Unit 1: Meningitis Flashcards
Meningitis
an inflammation of the meninges, the thin covering around the brain and spinal cord
- acute or chronic
- increased in settings where people live in close proximity (college dormitories, military barracks, and prisons)
Causes of Meningitis
- bacterial infection
- viral infection
- fungal infection
- aseptic meningitis
- secondary to traumatic injury or transmission of organisms during surgery or from invasive procedures or device
- can be caused by pericarditis (inflammation of the pericardium in the heart) and myocarditis (inflammation of heart muscle); assessment of heart murmurs and echocardiograms help r/o these causes
- other causes: infection from a cochlear implant, conjunctivitis, and exposure to animals and animal bites
Acute Meningitis
- bacterial cause
- clinical manifestations occurring in hours to days
- CSF pleocytosis (increased WBC in CSF)
- the inflammatory process within the meninges leads to increased turbidity of CSF; sluggish flow of CSF; lead to increased ICP
- acute = medical emergency
- bacterial more severe than viral
Chronic Meningitis
- onset of symptoms during weeks to months
- duration of symptoms longer than 4 weeks
Causes of Bacterial Infection
- d/t local infection from the skin, upper respiratory infection, or from GI/GU tracts
- occur secondary to traumatic injury or transmission of organisms during surgery, or from an invasive procedure or device
- can be caused by pericarditis and myocarditis; assessment of heart murmurs and echocardiograms help r/o these causes
Causes of Viral Infection
-herpes simplex virus, herpes zoster, mumps, and measles
Why is Meningitis a medical Emergency?
b/c the increased turbidity and sluggish flow of CSF can lead to increased ICP
-while ICP increases, herniation of the brain can occur b/c of displacement of brain tissue, CSF, and compression of blood vessels, culminating in severe brain damage, coma, and death
Viral Meningitis
- self-limiting form
- causes cell necrosis or results in enzymatic or neurotransmitter alterations depending on pathogen and cells involved
Clinical Manifestations of Meningitis
- fever (infections)
- headache
- altered mental status
- photophobia (light sensitivity)
- chills
- nausea
- vomiting
- nuchal rigidity and opisthodomos d/t meningeal irritation
- Brudzinski’s and Kernig’s sign
nuchal rigidity
neck stiffness
opisthodomos
severe hyperextension of the head w/ arching of the back
Clinical Manifestations of Meningeal Irritataion
- Nuchal rigidity (neck stiffness)
- Opisthodomos (severe hyperextension of the head w/ arching of the back)
Presentation of meningococcal meningitis
-faint petechial rash can develop; which can develop into disseminated intravascular coagulation (DIC)
Brudzinski’s Sign
as the neck is fixed, there is stretch on the inflamed meninges and the knees flex involuntarily to decreased the pain caused by the stretching of the meninges
Kernig’s Sign
as the hip and knee are flexed and then straightened, there is pain in the hamstring secondary to scratching of the inflamed meninges
What is the Hallmark of Diagnosis Meningitis?
examination of CSF via lumbar puncture
Lumbar Puncture
the opening pressure at the time of the lumbar puncture is recorded, and specimens are tested for glucose, protein, WBC, gram stain and culture
-suspicion for space-occupying lesions, new onset seizures and those w/ moderate to severe altered LOC require CT of the head before the procedure b/c they are at higher risk for herniation
What the examination of Lumbar Puncture (CSF) results look like
- decreased glucose (bacteria thriving; eats sugar up)
- increased protein
- increased WBC
- a gram stain and culture is done to identify the organism
Normal Cerebrospinal Fluid Exam
- Glucose: 50-75 mg/dl
- Protein: 14-40 mg/dl
- WBC: 0-5; lymphocytes
- Microbiology: negative