Postdural puncture headache (PDPH) is typified by severe headache that is usually frontal or fronto-occipital, bilateral, worsened by standing or sitting upright and relieved by lying. Atypical clinical presentations that lack a positional component are infrequent but have been described in some women. There may be associated neck stiffness, nausea, tinnitus, visual disturbances and photophobia. It is thought to arise from intracranial hypotension resulting from leakage of cerebrospinal fluid (CSF) through the dural hole, with stretching of the cranial nerve roots and meninges in the upright position. Thus, the incidence and severity of PDPH are greatest following dural puncture with large cutting needles that leave large holes in the dura (60-90% in parturients after accidental dural puncture with a 16 G Tuohy needle), whereas small non-cutting needles are associated with a low incidence (under 1% with 25-27 G pencil-point needles). Parturients are the patient group most susceptible to PDPH.
There may be associated cerebral vasodilatation, leading to similarities being made between PDPH and migraine.
Symptoms usually begin within 1-2 days of dural puncture, although later onset (up to 10 days) has been reported. Headache usually lasts for 1-2 weeks but may occasionally persist for several months.
Problems and special considerations
Symptoms may be severe enough to prevent the mother mobilising and caring for her baby; this is particularly unwelcome in the early postpartum period. Discharge from hospital may be delayed, increasing costs and the risks of hospital-acquired infection and thromboembolism.
Rarely, more sinister sequelae may occur. These include cranial nerve palsies (the sixth cranial nerve being most susceptible, owing to its long intracranial course), convulsions, hearing loss and subdural or intracranial haemorrhage, or cortical vein thrombosis. Nerve damage may persist, even on resolution of the headache.
Diagnosis
A full history should be taken and neurological examination performed, as other differential diagnoses need to be considered (Table 45.1). Neurological referral and neuroimaging may be wise in difficult or refractory cases. PDPH is suggested by a history of dural puncture and typical symptoms, especially the postural element.
In approximately one-third of cases, PDPH may follow apparently unremarkable regional anaesthesia. Possible causes include lack of recognition at the time of dural puncture; failure to report dural puncture for fear of retribution; a possible tear of the dura but not arachnoid at the time of epidural insertion, with rupture of the arachnoid subsequently; and migration of the epidural catheter intrathecally during labour.
Table 45.1 Causes of postpartum headache
Tension, stress, fatigue, depression
Intracranial hypotension, e.g. postdural puncture headache
Intracranial hypertension, e.g. tumour, haematoma, cortical vein thrombosis, idiopathic
intracranial hypertension
Migraine
Infection, e.g. meningitis, sinusitis, encephalitis
Pre-eclampsia (including posterior reversible encephalopathy syndrome)
Electrolyte imbalance, hypoglycaemia
Drugs, e.g. ondansetron
It has been suggested that an otherwise typical PDPH that only becomes severe hours after getting up is caused by a very small dural hole with slow leak of CSF, for example after spinal anaesthesia with a very fine needle. A useful confirmatory sign is the lessening of headache produced by gradually compressing the upright patient’s upper abdomen. This is thought to displace spinal CSF into the cranium by causing venous engorgement in the extradural space. Magnetic resonance imaging and computerised tomography scanning have been used to diagnose intracranial hypotension and to demonstrate cerebrospinal fluid leaks (in the latter case involving further diagnostic dural puncture), but are not widely used.
Management options
Initial management includes simple analgesics such as paracetamol and non-steroidal antiinflammatory drugs. Although frequently prescribed, there is no evidence that overhydration or bed rest has a preventive effect. Other medical management includes oral caffeine 150-300 mg every 6-8 hours, which has been shown to improve the symptoms temporarily. Caffeine may cause nausea and vomiting in overdosage and has been implicated in convulsions occurring after dural puncture. A recent Cochrane review concluded that the use of gabapentin, theophylline and hydrocortisone was associated with reduced pain severity scores in patients with PDPH. The use of sumatriptan and ACTH analogue has been described, but the evidence supporting their use is weak.
Invasive procedures involve infusion or injection of various substances such as saline or dextran into the extradural space, firstly to shift CSF from the spine into the skull and secondly to tamponade leakage of CSF through the dural hole and even to seal the hole. These are no longer recommended. However, epidural blood patch (EBP) is now generally accepted as the definitive treatment in persistent PDPH, with reported success rates of 60-70% after one patch and 80-90% after a second blood patch if the headache recurs. Many anaesthetists would now proceed to EBP early (e.g. within 24-48 hours of symptoms) if there is a good history, rather than delay for several days as was common previously (see Chapter 46, Epidural blood patch).
Full discussion with, and support of, the patient is of prime importance, since she may be more distressed by apparent indifference to the severity of her symptoms than by the complication itself. She should be regularly visited while in hospital and followed up in the initial period after discharge. The patient should be counselled - preferably by a senior anaesthetist - on the various therapeutic options and on the rare possibility of serious sequelae. It is not known whether EBP prevents these, although this is generally assumed if symptoms resolve. If the woman decides against an EBP, she should be reassured that she may come back at any time should her symptoms persist. Healthcare staff who provide postpartum care for the patient - including her general practitioner - must be made aware of her clinical course, outcome and also of ‘red flag’ features mandating further medical advice. Postpartum follow-up at 6-10 weeks is recommended in order to check that symptoms have resolved and to advise about future pregnancies.
Key points
• Postdural puncture headache occurs in 60-90% of parturients after accidental dural tap with a 16 G Tuohy needle.
• The postural element is the most important confirmatory feature, but atypical presentations have been reported.
• Initial management includes paracetamol, non-steroidal anti-inflammatory drugs, avoidance of dehydration, ± caffeine.
• Definitive treatment is with epidural blood patch.
Further reading
Arevalo-Rodriguez I, Ciapponi A, Roque i Figuls M, Munoz L, Bonfill Cosp X. Posture and fluids for preventing post-dural puncture headache. Cochrane Database Syst Rev 2016; (3): CD009199.
Basurto Ona X, Osario D, Bonfill Cosp X. Drug therapy for treating post-dural puncture headache. Cochrane Database Syst Rev 2015; (7): CD007887.
Klein AM, Loder E. Postpartum headache. Int J Obstet Anesth 2010; 19: 422-30.
Sachs A, Smiley R. Post-dural puncture headache: the worst common complication in obstetric anesthesia. Semin Perinatol 2014; 38: 386-94.