• Dural puncture is the inadvertent puncture of the dura during attempted epidural insertion.

• Dural puncture and post dural puncture headache (PDPH) are common complications of epidural analgesia and spinal anaesthesia. The rate of accidental dural puncture is 1.2%¹. Of such patients, 50-80% develop a PDPH²

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Abbreviations

This guideline is written to

• provide guidance on the recognition and management of accidental dural puncture during epidural insertion in pregnant women and to guide subsequent recognition and management of post-dural puncture headache should it occur in this population.

• identify and clarify management options at the time of dural puncture.

• clarify roles of care.

2.1 Recognition of a Dural Puncture

Dural puncture may result in obvious free flow of cerebrospinal fluid (CSF) through the Tuohy needle. However, it may only result in a slow drip via the Tuohy needle or be evident on aspiration via the catheter once threaded. In this situation, testing the temperature of the fluid on the back of the gloved hand and the use of urine dipstick testing on the fluid may assist in differentiating CSF from saline used in the loss of resistance technique.

Table 1: Differentiation of CSF and saline ³

Dural puncture may only be suspected after a higher than expected block is achieved once the test dose is given and, finally, may only be evident after development of a post dural puncture headache in the affected patient.

2.2 Immediate management of a dural puncture

The Consultant must be informed as soon as it is appropriate (e.g., at handover).

ADP may be managed in one of two ways highlighted below. The choice will depend on the anaesthetist performing the epidural at the time and should be based on their experience and clinical judgement.

EITHER

1. Intrathecal catheter

• Insert/leave the catheter in the intrathecal space^4. A length of 3cm should be left in the intrathecal space⁵. Consider this option particularly if:

- labour is well advanced

- dural puncture was diagnosed after catheter insertion

- location of the space was particularly difficult

• Label the catheter very clearly as INTRATHECAL, TOP UPS TO BE GIVEN BY ANAESTHETIST ONLY. All drugs given through the catheter MUST be administered by an anaesthetist. Use up to 3ml boluses of the epidural ‘low-dose local anaesthetic mixture’ (0.1% bupivacaine / levobupivacaine + 2 microgram/ml fentanyl) flushed with 2ml sodium chloride 0.9% (deadspace of a 16G Portex epidural catheter and filter is approximately 1ml)⁶.

• If the mother requires a caesarean section, the catheter may be topped up using 0.5-1ml aliquots of 0.5% heavy bupivacaine + 300microgram diamorphine until a suitable block is achieved (although diamorphine is used off-label for this purpose).

• Remove the catheter at the end of labour / caesarean section unless there is a very good reason not to (e.g., coagulopathy).

• There is insufficient evidence to support the avoidance of pushing in the second stage.

OR

2. Resite epidural

• Take the Tuohy needle out and resite the epidural at a different space. Note that here is a risk of a repeat dural puncture.

• Use smaller volumes to top up the epidural as there is a risk of subarachnoid spread.

• Label as
  EPIDURAL CATHETER BUT KNOWN DURAL PUNCTURE.

• Initially the anaesthetist should top up the epidural as needed.

• Check the level of the block at 20 minutes and hourly thereafter.

• PCEA may only be used once several top ups have been given which have shown no evidence of excessive spread – discuss with a consultant anaesthetist first. If there is doubt, continue with anaesthetist-delivered top ups.

IN EITHER CASE

• Inform the midwife looking after the mother, the midwife in charge and the obstetrician.

• Explain what has happened to the mother, apologise, and explain that she has a 50-80% chance of developing a severe headache.

• Ensure that you document clearly what has taken place in the labour record.

• Ensure the follow-up documentation is filled in appropriately and that a thorough handover is undertaken so that appropriate follow-up can occur.

• The midwife may remove the catheter after delivery in the usual way whether it is intrathecal or epidural.

2.3 Follow up

• The mother should be followed up daily until discharge. On discharge, the mother should be given the telephone number for the labour ward and asked to return to see the anaesthetist should she develop a severe headache.

• The consultant anaesthetist covering labour ward or on call should be heavily involved in the decision-making process for the management of the patient.

• The full details of the dural puncture and its management should be recorded on the discharge summary so that the community midwife and GP are fully informed.

2.4 Course of a post-dural puncture headache (PDPH)

• Ninety percent of headaches occur within the first three days and 66% within 48 hours. Rarely, the headache may occur between 5 and 14 days post dural puncture⁷. Rarer still, the headache may occur immediately post dural puncture, but this should prompt the search for alternative causes.

• PDPH is usually a self-limiting process. Untreated, 75% will resolve spontaneously within 1 week and 88% within 6 weeks of dural puncture.

• Rarely, untreated PDPH can progress to subdural haematoma.

2.5. Diagnosis of PDPH – symptoms and signs

Symptoms and signs:

• Severe headache, frontal, occipital or fronto-occipital, aggravated by upright posture and relieved in the supine position

• Nausea and vomiting, neck stiffness, photophobia, blurred vision and tinnitus may be present

• The headache is usually severe enough to prevent the mother from caring for her baby

2.6 Differential diagnosis

There are many other diagnoses that may present with similar symptoms and signs and hence a thorough neurological examination must be performed by the anaesthetist and suspicious cases thoroughly investigated.

• Intracranial haematoma

• Cerebral venous thrombosis

• Meningitis

• Intracranial tumour

• Migraine

• Pre-eclampsia

• Tension headache

2.7 Management of PDPH

As a first instance the patient should be offered a trial of conservative therapy². This should involve simple analgesics (regular paracetamol and diclofenac unless contraindicated) and rehydration. Rehydration should simply be the avoidance of dehydration rather than overhydration. This ensures CSF production is adequate. There is little evidence to support the use of caffeine, sumatriptan, steroids, ACTH analogues or gabapentinoids².

There is currently insufficient evidence to recommend the use of acupuncture, greater occipital nerve blocks or sphenopalatine blocks in the management of PDPH.²

If conservative treatment fails or the headache is severe the patient should be offered an epidural blood patch. There is evidence suggesting that delaying the blood patch until 48 hours post dural puncture may result in a better success rate⁸. However, in severe obstetric PDPH an epidural blood patch performed within 48 hours of headache for symptom control may be considered although it may need to be repeated².

2.8 Epidural blood patch

This should be performed by two anaesthetists; one of whom should be a consultant. The woman should be counselled as to the risks and benefits of a blood patch and full consent should be taken on a consent form.

The following should be consented for:

Back pain

Nerve injury/ radiculopathy

Failure

2^nd dural puncture

Epidural abscess/ arachnoiditis

Seizures

She should be told that the success rate of a first blood patch is between 50-80%² and that she may need a second patch if her symptoms do not resolve. A blood patch is contraindicated in the presence of systemic signs of infection or coagulopathy.

The procedure must be performed in theatre or in the anaesthetic room. Both venesection and the epidural should be performed under strict aseptic conditions. An attempt should be made to inject 20ml of blood into the epidural space⁹. Injection of blood should stop should the patient feel any pain. There is no evidence to support sending routine blood cultures. There is currently insufficient evidence to recommend exactly how long the patient should remain in bed for or in what precise position². It is recommended that maternal pulse, blood pressure and temperature be monitored after an epidural blood patch².

The patient should be advised to call back and speak to the anaesthetist on labour ward for further advice if the symptoms return post discharge.

3.1 This guideline will be discussed and ratified at the Labour ward forums at both sites.

3.2 Post-dural puncture and PDPH rates and management will be recorded and audited through the follow-up procedures for post-natal patients at each site.