Meningitis-Encephalitis

Question 1

Commonest organism in encephalitis

Answer 1

Enterovirus Herpes->HSV, EBV, CMV, VZV Arboviruses

Question 2

Important history

Answer 2

photophobia headache neck stiffness fever altered mental status confusion focal neurological deficit abnormal eye movement bulging fontanelle in infants photophobia vomiting seizures hypothermia (infants) irritability (infants) lethargy (infants) poor feeding (infants) apnoea (infants)

Question 3

Risk factors

Answer 3

Strong ≤5 years of age ≥60 years of age male gender low socio-economic status crowding exposure to pathogens non-immunised infants immunosuppression asplenia cranial anatomical defects ventriculoperitoneal shunt cochlear implants sickle cell disease

Question 4

Examination

Answer 4

Vital signs Mental state Nuchal rigidity (less reliable in younger children Rash Papilloedema Buldging fontanelle in children Evidence of infection as primary source->sinusitis, pneumonia, mastoiditis, UTI CN palsies-> 3, 4, 6 Kernig’s and brudzinski’s signs

Question 5

Explain kernig’s and brudzinski’s signs

Answer 5

Kernig’s sign: with the patient supine and the thigh flexed to a 90° right angle, attempts to straighten or extend the leg are met with resistance. Brudzinski’s signs: flexion of the neck causes involuntary flexion of the knees and hips, or passive flexion of the leg on one side causes contralateral flexion of the opposite leg.

Question 6

Investigations

Answer 6

Lumbar puncture->follow LP guidelines FBE Glucose UEC Blood cultures

Question 7

When does sterilisation of the CSF occur

Answer 7

within 2 hours after a dose of Ceftriaxone 50 mg/kg/dose (2g) iv 12H /Ceftriaxone for N. meningitidis and within 4 hours for S. pneumoniae

Question 8

Antibiotics and steroids in 2 months

Answer 8

2 months: Ceftriaxone 50mg/kg IV 12 H Dexamethasone 15 minutes prior to antibiotics if possible or within one hour of first dose

Question 9

If encephalitis suspected

Answer 9

Give Aciclovir

Question 10

Purpose of giving steroids

Answer 10

To reduce the risk of hearing loss

Question 11

Management of seizure in setting of meningitis

Answer 11

Need immediate benzodiazepines followed by loading with phenytoin

Question 12

Fluid management when N serum Na, hyponatremia, deH, or raised ICP/seizures

Answer 12

Normal serum [Na+] and no signs of hypovolaemia, dehydration or raised intracranial pressure –>Fluid guideline based on giving 3ml/kg/hour up to a weight of 10kg (about 70% of ‘maintenance fluid requirements’) as 0.9% (normal) saline + 5% dextrose. Hyponatraemia ([Na+]Fluid guideline based on giving 2ml/kg/hour up to a weight of 10kg (about 50% of ‘maintenance fluid requirements’) as normal saline + 5% dextrose. If the serum [Na+] is very low (Give repeated boluses of 10ml/kg of normal saline until hypovolaemia is corrected. Refer to ICU if signs of hypovolaemia persist. Ongoing fluid guideline based on giving 3ml/kg/hour up to a weight of 10kg as 0.9% (normal) saline + 5% dextrose. Signs of raised intracranial pressure or generalised oedema –>Fluid guideline based on giving 1-2ml/kg/hour up to 10kg (about 25-50% of ‘maintenance fluid requirements’) as normal saline + 5% dextrose

Question 13

Ongoing management in bacterial meningitis

Answer 13

Neurological Weight and head circumference Electrolytes and glucose Adequate analgesia Fluid management Chemoprophylaxis

Question 14

Chemoprophylaxis to those exposed to index case

Answer 14

Rifampicin

Question 15

Causes of persistent fever in bacterial meningitis

Answer 15

Nosocomial infection Subdural effusion Other foci of infection Inadequately treated meningitis

Question 16

Managment in adults and children >2m

Answer 16

ABC

1. History/examination
2. 2 large bore IV cannula
3. BC, FBC, UEC, CRP, glucose, clotting, ABG, PCR testing for meningicoccal
4. Consider need for CT prior to LP (if purpuric rash, it may delay treatment->Start antibiotics ASAP)
5. dexamethasone 10 mg (child: 0.15 mg/kg up to 10 mg) IV, starting before or with the first dose of antibiotic, then 6-hourly for 4 days
6. ceftriaxone 4 g (child: 100 mg/kg up to 4 g) IV, daily or ceftriaxone 2 g (child: 50 mg/kg up to 2 g) IV, 12-hourly If suspect listeria->add benzylpenicillin If suspect S. pneumoniae->OM/Sinusitis, pneumococcal antigen in CSF add vancomycin
7. Analgesia + antiemetic
8. IVF
9. Insert urinary catheter is septic/not passing urine
10. Consultant review
11. Admit
12. Infection precaution
13. Notification
14. Chemoprophylaxis
15. Followup with audiology and development

Question 17

When to suspect Listeria

Answer 17

Immunocompromised >50 Pregnant Debilitated ++Alcohol

Question 18

CSF findings in bacterial, viral, herpes, TB: pressure, WCC, glucose, protein, RCC

Answer 18

1. Bacterial: High pressure, +WCC neutrophils, low glucose, +protein, no RCC 2. Viral: N pressure, +WCC lymphoC, N glucose/protein/RCC 3. Herpes simplex: N/+ pressure, +WCC lymphoC, N glucose/protein, +RCC 4. TB: N/+ pressure, +monocytes, very low glucose, ++Protein, no RCC

Question 19

tests done on CSF

Answer 19

Gram stain PCR Culture

Question 20

Etiology neonate,

Answer 20

Neonate= GBS, E coli, Listeria 1-2= S. penumoniae, N. Meningitidis, HiB 2-18yo, Adult= N. meningitidis, S pneumoniae, HiB Elderly= S penumonia, Listeria, GBS