Meningitis Flashcards
Define meningitis
Inflammation of the inner meningeal/leptomeningeal (pia mater and arachnoid) coverings of the brain, most commonly due to infection
What is the most common cause of meningitis
Viral causes
Enteroviruses (coxsackie A/B)
Mumps
HSV
VZV
HIV
What is the most common cause of meningitis in neonates
Group B steptococcus
E. Coli
Listeria mnocytogenes
What is the most common cause of meningitis in children
Haemophilus Influenzae (Hib)
Neisseria meningitidis
Strep. pneumoniae
What is the most common cause of meningitis in teenagers
Neisseria meningitides (meningococcal B, gram -ve diplococci)
Haemophilus influenzae (unvaccinated)
Strep. pneumoniae
What are the risk factors for meningitis
Younger age
Winter season
Close communities
Immunodeficiency e.g. HIV, chemotherapy, leukaemia
Basal skull fracture
What are the symptoms of meningitis
Children usually present with non-specific symptoms: vomiting, fever, irritability, URTI
Behavioural:
- High pitched crying or fits
- Irritability / unsettled behaviour
- Drowsiness
Rash
- Non-blanching (N. meningitides)
Fever
Neck or backache
Headache
Seizures
What are the signs of meningitis on examination
Obs: fever, tachycardia, hypotension
General exam:
Rash
- non-blanching petechial rash (meningococcal)
- Darker skin: check the soles/palms/conjunctivae/palate (i.e. paler areas)
Altered mental state (reduced GCS)
Prolonged CRT
Cold extremities
High pitched cry
Meningitis specific:
Kernig’s sign = pain/resistance on passive knee extension with hips flexed
Brudzinski’s sign = flexing the neck causes automatic flexion of the hips and knees
Meningism: photophobia, neck stiffness
Bulging fontanelle
What investigations should be done for meningitis
(Initiate sepsis 6)
Bedside: ?petechial scraping
Bloods: Blood cultures, Blood gas, FBC, CRP , glucose, coagulation screen, PCR for meningococcal disease, U&Es, LFTs
Other: Lumbar puncture (Confirm diagnosis)
What results will you see for bacteral, viral, TB, and cryptococcal meningitis on lumbar puncture
Bacterial: Turbid/cloudy, high neutrophils (polymorphs), low glucose, high protien
Viral: clear, high lymphocytes (mononuclear), normal glucose, normal/high protein
TB: Fibrin web, high lymphocytes (mononuclear), low glucose, high protein
Cryptococcus: stains with india ink
When is a LP contraindicated
Raise ICP (reduced consciousness, bradycardia + HTN, focal neurologicla signs, unequal/unreponsive pupils, papilloedema)
Overlying skin infection
Extensive/spreading purpura (indicator of coagulopathy, DIC)
Shock
What is the management for bacterial meningitis in primary care (+doses)
IV/IM benzylpenicillin + Call for ambulance for urgent hospital referral
<1yo - 300mg
1-9yo - 600mg
>10yo - 1200mg
If there is no non-blanching rash → do NOT give Abx, call for hospital
What is the management of bacterial meningitis in secondary care
- ABCDE: Give oxygen, check airways, crystalloid fluids,
a. Fluid bolus of normal saline - Take blood cultures
- IMMEDIATE empirical IV/IM antibiotics
- Dexamethasone 10mg IV shortly before or with the first dose of antibiotics
- If severe → ITU admission
+ notify public health England (notifiable disease)
+ follow up + hearing test
What antibiotics are indicated for meningitis
<3 months: cefotaxime + amoxicillin/ampicillin
>3 months: IV ceftriaxone
Meningococcal: Benzylpeniciliin
Listeria: ampicillin/amoxicillin
?encephalitis: Acyclovir
Penicillin and cephalosporin resistant pneumococci: vancomycin and rifampicin
Penicillin allergic: Ceftaxime
Travel Hx/prolonged Abx exposure: add vancomycin
What is the management for viral meningitis
conservative management (self-limiting with good prognosis)
What is the prophylaxis for close contacts for meningitis
Ciprofloxacin for 2 days and vaccination
given to everyone who has had prolonged close contact with the case in a household-type setting during the 7 days BEFORE onset of illness
What are the complications of meningitis
Septicaemia, shock, DIC
Neuro: cerebral infarction, hearing loss, seziures, cognitive impairment, motor deficits, visual impairment, cerebral oedema
Clotting: DVT, peripheral gangrene
Hydrocephalus, learning difficulties
Water-house-Friderichsen syndrome
What is the prognosis for meningitis
Outcome is excellent with prompt and adequate antimicrobial and supportive therapy
Prognosis depends on age, presence of comorbidity, causative pathogen and severity at presentation
Mortality rate for bacterial meningitis is 10-40%
What factors increase risk of higher severity of meningitis
Age (higher at extremes)
Symptoms lasting >48 hours before admission
Presence of osteitis or sinusitis
Low GCS on admission
Prolonged seizures or fever
Shock
Respiratory distress
Tachycardia
Absence of rash
Thombocytopenia
What results on LP indicate the need for steroids and when are steroids contraindicated
Frankly purulent CSF
WBC > 1000/microlitre
Raised WBC with protein concentration >1g/L
Bacteria on Gram stain
<3months, high dose CI in meningococcal disease
