6Session Objectives Present a relevant patient case Discuss the indications and contraindications for lumbar puncture (LP)Review the procedure of LPPresent techniques to minimize post LP headacheState the indications for opening pressure determination and interpretation of measurements
8ED Presentation 77 yo previously healthy female 3 day history of confusion, and lethargyGlasgow Coma Scale 13 (E4,V4,M5)Key Aspects of Physical Exam:Unable to cooperate with full physical examination, +neck stiffness upon neck flexion54354
9ED Course Basic Labs CBC, Electrolytes normal Urinalysis: normal Chest radiograph: normal54354
10Why Consider This Case?Utility of lumbar puncture in the afebrile vs. febrile elderly patient with altered mental status: a pilot studyKaushal Shah MD , , Kathleen Richard† and Jonathan A. Edlow MD‡ †Dartmouth Medical School, Hanover, New Hampshire ‡Department of Emergency Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts Department of Emergency Medicine, St. Luke’s-Roosevelt Hospital, New York, New York .
11Lumbar PunctureDiagnostic Test for infectious and noninfectious neurologic conditionsRarely diagnostic as a single agentCombine with history, physical and selected lab tests54354
12Indications for Lumbar Puncture Diagnosis of central nervous system (CNS) infectionDiagnosis of subarachnoid hemorrhage (SAH)Evaluation and diagnosis of demylinating or inflammatory CNS processesInfusion of anesthetic, chemotherapy, or contrast agents into the spinal canalTreatment of idiopathic intracranial hypertension15% Of seizures result in injury or deathHead contusions and lacerations commonMortality rates1.2% of all seizures3 to 26% in SEMortality rate 10 times higher in adults (vs children)SE mortality highest with hypoxic or ischemic insultDeLorenzo et al. Neurology 1996;46:1029; J Clin Neurophysiol 1995;12:316;Epilepsia 1992;33(Suppl 4):S15. Hauser. Neurology 1990;40(Suppl 2):9. Kirby andSadler. Epilepsia 1995;36:25. Terrence et al. Ann Neurol 1981;9:458.
13Indications for pre-LP head CT scan focal exam/cranial nerve abnormalities, hx cancer, seizure, immuncompromised, altered mental status, papilledema
14Indications for pre-LP head CT scan focal exam/cranial nerve abnormalities, hx cancer, seizure, immuncompromised, altered mental status, papilledema
18Procedure Determine correct level of entry Highest points of the iliac crests should be identified and palpatedDirect line joining the crests identifies L4Spinous processes L3, L4, and L5 can be directly palpatedGoal: Subarachnoid space at L3/4 or L4/5
19Positioning: Key to Success Fetal position with neck, back, and limbs held in flexionLower lumbar spine flexed with back perfectly perpendicular to edge of bedHips and legs should be parallel to each other and perpendicular to table
21Skin Preparation Overlying skin cleaned with povidone-iodine Sterile drape placed with an opening over the LS
22Spinal Needle Insertion Local anesthesia infiltrated20 or 22 gauge spinal needle with styletAdvance spinal needle slowly, angling slightly toward the headFlat surface of bevel of needle positioned to face patient’s flanks15% Of seizures result in injury or deathHead contusions and lacerations commonMortality rates1.2% of all seizures3 to 26% in SEMortality rate 10 times higher in adults (vs children)SE mortality highest with hypoxic or ischemic insultDeLorenzo et al. Neurology 1996;46:1029; J Clin Neurophysiol 1995;12:316;Epilepsia 1992;33(Suppl 4):S15. Hauser. Neurology 1990;40(Suppl 2):9. Kirby andSadler. Epilepsia 1995;36:25. Terrence et al. Ann Neurol 1981;9:458.
23Post-LP HeadacheEtiology: Prolonged leakage of cerebrospinal fluid due to delayed closure of dural defectLow CSF pressureIncidence 1-70%Contributing factorsDiameter of needle, shape of needle, diagnostic vs. spinal anesthesia
24Minimizing Post-LP Headache Techniques:Needle choiceStandard Quincke vs. AtraumaticNumber of attemptsReinsertion of StyletBed Rest after Procedure
30Measuring Opening Pressure Once CSF appears attach manometer through stopcockNote the height of the fluid columnHave patient straighten legs to avoid falsely elevated pressure15% Of seizures result in injury or deathHead contusions and lacerations commonMortality rates1.2% of all seizures3 to 26% in SEMortality rate 10 times higher in adults (vs children)SE mortality highest with hypoxic or ischemic insultDeLorenzo et al. Neurology 1996;46:1029; J Clin Neurophysiol 1995;12:316;Epilepsia 1992;33(Suppl 4):S15. Hauser. Neurology 1990;40(Suppl 2):9. Kirby andSadler. Epilepsia 1995;36:25. Terrence et al. Ann Neurol 1981;9:458.
31Understanding Opening Pressures Normal: mm H2O (obese patients up to 250mm H20Elevated: Suggest increased intracranial pressures (>250 mm H20)Mass lesion (neoplasm, hemorrhage, infection)Overproduction of CSFDefective Outflow Mechanics15% Of seizures result in injury or deathHead contusions and lacerations commonMortality rates1.2% of all seizures3 to 26% in SEMortality rate 10 times higher in adults (vs children)SE mortality highest with hypoxic or ischemic insultDeLorenzo et al. Neurology 1996;46:1029; J Clin Neurophysiol 1995;12:316;Epilepsia 1992;33(Suppl 4):S15. Hauser. Neurology 1990;40(Suppl 2):9. Kirby andSadler. Epilepsia 1995;36:25. Terrence et al. Ann Neurol 1981;9:458.
32Case Resolution Fever, confusion, and Neck stiffness Head CT indicated PRIOR to LPUnable to complete full neurological examAltered mental statusInability to confirm absence of focal neurological deficit
33ConclusionsED seizure patient Rx needs to address both the immediate seizure and the long-term epilepsy managementIn general, ED seizure patient Rx focuses on parenteral AED useOral Rx, 2nd generation AEDs usefulMust understand principles that govern ED AED use and priorities of those that provide long-term epilepsy Rx
34RecommendationsBe able to identify the seizure type and optimal patient therapies based on etiology, demographics, and risk/benefitEstablish seizure and SE protocolUnderstand fully the optimal use of parenteral and 2nd generation AEDsStop the acute seizure & prevent SEWisely prescribe so that follow-up epilepsy management can be optimized
40Session Objectives Present a relevant patient case Discuss the indications and contraindications for lumbar puncture (LP)Differentiating between traumatic tap and a subarachnoid hemorrhageReview typical LP results for infectious processesThere are 3 Primary objectives for this session. In order to facilitate this discussion, we will start out with a relevant patient case. We will discuss the indications and contraindications for lumbar puncture. Who needs a head ct prior to the lumbar puncture and what objective criteria we can use to make that determination. We talk about differentiating a traumatic tap from a subarachnoid hemorrhage. And finally review normal csf composition of and what changes are typically seen with various infectious processes
42ED Presentation 77 yo previously healthy female 3 day history of fever, confusion, and lethargyGlasgow Coma Scale 13 (E4,V4,M5)Key Aspects of Physical Exam:Unable to cooperate with full neurological examination, +neck stiffness upon neck flexionWe have a 77 yo previously healthy female, brought to the ED with a 3 day history of confusion, and lethargy. We learn that she has had fevers at home Upon arrival to the ED, she has a glasgow coma scale of 13 (eye opening4, verbal 4, and 5 motor).Key findings on her physical exam: noted to have neck stifness upon flexion of neck. Of note, due to her mental status , she is unable to cooperate with a full neurological examIncluded in your differential in a patient with fever, mental status changes is meningitis54354
43Indications for Lumbar Puncture Diagnosis of central nervous system (CNS) infectionDiagnosis of subarachnoid hemorrhage (SAH)Evaluation and diagnosis of demylinating or inflammatory CNS processesInfusion of anesthetic, chemotherapy, or contrast agents into the spinal canalTreatment of idiopathic intracranial hypertensionWhat are the indications for lumber puncture? At the top of list is diagnosis of cns infection. LP is essential or extremely useful in the diagnosis of bacterial, fungal, mycobacterial, and viral CNS infection and represents the most common use of lp particular to diagnose or exclude meningitis in patients presenting with some combination of fever, altered mental status, headache, and or meningeal signsAnother indication is subarachnoid hemorrhage in a patient with a negative ct scan. If positive it has greater diagnostic sensitivity than a CT scan of the head without contrast, especially if the SAH has occurred more than 3-4 days prior to presentation. Patients with aneurysmal leaks (ie sentinel hemorrhages may present days after headache onset increasing the likelihood of a false-negative head ct scanLP can also be useful in diagnosis demylinating conditions such as MS,vasculitis, and guillian barre etc)
44Indications for pre-LP head CT scan focal exam/cranial nerve abnormalities, hx cancer, seizure, immuncompromised, altered mental status, papilledemaWho requires a head ct before LP Infectious Diseases Society of America (IDSA) guidelines for the management of bacterial meningitis, recommends a CT scan before LP only in patients with suspected bacterail meningitis who have one or more of the following risk factors for a mass lesion. Includes Immunocompromsed state (HIV infection, immunosuppressive therapy, post transplant); Hx of CNS disease (mass lesion, stroke, or focal infection), New onset seizure (within 1 week of presenttaion), papilledema, abnormal level of consciousness, focal neurologic deficit
45Contraindications Skin infection near site of LP Suspicion of increased intracranial pressure due to cerebral massUncorrected coagulopathyAcute spinal cord traumaWhat patients should a LP be avoided? Those with obvious skin infection near the site of LP . Suspicion of increased intracranial pressure due to cerebral mass because of concerns of cerebral herniation which is the most serious complication. A example of the magnitude of the risk is a report of 129 patients with increaed intracranial pressures 12% had a unfavorable outcome. Another series with 55 patients with SAH (13%) experienced neurologic deterioration during or soon after an LP. What clinical features identify patients at greatest risk for this complication.? 73% had focal findings on neurologic examination (dysphagia,hemiparesis, cranial nerve palsies), 30% had documented papilledema prior to LP, 30% had evidence of increased intracranial pressure on plain skull films (erosion of the posterior clinoid processes). Uncorrected coagulopathy is a contraindication, increasing the risk of epidural hemorrhage. In 1 study post LP complications look at 166 patients receiving anticoagulation compared with 171 patients not receiving anticoagulation and found a trend toward increased risk of paraparesis in the anticoagulated patients (RR 11) In all the patients experiencing paraparesis , anticoagulation had been started within an hour of the procedure. Final contraindication is acute spinal cord trauma.
46Cerebrospinal Fluid (CSF) CSF secretion and reabsorption balanced when CSF pressure < 150mm H20SO we have done our LP, so know we need to interpret the results. In the interest of time we wont spend a lot of time on the background of csf, other than stress one improtant point about csf. The csf secretion and reabsorption remains a balanced system as long as the csf pressure remains less than 150 mm H20. Becomes important when you have elevated opening pressures and aids in determing the source54354
47Opening Pressure Normal: 60-200 mm H2O (obese patients up to 250mm H20 Elevated: Suggest increased intracranial pressures (>250 mm H20)Mass lesion (neoplasm, hemorrhage, infection)Overproduction of CSFDefective Outflow MechanicsNormal opening pressures range from mm h20 . In obese patients the opening pressures can be a high as 250 mmh20 and not be consider abnormal. The ranges vary by textbook or source, however majority of sources consider opening pressures of 250 mm H20 or more abnormal. Remember our balanced system between secretion and reabsorption . Elevated opening pressures suggest increased intracranial pressures. Reasons included mass lesion neoplasm, hemoorhage, or infection. All which can alter the balance between CSF secretion and reabsoprtion resulting in intracranial hypertension
48CSF Composition Color Clear and colorless Turbid 200 WBCs or 400 RBCs Grossly Bloody6000 RBCsNormal CSF is clear and colorless. Both infectious and noninfectious can alter the appearance of the csf. As few as 200 wbcs or 400 rbcs will cause csf to appear turbid. CSF will appear grossly bloody if > 6000 rbc are present
49CSF Composition Cells Acellular ( up to 5 WBCs and 5 RBCs) More than 3 polymorphonuclear leuckocytes (PMNs) abnormalThe CSF is normally acellular, although up to 5 wbcs and 5 rbcs are considered normal in adults when the csf is sampled by LP. Newborns in contrast may have up to 20 wbcs in the csf. More than 3 polymorphonuclear leuckocytes (PMNs) abnormal in adults and despite a higher total wbc count in newborns, the PMNs remain low.
50CSF Pleocytosis CSF pleocytosis 10 white blood cells/µL, corrected for CSF red blood cells using a ratio of 1 WBC per 500 RBCsAn elevated CSF wbc concentration does not diagnose an infection since increases in the CSF wbc can occur in a variety of both infectious and noninfectious inflammatory states. CSF pleocytosis is defined as a 10 white blood cells/micro liter corrected for csf rbcs using a ratio of 1 wbc per 500 rbcs
51Clinical Prediction Rule for Identifying Children With Cerebrospinal Fluid Pleocytosis at Very Low Risk of Bacterial MeningitisIn jan of this year, jama published the results of a multicenter study develoing and validations a clinical prediction rule, the Bacterial Meningitis Score, that classifies patients at very low risk of bacterial meningitis based upon the absence of certain criteriaJAMA. 2007;297:52-60.
52CSF Pleocytosis & Bacterial Meningitis Score Criteria:positive CSF Gram stainCSF absolute neutrophil count (ANC) cells/µLCSF protein 80 mg/dLperipheral blood ANC>10,000/µLhistory of seizure before or at presentationThe criteria is as follows : positive CSF Gram stain, CSF absolute neutrophil count (ANC) of at least 1000 cells/µL, CSF protein of at least 80 mg/dL, peripheral blood ANC of at least 10 000 cells/µL, and a history of seizure before or at the time of presentation.
53Patient Flow Diagram, Including the Classification Performance of the Bacterial Meningitis Score This patient flow diagram highlights the classification performance of theBacterial Meningitis Score. I call your attention to the lower corner of theScreen. Patients with none of the 5 criteria were classifed as very low riskwith 1712/1714 having aspectic menigitisNigrovic, L. E. et al. JAMA 2007;297:52-60.Copyright restrictions may apply.
54Traumatic Tap Accidental trauma to a capillary or venule Increases both RBCs and WBCs in CSFIf peripheral WBC normal subtract 1 WBC for every 500 RBCWhat about the traumatic tap? Traumatic taps commonly occurs when the needle has advanced slightly too far and transfixed the internal vertebral plexus (the more densely packed area of the vasculature. As a result the is an increase in both the rbcs and wbcs in the csf. If the peripheral wbc count is not abnormally high or low, a good rule of thumb is to subtract one wbc for every 500 if a traumatic tap is suspected in order to better evaluate the significance of the observed wbc concentration in the csf
55Xanthochromia Rapid lysis of RBC in the CSF Results of breakdown of hemoglobinBegins to appear 2-4 hours after RBCs enter subarachnoid spacePersists for 2-4 weeksPerhaps the most reliable test to differenitate a traumatic tap from a subarachoind hemorrhage is the presence of xanthochromia. After blood has been in the CSF for at least 2 hours, the red cells begin to lyse in large quantites and the oxyhemoglobin and bilirubin cause the yellow orange discoloration of the csf. Xanthochromia peaks at 24 hours after blood enters the csf and persists for 2-4 weeks.Ideally xanthochromia is diagnosed by lab analysis. Because the traumatic tap is acute, there should be no xanthochromia. Presence of xanthochromia suggests there has been pervious csf bleeding
56Calculating Predicted CSF WBC count Predicted CSF WBC count/microL =CSF RBC count X (peripheral blood WBC count ÷ peripheral RBC count)A more accurate method is to calculate the predicted csf wbc count using this formula. Divide the peripheral wbc count by the peripheral rbc count and mulitple that number by the CSF RBC count. And this gives you the predicted CSF wbc count
57Validation of Prediction Calculation in Adults 720 patientsCSF WBC count >10X predicted valuePositive Predictive Value 48% for Bacterial MeningitisCSF WBC count < 10X predicted valueNegative Predictive Value 99% for meningitisWhy is the important to do? It has been validated in both adults and children. In adults, a study of 720 patients a csf wbc count > 10x predicted value had a positive predictive value of 48% for bacterial meningitis. Whereas a csf wbc count , <10x predicted value had a negative predicted value 99% for meningitis
58Validation of Prediction Calculation in Children CSF WBC count >10X predicted value28/30 children (93%) bacterial meningitis57 childrenCSF WBC count < 10X predicted100% for predicting the absence of meningitisIn children prediction calculation did very well A csf wbc count > 10x predicted value 93% bacterial meningitis. CSF wbc count < 10x predicted negative predictive value of 100%
59CSF Composition Protein Largely excluded from CSF by blood-CSF barrier Normal range (adults) mg/dLFalse elevationDiabetes, Presence of RBCSTrue elevationInfectious and Noninfectious ConditionsPersist for months in MeningitisThe two major tests performed on CSF are protein determination of protein and glucose concentrations. Proteins are largely excluded from CSF by blood-csf barrier Normal range mg/dL. The csf protein concentration may be mildly elevated in patients with diabetes mellitus, and falsely elevated in presence of rbcs from subarachnoid hemorrhage or traumatic lp. The presence of csf bleeding results in approx 1 mg of protein/dL per 1000 RBCs/microL.Elevations in the CSF protein concentration can occur in bth infectious and noninfectious conditions. CsF protein elevation may persist for weeks or months following recoveing from meningitis little use in assessing response to therapy
60CSF Composition Glucose CSF-to-serum glucose ratio Normal 0.6Low CSF glucose concentrationsBacterial meningitisMycobacterial and Fungal CNS infectionsM. pneumoniae and Noninfectious processesLess than 18 mg/dL strongly predictive of bacterial meningitisThe normal CSF-to serum glucose ratio is approximately 0.6 in normal individuals. The CSF glucose concentration may be altered in a variety of pathologic conditions. Abnormally low csf glucose concentrations can occur in bacterial meningitis and mycobacterial and fungal cns infectionsCSF glucose concentrations tends to normalize more rapidly than do the csf cell count and protein concentrations.CSF glucose concentrations less than 18 mg/dL are strongly predictive meningitis
61CSF Composition Glucose CSF-to-serum glucose ratio Limited utility in Neonates, and severe hyperglycemiaNormal CSF glucose concentrationsViral CNS infectionsExceptions:mumps, enteroviruses,lymphocytic choriomeningitis(LCM), herpes simplexThe csf to serum glucose ratio is of limited utility in neonates and in patients with severe hyperglycemia..The csf glucoe concentrations is normal in most viral cns infections There have been some reported exceptions in meningoencephalitis secondary to mumps, enterovirsus, lymphocytis choriomeningitis, and herpes simplex
62CSF Composition Lactate Elevated in bacterial meningitis One study higher sensitivity and specificity than blood glucose ratioLactate levels are used in some centers and has been observed to rise in experimental and clinical cases of bacterial meningitis. In 1 study in neurosurgical procedures, lactate levels had a higher sensitivity and specificty than determinations of the ratio of csf to blood glucose
63CSF in CNS Infection Bacterial Meningitis CSF WBC > 1000/microL ( with PMNs )CSF Protein >250 mg/dLCSF Glucose < 45 mg/dL (2.5 mmol/L)CSF-blood glucose ratio < 0.4 (LR 18)CSF Lactate >31.53 mg/dL(3.5 mmol/L)What is a typical csf results for bacterial meningitis. You would expect an elevated wbc count with a predominance with neutrophils. Protein elevated, Glucose less than 45, A csf blood glucose of 0.4 or less (LR of 18) And csf lactate greater than 31.
64CSF in CNS Infection Viral Meningitis CSF WBC < 250 /µL (lymphocytes)CSF Protein <150 mg/dLCSF Glucose more than 50% of serum concentrationIn viral menigitis, you would typically see a relatively small increase in wbc (when compared to a wbc count seen in bacterial meningitis), predominance of lymphocytes. I should mention that in the early stages of mengitis due to entroviruses PMNs predominate in the csf , with the shift to lymphocytic predominance occurs within 12 to 24 hours. This is why it is important to correlate csf cell count with clincial findings. Protein less than 150 and csf glucose is more than 50% of serum concentration
65Summary of Typical CSF Findings NormalBacterialViralTBCells0-5>1000<100025-500PolymorphsPredominateEarly+/- increasedLymphocytes5LateIncreasedGlucose60-80DecreasedCSF plasma:Glucose ratio66%<40%< 30%Protein5-40+/- IncreasedCultureNegativePositive+TBThis slide summarizes the typical csf findings in a side by side comparsion. regards to cells, glucose, protein, and culture.
66Case Resolution CT scan: No mass lesion CSF Results WBC 5000 /μLRBC 5 /microLCSF blood glucose ratio 0.2Gram stain: gram positive rodsQuickly, back to our patient. She met criteria for a head ct prior to LP because of her alterd mental status and the inability to perform a neurological exam to excluse any focal neruological deficit. Her LP showed 5000 wbc, RBCS 5, and a csf blood glucose ratio 0.2. Gram stain gram positive rods . Bacterial mengitis due to listeria
67ConclusionsPrimary indications for LP is to assess for meningitis or subarachnoid hemorrhageElevated opening pressures indicate increase intracranial pressuresXanthochromia is always pathologicalCSF is normally acellularCSF Pleocytosis does not diagnosis infectionIn conclusion, the primary indications for LP in our settings is to assess for meningitis or subarachnoid hemorrhage. When a lp is performed in the lateral decuibtus position, an opening pressure can be measured. Pressures above 250 mm H20 are abnormal and suggest increased intracranial pressures. When differentiated a traumatic tap from a subarachnoid hemmorhage, look for xanthochromia which if present is always pathological. CSf is normally aceelular; howver, csf pleocytosis does not diagnosis infection
68Recommendations Calculate CSF-blood glucose ratio. 0.4 or less (LR 18) bacterial meningitisDetermine the predicted CSF WBC countNegative Predictive Value 99% for bacterial meningitisUtilize the Bacterial Meningitis score in cases of CSF PleocytosisWhen evaluating the csf, calcuate the csf blood glucose ratio . If it is less than 0.4 stronly predictive of bacterial menigitis. Determine the predicted csf wbc count a negative predictive valuse 99% for bacterial meningitis Utilize the bacterial mengitis score in cses of csf pleocytosis.