Meningitis - PowerPoint

Document Sample
Meningitis - PowerPoint Powered By Docstoc
					Meningitis and
Lumbar Puncture
Jessica Kirk, MD
July 26, 2007

 Features of Bacterial Meningitis
 Features of Viral Meningitis

 Lumbar Puncture:
     Indications/Contraindications
     Procedure
     Interpreting Results
Bacterial Meningitis: an
   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, at a minimum, the
    following information:
      Course of illness (progressive vs. acute and
      Presence of symptoms c/w meningeal inflammation
      Presence of seizures
      Presence of predisposing factors (i.e. recent resp. or
        ear infection, penetrating head trauma, travel to
        endemic area, etc.)
      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 (chin to chest/ Kernig/
       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 diff
       Blood culture
       Chem 8
       Coags if any petechiae or purpura noted
   CSF:
       Cell Count
       Glucose and protein
       Gram stain
       Culture and sensitivity
       Other (meningococcal panel)
Bacterial Meningitis: Imaging
   CT scan may be performed to rule out an
    intracranial process that would
    contraindicate an LP, but does not exclude
    subsequent herniation.
   Indications for CT before LP:
       Coma
       CSF shunt
       Hx of hydrocephalus
       Hx of trauma/neurosurgery
       Papilledema
       Focal neurologic deficit
Bacterial Meningitis:
   Acute bacterial meningitis should be suspected in
    children with fever and signs of meningeal
   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
   1mo – 2yr:
     S. pneumoniae (*penicillin resistance)
     N. meningitidis
     GBS
   2yr – 18yr:
     N. meningitidis
     S. pneumoniae
     Hib
Bacterial Meningitis:
   Empiric treatment of meningitis should be started
    immediately after the LP is performed. You cannot
    delay treatment of there is a contraindication or
    inability to perform an LP. For example, 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 have good CSF penetrance, usually a third-
    generation cephalosporin (eg cefotaxime, ceftriaxone)
    and vancomycin.
   If cephalosporins or Vanc are contraindicated in a
    patient, consult ID.
Bacterial meningitis:
Treatment cont.
 Cefotaxime 200mg/kg/day or
  50mg/kg/dose IV Q6hrs
 Ceftriaxone 100mg/kg/day or
  50mg/kg/dose IV Q12hrs
       75mg/kg loading dose
   Vancomycin 60mg/kg/day or
    15mg/kg/dose IV Q6hrs
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:
   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:
 Hearing Evaluation: at or shortly after
 Developmental surveillance
Viral Meningitis: an overview

   Viral, or aseptic, meningitis is the
    most common type of meningitis. It is
    defined as:
     A febrile illness with clinical signs and
      symptoms of meningeal irritation
     No associated neurologic dysfunction
     No evidence of bacterial pathogens in
      the CSF (in a pt. who hasn’t received
Viral Meningitis: Clinical
   Common features include:
       Acute onset of fever, headache,
        nausea, vomiting, stiff neck.
   Physical findings are generally limited,
    nonspecific, and not necessarily
    present. The most prevalent are:
       Nuchal rigidity, bulging fontanel, and
        other signs of viruses such as rash,
        conjunctivitis, and pharyngitis.
Viral Meningitis: Laboratory
   CSF:
     WBC
     Glucose
     Protein
     Enterovirus PCR
     HSV PCR
Viral Meningitis: Causative
 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:
 Suspected CNS infection
 Suspected SAH

 Introducing chemotherapy or contrast

 Removal of CSF
Lumbar Puncture:
   Absolute:
       Increased ICP
   Relative:
     Cardiopulmonary instability
     Soft tissue infection at puncture site
     Bleeding diathesis:
        • Active bleeding
        • Platelet count <50,000
        • INR > 1.4
Lumbar Puncture: Patient
 Your job is to provide a clear
  explanation of the urgent 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
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:
   Local anesthesia can be provided with
    either lidocaine and/or EMLA.
   The patient must be well-positioned to see
       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
   Watch for respiratory function throughout
    the entire procedure!
Lumbar Puncture:
   An LP is performed using universal
    precautions and sterile technique.
   Put on sterile gloves and clean the puncture
    site with betadyne. The area should be
    large, including the PSIS to use as a
   Place sterile drapes around the puncture
   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
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.
Lumbar Puncture: Fluid
   You should label your own CSF. The label
    must include the tube number and what test
    you want ordered, 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,
    mening. 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:
   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.
   Taumatic Tap:
     Occurs when needle hits venous
     CSF typically clears if in subarachnoid
     Remove needle and reattempt with
      new needle if clot forms or fluid
      doesn’t clear.
       Lumbar Puncture:
       Interpreting Results Cont.

             Glucose Protein     # of      Organism
                                WBC’s       present

Bacterial       ↓        ↑       >1000     Gram stain
Meningitis                      ↑neutros   CSF/bld cx

  Viral        Nl or     Nl or   ~10-500      no
Meningitis   slightly↓ slightly↑ ↑lymphs
Lumbar Puncture:
Interpreting Results cont.
   When a tap is bloody it may be a
    traumatic tap, or it could be blood in
    the CSF. Your 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. This 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.
Lumbar Puncture

   Demonstration of the LP kit
Meningitis and Lumbar
   Questions?

   Sources will be available on website.