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10 Cards in this Set
- Front
- Back
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In which, if any, of the following patients is an LP NOT indicated in:
1. adult with fever of unknown origin and impaired immune system without meningeal signs 2. Child less than 3 years who cannot be comforted, is irritable and vomiting 3. Child less than one month appearing unwell without fever 4. A patient with normal CT scan with an unusual sudden headache which has since completely resolved and without meningism 5. Therapeutic lumbar puncture for pseudotumor cerebri |
ALL are indications
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What is the major ABSOLUTE contradindication to LP? Relative contraindications?
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ABSOLUTE = infection in tissues at puncture site
RELATIVE = presence increased intracranial pressure from space occupying lesion (as per R&H, elsewhere absolute) Other relative contraindications - anticoagulant therapy, low platelets, other bleeding diatheses....as per R&H LP may be performed in the presence of coag defect if expected to provide essential information e.g. meningitis dx. Consider giving platelets, clotting factors, FFP etc. as needed for specific coag defect. |
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Different needle types - which named needles are 'atraumatic'? What does this imply?
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The Quinke, Sprotte, Whitacre. These are noncutting styletted needles with a tapered 'pencil point' tip, supposedly separating rather than cutting fibres (Cf the usual bevelled 'cutting' needle). Lower incidence of postdural puncture headache.
As per R&H a 20g atraumatic needle may be the best overall choice for diagnostic lumbar puncture. Dunn suggests 22-25G with differing lengths according to age. Use a 19G cutting needle to pass to the interspinal ligament before using a noncutting 25G in the same soft tissue tract as may be technically difficult to pass otherwise |
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What are the landmarks?
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Line between Post sup iliac crests intersects midline at L4 spinous process. 2 spaces above (L2/3, 3/4) and below (L4/5, L5/S1) may be used in adults and older children. In infants only spaces below may be used as spinal cord finishes at L3 verebra level (body L2 in adults).
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Does flexion of the neck help?
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Apparently not! And in infants severe flexion may cause airway obstruction. Mid flexion in infants promotes CSF flow.
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What are the layers traversed in LP?
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Skin, subcut tissue, fat, supraspinous ligament, intraspinous ligament, ligamentum flavum, extradural space, dura mater, arachnoid mater, subarachnoid space (lumbar cistern inferior to cord termination)
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When reading a manometer, fluid column phasic changes with respirations and arterial pulsations ensure needle placement in Subarachnoid space. T/F
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T
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True or false
1. Lateral approach may be useful in older people with calcified interspinous ligament 2. A sitting position in newborn and preterm infants may prevent hypoxia 3. Complications of LP inlude epidermoid tumours resulting from use of nonstyletted needles 4. Post LP headache may be highest in older, female patients with prior headache history |
1 FALSE - SUPRAspinal ligament
2. TRUE 3. TRUE 4. FALSE - young female with prior HA hx |
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Regarding post LP headache which is incorrect
1. Most common complication post LP 2. Usually resolves within 48 hours 3. Type of needle used may influence 4. Epidural blood patches are a highly successful treatment in the first 2 weeks |
2. STARTS up to 48 hours, usually resolves within 14 days, cases lasting months described
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What are the three statistically significant predictors of new intracranial masses which mandate CT before LP (because of risk of raised ICP)?
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1. Papilloedema
2. Focal neurological findings 3. Altered mental status Other features mandating CT before LP are immunocompromise, age >50, seizure <1/52 before presentation, hx CNS disease |
