Post-Dural Puncture Headache (PDPH) Clinical Overview

Written By Danial Mirza

I. The "On-Call" Snapshot

  • Clinical Significance in Malaysia: This is a frequent complication following neuraxial anaesthesia (spinal/epidural) and diagnostic lumbar punctures, particularly in our young obstetric population. It causes significant morbidity and can prolong hospital stays if not managed effectively.

  • High-Yield Definition: As per the International Headache Society, PDPH is a headache attributed to low cerebrospinal fluid (CSF) pressure occurring within 5 days of a dural puncture. It's typically accompanied by neck stiffness and improves when supine.

  • Clinical One-Liner: Basically, the needle for the spinal or LP made a hole in the dura, CSF is leaking out, and now the brain is "sagging" when the patient sits up, causing a severe, postural headache.

II. Etiology & Risk Factors

  • Etiology: Iatrogenic dural puncture leading to CSF leakage at a rate exceeding CSF production. This results in intracranial hypotension.

  • Risk Factors:

    • Non-modifiable:

      • Young age (18-40 years)

      • Female gender

      • Pregnancy (especially during labour)

      • Previous history of PDPH

    • Modifiable (Procedural):

      • Large gauge needle (e.g., 18G Tuohy needle used for epidurals vs. 25-27G spinal needle)

      • Use of a cutting-tip needle (e.g., Quincke) versus a pencil-point needle (e.g., Whitacre, Sprotte)

      • Multiple puncture attempts

III. Quick Pathophysiology

It’s straightforward. A hole in the dura allows CSF to leak into the epidural space. This volume loss leads to a drop in intracranial pressure. When the patient is upright, gravity causes caudal displacement of the brain, leading to traction on pain-sensitive intracranial structures like the dura, bridging veins, and cranial nerves. This traction is what causes the characteristic severe, postural headache. There is also a component of compensatory cerebral vasodilation that contributes to the pain.

IV. Clinical Assessment

  • Red Flags & Immediate Actions:

    • Fever, neck stiffness (true meningismus), altered mental status: → Alert senior immediately, start sepsis workup. This could be meningitis, not PDPH.

    • New focal neurological deficit (e.g., cranial nerve palsy other than VI, limb weakness), seizure: → Urgent senior review, request urgent CT Brain. This could be a subdural haematoma, a rare but serious complication.

    • Sudden "thunderclap" onset or non-postural headache: → Consider subarachnoid haemorrhage or cerebral venous thrombosis. Escalate.

  • History:

    • Common (>50%): Severe, bilateral, fronto-occipital headache. Critically, it is postural: significantly worse on sitting or standing (often within minutes), and relieved by lying flat. Ask them to quantify the pain on a scale of 1-10 when lying down versus sitting up.

    • Less Common (10-50%): Nausea, neck stiffness, photophobia, phonophobia, tinnitus, dizziness.

    • Pertinent Negatives: No fever, no history of trauma, no preceding illness. Crucially, confirm the recent history of a spinal, epidural, or lumbar puncture (check the BHT and anaesthesia chart).

  • Physical Examination:

    • The neurological exam is almost always normal.

    • Check vital signs for any signs of sepsis.

    • Assess for neck stiffness – be gentle. It's often present but shouldn't be the rigid neck of meningitis.

    • Check the puncture site on the back for signs of infection or haematoma.

  • Clinical Pearl: The single most important diagnostic tool is the history. If a young patient develops a severe headache within 48-72 hours of a dural puncture that is dramatically better when lying flat, it is PDPH until proven otherwise.

V. Diagnostic Workflow

This is primarily a clinical diagnosis. Don't rush to order scans.

  • Differential Diagnosis:

    • Meningitis:

      • Points For: Headache, neck stiffness.

      • Points Against: Presence of fever, altered mental state, usually non-postural headache.

      • How to Differentiate: Clinical picture and, if necessary, a repeat LP for CSF analysis (but discuss with your senior first, as this can worsen PDPH).

    • Subdural Haematoma:

      • Points For: Severe headache.

      • Points Against: Usually non-postural, often associated with focal neurological deficits.

      • How to Differentiate: Urgent non-contrast CT Brain.

    • Cerebral Venous Sinus Thrombosis (CVST):

      • Points For: Can occur in postpartum women. Severe headache.

      • Points Against: Often associated with seizures, focal deficits. Not typically postural.

      • How to Differentiate: MRV or CTV is the gold standard.

  • Investigations Plan:

    • Bedside / Initial: None required for a typical presentation.

    • First-Line Labs & Imaging: Only if red flags are present or the diagnosis is uncertain. A baseline FBC and CRP might be useful if there's any suspicion of infection.

    • Confirmatory / Gold Standard: There is no "gold standard" test as it's a clinical diagnosis. In atypical or persistent cases, an MRI Brain with gadolinium may be requested by a specialist, which might show pachymeningeal (dural) enhancement and sagging of the brain.

VI. Staging & Severity Assessment

We don't use a formal staging system. We classify it based on functional impairment:

  • Mild: Patient has a postural headache but can still mobilise, eat, and care for her baby.

  • Moderate: Headache is severe enough to limit mobilisation for extended periods.

  • Severe: Patient is completely incapacitated by the headache, confined to bed, and unable to perform activities of daily living.

This severity assessment directly dictates the management plan. Mild cases get conservative treatment; severe cases may require definitive intervention.

VII. Management Plan

  • Immediate Stabilisation (The ABCDE Plan):

    • This is rarely needed unless there are red flags. The priority is pain relief.

    • Ensure the patient is comfortable and lying flat.

  • Definitive Treatment (The Ward Round Plan):

    • First-Line (Conservative Management for Mild-Moderate PDPH):

      • Analgesia: Start with regular Paracetamol 1g QDS and a course of NSAIDs like Mefenamic Acid 500mg TDS (if no contraindications, especially postpartum).

      • Hydration: Encourage oral fluids. IV hydration is often given but evidence is weak.

      • Caffeine: Oral caffeine (from coffee/tea) or a stat dose of IV Caffeine Benzoate 500mg can provide temporary relief via cerebral vasoconstriction.

      • Positioning: Advise bed rest and lying supine as much as possible for the first 24-48 hours.

    • Second-Line / Refractory Cases (Invasive Management for Severe PDPH):

      • Epidural Blood Patch (EBP): This is the gold standard.

        • Indication: Severe, debilitating headache unresponsive to 24-48 hours of conservative management.

        • Procedure: An anaesthetist will perform an epidural procedure, but instead of medication, they will inject 15-20mL of the patient's own sterilely-drawn venous blood into the epidural space at or near the level of the previous puncture.

        • Mechanism: The blood forms a clot over the dural hole (the "patch") and also increases epidural pressure, which in turn increases CSF pressure, providing immediate relief.

        • Success Rate: High, around 70-90% success with the first patch.

  • Long-Term & Discharge Plan:

    • Once the headache resolves, no specific follow-up is needed.

    • Document the event clearly in the discharge summary for future anaesthetic reference.

    • Advise the patient to avoid heavy lifting or straining for a few days after an EBP.

VIII. Complications

  • Immediate (first 24 hours):

    • Failed Conservative Treatment: Management: Escalate for consideration of EBP.

  • Short-Term (days to weeks):

    • Failed EBP: Management: May require a second EBP after 24-48 hours.

    • Chronic Headache/Backache: Management: Refer to anaesthetic pain clinic for follow-up.

  • Long-Term (Rare but serious):

    • Subdural Haematoma: From excessive brain sagging and tearing of bridging veins. Management: Urgent neurosurgical referral.

    • Infection from EBP (Epidural abscess/meningitis): Management: Urgent senior review, imaging, antibiotics, and possible surgical intervention.

IX. Prognosis

Excellent. Over 85% of cases resolve spontaneously within a week, and an EBP is highly effective for those that don't. The main prognostic factor for requiring an EBP is the initial severity of the headache. Recurrence is possible but uncommon.

X. How to Present to Your Senior

"Dr., for review please. This is Puan Siti in Bed 10, a 30-year-old P1D2 post-emergency LSCS under spinal anaesthesia. She is complaining of a severe, frontal headache, 9/10, which started yesterday. The key feature is that it is postural - it resolves completely when she lies flat but is severe on sitting up, preventing her from breastfeeding. Her neurological exam is normal, and she is afebrile. My diagnosis is a severe Post-Dural Puncture Headache. We have tried regular PCM and NSAIDs with minimal relief. I would like to ask if we should refer her to the anaesthetic team for consideration of an epidural blood patch."

XI. Summary & Further Reading

  • Top 3 Takeaways:

    1. The hallmark of PDPH is its postural nature: severe when upright, relieved when supine.

    2. Management is stepwise: start with conservative measures (analgesia, hydration, caffeine).

    3. For severe, incapacitating headaches, the Epidural Blood Patch (EBP) is the gold-standard treatment and you should not delay referral to the anaesthetist.

  • Key Resources:

Danial Mirza
Previous

Post Operative Nausea and Vomiting Clinical Overview
Next

Malignant Hyperthermia Clinical Overview