Friday, February 8, 2013

Meningitis


MENINGITIS




o   Inflammation of the meninges that surround the brain and the spinal cord.
o   Classified as Septic and Aseptic
o   Neisseria meningitidis (most common)
o   Haemophilus influenzae and streptococcus pneumoniae ((causative agents)
o   Neisseria and Streptococcus pneumoniae,most common cause ( Lippincott)

Pathophysiology
o   Infecting organism gains entry through bloodstream (20 infection) or direct extension
o   Infecting organism produce an inflammatory response
o   Meningeal vessels becomes hyperemic and increasingly permeable
o   Blood cells (neutrophils) migrate to SAS, producing exudate
o   Exudate formation causes meningeal irritation and increased ICP

Clinical Manifestations

o   Initial/ Classic:  fever, headache
o   Systemic infection
§  Fever, tachycardia, chills and petechial rash
o   Meningeal Irritation
§  Nuchal rigidity  - early sign
§  Positive Kernig’s sign
§  Positive Brudzinski’s sign
§  Photophobia
o   Neurologic signs
§  Decrease in consciousness
§  Cranial nerve palsies (ptosis, diplopia, facial weakness, tinnitus, vertigo, and deafness)
§  Focal neurologic deficits (ataxia and motor weakness)
§  Seizures
o   Petechial or purpuric rash to large area of ecchymosis from coagulopathy, especially with N. meningitidis.
o   Disorientation and memory impairment
o   Behavioral manifestation
o   Other signs f Increase ICP
o   Fulminating infection (10 % of Meningococcal meningitis)

Signs of septicemia
ü  Fever
ü  Extensive purpuric lesion over face and extrinmities
ü  Shock
ü  DIC

Diagnostic Evaluation
o   LP: elevated CSF pressure; cloudy, turbid, or clear in appearance; normal or increased protein; glucose decreased or normal; culture and sensitivity test; presence of polysaccharide antigen (supports bacterial meningitis)
o   Cultures: identify source of infection in blood, urine, and nose and throat secretions
o   X-rays: assess for fractures, abscesses, or signs of infection in chest, skull and sinuses
o   WBC count: elevated

Prevention
o   Vaccination: meningococcal meningitis (MCV4)
  • Antimicrobial prophylaxis for people in close contact with meningococcal patients
v  Rifampicin (Rifadin), Ciprofloxacin hydrochloride (Cipro), or ceftriaxone sodium (Rocephin)
  • Vaccination as an adjunct to antibiotic (H. influenzae and S. pneumoniae)

Medical Management

A.) Early antibiotic therapy
          - Penicillin ( ampicillin and piperacillin)
          - Cephalosporin (ceftriaxone sodium,
             cefotaxime sodium)
          - Vancomycin hydrochloride – alone or
            with rifampicin **
B.) Dexamethasone
          - given 15 to 20 minutes before 1st dose of
            antibiotic (q 6 hrs for 4 days)
C.) Fluid volume expanders – DHN and shock
D.) Phenytoin (dilantin)
E.) Meaures for increased ICP
F.) Diuretic, Isolation, and seizure precaution

Nursing Management
  • Provide continuous or on-going neurological assessment, monitor Vital signs
  • Pulse oximetry and ABG is monitored
  • Take measure to address Fever immediatey
  • Monitor body weight, serum electrolytes, and urine volume, specific gravity, and osmolality
  • Protect the patient from injury (seizure precaution)
  • Prevent complication secondary to immobility
  • Institute droplet precautions until 24 hours after the initiation of antibiotic therapy (isolation technique)
  • Report meningococcal meningitis to local health authority   



Brain Abscess






  • Localized collection of pus within the parenchyma of the brain and spinal cord
  • Relatively rare,  complication encountered by immuno-compromised patients

Pathophysiology
  • Direct invasion from intracranial trauma or surgery
  • Spread of infection from nearby sites (sinuses, ears, and teeth)
  • Spread of infection from other organs(lung abscess, infective endocarditis)

Clinical Manifestation
  • HEADACHE – worse in the morning (prevailing symptom)
  • Vomiting
  • Focal neurologic signs (depends on  the location of abscess)
  • Change in mental status
  • Fever may or may not be present

Diagnostics
ü  CT SCAN
ü  MRI
ü  Useful to obtain images of the Brain Stem and posterior  fossa
Medical Management
  • Antimicrobial therapy & Surgical incision or aspiration
v  Penicilin G (20 million U) and Chloramphenicol (4-6 g/day given IV in divided doses)
v  Given preoperatively and postoperatively
  • Corticosteroids
  • Antiseizure medications (phenytoid, phenobarbital)

Nursing Management
  • Focus is on Ongoing assessment
  • Blood laboratory test result , blood glucose and serum potassium levels
  • Patient safety is a key nursing responsibility

Encephalitis




  • Acute inflammatory process of the brain tissue
  • HERPES SIMPLEX VIRUS ENCEPHALITIS
  • Herpes Simplex virus (HSV) is the most common cause of acute encephalitis (HSV – 1)

PATHO:
- Infxn of buccal mucosa --- retrograde spread along trigeminal nerve --- to brain
- Latent virus in brain tissue is reactivated 

Clinical Manifestation
  • Inflammation and necrosis in the T – F – L (temporal, frontal and limbic system)
§  Initial : FEVER, HEADACHE, CONFUSION, and BEHAVIORAL ABNORMALITIES
§  Focal neurologic symptoms (within 7 days, last 14 – 21 days)
ü  Behavioral changes
ü  Focal seizures
ü  Dysphasia
ü  Hemiparesis
ü  Altered LOC

Diagnostics
  • EEG
  • CSF
§  High opening pressure
§  Low glucose and high protein levels
§  Viral cultures are almost always negative
§  PCR (polymerase chain reaction)
-          Identifies DNA bands of the HSV (3rd and 10th day of Sx onset)
  • NEUROIMAGING
v  MRI – is the neuroimaging study of choice

Medical Management
v  ACYCLOVIR (Zovirax) – medication of choice
ü  Continued for 3 weeks (prevent relapse)
ü  Slow administration (over 1 hour)
ü  Usual dose is decrease in patient with Hx of renal insufficiency
  • FOSCARNET SODIUM (Foscavir)
            - in rare cases of acyclovir resistance

Nursing Management
  • ON – Going Neurological Assessment
  • Comfort measure for headache:
§  Dimming of lights
§  Limiting noise
§  Administering analgesics
  • Use opioid medication cautiously – mask signs
  • Initiate injury prevention and safety
  • Monitor for renal complication (labs and I & O)

Fungal Encephalitis
  • Occur rarely in healthy people
  • COMPROMISED IMMUNE SYSTEM

Common agents:
ü  Cryptococcus neoformans
ü  Histoplasma capsulatum
ü  Aspergillus
ü  Candida Albicans


PATHO:
o   Fungal  Spores enters the body via inhalation
o   Initially through the lungs and bloodstream
o   CNS --- Meningitis – Encephalitis – brain abscess
o   also causes abscess of the SC = SC compression

Clinical Manifestation
ü  Common: Fever, malaise, headache, nuchal rigidity, lethargy and mental status changes
ü  Symptom of increase ICP from hydrocephalus

Assessment and Diagnostics
o   Presence of a compromised immune system and history of living or travel to certain areas
o   Elevated WBC and ANEMIA
o   Fungal antibodies in serum
o   Neuroimaging – CT scan and MRI

CSF :
o   Elevated WBC, and protein
o   Culture of fungi

Medical Management
o   ANTIFUNGAL AGENTS
-          Specific period or indefinite period (maintenance dose)

o   AMPOTHERICIN B (Abelcet, AmBisome, Amphocin, Amphotec, Fungizone, and Fungizone IV)
        - standard antifungal treatment
        - dose high enough without causing renal toxicity

o   FLUCONAZOLE (diflucan) or flucytosine (5-FC, 5- fluorocytosine, Ancobon)
                 - may be administered in conjunction with ampothericin B
                 - causes transient increase in liver enzyme
                 - S/E: Nausea, abdominal pain, headache, dizziness, rash, reversible alopecia 

Nursing management
o   On – Going assessment
o   Provide patient comfort:
§  Administering non-opioid analgesics
§  Limiting environmental stimuli
§  Positioning
o   Give diphenhydramine (Benadryl) and acetaminophen (Tylenol) approx. 30 mins before amphothericin B (fever, chills and body aches)
o   Monitor creatinine and blood urea nitrogen
o   Provide support to patient and family to cope up with work