5.4 Inadvertent Dural Puncture Flashcards
You are administering an epidural for labour analgesia in a 25-year-old
primigravida, with a 16 G Tuohy needle when a wet tap occurs.
What is your immediate course of management?
- Resite: Take the needle out and reinsert in an adjacent space (OR)
- Spinal catheter: Insert the epidural catheter into the subarachnoid space
- General: document, explain to patient, explain to team
State the advantages and disadvantages of both techniques
Spinal catheter *
+
Prevents another dural puncture
* Rapid and predictable analgesia
-
* Risk of infection
* Cauda equina syndrome
Resite
+
* Less chance of intrathecal dosing
* Operator expertise not very important
-
* Risk of another dural puncture
* Procedure can be difficult and may need more expertise
What special precautions would you take if you had inserted a spinal catheter?
- Labeling the catheter
- Handover to the team
- All top-ups given by the anaesthetist
- Regular neurological observations
- Aseptic precautions
What top-up would you give if you were inserting a spinal catheter?
2–3 mLs of the low dose mix
(0.1% bupivacaine + 2mcg/mL fentanyl)
or
1 mL of 0.25% Bupivacaine +/− fentanyl 15–25 mcg
What is the chance of this patient developing a post-dural puncture headache (PDPH)?
There is a 80% chance of her developing PDPH
as the Tuohy needle is wide-bore needle
- 16 G: 80%
- 20 G: 40%
- < 25 G: 1%–2%
What are the characteristics of PDPH?
- Fronto-occipital headache increasing in upright posture
(due to higher CSF pressure in upright posture)
- Nausea, vomiting, visual disturbances, general malaise
- Presents in < 3 days and lasts for 14 days
- Usually self-limiting
What are the risk factors that predispose one to the development of PDPH?
Patient:
Young
Female
Obstetric
Operator:
Experience
Fatigue/stress
LOR -> AIR
Needle:
>25needle
Cutting / non atraumatic needle
rotating in space
What is the mechanism of pain in PDPH?
CSF leakage leading to
- Loss of buoyancy—
sagging of brain causing traction on pain-sensitive
meninges, nerves, and veins - Compensatory dilation of cerebral veins
causing direct pressure on meninges
You are called to see the same patient in the postnatal ward.
She is Day 2 postpartum and is complaining of a headache.
How would you approach this
patient?
- Obtain history
- General examination
- Neurological examination
What is the differential diagnosis of postpartum headache?
- Obs
PDPH
Preeclampsia
Tension headache - Infective
Encephalitis
Meningitis - Neoplastic
SOL - Vascular
Migraine
Cortical vein thrombosis
Cerebral infarction
Subdural haematoma
Subarachnoid haemorrhage - Pharmacological
Dehydration
Caffeine withdrawal
You have diagnosed PDPH in this patient. What is your management plan?
- Adequate hydration
- Avoid abdominal binders as they are shown to be ineffective
- Conventional analgesics—
paracetamol, NSAIDS, codeine, opioids
- Conventional analgesics—
- Analgesic adjuvants—
caffeine, sumatriptan, theophylline, ACTH
- Analgesic adjuvants—
- Gold standard treatment—
Homologous Epidural Blood Patch (EBP)
- Gold standard treatment—
What is the mode of action of caffeine?
- Methyl xanthine analogue
- Cerebral vasoconstrictor
- 150–300 mgs oral every 6 to 8 hours
- 500 mgs intravenous infusion over one hour.
Repeat if needed. - Adverse effects (which are rare):
Cardiac arrhythmias,
seizures if dose > 300 mgs - Cerebral irritability in neonates
When is the suitable time to perform eBP?
24–48 hours.
Not effective if performed in less than 24 hours.
How would you perform EBP after establishing the diagnosis and having assessed the suitability?
- Explain to patient
- Two personnel with experience
- Strict aseptic precautions
- Locate epidural space as per usual technique—
a space higher - 10–20 mls of homologous blood
- Blood for culture, as per department policy
—no consensus - STOP if pain/discomfort on injection
- Supine
—2 hours and no straining for 1–2 weeks
to prevent patch blow-off - Follow-up
Name any three complications of eBP.
- Back pain
- Meningeal irritation
- Radicular pain
- Cranial nerve palsy
- Infection
