Lecture 35 Meningitis Flashcards
What does the pathogenesis of meningitis look like?
inflammation damages the BBB ⇒ increased permeability, allowing entry of serum protein, impairing glucose transport ⇒ could lead to progressive cerebral edema, increased intracranial pressure and decreased cerebral blood flow with irreversible ischemic damages
What are acute complications and sequelae of meningitis?
Acute Complications: altered mental status, coma, increased intracranial pressure (ICP), seizures, subdural effusions, abscess, intracerebral abscess, shock, respiratory distress/failure/arrest, apnea, disseminated intravascular coagulation, death
Sequelae: focal neurological deficits ⇒ deafness/sensorineural hearing loss, blindness, paralysis, paresis
structural ⇒ hydrocephalus, brain abscess, epidural abscess, subdural abscess/effusion/empyema, cerebral thrombosis, vasculitis
seizure disorder, personality changes, gait disturbance, impaired fxn, cognition
What are S&S of meningitis?
Classic triad ⇒ fever, H/A (vs altered mental status), neck stiffness
other ⇒ N/V, photophobia, rash, seizures, confusion, irritability, delirium, drowsiness, coma
What are physical exams or signs that may be present in meningitis?
Kernig Sign: knee is flexed to 90 degrees then the hip, extension of knee is painful or limited in extension
Brudzinski Sign: while lying down someone pulls the neck upward and this elicits hip and knee flexion
Petechial Rash: usually located on trunk and legs and may rapidly evolve into purpura, more likely to see this in N. meningitidis
Regarding lab values in meningitis, what are ones to look at for differentiating between normal levels, bacterial levels, and viral levels (format: N/B/V)?
WBCs: (0-5)/(400-20000)/(5-100)
WBC diff: (no predominance)/(>80% PMNs)/(>50% lymphs, <20% PMNs)
Protein g/L: (2.5-3.5)/(<2.2 low)/(normal or slightly low)
CSF/Serum glucose: (>/= 0.6)/(<0.4)/(>/= 0.6)
What are organisms that may involved in meningitis?
GPC pairs/chains/diplococcus: S. pneumoniae, GBS, GAS, Enterococcus spp
GPC clumps/clusters: S. aureus, CoNS
GNC: N. meningitidis
GNB or GN coccobacilli: H. influenzae
GNB: E. coli, P. aeruginosa, Klebsiella, other aerobic
GPB: L. monocytogenes, Propionibacterium, Corynebacterium
What organisms are most common in different ages in meningitis, or different predisposing factors (skull related)?
<1 month: GBS, E. coli, L. monocytogenes
1-3 Months: GBS, E. coli, L. monocytogenes, S. pneumoniae, N. meningitidis, H. influenzae
3 months-18 years: S. pneumoniae, N. meningitidis, H. influenzae type b if incomplete immunization
18-50: S. pneumoniae, N. meningitidis, H. influenzae
> 50 or immunocompromised, alcohol abuse, debilitating illness, pregnancy: S. pneumoniae, N. meningitidis, L. monocytogenes, Enterobacterales
Basilar Skull Fracture: S. pneumoniae, H. influenzae, GAS, possibly S. aureus and Enterobacterales if prolonged hospital stay
Head-Trauma, post-neurosurgery: S. pneumoniae, S. aureus, CoNS, Enterobacterales, P. aeruginosa, Propionibacterium spp
CSF Shunt: S. aureus, CoNS, Enterobacterales, Propionibacterium, Corynebacterium, Enterococcus
What is empiric tx for meningitis in <1 month olds (Pathogens, Tx)?
Pathogens: GBS, E. coli, L. monocytogenes
Tx: Ampicillin 300 mg/kg/day IV Q6H + (Gentamicin 4-5 mg/kg IV Q24H or Cefotaxime 200 mg/kg/day IV Q6H)
What is empiric tx for meningitis in ages 1-3 months (Pathogens, Tx)?
Pathogens: S. agalactiae, E. coli, S. pneumoniae, N. meningitidis, H. influenzae, L. monocytogenes
Tx: Ceftriaxone 100 mg/kg/day Q12H and if immunocompromised add Ampicillin 300 mg/kg/day IV Q6H
What is empiric tx for meningitis in ages 3 months to 18 years (Pathogens, Tx)?
Pathogens: S. pneumoniae, N. meningitidis, H. influenzae
Tx: Ceftriaxone 100 mg/kg/day IV Q12H + Vancomycin 60 mg/kg/day IV Q6H
What is empiric tx for meningitis in pediatric basilar skull fracture patients (Pathogens, Tx)?
Pathogens: S. pneumoniae, H. influenzae, GAS, if prolonged hospital stay then S. aureus, Enterobacterales
Tx: Ceftriaxone 100 mg/kg/day IV Q12H + Vancomycin 60 mg/kg/day IV Q6H
What is empiric tx for meningitis in pediatric CSF shunts (Pathogens, Tx)?
Pathogens: CoNS, S. aureus, Enterobacterales, rarely Pseudomonas
Tx: Ceftriaxone 100 mg/kg/day IV Q12H + Vancomycin 60 mg/kg/day IV Q6H
What is empiric tx for meningitis in 18-50 years (Pathogens, Tx)?
Pathogens: S. pneumoniae, N. meningitidis, H. influenzae
Tx: Ceftriaxone 2 g IV Q12H + Vancomycin 15 mg/kg IV Q8-12H
What is empiric tx for meningitis in >50 years old, immunocompromised, alcohol abuse, debilitating illness, pregnancy (Pathogens, Tx)?
Pathogens: S. pneumoniae, L. monocytogenes, N. meningitidis, Enterobacterales
Tx: Ceftriaxone 2 g IV Q12H + Vancomycin 15 mg/kg IV Q8-12H + Ampicillin 2 g IV Q4H
What is empiric tx for meningitis in adult basilar skull fractures (Pathogens, Tx)?
Pathogens: S. pneumoniae, H. influenzae, GAS, N. meningitidis, if prolonged hospital then S. aureus, Enterobacterales
Tx: Ceftriaxone 2 g IV Q12H + Vancomycin 15 mg/kg IV Q8-12H
What is empiric tx for meningitis in adult head trauma, post-neurosurgery (Pathogens, Tx)?
Pathogens: S. pneumoniae, S. aureus, CoNS, Enterobacterales, P. aeruginosa, C. acnes (if foreign material)
Tx: Ceftazidime 2 g IV Q8H OR Meropenem 2 g IV Q8H + Vancomycin 15 mg/kg IV Q8-12H
What is empiric tx for meningitis in adult CSF shunts (Pathogens, Tx)?
Pathogens: CoNS, S. aureus, C. acnes, Corynebacterium, Enterobacterales, P. aeruginosa, A. baumannii
Tx: Ceftriaxone 2 g IV Q12H + Vancomycin 15 mg/kg IV Q8-12H
What does the duration of tx look like in meningitis?
10-14 days if no organism cultured
S. pneumoniae: 10-14 days
GBS: 14-21 days
Enterococcus: 14 days
L. monocytogenes: 14-21 days peds and >/= 21 for adults
N. meningitidis: 5-7 days
H. influenzae: 7-10 days
Enterobacterales: 21 days
When might acyclovir be involved in meningitis and encephalitis treatment?
there aren’t many viral causes we can treat ⇒ acyclovir age dosing IV Q8H SOMETIMES given for HSV meningitis F10-14D
encephalitis dose for HSV1 encephalitis: </= 12 - 60 mg/kg/day IV Q8H, >12 - 30 mg/kg/day IV Q8H, >18 - 10 mg/kg based on IBW or ABW IV Q8H F14-21D
What are viral causes of meningitis and possible physical findings?
HSV (less common): oral lesions, genital lesions
Varicella Zoster Virus: rash, lesions - dermatomes
What do steroids do in meningitis?
inhibits synthesis of IL-1 and TNF at mRNA level
decreases CSF outflow resistance ⇒ brain edema
stabilizing BBB ⇒ decreases entrance of more leukocytes
How are steroids used in meningitis for children and adults?
Child: infants >/= 6 weeks, DEXAMETHASONE 0.15 mg/kg/DOSE (MAX of 10 mg/dose) IV Q6H F4D
if S. pneumoniae or H. influenzae or no pathogen identified ⇒ continue dexamethasone F4D
Adults: dexamethasone 0.15 mg/kg/DOSE (max 10 mg/dose) IV Q6H F2-4D
if S. pneumoniae or H. influenzae or no pathogen identified ⇒ continue dexamethasone F4D
BOTH start within 15-20 min before or at same time as first dose of antimicrobials, NOT AFTER (some will still given within 30 min-12 hours)
What is the etiology of encephalitis, S&S?
UNKNOWN in most pt but for those where it is identified ⇒ 2/3 are viral
includes 2 major viral groups ⇒ Vector/arthropod-borne vs person to person + animal to human (rabies)
S&S: H/A, visual or auditory hallucinations, odd higher motor fxn, seizures, ataxia
What are S&S of HSV1 and 2?
acute onset fever, confusion, focal neurologic sx ⇒ up to 2/3 have convulsive seizures
commonly temporal lobes, associated with meningitis and encephalitis
Encephalitis: fever, change in consciousness, personality changes, seizures, focal neurologic findings, acute onset, leading to coma and death if untreated
What are CSF findings in HSV encephalitis/meningitis?
lymphocytic pleocytosis, normal or low glucose, mild increase in protein, RBCs may be present when hemorrhagic lesions present
PCR ⇒ high sensitivity and sensitivity BUT may be falsely negative until several days into illness with tx
Repeat CSF in 24-72 hours may be needed
What is involved in tx of HSV encephalitis/meningitis?
Acyclovir 10 mg/kg IV Q8H F14-21D
use ABW or IBW whichever is less, must adjust for renal fxn
can cause crystal nephropathy if inadequate hydration
