Heather Prendergast, MD, FACEP Lumbar Puncture: Indications, Procedure & Interpretation

Heather Prendergast, MD, FACEP Heather M. Prendergast, MD, MPH, FACEP Associate Professor Department of Emergency Medicine University of Illinois College of Medicine Chicago, IL

Heather Prendergast, MD, FACEP Disclosures NoneNone

Heather Prendergast, MD, FACEPObjectives Present a relevant patient case Present a relevant patient case Discuss the indications and contraindications for lumbar puncture (LP) Discuss the indications and contraindications for lumbar puncture (LP) Review the procedure of LP Review the procedure of LP Differentiating between traumatic tap and a subarachnoid hemorrhage Differentiating between traumatic tap and a subarachnoid hemorrhage Review typical LP results and post LP headaches Review typical LP results and post LP headaches

Heather Prendergast, MD, FACEP A Clinical Case

Heather Prendergast, MD, FACEP ED Presentation 77 yo previously healthy female77 yo previously healthy female 3 day history of fever, confusion, and lethargy3 day history of fever, confusion, and lethargy Glasgow Coma Scale 13 (E4,V4,M5)Glasgow Coma Scale 13 (E4,V4,M5) Key Aspects of Physical Exam:Key Aspects of Physical Exam: Unable to cooperate with full neurological examination, +neck stiffness upon neck flexionUnable to cooperate with full neurological examination, +neck stiffness upon neck flexion

Heather Prendergast, MD, FACEP ED Course Basic Labs Basic Labs CBC: WBC 11K CBC: WBC 11K Electrolytes normal Electrolytes normal Urinalysis: normal Urinalysis: normal Chest Radiograph: normal Chest Radiograph: normal Husband consented for Lumbar Puncture Husband consented for Lumbar Puncture

Heather Prendergast, MD, FACEP Indications for Lumbar Puncture Diagnosis of central nervous system (CNS) infection Diagnosis of central nervous system (CNS) infection Diagnosis of subarachnoid hemorrhage (SAH) Diagnosis of subarachnoid hemorrhage (SAH) Evaluation and diagnosis of demylinating or inflammatory CNS processes Evaluation and diagnosis of demylinating or inflammatory CNS processes Infusion of anesthetic, chemotherapy, or contrast agents into the spinal canal Infusion of anesthetic, chemotherapy, or contrast agents into the spinal canal Treatment of idiopathic intracranial hypertension Treatment of idiopathic intracranial hypertension

Heather Prendergast, MD, FACEP focal exam/cranial nerve abnormalities, hx cancer, seizure, immuncompromised, altered mental status, papilledema Indications for pre-LP head CT scan

Heather M. Prendergast, MD, MPHContraindications Skin infection near site of LP Suspicion of increased intracranial pressure due to cerebral mass Uncorrected coagulopathy Acute spinal cord trauma

Heather Prendergast, MD, FACEP Technique Lateral Recumbent position Lateral Recumbent position Sitting upright Sitting upright

Heather Prendergast, MD, FACEP Positioning: Key to Success Fetal position with neck, back, and limbs held in flexion Fetal position with neck, back, and limbs held in flexion Lower lumbar spine flexed with back perfectly perpendicular to edge of bed Lower lumbar spine flexed with back perfectly perpendicular to edge of bed Hips and legs should be parallel to each other and perpendicular to table Hips and legs should be parallel to each other and perpendicular to table

Heather Prendergast, MD, FACEP Positioning INCORRECT CORRECT

Heather Prendergast, MD, FACEP

Predicting difficult and traumatic lumbar punctures. The American Journal of Emergency Medicine 2007, Volume 25, Issue 6, Pages K. Shah, D. McGillicuddy, J. Spear, J. Edlow Difficult LP Difficult LP Requires 3 or more needle sticks or attempt by another clinician Requires 3 or more needle sticks or attempt by another clinician Spine visibility Spine visibility Ability to see the contour of the spinous processes Ability to see the contour of the spinous processes Spine palpability Spine palpability Ability to palpate distinct spinous processes Ability to palpate distinct spinous processes

Heather Prendergast, MD, FACEP Comparison of Clinical Groups Difficult Traumatic Spine visible Spine visible Spine not visible Spine not visible Spine palpable Spine palpable Spine not palpable Spine not palpable BMI > BMI > BMI < BMI < Age > Age > Age < Age <

Heather Prendergast, MD, FACEP Ultrasound Assisted Lumbar Puncture 46 patients 46 patients 22 Palpation Landmarks (PL) 22 Palpation Landmarks (PL) 24 Ultrasound Landmarks (UL) 24 Ultrasound Landmarks (UL) Failure Rates Failure Rates 6/22 PLs 6/22 PLs 1/24 ULs 1/24 ULs Obese Patients Obese Patients 4/7 failed PLs 4/7 failed PLs 0/5 failed ULs 0/5 failed ULs Nomura JT, et al. A randomized controlled trial of ultrasound-assisted lumbar puncture J Ultrsound Med ; 26(10):1341-8

Heather Prendergast, MD, FACEP

Cerebrospinal Fluid (CSF) CSF secretion and reabsorption balanced when CSF pressure < 150mm H20CSF secretion and reabsorption balanced when CSF pressure < 150mm H20

Heather M. Prendergast, MD, MPH Understanding Opening Pressures Normal: mm H 2 O (obese patients up to 250mm H 2 0 Elevated: Suggest increased intracranial pressures (>250 mm H 2 0) –Mass lesion (neoplasm, hemorrhage, infection) –Overproduction of CSF –Defective Outflow Mechanics

Heather Prendergast, MD, FACEP CSF Composition Color Color Clear and colorless Clear and colorless Turbid Turbid 200 WBCs or 400 RBCs 200 WBCs or 400 RBCs Grossly Bloody Grossly Bloody 6000 RBCs 6000 RBCs

Heather Prendergast, MD, FACEP CSF Composition Cells Cells Acellular ( up to 5 WBCs and 5 RBCs) Acellular ( up to 5 WBCs and 5 RBCs) More than 3 polymorphonuclear leuckocytes (PMNs) abnormal More than 3 polymorphonuclear leuckocytes (PMNs) abnormal

Heather M. Prendergast, MD, MPH CSF Pleocytosis CSF pleocytosis – 10 white blood cells/µL, corrected for CSF red blood cells using a ratio of 1 WBC per 500 RBCs

Heather M. Prendergast, MD, MPH Clinical Prediction Rule for Identifying Children With Cerebrospinal Fluid Pleocytosis at Very Low Risk of Bacterial Meningitis JAMA. 2007;297:52-60.

Heather M. Prendergast, MD, MPH CSF Pleocytosis & Bacterial Meningitis Score Criteria: – positive CSF Gram stain – CSF absolute neutrophil count (ANC) 1000 cells/µL – CSF protein 80 mg/dL – peripheral blood ANC 10,000/µL – history of seizure before or at presentation.

Heather M. Prendergast, MD, MPH Copyright restrictions may apply. Nigrovic, L. E. et al. JAMA 2007;297: Patient Flow Diagram, Including the Classification Performance of the Bacterial Meningitis Score

Heather M. Prendergast, MD, MPH Traumatic Tap Accidental trauma to a capillary or venule Increases both RBCs and WBCs in CSF If peripheral WBC normal subtract 1 WBC for every 500

Heather M. Prendergast, MD, MPH Clearing of Red Cells = Traumatic Tap ? Rule of thumb –Decrease in # of RBCs between 1 st and 4 th tube Other theories –25% reduction in RBCs 123 patients (ANJR , April 2005) –22 no SAH on CT scan –CSF clearing in 25% WITH aneurysm (2/8) –CSF clearing in 21% WITHOUT aneurysm (3/14) –CSF no clearing in 6 cases WITH aneurysm –CSF no clearing in 14 cases WITHOUT aneurysm

Heather M. Prendergast, MD, MPH Xanthochromia Rapid lysis of RBC in the CSF Results of breakdown of hemoglobin Begins to appear 2-4 hours after RBCs enter subarachnoid space Persists for 2-4 weeks

Heather M. Prendergast, MD, MPH Calculating Predicted CSF WBC count Predicted CSF WBC count/microL = CSF RBC count X (peripheral blood WBC count ÷ peripheral RBC count)

Heather M. Prendergast, MD, MPH Validation of Prediction Calculation in Adults 720 patients –CSF WBC count >10X predicted value Positive Predictive Value 48% for Bacterial Meningitis –CSF WBC count < 10X predicted value Negative Predictive Value 99% for meningitis

Heather M. Prendergast, MD, MPH Validation of Prediction Calculation in Children 92 children –CSF WBC count >10X predicted value 28/30 children (93%) bacterial meningitis 57 children –CSF WBC count < 10X predicted 100% for predicting the absence of meningitis

Heather M. Prendergast, MD, MPH CSF Composition Protein –Largely excluded from CSF by blood- CSF barrier –Normal range (adults) mg/dL –False elevation Diabetes, Presence of RBCS –True elevation Infectious and Noninfectious Conditions

Heather Prendergast, MD, FACEP CSF Composition Glucose Glucose CSF-to-serum glucose ratio CSF-to-serum glucose ratio Normal 0.6 Normal 0.6 Low CSF glucose concentrations Low CSF glucose concentrations Bacterial meningitis Bacterial meningitis Mycobacteial and Fungal CNS infections Mycobacteial and Fungal CNS infections M. pneumoniae and Noninfectious processes M. pneumoniae and Noninfectious processes Less than 18 mg/dL strongly predictive of bacterial meningitis Less than 18 mg/dL strongly predictive of bacterial meningitis

Heather Prendergast, MD, FACEP CSF Composition Glucose Glucose CSF-to-serum glucose ratio CSF-to-serum glucose ratio Limited utility in Neonates, and severe hyperglycemia Limited utility in Neonates, and severe hyperglycemia Normal CSF glucose concentrations Normal CSF glucose concentrations Viral CNS infections Viral CNS infections Exceptions: Exceptions: –mumps, enteroviruses,lymphocytic choriomeningitis(LCM), herpes simplex

Heather Prendergast, MD, FACEP CSF Composition Lactate Lactate Elevated in bacterial meningitis Elevated in bacterial meningitis One study higher sensitivity and specificity than blood glucose ratio One study higher sensitivity and specificity than blood glucose ratio

Heather Prendergast, MD, FACEP CSF in CNS Infection Bacterial Meningitis Bacterial Meningitis CSF WBC > 1000/microL ( with PMNs ) CSF WBC > 1000/microL ( with PMNs ) CSF Protein >250 mg/dL CSF Protein >250 mg/dL CSF Glucose < 45 mg/dL (2.5 mmol/L) CSF Glucose < 45 mg/dL (2.5 mmol/L) CSF-blood glucose ratio 0.4 or less (LR 18) CSF-blood glucose ratio 0.4 or less (LR 18) CSF Lactate >31.53 mg/dL(3.5 mmol/L) CSF Lactate >31.53 mg/dL(3.5 mmol/L)

Heather Prendergast, MD, FACEP CSF in CNS Infection Viral Meningitis Viral Meningitis CSF WBC < 250 /microL ( with lymphocytes ) CSF WBC < 250 /microL ( with lymphocytes ) CSF Protein <150 mg/dL CSF Protein <150 mg/dL CSF Glucose more than 50% of serum concentration CSF Glucose more than 50% of serum concentration

Heather Prendergast, MD, FACEP Summary of Typical CSF Findings NormalBacterialViralTB Cells >1000< Polymorphs 0PredominateEarly +/- increased Lymphocytes 5LatePredominateIncreased Glucose60-80DecreasedNormalDecreased CSF plasma: Glucose ratio 66%<40%Normal < 30% Protein5-40Increased +/- Increased Increased CultureNegativePositiveNegative+TB

Heather M. Prendergast, MD, MPH Post-LP Headache Etiology: Prolonged leakage of cerebrospinal fluid due to delayed closure of dural defect –Low CSF pressure –Incidence 1-70% –Contributing factors Diameter of needle, shape of needle, diagnostic vs. spinal anesthesia

Heather M. Prendergast, MD, MPH Minimizing Post-LP Headache Techniques: –Needle choice Standard Quincke vs. Atraumatic –Number of attempts –Reinsertion of Stylet –Bed Rest after Procedure

Heather M. Prendergast, MD, MPH Post LP Headache Quincke: –Reduction in post LP headache as great as 50% “Atraumatic” –Post LP headache rates of 2-6%

Heather M. Prendergast, MD, MPH

Standard vs. Atraumatic Needles

Heather M. Prendergast, MD, MPH Should One Reinsert the Stylet during Lumbar Puncture? Previous Previous Next Next Volume 336:1190 April 17, 1997 Number 16

Heather M. Prendergast, MD, MPH Study of 600 patients Post-lumbar puncture syndrome –49/300 (16%) no reinsertion –15/300 (5%) reinsertion (p<0.005) Conclusions –Stylet should always be reinserted

Heather M. Prendergast, MD, MPH Bed Rest vs. Mobilization

Heather Prendergast, MD, FACEP Case Resolution CT scan: No mass lesionCT scan: No mass lesion CSF ResultsCSF Results WBC 5000 /μLWBC 5000 /μL RBC 5 /microLRBC 5 /microL CSF blood glucose ratio 0.2CSF blood glucose ratio 0.2 Gram stain: gram positive rodsGram stain: gram positive rods

Heather Prendergast, MD, FACEPConclusions Primary indications for LP is to assess for meningitis or subarachnoid hemorrhage Elevated opening pressures indicate increase intracranial pressures Xanthochromia is always pathological CSF is normally acellular CSF Pleocytosis does not diagnosis infection

Heather Prendergast, MD, FACEPRecommendations Calculate CSF-blood glucose ratio. 0.4 or less (LR 18) bacterial meningitis Determine the predicted CSF WBC count Negative Predictive Value 99% for bacterial meningitis Utilize the Bacterial Meningitis score in cases of CSF Pleocytosis

Heather Prendergast, MD, FACEPRecommendations LP performed in lateral recumbent procedure with knees flexed. Assess for spine visibility and/or palpation Use of small gauge atraumatic needles for diagnostic LPs Reinsertion of stylet prior to removal of spinal needle. Mobilization of patients after completing LP

Heather Prendergast, MD, FACEP Questions?