaking them like a cocktail.


`[CUE 5]` *Complication responses: nerve pain, arterial puncture, haematoma, each with the immediate action.*

**AMARA**  [05:55]
Right. The patient suddenly says there is a sharp pain shooting down to their fingers.

**NADIA**  [06:01]
Needle out. Immediately. Not adjust, not wait to see, not one more try. That description means nerve, and the difference between a temporary problem and a permanent one is often how fast the needle came out.

**AMARA**  [06:16]
And I do not try the other vein in that arm?


`[CUE 6]` *Needlestick sequence: bleed, wash, cover, report now, with a clock emphasising hours.*

**NADIA**  [06:20]
Not that arm. Document it, report it, tell somebody senior. I know there is a pull to finish the job. Resist it.

**AMARA**  [06:29]
What if the blood is bright red and coming in fast?

**NADIA**  [06:33]
Think artery. Out, and firm pressure for a full five minutes, longer if they are on anticoagulants, and you stay with them until it has genuinely stopped. Then tell the clinical team. Arterial punctures can bleed deep into the arm afterwards, and that is compartment syndrome territory.

**AMARA**  [06:52]
Last one. I stick myself.

**NADIA**  [06:54]
Encourage it to bleed, wash under running water, do not scrub it, cover it, report it now. Not at the end of your list. Now.

**AMARA**  [07:04]
Why so absolute about the timing?

**NADIA**  [07:06]
Because post exposure prophylaxis for HIV works best measured in hours. A needlestick reported the next morning is a needlestick reported too late. And people delay for the worst possible reason, which is embarrassment. Nobody has ever been disciplined for reporting one promptly. People have been very seriously harmed by sitting on one.

### Sources for the on screen credit

- WHO guidelines on drawing blood: best practices in phlebotomy, World Health Organization
- Health and Safety (Sharp Instruments in Healthcare) Regulations 2013, legislation.gov.uk
- Management of exposure to bloodborne viruses, UK Health Security Agency

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