Meningitis and Lumbar Puncture

Kari Bradham, DO

August 4th, 2011

Overview

Features of Bacterial Meningitis Features of Viral Meningitis Lumbar Puncture:

Indications/ContraindicationsProcedureInterpreting Results

Bacterial Meningitis

Suspected bacterial meningitis is a medical emergency, and IMMEDIATE steps must taken to identify the specific cause.

These steps include: History Physical Exam Laboratory Data Imaging

Bacterial Meningitis: History

The History should include: Birth Hx Presence of predisposing factors (i.e. recent

infection, penetrating head trauma, travel to endemic area, etc.)

Course of illness (progressive, acute, etc.) Presence of symptoms Presence of seizures Immunization Hx Hx of drug allergies (may affect therapy) Recent use of antibiotics

Bacterial Meningitis: Physical Exam Important aspects of the physical exam are

as follows: Vital signs: provide clues about volume

status, presence of shock/increased ICP HC in children <18mo Meningeal signs (Kernig/ Brudzinski) Neurologic exam Integumentary exam (petichiae and purpura

most commonly assoc. with N. meningitidis) Signs of other bacterial infections (i.e.

cellulitis, sinusitis, otitis media, etc.)

Bacterial Meningitis: Laboratory Data Blood Tests:

CBC with differential Blood culture Chem 8 Coagulation studies if any petechiae or

purpura noted CSF:

Cell Count Glucose and protein Gram stain Culture and sensitivity Other (Latex panel)

Bacterial Meningitis: Imaging

CT scan may be performed to rule out an intracranial process that might be a contraindication to an LP.

Indications: Coma CSF shunt Hx of hydrocephalus Hx of trauma/neurosurgery Papilledema Focal neurologic deficit

Bacterial Meningitis: Diagnosis A HIGH LEVEL OF SUSPICION IS KEY TO

DIAGNOSING MENINGITIS IN CHILDREN. Acute bacterial meningitis should be suspected in

children with fever and signs of meningeal inflammation.

In infants the signs may include fever, hypothermia, lethargy, resp. distress, jaundice, poor feeding, vomiting, diarrhea, seizures, restlessness, irritability, and/or bulging fontanel.

No single clinical sign is pathognomonic. Either isolation of bacteria in CSF, OR isolation of

bacteria in blood cultures in a patient with CSF pleocytosis confirms the diagnosis.

Bacterial Meningitis: Causative Organisms 0-1mo

GBS E.coli Listeria

1mo – 2yr: S. pneumoniae N. meningitidis GBS

2yr – 18yr: N. meningitidis S. pneumoniae Hib

Bacterial Meningitis: Treatment Start empiric antibiotics immediately after the

LP is performed. If the LP is delayed due to a need for imaging,

blood cultures should be obtained and antibiotics started before the imaging study.

Empiric treatment consists of bactericidal antibiotics that can penetrate the CSF, usually a third-generation cephalosporin (eg cefotaxime, ceftriaxone) and vancomycin.

Bacterial meningitis: Treatment cont.

Cefotaxime 200mg/kg/day or 50mg/kg/dose IV Q6hrs

Ceftriaxone 100mg/kg/day or 50mg/kg/dose IV Q12hrs75mg/kg loading dose

Vancomycin 60mg/kg/day or 15mg/kg/dose IV Q6hrsDo not forget to order a trough

Bacterial Meningitis: Treatment cont.

Duration of treatment is determined on a case-by-case basis with assistance from Peds ID. Contributing factors may include positive CSF cx, clinical course, causative pathogen, and response to therapy.

Bacterial Meningitis: Outcomes The mortality rate of untreated bacterial

meningitis approaches 100%. Meta-analysis has shown a mortality rate of

~5% in developed countries, depending on causative organism.

The most common sequelae are neurologic, and occur in 15-25% of survivors: Deafness Mental Retardation Spasticity/Paresis Seizures

Bacterial Meningitis: Follow-up

Hearing Evaluation: at or shortly after discharge

Developmental surveillance

Viral Meningitis:

Also referred to as aseptic Most common type of meningitis

A febrile illness with clinical signs and symptoms of meningeal irritation

No associated neurologic dysfunctionNo evidence of bacterial pathogens in

the CSF (in a pt. who has not received antibiotics)

Viral Meningitis: Clinical Manifestations Common features include:

Acute onset of fever, headache, nausea, vomiting, neck stiffness

Physical findings are generally limited and nonspecific. The most prevalent are:Nuchal rigidity, bulging fontanel, and

other signs of viruses such as rash, conjunctivitis, and pharyngitis.

Viral Meningitis: Laboratory Data

CSF: WBCGlucoseProteinEnterovirus PCRHSV PCR

Viral Meningitis: Causative Organisms

Enteroviruses Herpesviruses Arboviruses Influenza

Viral Meningitis: Treatment

Herpes meningitis in children is treated with Acyclovir 30mg/kg/day, or 10mg/kg/dose IV Q8hrs, for a minimum of 14-21 days Neonatal dosing is 60mg/kg/day, or

20mg/kg/dose IV Q8hrs for 21 days. EV infections are treated symptomatically

and rarely require hospitalization beyond the neonatal period.

Treatment for EBV, Arbovirus, and Influenza meningitis is mainly supportive.

Lumbar Puncture: Indications

Diagnostic:Suspected CNS infectionOpening pressure measurement

Therapeutic:Introducing chemotherapy or contrastRemoval of CSF

Lumbar Puncture: Contraindications Absolute:

Increased ICP Relative:

Cardiopulmonary instabilitySoft tissue infection at puncture siteBleeding diathesis:

• Active bleeding• Platelet count <50,000• INR > 1.4

Lumbar Puncture: Patient Counseling

Provide a clear explanation of the indications of the procedure, as well as the details of the procedure itself.

In order to obtain informed consent, you must list both risks and benefits.

Lumbar Puncture: Patient Counseling cont. Risks:

Postspinal headache Epidermoid tumor Infection Cerebral herniation Spinal hematoma

Benefits: The benefit of early diagnosis far outweighs

the risk of the procedure if there are no contraindications.

Lumbar Puncture: Anatomy

In older children, LP can be performed from the L2-L3 interspace to the L5-S1 interspace.

In children younger than 12mo, LP must be performed below the L2-L3 interspace.

An imaginary line that connects the 2 PSIC intersects the spine at approximately L4.

Lumbar Puncture: Pre-procedure Local anesthesia can be provided with

either lidocaine and/or EMLA. The patient must be well-positioned to see

landmarks: Hips and shoulders should be perpendicular

to the exam table The gluteal crease should align with the

spinous processes. Feel free to ask the nurse to reposition the

patient. Watch for respiratory function throughout

the entire procedure!

Lumbar Puncture: Procedure An LP is performed using universal

precautions and sterile technique. Put on sterile gloves and clean the puncture

site with betadine. The area should include the PSIS to use as a landmark.

Place sterile drapes around the puncture site.

If infiltrating with Lidocaine, do this now.

Lumbar Puncture: Procedure cont. Check your spinal needle- Is the stylet in

place? Is it the appropriate diameter and length? Is it a spinal needle?

Are your collection tubes upright and open? Find your landmark- you may want to mark

it with your fingernail. Advance the spinal needle, bevel up,

parallel to the exam table, with the tip of the needle advancing toward the patient’s umbilicus.

Lumbar Puncture: Procedure cont. Advance SLOWLY. In newborns, you may

only get the bevel in before you are in the subarachnoid space.

The stylet may be removed as the needle is advanced to look for CSF.

Use of a manometer is optional at this time to measure opening pressure.

Put ~1cc, or about 15-20 drops in each of the 4 tubes.

Replace the stylet and remove the needle. DISPOSE OF YOUR SHARPS IMMEDIATELY. Do not forget to write a procedure note.

Lumbar Puncture: Fluid Collection You should label your own CSF. The label

must include the tube number as well as your initials, time, and date.

CSF #1: Gram stain and culture

CSF #2: Glucose and protein

CSF #3: Cell count

CSF #4: Save (or Herpes PCR, EV PCR, Latex Panel, etc.)

Lumbar Puncture: Misc.

Please be courteous and clean up your own mess. Dispose of all unused sharps before throwing away the kit.

Lumbar Puncture: Troubleshooting Bony resistance:

Increase flexion of patient, or Withdraw needle to soft tissue and re-

palpate to make sure spine is not rotated. Poor flow:

Rotate needle by 90 degrees Replace stylet and advance slightly Pull needle back and redirect Remove needle and attempt different site

*You must use a new needle at this time.

Lumbar Puncture: Troubleshooting cont.

Traumatic Tap:Occurs when needle hits venous

plexusCSF typically clears if in subarachnoid

spaceRemove needle and reattempt with

new needle if clot forms or fluid doesn’t clear.

Lumbar Puncture: Interpreting Results Cont.

Glucose Protein # of WBC’s

Organism present

Bacterial Meningitis

↓ ↑ >1000 ↑neutros

Gram stain CSF/bld cx

Viral Meningitis

nl or slightly↓

nl or slightly↑

~10-500 ↑lymphs

none

Lumbar Puncture: Interpreting Results cont. If an LP is bloody it may be a

traumatic tap, or it could be blood in the CSF.

CSF analysis will provide % crenated and uncrenated RBC’s. Crenated means the RBC’s have started breaking down, and therefore have likely been in the CSF longer.

May be a sign that you are dealing with Herpes meningitis.

Lumbar Puncture: Interpreting Results Interpreting CSF can be subjective in many

cases. Results will vary based on timing of the tap in the course of the illness, antibiotics given, other cultures obtained, and quality of the tap.

You should use the resources available to you such as your teammates’ experience and Peds ID consult to help you decide on a course of action.

Meningitis and Lumbar Puncture

Questions?

You admitted a patient to the hospital yesterday who had acute onset of fever (temperature of 103.0°F [39.4°C]), a petechial rash, meningismus, and shock. She required blood pressure support and mechanical ventilation during the night. As per the protocol for your hospital, you placed this child into respiratory isolation upon admission. Today you are told that her blood culture is growing Neisseria meningitidis. The nurse taking care of her asks you how long the child needs to remain in respiratory isolation.

Of the following, the BEST answer is until the childA. Complete one day of antimicrobial therapyB. DefervescesC. Is clinically stableD. Is extubatedE. Is proven not to have meningitis

This patient should remain in respiratory isolation until 24 hrs after the initiation of effective antibiotics. The presence of continued fever, prolonged intubation, clinical instability, or meningitis is irrelevant to isolation. Patients treated for invasive disease w/any antibiotic other than cefotaxime or ceftriaxone also must receive 2 days of rifampin, 1 dose of ceftriaxone, or 1 dose of cipro prior to hospital D/C to eradicate the NP carriage of N meningitidis. Family members & individuals who have had close contact w/the patient should be given chemoprophylaxis. Exposed individuals who have received either the polysaccharide or conjugate meningococcal vaccine still should receive chemoprophylaxis b/c the vaccine may not contain the serotype that is specific for the patient's

A 6-month-old boy is brought to the emergency department for evaluation of a 2-day history of a temperature to 39.8°C, increasing irritability, constant crying, decreased activity, and emesis. His mother states that everyone in the house has been ill with colds and that the baby has had a runny nose and nasal congestion for the past week. He has only had his 2-month set of immunizations because he has been ill each time he is brought in for his vaccines. On physical examination, the infant has a temperature of 40.0°C, appears ill, and is extremely irritable. His anterior fontanelle is full, and he has a stiff neck. Studies obtained on his cerebrospinal fluid show: Glucose, 5.0 mg/dL, protein, 170.0 mg/dL, WBC 550/mm3 2 RBC. Gram stain is positive for many WBCs and gram-positive cocci.

Of the following, the MOST appropriate empiric antibiotic regimen for the treatment of this patient isA.Amp and GentB.High dose ceftriaxoneC.High dose ceftriaxone and GentD.High dose ceftriaxone and VancE.High dose cefuroxime

Over the past several decades, an increasing proportion of S pneumoniae strains worldwide have been shown to be nonsusceptible to PCN and amp; to the third-generation cephalosporins (cefotaxime , ceftriaxone); & to a # of other agents, including erythromycin, macrolides, clindamycin, & TMP-SMX in some areas of the US. In general, due to the presence of cross-resistance, the susceptibility of the pneumococcus to other antibiotics decreases in parallel to decreasing PCN susceptibility. Beta-lactam antibiotics (PCNs & cephalosporins) generally are clinically effective in treating the nonsusceptible S pneumoniae strains, except in meningitis. For proven or suspected bacterial meningitis, the initial treatment involves a combo of vanc & a third-generation parenteral cephalosporin (cefotaxime or ceftriaxone). For children who cannot receive cephalosporins due to a serious cephalosporin or PCN allergy (eg, hives or anaphylaxis), rifampin is added to the vanc regimen. Once susceptibility testing results are available, the treatment regimen can be tailored accordingly.