When an ADP occurs during the insertion of an epidural, this is normally obvious as CSF flows rapidly down the Tuohy needle. Management of ADP varies depending on local policy. 

• The anaesthetist may remove the Tuohy needle and attempt to site another epidural at a different space. The anaesthetist must be vigilant when passing the epidural catheter as there is a possibility that its tip may enter the subarachnoid space via the hole in the dura. Additionally, all top ups must be given with caution as some local anaesthetic may reach the CSF.
• Insertion of an intrathecal catheter has been shown to reduce the incidence of PDPH, but in order to maximise this benefit the catheter should be left in place for up to 24 hours.³ Concerns about sterility may mean that the catheter cannot be left this long. An intrathecal catheter must be labelled clearly as such and all top-ups must be administered by an anaesthetist. If an intrathecal catheter is inserted, the consultant anaesthetist covering the labour ward must be made aware.
• Prophylactic epidural blood patch after ADP does not reliably reduce the incidence of PDPH.⁴ It also exposes the patient to the risks of blood patch when they may not have gone on to develop a PDPH in any case.

PDPH normally manifests 24-72 hours after the causative intervention. The characteristic headache is bilateral, frontal or occipital, and varies with posture, worsening within 15 minutes of standing and improving within 15 minutes of lying down. Associated symptoms may include nausea, neck stiffness, tinnitus, photophobia and hyperacusis (sensitivity to sound).⁵

Most PDPHs will resolve spontaneously, with about 70% resolving in a week. However, some may persist for several months.⁶

Simple treatment:

• Strict bed rest is not of benefit in reducing the symptoms of PDPH; however a well-rested patient may be better able to cope with the headache.
• Ensuring the patient is well hydrated may improve symptoms.
• Abdominal binders may help relieve symptoms in some patients by increasing intraabdominal pressure. However, these can be uncomfortable and are not suitable if the patient has had an abdominal operation. They are not widely used.
• Oral analgesia (paracetamol and NSAID if tolerated) should be prescribed regularly, and the patient encouraged to continue regular analgesia until the headache has subsided. If weak opioids are prescribed, ensure a laxative is also prescribed.
• Caffeine is widely used because it is easy to administer, although its evidence base is not great. The assumed mechanism is vasoconstriction of cerebral blood vessels. 300-500mg caffeine daily has been recommended, which is the equivalent of 4-6 cups of coffee. Caffeine may cause tremor and arrhythmias in high doses.
• If the patient is confined to bed, she may require thromboprophylaxis. If prophylactic LMWH is prescribed, ensure it is for a time of day to allow 12 hours to elapse after the dose, so that blood patch can be safely carried out if indicated.

Epidural blood patch

Epidural blood patch (EBP) is considered the gold standard treatment. Its success rate for PDPH following small gauge spinal needle puncture may be as high as 95%; for punctures involving larger needles, it is around 50-75%. The headache may return in about 30% of patients who receive an initially successful EBP. Up to 40% of patients may require a second blood patch.⁷ Remember to carefully consider other diagnoses in patients where an EBP has been unsuccessful.

It is recommended that EBP is performed 24-48 hours after the onset of PDPH symptoms, as some patients will respond to the simple treatments above. If the headache is so severe that the patient is having trouble caring for her baby, it may be sensible to offer EBP earlier.

Contraindications to EBP include:

• Patient refusal.
• Systemic infection.
• Raised intracranial pressure.

Potential complications include:

• Early/immediate:
  • Backache (30-70%).
  • Bradycardia (common).
  • Fever (common).
  • Second accidental dural puncture (uncommon).
• Late:
  • Persisting radicular pain (may be more common than once believed).
  • Meningitis (rare).
  • Cranial nerve palsy (rare).
  • Seizures (rare).
  • Subdural haematoma (rare).

Technique of epidural blood patch

• The patient should give informed consent. There is a GGC patient information leaflet available on the intranet here, and the Obstetric Anaesthetists’ Association one is here.
  Document consent on a new anaesthetic chart.
• Make sure each case has been discussed with the consultant covering the labour ward (who may wish to be involved with the procedure).
• It should be done in daylight hours, but this includes the weekend.
• This is a two person job. As well as two anaesthetists (epiduralist and venepuncturist), there should be an anaesthetic assistant to help, and a midwife to look after the patient.
• The patient have an intravenous cannula and be fully monitored, and should be sitting upright unless the severity of her symptoms prevents this, when the procedure should be done in the lateral position.
• The venepuncturist should identify their intended puncture site before performing a full surgical scrub. The site should be prepped and draped as for an epidural insertion.
• The epiduralist should identify their intended space (which does not need to be the same as the initial space where the ADP occurred), before scrubbing, preparing the patient’s back and applying a sterile drape.
• The epiduralist should perform the epidural using loss of resistance to saline.
• The venepuncturist should then remove 20mls of blood from the patient and carefully pass this syringe to the epiduralist, taking care to preserve sterility at all times.
• The epiduralist should then slowly inject the blood into the Tuohy needle until either:
  • The patient complains of back pain or radicular pain.
  • All 20 mls have been injected.
• The Tuohy needle should then be removed and the patient lain on her back.
• Vital signs should be recorded every ten minutes for 30 minutes.
• There is no need for the patient to remain supine for a prolonged period, although she should avoid heavy lifting or straining.
• There is no need to obtain blood cultures at the same time as performing EBP.
• If she is asymptomatic on mobilising after the procedure, the patient may be discharged.

It is a recommendation of the most recent MBBRACE report that “Any woman who suffers a dural tap or post-dural puncture headache must be notified to her GP and routine follow-up arranged.”⁸

It is the responsibility of the anaesthetic consultant involved in the management of the patient to ensure that GP is notified, and that the patient has had a follow up appointment arranged. Sample letters to the GP are in Appendix A and Appendix B below.

The follow up could either be a face-to-face appointment in around 6 weeks, or a telephone call at around the same time.

The patient should know who to contact if the headache recurs after discharge.

Department of Anaesthesia

XXXXXXX Hospital

Tel: 0141 XXXXXXX

01/09/2016

Dear Doctor,

Re: PATIENT NAME, CHI

Your patient had a spinal or epidural performed in the Maternity Hospital on DATE, and is at risk of developing a post dural puncture headache (PDPH).

A PDPH normally develops within 72 hours of the spinal or epidural procedure but may develop as much as a week later. The symptoms are normally of a severe, frontal or occipital, bilateral headache, which gets significantly worse when the patient stands. Some PDPHs respond to simple analgesia although it may take several weeks to resolve completely. 

An epidural blood patch is the definitive treatment for PDPH. If the patient develops a headache matching the above description, please do not hesitate to contact the obstetric anaesthetic consultant on the number above, so that she can be assessed and treated if appropriate. Out of hours please contact the on call resident anaesthetist on 0141 XXXXXX, page# XXXX.

Many thanks.

Kind regards,

Consultant Anaesthetist

Department of Anaesthesia

XXXXXXX Hospital

Tel: 0141 XXXXXXX

01/09/2016

Dear Doctor,

Re: PATIENT NAME, CHI

Your patient had a spinal or epidural performed in the Maternity Hospital on DATE, and developed a post dural puncture headache (PDPH).

This was treated with an epidural blood patch on DATE and she was discharged on DATE.

It is expected that up to 70% of patients’ PDPH symptoms will improve following a blood patch, although in a small proportion of patients the headache may recur.

If your patient develops a severe, worsening or persistent headache, or any neurological signs or symptoms, please do not hesitate to contact the obstetric anaesthetic consultant on the number above, so that the patient can be assessed and treated if appropriate. Out of hours please contact the on call resident anaesthetist on 0141 XXXXXXX, page# XXXXX.

Many thanks.

Kind regards,

Consultant Anaesthetist