Emergency Medicine

LUMBAR PUNCTURE

482 Practical Procedures

COMPLICATIONS

1 Failure – malposition (slips off bone).

2 Through-and-through penetration.

3 Local haematoma.

4 Extravasation, if opposite cortex broached or multiple attempts.

5 Cellulitis at insertion site, or osteomyelitis (rare).

LUMBAR PUNCTURE

INDICATIONS

1 Diagnostic

(i) Analyse cerebrospinal fluid (CSF) in suspected meningitis,

subarachnoid haemorrhage (SAH), syndromes such as Guillain–

Barré, multiple sclerosis and carcinomatosis.

(ii) Measure CSF pressure.

2 Therapeutic

(i) Removal of CSF in benign intracranial hypertension

(pseudotumour cerebri).

(ii) Blood patch (post-lumbar puncture [LP] headache).

(iii) Intrathecal administration of medications.

CONTRAINDICATIONS

1 Indicators of raised intracranial pressure (ICP) with or without mass effect

such as focal neurological signs, papilloedema, altered conscious level,

bradycardia, hypertension and abnormal respiratory pattern (irrespective of

what t he computed tomography (CT) scan shows).

2 Space-occupying lesion on CT, particularly posterior fossa.

3 Uncorrected bleeding diathesis (in particular platelets <50 or INR >1.5).

4 Local skin infection.

5 Uncooperative patient.

TECHNIQUE

1 Explain the procedure and gain verbal consent. Give 0.05 mg/kg midazolam

i.v. if the patient is anxious or unable to lie still for up to 15–30 min.

2 Position the patient. Take your time with this:

(i) Lie the patient on a bed/trolley on their left side as close as

possible to the right edge of the bed.