Meningitis, Encephalitis, & Brain Abscess Flashcards
Viral
- Most common causes are Enterovirus (intestine), Arbovirus (insects/mosquitoes/ticks), HIV, VZV, & HSV-2, mumps (paramyxovirus)
- Most often spread through direct contact w/resp secretions
Bacterial
- Streptococcus pneumoniae
- Neisseria meningitidis
Viral Meningitis aka Aseptic meningitis
- Usually presents as HA, fever, photophobia, & stiff neck
> Fever may be moderate or high - Usually no sx’s of brain involvement
- Diagnostic testing of CSF
- Rapid dx w/Xpert EV test
> Sample of CSF is evaluated for enteroviruses
> Results avail within hrs - LP
> CSF may be clear or cloudy
> Lymphocytosis
> Organisms not seen on Gram-stain or acid-fast smears - PCR to detect viral-specific DNA/RNA (is a highly sensitive method)
- Treat w/abx >obtaining diag sample but before receiving test results
- Symptomatic management
> Rare sequelae incl persistent ha’s, mild mental impairment, & incoordination - Typical treatment of antiviral medications
- Full recovery expected
Bacterial Meningitis
- Acute inflammation of meningeal tissue surrounding brain & spinal cord
- Usually occurs in fall, winter, or early spring
- Often 2° to viral resp dz
- Is a medical emergency
- Untreated has a high mortality rate near 100%
Etiology & Pathophysiology
- Vaccine for Haemophilus has greatly diminished most common cause of the past
- Organisms enter CNS from resp tract or bloodstream
- May enter through wounds of skull or fractured sinuses
- Incr CSF production
- Purulent secretions spread to other areas of brain through CSF
- If process extends into parenchyma or if concurrent encephalitis is present, cerebral edema & incr ICP become problematic
Clinical Manifestations
! Key signs of meningitis
- Fever
- Severe HA
- N/V
- Nuchal rigidity (classic sign; neck stiffness & pain)
- If the infecting organism is a meningococcus, a skin rash is common, and petechiae may be seen
- Coma is assoc w/poor prognosis & occurs in 5-10% of cases
Other sx’s that may be present
- Photophobia
- ↓ LOC
Signs of ↑ ICP
> Seizures occur in 1/3 of all cases
> HA becomes progressively worse & may be accompanied by vomiting & irritability
Complications
- Acute complication is ↑ ICP
- Major cause of AMS
- Residual neurologic dysfunction
- CN’s III, IV, VI, VII, or VIII can become dysfunctional
- Sequelae varies by CN
___ ___ (CN ___) is compressed by increased ICP
Optic nerve; II
Ocular movements affected w/irritation to nerves III, IV, & VI
- Ptosis
- Unequal pupils
- Diplopia
- CN V irritation results in sensory loss & loss of corneal reflex
- CN VII irritation results in facial paresis
- CN VIII causes tinnitus, vertigo, & deafness
> Hearing loss may be permanent
- Hemiparesis, dysphagia, & hemianopsia may occur & resolve over time
- If resolution doesn’t occur, the following may be suspected:
> Cerebral abscess, subdural empyema, or persistent meningitis
Acute cerebral edema may cause
- Seizures
- CN III palsy
- Bradycardia
- Hypertensive coma
- Death
Diagnostic Studies
- Blood, urine, throat, &/or nose cultures
- Diagnosis verified by LP & analysis of CSF
- Protein lvls high (esp in bacterial)
- Glucose conc commonly dec in bacterial but can be normal in viral
- Specimens of CSF, sputum, nasopharyngeal secretions to identify causative organism
- Gram-stained smear to detect bacteria
> Presence of neutrophils
- Variations in the CSF depend on the causative organism
- X-rays of skull
> Infected sinuses - MRI, CT scans
> Show evidence of IICP or hydrocephalus
Collaborative Care
- Rapid diagnosis crucial
- Based on HPE as pt is usually critical when healthcare is initiated
- Abx therapy instituted after collection of specimens & before dx is confirmed
> Able to cross BBB
> Dexamethasone (a corticosteroid) may also be prescribed before or w/the 1st dose of abx
Nursing Assessment
- VS
- Neurologic eval
- Fluid I&O
- Evaluation of lungs & skin
Planning
Overall goals
- Return to maximal neurologic functioning
- Resolve the infection
- Control pain & discomfort
Nursing Implementation: Health Promotion
- Vaccination against resp infections
- Meningococcal vaccines
____ - preferred for people ≤ 55
____ - licensed for people >55 - Prophylactic abx for anyone exposed to bacterial meningitis
MCV4 (meningococcal conjugate vaccine)
MPSV4 (meningococcal polysaccharide vaccine)
Acute Interventions
Revolve around the nurses diagnoses of
* ↓ intracranial adaptive capacity
* Risk for ineffective cerebral perfusion
* ↑ fever
* Acute pain
- Close observation & assessment
- Provide relief for head & neck pain
- Position for comfort
- Darkened room & cool cloth over the eyes for photophobia
> Minimize environmental stimuli
- Mental distortion & hypersensitivity are typical
- Convey caring & unhurried gentleness while providing efficient care
- Provide safety
> Observe & record seizures
- Prevent injury
- Administer anti-seizure medications
> Vigorously manage fever
- Fever incr cerebral edema & the freq of seizures
- Neurologic damage may result from high, prolonged fever
> Maintain therapeutic blood lvls of abx
- Resp isolation until cultures are negative
! Meningococcal meningitis is highly contagious
Ambulatory & Home Care
- Provide for several wks of convalescence
- Incr activity as tol
- Stress adequate nutrition
> High protein, high calorie diet - Encourage adequate rest & sleep
- Progressive ROM exercises & warm baths for muscle rigidity
- Ongoing assessment for recovery of vision, hearing, cognitive skills, motor, & sensory abilities
- Tend to signs of anxiety & stress of family & caregivers
Evaluation
Patient will…
- Demonstrate appropriate cognitive function
- Be oriented to person, place, & time
- Maintain body temp within normal range
- Report satisfaction w/pain control
?
Swelling of the brain
Encephalitis
Encephalitis
- Acute inflammation of the brain
- Serious, sometimes fatal dz
- C/b a # of viruses
- Some are endemic to spec geographic areas & seasons
> Ticks or mosquitoes can transmit epidemic encephalitis
> CMV encephalitis is common w/AIDS
- Non-epidemic encephalitis may occur as a complication of measles, chickenpox, or mumps
- HSV encephalitis is the most common cause of acute non-epidemic viral encephalitis
Manifestations
Nonspecific onset
* Fever, HA, n/v
Signs appear in 2-3 days
* May vary from minimal alterations in mental status to coma
* Any CNS abnormality can occur
Diagnostic Studies
* Early dx & treatment are essential for favorable outcomes
- CT, MRI, PET
- PCR tests for HSV DNA/RNA
- Blood test for West Nile viral RNA
Nursing Management
- Mosquito control for prevention
> Nursing management is symptomatic & supportive for care of cases of encephalitis incl West Nile virus infection - Intensive care may be req’d initially
- Acyclovir (Zovirax), Ganciclovir (Cytovene), & Foscarnet (Foxcavir)
> Reduce mortality rates but not necessarily neurologic complications
> Start before onset of coma - Anti-seizure drugs for seizures
> May be initiated prophylactically
?
Is a purulent infection of the brain; pus can form in the extradural, subdural, or intracranial area of the brain
Usually result from a bacterial infection; some may be a complication of meningitis
brain abscess
- Organisms can travel to the brain from the ear, sinus, or mastoid area via cerebral veins
- Bacteria can travel from the lungs, or from an injury/illness such as a knife wound, bullet wound, or neurosurgery; additionally, organisms can destroy bone & form a tract into the brain
- Other ways that these can occur is for the organism to travel from a distant organ such as tonsils, or heart by way of a systemic infection
- It creates a local infection in the brain & then within a few days necrosis of the tissue occurs & pus forms; streptococci are the most common organism found but many others have been found as well
- Similar care involves assessing for sx’s of ICP, & neurological functions
- Diagnostics/labs, WBC, ESR, CT head, EEG, xrays, needle biopsies
- Drug therapy - abx, shunts, if needed; anti-epileptic meds to prevent/treat seizures, pain meds for HA’s
- Surgical intervention/craniotomy if needed, then pts may be d/c’d home if there are no persistent neurological deficits, or to a long-term/subacute rehab if they do