Bacterial Meningitis and Clostridiodes Difficile Flashcards
What drugs may cause BM?
Co-trimoxazole, ibuprofen
What are the predisposing factors for BM? (8)
- Head trauma
- CNS shunts
- Neurosurgical patients
- CSF fistula or leak
- Local infections (sinusitis, otitis media, pharyngitis)
- Immunosuppression
- Splenectomized pts
- Congenital defects
Risk factors for BM?
- Prolonged close contact with infected pts
- Travel to endemic areas
- Invasion of mucosal surface (ie respiratory tract), then hematogenous spread to brain
Clinical presentations of BM?
- Fever, chills
- Classic triad: headache, backache, nuchal (neck) rigidity
- Mental status changes (Irritability)
- Photophobia
- N/V, anorexia, poor feeding habits (infants)
- Petechiae or purpura (Neisseria meningitidis meningitis)
- Kernig sign
- Brudzinski sign
- Bulging fontane
What are the values of glucose, protein and WBC for a normal CSF?
Glucose: 2.6 - 4.5 mmol/L
CSF : blood > 0.66
Protein < 0.4g/L
WBC < 5 cells/mm^3
What are the values of glucose, protein and WBC for CSF with BM?
Glucose very low
CSF : blood < 0.4
Protein raised > 1.5g/L
WBC raised > 100 cells/mm^3
What are the values of glucose, protein and WBC for CSF with viral meningitis?
Glucose: normal to slightly low
Protein: normal to mildly raised
WBC raised (5-1000 cells/mm^3)
For BM, what are the pathogens we need to treat for neonates (<1 month)? (BEL)
- Group B Streptococcus (Strep. agalactiae)
- Listeria monocytogenes
- E. coli
For BM, what are the pathogens we need to treat for infants and children (1-23 months)? (BENS)
- Strep. pneumoniae
- Group B Streptococcus (Strep. agalactiae)
- Neisseria meningitidis
- E. coli
For BM, what are the pathogens we need to treat for children and adults (2-50y/o)? (SN)
Strep. pneumoniae
Neisseria meningitidis
For BM, what are the pathogens we need to treat for adults > 50 y/o? (NALS)
Strep. pneumoniae
Listeria monocytogenes
Neisseria meningitidis
Aerobic gram -ve bacilli (E coli., Klebsiella spp etc)
When do we start empiric Abx for BM?
ASAP, within 1h
Tx for BM in neonates (< 1 month)?
Ceftriaxone + Ampicillin
Tx for BM in infants, children (1-23 months)?
Ceftriaxone + Vancomycin
Tx for BM in children, adults (2-50 y/o)?
Ceftriaxone + Vancomycin
Tx for BM in adults > 50 y/o?
Ceftriaxone + Vancomycin + Ampicillin
For culture-directed Tx of BM for Strep. pneumoniae, what is the Tx and duration?
- Penicillin susceptible: Pen G or Ampicillin
- Penicillin resistant, cephalosporin susceptible: Ceftriaxone
- Penicillin, cephalosporin resistant: vancomycin + rifampicin
Treat for 10-14 days
For culture-directed Tx of BM for Neisseria meningitidis, what is the Tx and duration?
- Penicillin susceptible: Penicillin or Ampicillin
- Penicillin resistant or mild allergy: Ceftriaxone
Treat for 5-7 days
For culture-directed Tx of BM for Listeria monocytogenes, what is the Tx and duration?
- Penicillin G or Ampicillin
- Penicillin allergy: co-trimoxazole, meropenem
Treat for ≥ 21 days
For culture-directed Tx of BM for Group B Strep (Strep. agalactiae), what is the Tx and duration?
- Penicillin G or Ampicillin
- Penicillin, mild allergy: ceftriaxone
Treat for 14-21 days
What other medication can we prescribe for BM?
When is it recommended?
What are the benefits and risks?
Adjunctive corticosteroid Tx
Recommended for pts with bacterial meningitis beyond neonatal age (6w onwards)
Benefits:
- Less hearing loss and other neurologic sequelae in H. influenzae and S. pneumoniae meningitis
- ↓ mortality in S. pneumoniae meningitis
Risks:
- May ↓ abx penetration (which ↑ due to inflamed meninges)
- ADRs: mental status changes, hyperglycemia, HTN
Dosage and administration for dexamethasone for BM?
Administer 10-20 mins before or at the same time as the first abx dose
Adult dose: 10mg q6h up to 4 days
Stop if pt discovered not to have BM or if bacteria causing meningitis is not H. influenzae or S. pneumoniae
What are the 3 drugs used for chemoprophylaxis of BM?
Rifampicin, ciprofloxacin and ceftriaxone
Rifampicin:
- Adults: 600mg q12h x 4 doses
- Children: 10mg/kg q12h x 4 doses
- Infants (<1 month): 5mg/kg q12h x 4 doses
Ciprofloxacin:
- Adult: 500mg PO x 1 dose
Ceftriaxone:
- 125-250mg IM x 1 dose
What are the risk factors of CDAD? (11)
- Advanced age > 65 y/o
- Multiple/ severe co-morbs
- Immunosuppression
- History of CDI
- GI surgery
- Tube/ enteral feeding
- Prior hospitalisation (past 1 year)
- Duration of hospitalisation
- Residence in nursing home/ long-term care facilities
- Use of abx
- Gastric acid suppressive therapy (PPIs, H2RAs, antacids)
Can all abx potentially cause CDAD development?
Which abx have high risk of causing CDAD?
When is the risk the highest?
Yes.
Clindamycin > 3rd and 4th gen cephalosporins > FQs (esp ciprofloxacin)
Risk highest while receiving abx but still elevated risk up to 12w
Which abx may actually be protective against CDAD?
Doxycycline/ tigecycline
Should we test/ treat asymptomatic CDAD pts?
No.
Only test and treat for CDI in symptomatic pts
What does diagnosis of CDAD require?
Presence of diarrhoea (≥ 3 loose stools in 24h)
OR
Radiographic evidence: ileus, toxic megacolon
PLUS
Positive stool test result for C. diff or its toxins
OR
Colonoscopic or histopathologic evidence
Before testing pts for CDAD, what must we ensure?
Should we repeat test to see if pts have been cured?
Before testing, ensure that pt has not received laxative 48h prior to sending test
No. Just look for improved clinical response.
Clinical presentation of CDAD? (what is the cardinal s/sx?)
Cardinal symptom: watery diarrhoea (≥ 3 loose stools in 24h)
What are the s/sx of MILD CDAD? (objective and subjective)
Objective:
- diarrhoea
- abdominal cramps
Subjective:
(non-severe)
- WBC < 15 x 109/L AND
- SCr < 133 μmol/L = 1.5mg/dL
What are the s/sx of MODERATE CDAD? (objective and subjective)
Objective:
- fever
- diarrhoea
- nausea
- malaise
- abdominal cramps, distension
- leukocytosis
- hypovolemia (dehydration s/sx)
Subjective:
Use own clinical judgement → in-between mild → severe CDI
Tx for MILD/ MODERATE CDAD? (first-line and alternatives)
First-line:
- PO fidaxomicin 200mg BD (not avail in SG)
- PO vancomycin 125mg QDS
Alternative:
- PO metronidazole 400mg TDS
What are the s/sx of SEVERE CDAD? (objective and subjective)
Objective:
- fever
- diarrhoea
- diffused abdominal cramps, distenison
Subjective:
- WBC ≥ 15 x 109/L OR
- SCr ≥ 133 μmol/L = ≥ 1.5mg/dL
First-line Tx for SEVERE CDAD?
- PO fidaxomicin 200mg BD
- PO vancomycin 125mg QDS
What are the s/sx of FULMINANT CDAD? (objective and subjective)
Objective:
- hypotension/ shock OR
Subjective (radiographic evidence):
- ileus OR
- megacolon
First-line Tx for FULMINANT CDAD?
- IV metronidazole 500mg q8h
PLUS - PO vancomycin 500mg QDS
+/- - PR vancomycin 500mg QDS (rectal route enema)
How long is the duration of Tx for CDAD?
Treat for 10 days, may extend to 14 days if s/sx not completely resolved
Risk factors for recurrent CDAD?
- Administration of other abx during of after initial Tx of CDI
- Defective humoral immune response against C. diff toxins
- Advanced age
- Severe underlying disease
- Continued use of PPIs
Tx for first recurrence of CDAD if fidaxomicin or vancomycin was used for initial episode?
- PO fidaxomicin 200mg BD x 10d
- PO fidaxomicin 200mg BD x 5 days then 200mg EOD x 20d
(FYI) vancomycin tapered/ pulsed dose
Tx for first recurrence of CDAD if metronidazole was used for initial episode?
PO vancomycin 125mg QDS x 10d