Lumbar puncture - Revision history

Aidan: /* Interpretation */

2021-11-03T13:11:04Z

Interpretation

← Older revision		Revision as of 13:11, 3 November 2021
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	*[[Hypoglycorrhachia]] refers to low CSF glucose		*[[Hypoglycorrhachia]] refers to low CSF glucose

	===~~CSF~~ After Antibiotics===		===Interpretation After Antibiotics===

	*Glucose increases first, then protein, and both are often normalized within 12 hours		*Glucose increases first, then protein, and both are often normalized within 12 hours
	*WBC normalizes last, and can still be useful even the following day		*WBC normalizes last, and can still be useful even the following day

			=== Opening Pressure ===

			* Usual range is 5 to 20 cm H<sub>2</sub>O
			* See [[Increased intracranial pressure#Differential Diagnosis\|causes of increased intracranial pressure]]

			=== Protein ===

			* May be increased by disruption of the blood-brain barrier (most commonly), intracranial synthesis of IgG, or impaired CSF resorption of proteins by the arachnoid villi
			* Highly suggestive of CNS disease

			=== Correction for Traumatic Tap ===

			* If increased RBCs are seen, may need to adjust
			* Allow 1 WBC for every 700-1000 RBCs
			* Allow 0.01 mg/mL protein for every 1000 RBCs

	==Further Reading==		==Further Reading==

Aidan: /* Interpretation */

2020-08-12T20:54:12Z

Interpretation

← Older revision		Revision as of 20:54, 12 August 2020
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	*Correction for a bloody tap is 1 excess WBC for every 700 RBCs		*Correction for a bloody tap is 1 excess WBC for every 700 RBCs
	*Lymphocytosis may be seen in bacterial meningitis if Listeria infection or prior antibiotics		*Lymphocytosis may be seen in bacterial meningitis if [[Listeria]] infection or prior antibiotics
	*[[Xanthochromia]] suggests subarachnoid hemorrhage		*[[Xanthochromia]] suggests subarachnoid hemorrhage
	*[[Hypoglycorrhachia]] refers to low CSF glucose		*[[Hypoglycorrhachia]] refers to low CSF glucose

Aidan: /* Investigations */

2020-08-12T20:53:23Z

Investigations

← Older revision		Revision as of 20:53, 12 August 2020
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	==Contraindications==		==Contraindications==

	*Increased intracranial pressure, with focal neurological deficits, new seizures, or papilledema		*Increased intracranial pressure, with focal neurological deficits, new seizures, or papilledema (CT head first; see Investigations, below)
	*Infection at the procedure site		*Infection at the procedure site
	*Coagulopathy		*Coagulopathy
	**Platelets <30		**Platelets <30-40
	**INR ~~>~~1.6		**INR ≥1.4-1.6
	**Hemophilia		**[[Hemophilia]]
	**Anticoagulation		**Anticoagulation
			***Within 4 hours of prophylactic [[low molecular weight heparin]] (LMWH)
			***Within 24 hours of therapeutic [[LMWH]]
			***Within 7 days of [[clopidogrel]] (but no delay for [[aspirin]])

	==Procedure==		==Procedure==
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	*Consider INR/PTT if concern about coagulopathy		*Consider INR/PTT if concern about coagulopathy
	*Consider platelet count (should be >100)		*Consider platelet count (should be >100)
	*Consider CT head		*Consider CT head if focal neurological signs, papilledema, GCS ≤12
			**IDSA: immunocompromised, history of CNS disease (including stroke and mass lesion), or new, uncontrolled, or continuous seizures

	==Complications==		==Complications==

Aidan: /* Interpretation */ added hypoglyco

2020-08-10T21:35:51Z

Interpretation: added hypoglyco

← Older revision		Revision as of 21:35, 10 August 2020
Line 1:		Line 1:
	== Contraindications ==		==Contraindications==

	* Increased intracranial pressure, with focal neurological deficits, new seizures, or papilledema		*Increased intracranial pressure, with focal neurological deficits, new seizures, or papilledema
	* Infection at the procedure site		*Infection at the procedure site
	* Coagulopathy		*Coagulopathy
	** Platelets <30		**Platelets <30
	** INR >1.6		**INR >1.6
	** Hemophilia		**Hemophilia
	** Anticoagulation		**Anticoagulation

	== Procedure ==		==Procedure==

	* Position appropriately: lateral decubitus or sitting and leaning over a table		*Position appropriately: lateral decubitus or sitting and leaning over a table
	* Landmark using posterior superior iliac crests (PSIS) (marks L4)		*Landmark using posterior superior iliac crests (PSIS) (marks L4)
	** Can go above (L4/L5 space) or below (L3/L4 space)		**Can go above (L4/L5 space) or below (L3/L4 space)
	* Inset spinal needle in the midline		*Inset spinal needle in the midline
	* Measure opening pressure		*Measure opening pressure

	== Investigations ==		==Investigations==

	* Consider INR/PTT if concern about coagulopathy		*Consider INR/PTT if concern about coagulopathy
	* Consider platelet count (should be >100)		*Consider platelet count (should be >100)
	* Consider CT head		*Consider CT head

	== Complications ==		==Complications==

	* Local pain		*Local pain
	* Post-LP headache, better when supine		*Post-LP headache, better when supine
	** Treat with caffeine, fluids, and acetaminophen		**Treat with caffeine, fluids, and acetaminophen
	* Brief radicular pain		*Brief radicular pain
	* Rare:		*Rare:
	** Spinal epidural hematoma		**Spinal epidural hematoma
	** Bacterial meningitis or spinal abscess		**Bacterial meningitis or spinal abscess
	** Cerebral herniation		**Cerebral herniation

	== Interpretation ==		==Interpretation==

			{\| class="wikitable"
	{\|
	! Etiology		!Etiology
	! Gram stain		!Gram stain
	! Cell count		!Cell count
	! CSF glucose		!CSF glucose
	! CSF protein		!CSF protein
	\|-		\|-
	\| Bacterial meningitis		\|[[Bacterial meningitis]]
	\| Positive in 60-80%		\|Positive in 60-80%
	\| Elevated >1000 neutrophils		\|Elevated >1000 neutrophils
	\| Reduced <0.4 CSF:serum		\|Reduced <0.4 CSF:serum
	\| Elevated >1g/L		\|Elevated >1g/L
	\|-		\|-
	\| Viral meningitis		\|[[Viral meningitis]]
	\| Negative		\|Negative
	\| Moderate elevation <100 lymphocytes		\|Moderate elevation <100 lymphocytes
	\| Normal or mildly reduced		\|Normal or mildly reduced
	\| Normal or mildly elevated		\|Normal or mildly elevated
	\|-		\|-
	\| Fungal or tuberculous meningitis		\|[[Fungal meningitis\|Fungal]] or [[tuberculous meningitis]]
	\| Negative, except for ~~cryptococcus~~ on India ink or TB on acid-fast		\|Negative, except for [[Cryptococcus]] on [[India ink]] or TB on acid-fast stain
	\| Moderate elevation, usually lymphocytes		\|Moderate elevation, usually lymphocytes
	\| Often very low		\|Often very low
	\| Elevated		\|Elevated
	\|}		\|}

	* Correction for a bloody tap is 1 excess WBC for every 700 RBCs		*Correction for a bloody tap is 1 excess WBC for every 700 RBCs
	* Lymphocytosis may be seen in bacterial meningitis if Listeria infection or prior antibiotics		*Lymphocytosis may be seen in bacterial meningitis if Listeria infection or prior antibiotics
	* Xanthochromia suggests subarachnoid hemorrhage		*[[Xanthochromia]] suggests subarachnoid hemorrhage
			*[[Hypoglycorrhachia]] refers to low CSF glucose

	=== CSF After Antibiotics ===		===CSF After Antibiotics===

	* Glucose increases first, then protein, and both are often normalized within 12 hours		*Glucose increases first, then protein, and both are often normalized within 12 hours
	* WBC normalizes last, and can still be useful even the following day		*WBC normalizes last, and can still be useful even the following day

	== Further Reading ==		==Further Reading==

	* Straus S, ''et al.'' [https://doi.org/10.1001/jama.296.16.2012 How Do I Perform a Lumbar Puncture and Analyze the Results to Diagnose Bacterial Meningitis?] ''JAMA''. 2006;296(16):2012-2022.		*Straus S, ''et al.'' [https://doi.org/10.1001/jama.296.16.2012 How Do I Perform a Lumbar Puncture and Analyze the Results to Diagnose Bacterial Meningitis?] ''JAMA''. 2006;296(16):2012-2022.

	[[Category:Neurology]]		[[Category:Neurology]]

Maintenance script: Imported from text file

2020-07-04T01:17:43Z

Imported from text file

New page

== Contraindications ==

* Increased intracranial pressure, with focal neurological deficits, new seizures, or papilledema
* Infection at the procedure site
* Coagulopathy
** Platelets <30
** INR >1.6
** Hemophilia
** Anticoagulation

== Procedure ==

* Position appropriately: lateral decubitus or sitting and leaning over a table
* Landmark using posterior superior iliac crests (PSIS) (marks L4)
** Can go above (L4/L5 space) or below (L3/L4 space)
* Inset spinal needle in the midline
* Measure opening pressure

== Investigations ==

* Consider INR/PTT if concern about coagulopathy
* Consider platelet count (should be >100)
* Consider CT head

== Complications ==

* Local pain
* Post-LP headache, better when supine
** Treat with caffeine, fluids, and acetaminophen
* Brief radicular pain
* Rare:
** Spinal epidural hematoma
** Bacterial meningitis or spinal abscess
** Cerebral herniation

== Interpretation ==

{|
! Etiology
! Gram stain
! Cell count
! CSF glucose
! CSF protein
|-
| Bacterial meningitis
| Positive in 60-80%
| Elevated >1000 neutrophils
| Reduced <0.4 CSF:serum
| Elevated >1g/L
|-
| Viral meningitis
| Negative
| Moderate elevation <100 lymphocytes
| Normal or mildly reduced
| Normal or mildly elevated
|-
| Fungal or tuberculous meningitis
| Negative, except for cryptococcus on India ink or TB on acid-fast
| Moderate elevation, usually lymphocytes
| Often very low
| Elevated
|}

* Correction for a bloody tap is 1 excess WBC for every 700 RBCs
* Lymphocytosis may be seen in bacterial meningitis if Listeria infection or prior antibiotics
* Xanthochromia suggests subarachnoid hemorrhage

=== CSF After Antibiotics ===

* Glucose increases first, then protein, and both are often normalized within 12 hours
* WBC normalizes last, and can still be useful even the following day

== Further Reading ==

* Straus S, ''et al.'' [https://doi.org/10.1001/jama.296.16.2012 How Do I Perform a Lumbar Puncture and Analyze the Results to Diagnose Bacterial Meningitis?] ''JAMA''. 2006;296(16):2012-2022.

[[Category:Neurology]]
[[Category:Procedure]]