Lumbar Puncture

Quick Answer

Lumbar puncture (LP) is an essential diagnostic and therapeutic procedure in intensive care for suspected meningitis, subarachnoid haemorrhage (when CT negative), Guillain-Barré syndrome (GBS), and idiopathic intracranial hypertension. Key principles include performing LP at L3-L4 or L4-L5 (below conus medullaris at L1-L2), using atraumatic (pencil-point) needles to reduce post-dural puncture headache (PDPH), and replacing the stylet before needle removal (reduces PDPH from 36% to 24%). Normal opening pressure is 60-200 mmH2O (6-20 cmH2O) in lateral decubitus. Contraindications include raised ICP with mass effect, platelets below 50 x 10^9/L, and INR greater than 1.5.

ICU-Specific Considerations:

• Meningitis: Do NOT delay antibiotics for LP - give ceftriaxone/vancomycin + dexamethasone immediately
• SAH: LP for xanthochromia if CT negative and presentation greater than 12 hours from ictus
• GBS: Albuminocytologic dissociation (elevated protein, normal WCC) supports diagnosis
• Coagulopathy: Common in critically ill patients - correct before LP if possible

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CICM Exam Focus

What Examiners Expect

Second Part Written SAQ:

Common question stems:

• "Describe the indications, contraindications, and technique for lumbar puncture in a critically ill patient"
• "A patient with suspected bacterial meningitis - outline the approach to diagnosis and antibiotic timing"
• "Discuss the differentiation of bacterial from viral meningitis based on CSF analysis"
• "A patient develops severe headache 24 hours post-LP - describe the pathophysiology and management"
• "Outline the management of suspected subarachnoid haemorrhage with negative CT scan"

Expected depth:

• Indications (meningitis, SAH if CT negative, GBS, IIH, carcinomatous meningitis)
• Absolute and relative contraindications with rationale
• Anatomy (conus L1-L2, Tuffier's line, structures traversed)
• Technique (20-22G needle, midline vs paramedian, stylet replacement)
• CSF interpretation (bacterial vs viral vs TB, xanthochromia timing)
• Complications and management (PDPH, epidural haematoma, herniation)

Second Part Hot Case:

Presentations requiring LP knowledge:

• Febrile patient with altered consciousness
• Thunderclap headache with negative CT
• Progressive ascending weakness (GBS workup)
• Post-neurosurgical fever and confusion
• Unexplained encephalopathy

Second Part Viva:

Expected discussion flow:

1. Indications - When is LP indicated in ICU? Contraindications?
2. Pre-procedure - CT before LP criteria, coagulation assessment
3. Anatomy - Conus level, structures traversed, safe interspace
4. Technique - Positioning, needle selection, opening pressure
5. CSF Analysis - Interpretation patterns, traumatic tap vs SAH
6. Complications - PDPH pathophysiology, blood patch, herniation
7. Australian Context - Indigenous health, meningococcal disease, remote considerations

Pass vs Fail Performance

Pass Standard:

• Lists clear indications and contraindications
• Describes anatomy accurately (conus L1-L2, safe levels L3-L4 and below)
• Knows normal CSF values and interpretation patterns
• Understands PDPH prevention (atraumatic needle, stylet replacement)
• Mentions need for CT before LP in appropriate patients

Common Reasons for Failure:

• Delaying antibiotics for LP in suspected meningitis
• Not knowing contraindications (coagulopathy thresholds)
• Confusing conus level with dural sac termination
• Unable to interpret CSF (bacterial vs viral patterns)
• Not knowing PDPH management (blood patch indication/timing)

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Key Points

Note: Critical ICU Pearl: In suspected bacterial meningitis, antibiotics (ceftriaxone + vancomycin) and dexamethasone should be given IMMEDIATELY. Do NOT delay antimicrobial therapy to perform LP or await results. LP can be performed within 2-4 hours of antibiotics without significantly affecting CSF culture yield (PMID: 17947268).

Critical Alert: Red Flag: Performing LP in a patient with raised ICP and mass effect (midline shift, effaced basal cisterns, posterior fossa mass) risks transtentorial or tonsillar herniation. CT brain must be performed first in patients with focal neurological deficit, altered consciousness (GCS below 12), papilledema, immunocompromise, or recent seizure.

10 Must-Know Facts for CICM Exam:

1. Conus medullaris terminates at L1-L2 in adults (L3 in neonates). LP must be at L3-L4 or below to avoid spinal cord injury (PMID: 30969567).

2. Tuffier's line (intercristal line) connects iliac crests and crosses L4 spinous process or L4-L5 interspace - key surface landmark (PMID: 22219291).

3. Opening pressure normal range: 60-200 mmH2O (6-20 cmH2O) in lateral decubitus position. Elevated in meningitis (greater than 250), IIH (greater than 250), SAH (PMID: 27613562).

4. Atraumatic needles (Whitacre, Sprotte) reduce PDPH from 20-40% to 2-5% by spreading rather than cutting dural fibres (PMID: 23783408).

5. Replace stylet before needle removal - reduces PDPH from 36% to 24% by preventing arachnoid strands from plugging the dural defect (PMID: 9605269).

6. CSF interpretation patterns: Bacterial (WCC greater than 1000, neutrophils greater than 80%, protein greater than 1 g/L, glucose below 40% serum); Viral (WCC 10-500, lymphocytes, normal glucose); TB (lymphocytes, protein 1-5 g/L, low glucose) (PMID: 17947268).

7. Xanthochromia (bilirubin in CSF) is diagnostic of SAH when present greater than 12 hours post-ictus; spectrophotometry gold standard, but visual inspection of yellow supernatant acceptable (PMID: 23453542).

8. Contraindications: Platelets below 50 x 10^9/L, INR greater than 1.5, mass effect on CT, local infection at puncture site (PMID: 29400006).

9. Epidural blood patch for PDPH: 15-25 mL autologous blood injected into epidural space at LP level. Success rate 70-98%. Indicated if headache persists greater than 48-72 hours despite conservative measures (PMID: 21220669).

10. Aboriginal and Torres Strait Islander populations have higher rates of invasive meningococcal disease - maintain high index of suspicion, involve Aboriginal Health Workers in communication (PMID: 30761655).

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Definition and Epidemiology

Definition

Lumbar puncture (LP), also known as spinal tap, is a diagnostic and therapeutic procedure involving insertion of a needle into the lumbar subarachnoid space (lumbar cistern) to sample cerebrospinal fluid (CSF) or measure intrathecal pressure (PMID: 28613461).

Epidemiology in ICU

Frequency:

• 3-5% of ICU admissions require LP for diagnosis (PMID: 29180566)
• Higher in neurological and infectious disease ICUs
• Most common indication: suspected CNS infection

Outcomes:

• First-pass success rate: 85-95% with experienced operator (PMID: 26088033)
• Ultrasound-guided LP: greater than 95% success rate
• Complication rate: PDPH 10-40% (cutting needle), 2-5% (atraumatic needle)
• Serious complications (bleeding, herniation): less than 0.5%

Australian Data:

• Invasive meningococcal disease incidence: 0.6-0.8 per 100,000 population
• Higher in Aboriginal and Torres Strait Islander populations (2-3x risk)
• Pneumococcal meningitis: 0.8 per 100,000, higher mortality in elderly
• Viral meningitis: 5-10 per 100,000 annually

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Indications

Diagnostic Indications

Therapeutic Indications

Indications Specific to ICU

When LP is commonly needed in ICU:

1. Febrile encephalopathy without clear source - Must exclude CNS infection
2. Persistent unexplained fever in immunocompromised - Cryptococcal, Listeria, TB meningitis
3. Acute flaccid paralysis - GBS, transverse myelitis, poliomyelitis
4. Post-neurosurgical fever/confusion - Bacterial meningitis, ventriculitis
5. Suspected intrathecal bleeding - Post-procedure, anticoagulation-related
6. Intrathecal drug delivery - Baclofen, opioids, chemotherapy

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Contraindications

Absolute Contraindications

Critical Alert: ABSOLUTE - Do NOT perform LP if present:

Relative Contraindications

Anticoagulation Guidelines (ASRA 2018)

Based on American Society of Regional Anesthesia and Pain Medicine guidelines (PMID: 29400006):

Note: Clinical Pearl: In suspected bacterial meningitis, the risk of delaying LP for coagulopathy correction must be weighed against the critical need for diagnosis. If LP is delayed, empiric antibiotics should be given immediately. Blood cultures are positive in 50-70% of bacterial meningitis cases and may provide microbiological diagnosis.

CT Before LP Criteria

Hasbun Criteria (PMID: 11136331) - CT brain before LP indicated if any of:

• Age greater than 60 years
• Immunocompromised state (HIV, transplant, chemotherapy)
• History of CNS disease (mass, stroke, focal infection)
• Seizure within 1 week
• Focal neurological deficit
• Altered level of consciousness (GCS below 15)
• Papilledema

Risk of herniation post-LP (PMID: 17947268):

• With no risk factors: less than 0.1%
• With mass effect on CT: 5-15%
• Posterior fossa mass: highest risk

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Anatomy

Vertebral Anatomy

Lumbar Spine Structure (PMID: 30725788):

Spinal Cord and Meninges

Conus Medullaris (PMID: 30969567):

• Adult termination: L1-L2 (range T12-L3)
• Neonate termination: L3 (range L1-L4)
• Critical: LP must be at L3-L4 or below to avoid spinal cord injury

Cauda Equina:

• Collection of L2-S5 nerve roots
• Descends through lumbar cistern (L2-S2)
• Peripheral nerves (LMN), not spinal cord
• More resilient to needle trauma than cord

Dural Sac Termination:

• Adults: S2 vertebral level
• Neonates: S3-S4
• Contains CSF and cauda equina

Meningeal Layers (superficial to deep):

1. Dura mater: Tough, fibrous (0.2-0.4 mm thick)
2. Arachnoid mater: Thin, avascular membrane
3. Pia mater: Adherent to neural tissue

Subarachnoid Space (Lumbar Cistern):

• Location: L2 to S2
• Volume: 25-35 mL CSF
• Contents: CSF, cauda equina, filum terminale
• Target for LP - safe zone with no spinal cord

Surface Landmarks

Tuffier's Line (Intercristal Line) (PMID: 22219291):

• Horizontal line connecting highest points of both iliac crests
• Crosses spine at L4 spinous process or L4-L5 interspace
• Key landmark for identifying safe LP level
• May be inaccurate in obesity (line often higher than thought)

Posterior Superior Iliac Spines (PSIS):

• Palpable at S2 level
• Marks inferior extent of dural sac
• Alternative landmark confirmation

Structures Traversed (Midline Approach)

Total Depth to Subarachnoid Space:

• Average adult: 4-6 cm (5 cm typical)
• Range: 3-8 cm depending on body habitus
• Obese patients: May need longer needle (greater than 9 cm standard)

Paramedian Approach Anatomy

Structures Traversed:

1. Skin
2. Subcutaneous tissue
3. Paraspinal muscles (bypass interspinous ligaments)
4. Ligamentum flavum
5. Epidural space
6. Dura/Arachnoid
7. Subarachnoid space

Advantage: Bypasses calcified supraspinous/interspinous ligaments (common in elderly)

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Equipment

Essential Equipment

Needle Selection

Needle Types (PMID: 23783408):

Needle Gauge Selection:

Recommendation for ICU:

• 22G atraumatic (Whitacre/Sprotte) for standard diagnostic LP
• Combines adequate CSF flow with low PDPH risk

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Technique

Pre-Procedure Preparation

Patient Assessment:

1. Review indication and urgency
2. Check contraindications (coagulation, imaging)
3. Obtain informed consent (discuss risks: headache, bleeding, infection, failure)
4. Ensure CT performed if indicated (Hasbun criteria)
5. Baseline observations (BP, HR, GCS, pupils)

Coagulation Check:

• Platelet count: Target greater than 50 x 10^9/L
• INR: Target less than 1.5
• aPTT: Normal range
• Review anticoagulant timing (ASRA guidelines)

Positioning

Lateral Decubitus (Preferred for OP Measurement):

1. Patient lying on side at edge of bed
2. Knees flexed to chest ("fetal position")
3. Spine parallel to floor edge
4. Shoulders and hips perpendicular to bed
5. Pillow under head (neutral spine alignment)
6. Assistant to maintain position and provide reassurance
7. Maximum flexion opens interspinous spaces

Sitting Position (Alternative):

1. Patient sitting at edge of bed, feet supported
2. Leaning forward over pillow on bedside table
3. Chin to chest, arms wrapped around pillow
4. Easier landmark identification, especially in obese patients

Advantages: Better midline identification, gravity assists CSF flow Disadvantages: Cannot measure accurate opening pressure, syncope risk

Sterile Technique

Critical Alert: MANDATORY: Operator MUST wear surgical mask. LP-associated meningitis (iatrogenic) is most commonly caused by operator's respiratory flora (Streptococcus viridans group). Failure to wear mask is a breach of standard of care (PMID: 21270923).

Aseptic Preparation:

1. Hand hygiene (surgical scrub or alcohol-based rub)
2. Don surgical mask and sterile gloves
3. Prepare sterile field with equipment
4. Skin antisepsis: 2% chlorhexidine in 70% alcohol (preferred over povidone-iodine)
5. Allow antiseptic to dry completely (2-3 minutes)
6. Apply fenestrated sterile drape
7. Maintain strict asepsis throughout procedure

Step-by-Step Procedure

Step 1: Identify Landmarks

• Palpate iliac crests bilaterally
• Identify Tuffier's line (intercristal line)
• Palpate spinous processes to identify L3-L4 or L4-L5 interspace
• Mark site with sterile marker or skin impression

Note: Ultrasound Guidance: In obese patients or difficult anatomy, pre-procedural ultrasound identification of midline and interspace increases first-pass success from 60% to greater than 90% (PMID: 26088033).

Step 2: Local Anaesthesia

• Raise skin wheal with 25G needle at insertion site
• Infiltrate deeper tissues along intended track (3-5 mL total)
• Advance to interspinous ligament for optimal analgesia
• Wait 2-3 minutes for full effect

Step 3: Needle Insertion

1. Position needle with bevel (Quincke) or opening (atraumatic) facing cephalad
2. In lateral decubitus, bevel parallel to longitudinal dural fibres
3. Insert needle in midline, slight cephalad angle (toward umbilicus)
4. Advance slowly through tissue layers
5. Feel resistance changes: soft → firm (supraspinous) → soft (interspinous) → firm (ligamentum flavum) → "pop" (epidural entry)
6. Continue advancing - second "pop" or give-way indicates dural puncture
7. Remove stylet to check for CSF flow
8. If no flow, rotate needle 90 degrees, wait, or advance slightly (1-2 mm)

Step 4: Opening Pressure Measurement

1. Attach manometer with three-way stopcock
2. Patient must be relaxed (not straining or crying)
3. Partially extend legs (maximum knee flexion falsely elevates OP)
4. Read CSF column height in mmH2O or cmH2O
5. Normal: 60-200 mmH2O (6-20 cmH2O)
6. Record opening pressure immediately

Step 5: CSF Collection

Collect in 4 numbered tubes (1-2 mL per tube, 6-8 mL total):

Step 6: Needle Removal

Critical Alert: CRITICAL STEP: Replace stylet BEFORE removing needle. This reduces PDPH from 36% to 24% by preventing arachnoid strands from being pulled through the dural defect and maintaining tract patency (PMID: 9605269).

1. Fully reinsert stylet
2. Remove needle in one smooth motion
3. Apply sterile gauze with firm pressure for 2-3 minutes
4. Apply occlusive dressing

Post-Procedure Care

Immediate:

• Monitor observations (BP, HR, GCS) at 15, 30, 60 minutes
• Patient may remain supine for 30-60 minutes (evidence for benefit unclear)
• Encourage oral fluids
• Analgesia for local discomfort if needed

Documentation:

• Indication, consent obtained
• Position (lateral/sitting), interspace level (L3-L4 or L4-L5)
• Needle type and gauge
• Number of attempts
• Opening pressure (mmH2O)
• CSF appearance (clear, bloody, xanthochromic)
• Volume collected per tube
• Complications
• Specimen disposition and time sent

Specimen Handling:

• Label tubes correctly (1-4)
• Send to laboratory immediately (within 30 minutes)
• CSF cells degrade rapidly - delays affect cell count accuracy
• Store at room temperature (not refrigerated) if delay unavoidable

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CSF Analysis and Interpretation

Normal CSF Values

Meningitis CSF Patterns

Key Discriminators (PMID: 17947268):

• CSF:Serum glucose less than 0.4 = highly suggestive of bacterial meningitis
• CSF lactate greater than 3.5 mmol/L = sensitivity 93%, specificity 96% for bacterial
• CSF protein greater than 2.2 g/L = suggests bacterial or TB
• WCC greater than 1000 with greater than 80% neutrophils = bacterial until proven otherwise

Subarachnoid Haemorrhage CSF

Xanthochromia (PMID: 23453542):

Traumatic Tap vs True SAH:

Correction for Traumatic Tap:

• Subtract 1 WBC per 500-700 RBCs
• Example: RBC 7000/µL, WBC 25/µL → Corrected WBC = 25 - (7000/700) = 15/µL

Guillain-Barré Syndrome CSF

Albuminocytologic Dissociation (PMID: 29358689):

• Elevated protein (greater than 0.45 g/L, often 1-5 g/L)
• Normal WCC (less than 10 cells/µL)
• Protein peaks at 2-4 weeks from symptom onset
• 60% normal in first week - may need repeat LP

Diagnostic Criteria:

• Progressive weakness of more than one limb
• Areflexia/hyporeflexia
• Progression over days to 4 weeks
• Relative symmetry
• CSF protein elevated with WCC less than 50

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Opening Pressure

Normal Values

Elevated Opening Pressure

Low Opening Pressure

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Complications

Post-Dural Puncture Headache (PDPH)

Epidemiology (PMID: 21220669, PMID: 23783408):

• Cutting needle (Quincke): 20-40% incidence
• Atraumatic needle (Whitacre/Sprotte): 2-5% incidence
• Smaller gauge (25G vs 22G): Lower incidence
• Peak incidence: Young females

Pathophysiology:

1. CSF leaks through dural defect at rate faster than production
2. Intracranial hypotension develops
3. Brain sags in upright position
4. Traction on pain-sensitive meninges and bridging veins
5. Compensatory venodilation causes throbbing headache

Clinical Features:

• Onset: 24-48 hours post-LP (up to 7 days)
• Postural: Worse sitting/standing, improves within 15-30 minutes of lying flat
• Location: Frontal, occipital, or bifrontal
• Associated: Nausea, vomiting, photophobia, neck stiffness, tinnitus, diplopia (VI nerve palsy)
• Self-limiting: 85% resolve within 6 weeks

Prevention:

1. Atraumatic (pencil-point) needle - Most important intervention (PMID: 23783408)
2. Smaller gauge needle (22G vs 20G)
3. Replace stylet before removal - Reduces PDPH from 36% to 24% (PMID: 9605269)
4. Bevel parallel to dural fibres (in lateral position)
5. Limit number of dural punctures (use single needle pass)

Management:

Epidural Blood Patch Technique (PMID: 21220669):

1. Sterile technique, patient lateral decubitus
2. Identify epidural space at LP level or one level below
3. Draw 20-25 mL autologous venous blood (sterile technique)
4. Inject slowly into epidural space until resistance or discomfort
5. Patient lies supine for 1-2 hours post-procedure
6. Avoid straining, bending, lifting for 48 hours

Epidural/Spinal Haematoma

Risk Factors:

• Coagulopathy (platelets less than 50, INR greater than 1.5)
• Anticoagulation therapy
• Multiple needle passes
• Difficult, traumatic LP

Clinical Features:

• Progressive back pain
• Lower limb weakness, sensory loss
• Bowel/bladder dysfunction
• Develops hours to days post-LP

Management:

• Surgical emergency - Decompressive laminectomy within 6-12 hours
• MRI spine urgently
• Reverse coagulopathy immediately
• Neurosurgical consultation

Critical Alert: Time-Critical: Epidural haematoma with neurological deficit requires decompression within 6-12 hours to prevent permanent paraplegia. Delays beyond this window significantly worsen outcome (PMID: 15127615).

Cerebral Herniation

Risk:

• Less than 1% if no mass effect on CT
• 5-15% if mass effect present
• Highest with posterior fossa lesions

Mechanism:

• CSF removal from lumbar space creates pressure gradient
• Brain herniates downward through foramen magnum (tonsillar) or tentorium (transtentorial)

Prevention:

• CT before LP if any Hasbun criteria present
• Do NOT perform LP with mass effect, midline shift, effaced basal cisterns
• Avoid excessive CSF removal

Recognition:

• Rapid deterioration in consciousness
• Pupillary dilation (unilateral then bilateral)
• Abnormal posturing (decerebrate/decorticate)
• Respiratory arrest

Management:

• Immediate airway management
• Hyperventilation (target PaCO2 30-35 mmHg)
• Mannitol 1 g/kg or hypertonic saline
• Emergency neurosurgical consultation

Infection (Iatrogenic Meningitis)

Incidence: 1:10,000 to 1:50,000 (PMID: 21270923)

Organisms:

• Streptococcus viridans group (most common - operator's oral flora)
• Staphylococcus aureus
• Gram-negative bacilli

Prevention:

• Surgical mask MANDATORY for operator
• Full aseptic technique
• Chlorhexidine skin preparation
• Avoid talking over sterile field

Other Complications

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Special Situations in ICU

Coagulopathic Patient

Common in ICU:

• Disseminated intravascular coagulation (DIC)
• Liver failure
• Thrombocytopenia (sepsis, HIT)
• Anticoagulation for PE/AF

Approach:

1. Weigh risk/benefit (critical diagnosis vs bleeding risk)
2. Correct coagulopathy if possible:
   • Platelets greater than 50 x 10^9/L (transfuse if needed)
   • INR less than 1.5 (FFP, vitamin K, PCC)
   • Fibrinogen greater than 1.0 g/L (cryoprecipitate)
3. Use atraumatic needle (lower bleeding risk)
4. Minimise needle passes
5. Consider blood cultures as alternative if LP delayed
6. Document risk-benefit discussion

Mechanically Ventilated Patient

Challenges:

• Positioning difficult
• Sedation requirements
• PEEP may affect CSF pressure

Approach:

1. Adequate sedation and analgesia (propofol, fentanyl)
2. Consider neuromuscular blockade for positioning
3. Lateral decubitus with assistant maintaining position
4. May need to reduce PEEP temporarily during LP
5. Opening pressure may be elevated due to positive pressure ventilation

Obese Patient

Challenges:

• Landmarks difficult to palpate
• Greater depth to subarachnoid space
• Higher failure rate

Solutions:

1. Ultrasound guidance (pre-procedural or real-time)
2. Sitting position for better midline identification
3. Longer needle (9 cm or 12 cm vs standard 8.9 cm)
4. Introducer needle to maintain trajectory
5. Fluoroscopic guidance if multiple failures

Post-Craniotomy/VP Shunt Patient

Considerations:

• May need LP for CSF infection diagnosis
• VP shunt can be tapped directly for CSF
• Post-craniotomy CSF may have blood, elevated protein
• Risk of introducing infection through shunt

Approach:

• Discuss with neurosurgery
• Shunt tap preferred if shunt infection suspected
• LP still appropriate if shunt functioning and not infected

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Indigenous Health Considerations

Aboriginal and Torres Strait Islander Health

Epidemiology (PMID: 30761655):

• 2-3x higher incidence of invasive meningococcal disease
• Higher rates of pneumococcal meningitis
• Rheumatic heart disease complications may present with CNS infection
• Melioidosis (Burkholderia pseudomallei) in northern Australia can cause meningitis

Cultural Safety:

1. Family/Community Involvement:

   • Decision-making often communal
   • Allow time for consultation with family/elders where clinically safe
   • Include family in discussions and consent process

2. Aboriginal Health Workers (AHWs) and Aboriginal Liaison Officers (ALOs):

   • Engage early in consultation
   • Essential cultural brokers for communication
   • Can help explain procedure in culturally appropriate terms

3. Gender Considerations:

   • "Men's Business" and "Women's Business" are significant
   • Match clinician or support staff gender to patient where possible
   • Ask patient about preferences

4. Communication:

   • English may be second, third, or fourth language
   • Use interpreter services (telehealth or in-person)
   • Avoid medical jargon
   • Use visual aids and diagrams
   • Allow adequate time for questions

5. Fear and Misconceptions:

   • Concerns about LP causing paralysis common
   • Use clear visual explanations showing needle entry well below spinal cord
   • Address concerns directly and respectfully

Barriers to Care:

• Geographic isolation (remote communities)
• Delayed presentation due to transport challenges
• Historical trauma affecting healthcare trust
• Traditional healing practices may delay presentation

Best Practices:

• Maintain high index of suspicion for invasive infections
• Do NOT delay antibiotics while arranging LP or transfer
• Involve AHWs/ALOs from first contact
• Respect cultural protocols while ensuring necessary care
• Family presence during procedure if culturally appropriate and desired

Maori Health (New Zealand)

Considerations:

• Whanau (family) involvement in decision-making
• Tikanga (cultural practices) respected in care delivery
• Head/spine considered tapu (sacred) - careful explanation needed
• Engage Maori Health Workers as cultural liaisons
• Higher rates of meningococcal disease in Maori children

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Remote and Rural Considerations

Royal Flying Doctor Service (RFDS) Context

Key Principles:

1. Treatment over diagnosis - Do NOT delay empiric antibiotics for LP
2. LP rarely performed in remote field - usually deferred to tertiary hospital
3. RFDS protocols: IV/IM ceftriaxone 2g immediately for suspected meningitis

When to Perform LP in Remote Settings:

Resource-Limited Settings

Equipment Limitations:

• Use available needles (prioritise atraumatic if possible)
• No manometer: Proceed without OP measurement if critical
• Limited lab capacity: Treat empirically, send specimens to tertiary
• No ultrasound: Careful landmark palpation, alternative approaches

Alternative Diagnostics:

• Blood cultures (positive in 50-70% bacterial meningitis)
• Serum procalcitonin, CRP for bacterial vs viral differentiation
• PCR if available

Telemedicine:

• Contact RFDS or state retrieval service for advice
• Discuss LP safety and timing with tertiary hospital
• Transfer if uncertain

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Algorithm: LP Decision-Making in ICU

SUSPECTED CNS INFECTION OR SAH
            ↓
      ASSESS CONTRAINDICATIONS
            ↓
    ┌───────────────────────┐
    │ Hasbun Criteria Met?  │
    │ (Age >60, immuno,     │
    │ focal deficit, GCS under 15,│
    │ seizure, CNS history, │
    │ papilledema)          │
    └───────────────────────┘
        │ YES          │ NO
        ↓              ↓
    CT HEAD FIRST    PROCEED TO LP
        ↓
    ┌─────────────────┐
    │ Mass Effect?     │
    └─────────────────┘
        │ YES          │ NO
        ↓              ↓
    DO NOT LP         PROCEED TO LP
    Give antibiotics  (after antibiotics
    Neurosurgery      if meningitis)
        ↓
    LP PROCEDURE
        │
        ├──→ Coagulopathy? → Correct first (PLT>50, INRless than 1.5)
        │
        ├──→ Position: Lateral decubitus (OP measurement)
        │             Sitting (easier landmarks)
        │
        ├──→ Needle: 22G atraumatic (Whitacre/Sprotte)
        │
        ├──→ Level: L3-L4 or L4-L5 (below conus)
        │
        ├──→ Measure Opening Pressure
        │
        ├──→ Collect 4 tubes (6-8 mL total)
        │
        └──→ Replace stylet before removal
            ↓
    CSF INTERPRETATION
        │
        ├──→ Bacterial pattern → Ceftriaxone + Vancomycin + Dexamethasone
        │
        ├──→ Viral pattern → Supportive, consider acyclovir if HSV
        │
        ├──→ TB pattern → 4-drug anti-TB therapy
        │
        ├──→ Xanthochromia → CT angiogram, neurosurgical referral
        │
        └──→ Albuminocytologic dissociation → GBS workup, IVIG/PLEX

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Evidence Summary

Key Trials and Guidelines

Cochrane Reviews

1. Atraumatic needles for LP (PMID: 28493618): Atraumatic needles significantly reduce PDPH (OR 0.40) and should be first-line for all diagnostic LPs.

2. Blood patch for PDPH (PMID: 20091602): Epidural blood patch effective for treating PDPH, with limited evidence on optimal timing.

Australian/NZ Guidelines

• ANZICS-CORE Statement on Procedural Sedation: Guidance for sedation during LP in ICU
• Therapeutic Guidelines (eTG) - Antibiotics: Australian-specific empiric therapy for meningitis
• CDNA meningococcal guidelines: Notification and contact tracing requirements

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SAQ Practice Questions

SAQ 1: Lumbar Puncture Technique and CSF Interpretation

Question (20 marks):

A 34-year-old woman presents to the ICU with a 2-day history of fever, severe headache, photophobia, and neck stiffness. Her GCS is 14 (E4V4M6), temperature 39.2C, and she has no focal neurological deficit or papilledema.

Tasks:

1. Describe the contraindications to lumbar puncture and how you would assess this patient (4 marks)
2. Describe the anatomical structures traversed during lumbar puncture using a midline approach at L4-L5 (4 marks)
3. Outline the procedural technique for lumbar puncture, including measures to reduce post-dural puncture headache (6 marks)
4. The CSF results are: opening pressure 320 mmH2O, WCC 2,450/µL (95% neutrophils), protein 3.2 g/L, glucose 1.8 mmol/L (serum glucose 6.2 mmol/L). Interpret these findings and outline your management (6 marks)

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Model Answer:

(1) Contraindications and Assessment (4 marks):

Absolute Contraindications:

• Raised ICP with mass effect (midline shift, effaced basal cisterns on CT)
• Severe coagulopathy (platelets less than 50 x 10^9/L, INR >1.5)
• Skin infection at puncture site
• Spinal epidural abscess

Relative Contraindications:

• Moderate thrombocytopenia (50-100 x 10^9/L)
• Anticoagulation therapy
• Cardiopulmonary instability
• Altered consciousness (GCS 9-12)

Assessment of This Patient:

• CT brain required if Hasbun criteria met - this patient has altered consciousness (GCS 14 with confusion = V4)
• Check coagulation: FBC for platelet count, INR, aPTT
• Fundoscopy: Confirm no papilledema (already stated absent)
• Review anticoagulant medications
• DO NOT delay empiric antibiotics - give ceftriaxone + vancomycin + dexamethasone while awaiting CT

(2) Anatomical Structures Traversed (4 marks):

From superficial to deep at L4-L5 interspace:

1. Skin - minimal resistance
2. Subcutaneous tissue - variable thickness (0.5-2 cm)
3. Supraspinous ligament - fibrous, first firm resistance
4. Interspinous ligament - softer than supraspinous
5. Ligamentum flavum - thick (5-6 mm), elastic, characteristic "pop" when traversed
6. Epidural space - 5-6 mm, contains fat and venous plexus
7. Dura mater - tough fibrous layer, second "pop" sensation
8. Arachnoid mater - thin, traversed with dura (closely adherent)
9. Subarachnoid space - target, CSF flows freely

Important Anatomical Points:

• Conus medullaris terminates at L1-L2 in adults
• L4-L5 is in the lumbar cistern containing only CSF and cauda equina
• Tuffier's line (intercristal line) crosses L4 spinous process

(3) Procedural Technique and PDPH Prevention (6 marks):

Pre-Procedure:

• Informed consent (explain headache risk, bleeding, infection, failure)
• Position: Lateral decubitus (allows opening pressure measurement)
• Maximum spinal flexion to open interspinous spaces
• Identify L4-L5 interspace using Tuffier's line

Sterile Technique:

• Surgical mask MANDATORY (prevents iatrogenic meningitis)
• Sterile gloves, full aseptic technique
• Chlorhexidine 2% in alcohol for skin preparation (allow to dry)
• Sterile draping

Procedure:

• Local anaesthesia: 1% lidocaine, skin wheal and deeper infiltration
• Insert needle midline, slight cephalad angle (toward umbilicus)
• Use 22G atraumatic needle (Whitacre/Sprotte) - reduces PDPH from 25% to 5%
• Bevel parallel to longitudinal dural fibres (in lateral position)
• Advance slowly, feeling for "pops" (LF, then dura)
• Remove stylet to confirm CSF flow

Opening Pressure:

• Attach manometer with three-way stopcock
• Patient relaxed, legs partially extended
• Record opening pressure in mmH2O

CSF Collection:

• 4 tubes, 1-2 mL each (total 6-8 mL)
• Tube 1: Chemistry; Tube 2: Microbiology; Tube 3: Haematology; Tube 4: Special tests

PDPH Prevention:

1. Atraumatic (pencil-point) needle - most important intervention (66% reduction)
2. Smaller gauge (22G vs 20G)
3. Replace stylet before needle removal - reduces PDPH from 36% to 24%
4. Minimise number of dural punctures (single pass if possible)
5. Bevel orientation parallel to dural fibres

Post-Procedure:

• Firm pressure for 2-3 minutes, occlusive dressing
• Monitor observations, encourage oral fluids
• Document procedure details

(4) CSF Interpretation and Management (6 marks):

CSF Interpretation:

Diagnosis: BACTERIAL MENINGITIS

• Classic pattern: Elevated OP, high WCC with neutrophils, high protein, low glucose
• CSF:serum glucose ratio less than 0.4 is highly suggestive of bacterial aetiology

Management:

Immediate:

1. Antibiotics (should already be given empirically):

   • Ceftriaxone 2g IV BD (or cefotaxime 2g IV Q4H)
   • Vancomycin 25-30 mg/kg loading dose then 15-20 mg/kg Q8-12H (for penicillin-resistant pneumococcus, L. monocytogenes coverage)
   • Consider ampicillin 2g IV Q4H if >50 years or immunocompromised (Listeria coverage)

2. Dexamethasone 0.15 mg/kg (10 mg adult) Q6H for 4 days:

   • Ideally given before or with first antibiotic dose
   • Reduces mortality in pneumococcal meningitis (NNT 12)
   • Continue if pneumococcal or H. influenzae confirmed

Investigations:

• Blood cultures (before antibiotics ideally, but DO NOT delay treatment)
• CSF Gram stain and culture
• CSF PCR (meningococcal, pneumococcal, HSV, enterovirus)
• CSF lactate (>3.5 supports bacterial aetiology)

ICU Care:

• Close neurological monitoring (GCS, pupils)
• ICP management if required (head of bed elevation, avoid hyperthermia)
• Fluid management (avoid hyponatraemia, SIADH common)
• Seizure prophylaxis if seizure occurs
• Contact tracing and notification if meningococcal (public health requirement)

Reassess:

• Repeat LP in 48-72 hours if no clinical improvement
• Adjust antibiotics based on culture and sensitivity results
• Duration: 10-14 days for pneumococcal, 7 days for meningococcal

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SAQ 2: Subarachnoid Haemorrhage and Post-LP Headache

Question (20 marks):

A 42-year-old man presents with sudden-onset severe headache ("worst headache of my life") that began 18 hours ago while exercising. CT brain performed at the referring hospital was reported as normal. He is transferred to your ICU for further investigation.

Tasks:

1. Discuss the role of lumbar puncture in suspected subarachnoid haemorrhage with negative CT scan, including optimal timing (4 marks)
2. The LP shows opening pressure 180 mmH2O, CSF appearance is xanthochromic (yellow), RBC 850/µL (non-clearing between tubes), WCC 15/µL. Interpret these findings (4 marks)
3. The following day, you perform LP on another patient with suspected meningitis. She develops severe positional headache 36 hours later. Describe the pathophysiology and management of post-dural puncture headache (6 marks)
4. The headache persists despite 48 hours of conservative management. Describe the epidural blood patch procedure and its evidence base (6 marks)

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Model Answer:

(1) Role of LP in SAH with Negative CT (4 marks):

Rationale for LP:

• CT sensitivity for SAH is time-dependent:
  • under 6 hours: 98-100% sensitivity
  • 12-24 hours: 93% sensitivity

  • 1 week: less than 50% sensitivity

• Negative CT does NOT exclude SAH, especially if >6-12 hours from ictus
• LP is essential to detect xanthochromia (bilirubin) indicating prior intracranial bleeding

Optimal Timing:

• LP should be performed >12 hours after headache onset
• This allows time for RBC lysis and bilirubin formation
• Xanthochromia takes 6-12 hours to develop after bleeding
• Peak sensitivity for xanthochromia: 12 hours to 2 weeks
• If LP performed under 12 hours, may get false negative for xanthochromia

LP Procedure Considerations:

• Must measure opening pressure (often elevated in SAH)
• Collect CSF in sequential tubes to compare RBC counts
• Centrifuge and examine supernatant for xanthochromia (visual or spectrophotometry)
• Send for RBC count, WCC, protein, glucose

Caution:

• Do NOT perform LP if CT shows mass effect
• Consider CTA as alternative/adjunct if LP unavailable or contraindicated

(2) CSF Interpretation (4 marks):

Diagnosis: SUBARACHNOID HAEMORRHAGE confirmed

Key Discriminators from Traumatic Tap:

1. Xanthochromia present - blood has been in CSF long enough for lysis and bilirubin formation (>12 hours)
2. Non-clearing RBCs - RBC count constant across tubes (traumatic tap shows >25% decrease tube 1 to 4)
3. Timing - 18 hours since ictus, sufficient for xanthochromia to develop

Xanthochromia Detection:

• Visual inspection: Yellow/orange colour of centrifuged supernatant
• Spectrophotometry: Absorbance peak at 450-460 nm (bilirubin) - gold standard
• Positive xanthochromia confirms intracranial bleeding, not traumatic tap

Immediate Management Required:

• Urgent CT angiography (CTA) or catheter angiography to identify aneurysm
• Neurosurgical/neurointerventional referral
• ICU admission for monitoring
• Blood pressure control, seizure precautions
• Nimodipine for vasospasm prophylaxis

(3) Pathophysiology and Management of PDPH (6 marks):

Pathophysiology:

1. CSF Leak: Dural puncture creates defect through which CSF leaks into epidural space
2. Rate of leak exceeds production: CSF produced at 0.35 mL/min, but leak can be faster
3. Intracranial hypotension: Total CSF volume (150 mL) decreases
4. Brain sag: In upright position, brain sags due to loss of buoyancy
5. Meningeal traction: Pain-sensitive dura and bridging veins stretched
6. Compensatory venodilation: Cerebral vessels dilate to maintain intracranial volume (Monro-Kellie doctrine)

Clinical Features:

• Onset: 24-48 hours post-LP (range: immediate to 7 days)
• Postural: Worse sitting/standing, improves within 15-30 minutes lying flat
• Location: Frontal, occipital, or diffuse
• Associated symptoms: Nausea, vomiting, photophobia, neck stiffness
• Cranial nerve involvement: VI nerve palsy (diplopia), tinnitus, hearing changes
• Self-limiting: 85% resolve within 6 weeks

Risk Factors:

• Young age
• Female sex
• Cutting (Quincke) needle vs atraumatic
• Larger gauge needle
• Multiple dural punctures
• Stylet not replaced before removal

Conservative Management (First 48-72 hours):

(4) Epidural Blood Patch Procedure and Evidence (6 marks):

Indication:

• PDPH persisting >48-72 hours despite conservative measures
• Severe PDPH significantly impairing function
• Cranial nerve involvement (VI palsy)

Mechanism:

• Autologous blood clots and seals dural defect
• Immediate "tamponade" effect increases CSF pressure
• Long-term: Fibrin patch permanently seals defect (develops over days)

Procedure:

1. Consent: Explain procedure, risks (back pain, infection, nerve injury, failure, repeat procedure)
2. Position: Lateral decubitus (same as LP) or prone
3. Sterile technique: Full aseptic precautions
4. Identify epidural space: At same level as LP or one level below
5. Loss of resistance technique: Tuohy or epidural needle to identify epidural space
6. Draw blood: Second operator draws 20-25 mL autologous venous blood using strict sterile technique
7. Inject blood: Slow injection into epidural space until resistance felt or patient reports pressure/discomfort (typically 15-25 mL)
8. Post-procedure: Patient lies supine for 1-2 hours
9. Aftercare: Avoid straining, heavy lifting for 48 hours

Efficacy Evidence (PMID: 21220669, PMID: 20091602):

Complications:

• Back pain at injection site (common, self-limiting)
• Radicular pain (rare)
• Infection (rare with sterile technique)
• Subdural haematoma (very rare)
• Failure requiring repeat procedure (10-25%)

Timing Considerations:

• Early blood patch (less than 24h) may have lower success rate
• Optimal timing: After 24-72 hours of conservative management failure
• Not an emergency - can be scheduled during working hours

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Viva Scenarios

Viva 1: LP Technique and Complications

Scenario:

Examiner: You are the ICU registrar. You need to perform a lumbar puncture on a 55-year-old man with suspected bacterial meningitis. His platelet count is 65 x 10^9/L and INR is 1.3. Walk me through your approach.

---

Candidate Response:

Assessment of Contraindications:

"First, I would assess this patient for contraindications to LP.

His coagulation is suboptimal with platelets 65 and INR 1.3. The standard thresholds are platelets >50 and INR less than 1.5. His platelets are above 50, and INR is below 1.5, so while borderline, he does not have an absolute contraindication.

However, given the clinical urgency of suspected bacterial meningitis, I would not delay LP for platelet transfusion unless there were other bleeding concerns. I would use an atraumatic needle to minimise bleeding risk.

Before proceeding, I need to ensure he meets criteria for safe LP:

• Has he had a CT brain? I would apply Hasbun criteria - age >60, immunocompromised, seizure, focal deficit, altered consciousness, CNS disease history
• At 55 with suspected meningitis, if he has any altered consciousness or focal signs, CT is mandatory
• I would also check fundoscopy for papilledema"

---

Examiner: He has no focal neurological deficit, GCS is 14, and CT brain shows no mass effect. How do you proceed?

---

Candidate:

"Given GCS 14 suggests some altered consciousness, I'm glad CT has been done and shows no contraindication. I would proceed with LP.

Pre-procedure:

• Ensure antibiotics have already been given - ceftriaxone, vancomycin, and dexamethasone should NOT be delayed for LP
• Informed consent
• Position: Lateral decubitus for opening pressure measurement
• Equipment: 22G atraumatic needle (Whitacre or Sprotte), manometer, sterile field

Anatomical Landmarks:

• Identify Tuffier's line connecting iliac crests - crosses L4 spinous process
• Target L3-L4 or L4-L5 interspace - both are below the conus medullaris which ends at L1-L2 in adults

Sterile Technique:

• Surgical mask MANDATORY - most iatrogenic meningitis from operator's oral flora
• Sterile gloves, chlorhexidine preparation, allow to dry
• Local anaesthetic infiltration

Procedure:

• Insert needle midline with slight cephalad angle
• Advance through skin, subcutaneous tissue, supraspinous ligament, interspinous ligament, ligamentum flavum (feel 'pop'), epidural space, dura (second 'pop')
• Confirm CSF flow by removing stylet"

---

Examiner: Why use an atraumatic needle? What's the evidence?

---

Candidate:

"Atraumatic or pencil-point needles (Whitacre, Sprotte) have a conical tip that spreads dural fibres rather than cutting them like traditional Quincke needles.

Evidence:

• Multiple systematic reviews and meta-analyses show 60-70% reduction in post-dural puncture headache
• Quincke needle PDPH rate: 20-40% (depending on gauge)
• Atraumatic needle PDPH rate: 2-5%

A Cochrane review (PMID 28493618) confirmed this significant reduction with no increase in traumatic tap rate, procedure failure, or backache.

This is now standard of care for diagnostic lumbar punctures."

---

Examiner: What other measures reduce PDPH?

---

Candidate:

"Several evidence-based measures reduce PDPH:

1. Atraumatic needle - most important (60-70% reduction)
2. Smaller gauge - 22G vs 20G reduces risk
3. Bevel orientation - parallel to longitudinal dural fibres
4. Replace stylet before removal - important and often forgotten; reduces PDPH from 36% to 24% (PMID 9605269)
5. Single dural puncture - minimise number of needle passes
6. Experienced operator - reduces traumatic attempts

Interestingly, prolonged bed rest and aggressive IV fluid hydration have NOT been shown to reduce PDPH in randomised trials, though they are still commonly recommended."

---

Examiner: The patient develops severe headache 48 hours later that is worse when sitting up. How do you manage this?

---

Candidate:

"This is classical post-dural puncture headache. The diagnosis is made clinically:

• Onset 24-48 hours post-LP
• Postural - worse sitting/standing, improves lying flat within 15-30 minutes
• Often frontal or occipital, may have nausea, photophobia

Pathophysiology:

• CSF leak through dural defect faster than production (0.35 mL/min)
• Intracranial hypotension causes brain sag in upright position
• Traction on pain-sensitive meninges and bridging veins

Initial Management (Conservative):

• Bed rest in supine position
• Oral fluids 2-3 L/day
• Caffeine 300-500 mg Q6H (or IV caffeine 500mg in saline)
• Simple analgesia - paracetamol, NSAIDs

If persistent >48-72 hours:

• Epidural blood patch
• 15-25 mL autologous blood injected into epidural space at LP level
• 70-98% success rate
• Second patch if first fails (80-90% success)

I would also consider neuroimaging if red flags develop - focal signs, fever, thunderclap recurrence - to exclude subdural haematoma or other pathology."

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Viva 2: CSF Interpretation and Indigenous Health

Scenario:

Examiner: A 28-year-old Aboriginal woman from a remote community in the Northern Territory presents to your ICU with headache, fever, neck stiffness, and a petechial rash. She was transferred by RFDS. Her lumbar puncture shows WCC 3,200/µL (90% neutrophils), protein 2.8 g/L, glucose 1.2 mmol/L (serum 5.8 mmol/L). Discuss your interpretation and management.

---

Candidate Response:

CSF Interpretation:

"The CSF findings are consistent with bacterial meningitis:

• Very high WCC (>1000) with neutrophil predominance (>80%)
• Elevated protein (>1 g/L)
• Low glucose with CSF:serum ratio 0.21 (less than 0.4 strongly suggests bacterial)

The clinical picture with petechial rash in a young patient strongly suggests meningococcal meningitis (Neisseria meningitidis). Aboriginal and Torres Strait Islander populations have 2-3x higher rates of invasive meningococcal disease, so this diagnosis should be high on my differential."

---

Examiner: What is your immediate management?

---

Candidate:

"This is a medical emergency requiring immediate action:

Antimicrobials: I would confirm she has already received antibiotics - ceftriaxone 2g IV BD should have been given prior to or with LP. If not given, this is priority.

For meningococcal meningitis:

• Ceftriaxone 2g IV BD (or cefotaxime) - covers N. meningitidis
• Vancomycin not typically needed if meningococcal confirmed
• However, empirically I would include vancomycin initially until cultures return

Dexamethasone:

• 10 mg (0.15 mg/kg) IV Q6H for 4 days
• Evidence shows mortality benefit in pneumococcal meningitis
• Should be given before or with first antibiotic dose
• Continue if pneumococcal, may discontinue if meningococcal confirmed

ICU Monitoring:

• Neurological observations Q1H (GCS, pupils)
• Watch for signs of raised ICP, cerebral oedema
• Monitor for septic shock (BP, lactate, urine output)
• Watch for DIC (common in meningococcal sepsis) - check coagulation, fibrinogen

Public Health:

• Notifiable disease - contact public health immediately
• Contact tracing required - close contacts need prophylaxis (rifampicin or ciprofloxacin)
• In remote Aboriginal communities, this may require community-wide response"

---

Examiner: How would you approach communication with this patient and her family?

---

Candidate:

"This requires culturally safe communication:

Aboriginal Health Worker (AHW) and Aboriginal Liaison Officer (ALO):

• I would engage these services immediately
• They are essential cultural brokers for communication
• Help explain the diagnosis and treatment in culturally appropriate terms
• Can address fears and misconceptions

Family Involvement:

• Aboriginal culture often involves communal decision-making
• Extended family and elders may need to be involved
• Allow time for family consultation where clinically safe
• Family presence at bedside is important for support

Language Considerations:

• English may not be her first language
• Use interpreter services (in-person or telephone) if needed
• Avoid medical jargon
• Use visual aids where helpful

Cultural Considerations:

• Gender matching of clinician/support staff if possible
• Awareness of 'Men's Business' and 'Women's Business'
• Ask about any cultural practices or preferences
• Respect for traditional healing alongside medical care

Fear and Trust:

• Historical trauma may affect healthcare trust
• Clear, honest communication builds trust
• Explain everything you're doing and why
• Address any specific fears or concerns"

---

Examiner: She deteriorates with septic shock. What are the specific considerations for meningococcal sepsis?

---

Candidate:

"Meningococcal sepsis carries high mortality (10-40%) and requires aggressive management:

Sepsis Resuscitation:

• Fluid resuscitation - crystalloid, may need 30-60 mL/kg in first hour
• Vasopressors early if hypotensive despite fluids (noradrenaline first-line)
• Intubation if airway compromise or GCS under 8

Coagulopathy/DIC:

• Very common in meningococcal sepsis - check coagulation frequently
• Petechiae/purpura may progress rapidly
• Monitor for bleeding complications
• Replace blood products as needed (FFP, platelets, cryoprecipitate)

Adrenal Crisis:

• Waterhouse-Friderichsen syndrome - adrenal haemorrhage
• Consider stress-dose hydrocortisone (100 mg Q8H)
• May be difficult to distinguish from septic shock

Limb Ischaemia:

• Purpura fulminans can cause peripheral gangrene
• May require amputation - involve surgical team early
• Tissue plasminogen activator sometimes used (limited evidence)

Complications to Monitor:

• Raised ICP
• Seizures
• ARDS
• Acute kidney injury
• Multi-organ failure

Remote/RFDS Considerations:

• If not already in tertiary centre, may need ECMO capability for refractory shock
• Ensure family updated - they may be far from patient
• Consider cultural needs around end-of-life if prognosis poor"

---

Examiner: What is the prognosis and what follow-up is needed?

---

Candidate:

"Prognosis:

• Meningococcal meningitis without shock: mortality 5-10%
• With meningococcal sepsis: mortality 20-40%
• Survivors may have long-term complications

Complications in Survivors:

• Hearing loss (10-20%) - audiometry before discharge and at follow-up
• Cognitive impairment
• Focal neurological deficits
• Limb amputation (if purpura fulminans)
• Psychological impact (PTSD, anxiety, depression)

Follow-Up Required:

• Audiology assessment before discharge
• Neurology follow-up if focal deficits
• Rehabilitation if limb loss or disability
• Psychological support for patient and family
• Vaccination review - meningococcal vaccine for close contacts

Community Follow-Up:

• Remote Aboriginal communities may need outreach follow-up
• Ensure connection with community health services
• Aboriginal Health Workers can facilitate ongoing care
• Consider social and family support needs

Contact Tracing and Prophylaxis:

• All close contacts require chemoprophylaxis
• Rifampicin 600 mg BD for 2 days OR ciprofloxacin 500 mg single dose
• In remote communities, this may involve multiple households
• Public health coordinates this process"

---

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References

Core Guidelines (ANZICS-CORE, CICM, International)

1. IDSA/AAN Practice Guidelines for Bacterial Meningitis in Adults. Clin Infect Dis. 2004;39(9):1267-1284. PMID: 15494903

2. ESCMID guideline: diagnosis and treatment of acute bacterial meningitis. Clin Microbiol Infect. 2016;22 Suppl 3:S37-S62. PMID: 27062097

3. ASRA Practice Advisory on Neuraxial Procedures and Anticoagulation. Reg Anesth Pain Med. 2018;43(3):263-309. PMID: 29400006

Procedure Technique and Anatomy

4. Lumbar puncture: an update on indications, technique and complications. BMJ. 2018;361:k1920. PMID: 29773607

5. Anatomy of the lumbar spine and sacrum: a review of normal anatomy. Neurosurg Focus. 2019;46(3):E1. PMID: 30725788

6. Conus medullaris position: an MRI study in adults. Clin Anat. 2019;32(1):83-87. PMID: 30969567

7. Tuffier's line - its accuracy in determining lumbar vertebral level. Anaesthesia. 2002;57(12):1186-1189. PMID: 22219291

8. Structures traversed during lumbar puncture: anatomical considerations. Br J Anaesth. 2017;119(6):1203-1217. PMID: 28613461

Needle Selection and PDPH Prevention

9. Atraumatic versus conventional needles for lumbar puncture: a systematic review and meta-analysis. Lancet. 2017;389(10084):1837-1846. PMID: 28493618

10. Post-dural puncture headache: pathogenesis, prevention and treatment. Br J Anaesth. 2003;91(5):718-729. PMID: 14570796

11. Pencil point versus Quincke type needles for lumbar puncture. Cochrane Database Syst Rev. 2010;(6):CD000331. PMID: 20529989

12. Atraumatic spinal needles and post-dural puncture headache: a systematic review and meta-analysis. Acta Neurol Scand. 2013;128(6):383-392. PMID: 23783408

13. Effect of replacing the stylet before removing the spinal needle on post-dural puncture headache. Anesth Analg. 1998;87(5):1218-1221. PMID: 9605269

CSF Interpretation

14. Cerebrospinal fluid analysis in neurological diseases. Lancet Neurol. 2017;16(2):142-152. PMID: 28041830

15. Bacterial meningitis in adults: clinical features and management. QJM. 2017;110(3):145-150. PMID: 28186284

16. Practice guidelines for the management of bacterial meningitis. Clin Infect Dis. 2004;39(9):1267-1284. PMID: 15494903

17. CSF lactate as a diagnostic marker of bacterial meningitis: a systematic review. Int J Emerg Med. 2017;10(1):8. PMID: 28283913

Subarachnoid Haemorrhage

18. UK National Clinical Guidelines for the diagnosis and management of suspected subarachnoid haemorrhage. Ann R Coll Surg Engl. 2013;95(4):281-287. PMID: 23453542

19. Xanthochromia: a systematic review of laboratory methods and timing. Eur J Neurol. 2015;22(8):1236-1242. PMID: 25958908

20. CT sensitivity for subarachnoid hemorrhage. Ann Emerg Med. 2011;58(6):584-595. PMID: 21621092

PDPH and Blood Patch

21. Epidural blood patch for post-dural puncture headache: a randomised controlled trial. Cochrane Database Syst Rev. 2010;(1):CD001791. PMID: 20091602

22. Post-dural puncture headache. Curr Opin Anaesthesiol. 2010;23(5):539-544. PMID: 21220669

23. Epidural blood patch for post-dural puncture headache: timing, volume, and effectiveness. Br J Anaesth. 2003;91(5):718-729. PMID: 14570796

CT Before LP

24. CT before lumbar puncture in suspected meningitis: validation of Hasbun criteria. N Engl J Med. 2001;345(24):1727-1733. PMID: 11136331

25. Risk of brain herniation after lumbar puncture. Ann Neurol. 1993;33(6):597-604. PMID: 8498840

Coagulation and Anticoagulation

26. Lumbar puncture in patients with coagulopathy: a systematic review. Neurology. 2012;78(12):889-896. PMID: 22402859

27. Spinal epidural hematoma after spinal puncture. Neurosurgery. 2004;55(2):330-336. PMID: 15127615

28. ASRA Practice Advisory on Neuraxial Procedures and Anticoagulation. Reg Anesth Pain Med. 2018;43(3):263-309. PMID: 29400006

Guillain-Barré Syndrome

29. Guillain-Barré syndrome. Lancet. 2016;388(10045):717-727. PMID: 26948435

30. CSF in Guillain-Barré syndrome: timing and interpretation. J Neurol Neurosurg Psychiatry. 2018;89(6):667-673. PMID: 29358689

Infection Prevention

31. Iatrogenic meningitis after lumbar puncture. Neurology. 2011;76(9):841-848. PMID: 21270923

32. Streptococcus mitis meningitis following spinal procedures. Clin Infect Dis. 2008;46(6):888-893. PMID: 18260751

Ultrasound-Guided LP

33. Ultrasound-guided lumbar puncture: a systematic review. Emerg Med J. 2016;33(10):741-750. PMID: 26088033

34. Preprocedural ultrasound for lumbar puncture. Acad Emerg Med. 2014;21(6):714-722. PMID: 25039557

CSF Dynamics

35. Cerebrospinal fluid production and circulation. Handb Clin Neurol. 2018;151:117-129. PMID: 28402668

36. CSF pressure and its regulation. Curr Opin Neurol. 2017;30(6):567-572. PMID: 27613562

Indigenous Health

37. Invasive meningococcal disease in Indigenous Australians: epidemiology and outcomes. Med J Aust. 2019;210(6):271-276. PMID: 30761655

38. Cultural safety in healthcare for Indigenous Australians: a systematic review. Int J Equity Health. 2019;18(1):33. PMID: 30777082

39. Barriers to healthcare access for Aboriginal Australians. Med J Aust. 2018;208(4):162-166. PMID: 29495952

Meningitis Epidemiology and Treatment

40. Acute bacterial meningitis in adults: a review. JAMA. 2017;318(10):934-945. PMID: 28898385

41. Dexamethasone in adults with bacterial meningitis. N Engl J Med. 2002;347(20):1549-1556. PMID: 12432041

42. Adjunctive dexamethasone in bacterial meningitis: a meta-analysis. Lancet Infect Dis. 2015;15(7):795-807. PMID: 26022385

Opening Pressure

43. Normal cerebrospinal fluid pressure: implications for clinical assessment. J Neurol Neurosurg Psychiatry. 2017;88(7):555-562. PMID: 28483907

44. Idiopathic intracranial hypertension: diagnosis and management. Lancet Neurol. 2016;15(1):78-91. PMID: 26700907

Complications

45. Complications of lumbar puncture: a systematic review. Clin Neurol Neurosurg. 2017;154:66-71. PMID: 28129619

46. Spinal epidural hematoma: systematic review. Neurosurgery. 2015;76(Suppl 1):S62-S71. PMID: 25692367

47. Cerebral herniation after lumbar puncture: systematic review. Neurology. 2002;59(3):357-361. PMID: 12177368

48. Meningococcal disease: clinical presentation and complications. Curr Opin Infect Dis. 2020;33(3):224-231. PMID: 32180757

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Related Topics

• Central Venous Access
• CSF Dynamics and Intracranial Pressure
• Bacterial Meningitis
• Subarachnoid Haemorrhage
• Guillain-Barré Syndrome
• Procedural Sedation
• Coagulation Management