Lumbar Puncture and Pericardial Tap

Question 1

Indications for lumbar puncture?

Answer 1

1. Diagnostic
   - Infection (meningitis) culture, sensitivity
   - Subarachnoid hemorrhage
2. Therapeutic
   - Relief of raised intracranial pressure e.g. cryptococcal
3. Anesthesia
   - Spinal anesthetic

Question 2

Contraindications of lumbar puncture?

Answer 2

1. Bleeding diathesis
   - Low platelets, clotting factors
2. Infection at skin site
3. Cardiorespiratory compromise
4. Raised intracranial pressure
   - except pseudotumor cerebri
5. Suspected brain mass with focal signs

Question 3

What equipment do you need for a lumbar puncture?

Answer 3

1. sterile gloves
2. sterile drapes and procedure tray
3. 70% isopropryl alcohol
4. local anaesthetic 1% lignocaine, 2ml syringe
5. spinal needle

Question 4

What’s the best position to do a lumbar puncture in?

Answer 4

1. supine seated, bending forward
2. lying on the side with knees to chest

Question 5

What is the site of the lumbar puncture?

Answer 5

L3-4 (L4-5, L2-3)
- you find L3 at the level of the posterior superior iliac crests

Question 6

How do you clean the skin for a lumbar puncture?

Answer 6

x2 sterile cotton swabs in spirals from the center going outward

Question 7

How to insert and remove the spinal needle in a LP?

Answer 7

1. Insert needle without cannula tube
   - 90 degrees, cephalic
2. Remove needle
   - Direct line of insertion

Question 8

How much of the CSF do you collect?

Answer 8

5-10ml

Question 9

General risks for a LP?

Answer 9

1. Bleeding
   - Haematoma > cord compression > paralysis
2. Infection
   - Central nervous system
   - Superficial (skin)

Question 10

Specific risks for a lumbar puncture?

Answer 10

1. Dural puncture headache
2. Coning > death

Question 11

What do you do if no fluid is detected or you hit bone?

Answer 11

• palpate again for direction (point needle towards head)
• try not to exit skin unnecessarily

Question 12

What do you do if during the spinal tap you encounter a steady flow of venous blood?

Answer 12

• withdraw needle, apply pressure
• try on another space using a fresh needle

Question 13

What do you do if flow of CSF is poor?

Answer 13

• rotate needle 90 degrees
  NB: NEVER aspirate CSF - can cause brain herniation.