Infection & Immunity - Meningococcaemia & Sepsis Flashcards
Incidence of meningococcemia?
> 80% patients with bacterial meningitis younger than 16, 5-10% mortality
10% survivors left with long-term neurological impairment
Describe the pathphysiology of Neisseria meningitides
- Meningitis after bacteraemia
- Damage caused by host response to infection + not from organism itself
- Release of inflammatory mediators + activated leucocytes
- Endothelial damage
- Result in raised ICP + decreased cerebral blood flow
- If inflammatory response below meninges causing vasculopathy resulting in cerebral cortical infarction
- Fibrin deposits may block resorption of CSF by arachnoid villi, resulting in hydrocephalus
How does meningococcaemia present?
fever headache photophobia lethargy poor feeding/vomiting irritability hypotonia drowsiness loss of consciousness seizures purpuric rash neck stiffness bulging fontanelle opisthotonus signs of shock - tachycardia, tachypnoea, prolonged cap refill, hypotension
What is the Brudzinski sign?
flexion of neck with child supine, causing flexion of knees and hips
What is the Kernig sign?
child lying supine and with hips and knees flexed
back pain on knee extension
What is the NICE guidelines on febrile children with purpura?
Purpura in a febrile child pf any age should be assumed to be meningococcal sepsis
Give IM benzylpenicilllin immediately and transfer to hospital
What is purpura?
characteristic non blanching purpuric skin lesions, irregular in size and outline with a necrotic centre
fulminant - extensive lesions
What is the acute management of fulminant meningococcal sepsis and meningitis?
antibiotics and supportive therapy
cefotaxime or ceftriaxone preferred
length of course depends on causative organism and clinical response
dexamethasone reduces deafness
What is important to remember about meningococcal sepsis and meningitis?
Notifiable disease
Prophylactic treatment to all household contacts
What are the potential complications of meningitis?
hearing loss
local vasculitis - may lead to cranial nerve palsies
local cerebral infarction - focal or multifocal seizures
subdural effusion
hydrocephalus
cerebral abscess
What rare underlying immunological deficits may lead to recurrent meningococcaemia?
lack of proteins that are responsible for bactericidal killing of N.meningitidis
What is sepsis?
presence of infection in conjunction with the systemic inflammatory response syndrome
What are the causative organisms for early neonatal sepsis?
ascending infection from birth canal
GBS
E.coli
H.Influenza
Listeria
What are the causative organisms for late neonatal sepsis?
Staph. Epidermidis Staph. Aureus E. Coli Klebsiella Pseudomonas Enterobacter Serratia Candida
What are the causative organisms for sepsis in infants and childhood?
Hib
Strep pneumonia
N. meningitides
Salmonella
What is the main causative organism in immunodeficient patients and those with chronic respiratory illness?
pseudomonas
How does sepsis present clinically?
fever poor feeding miserable, irritable, lethargy Hx of focal infection Predisposing conditions Tachycardia, tacypnoea, low BP Purpuric rash in meningococcal sepsis Shock Muli-organ failure
What are the red flags in children with sepsis?
Fever >38 if <3 months or >39 if 3-6 months
Colour – pale, mottled, blue
Level of consciousness reduced, neck stiffness, bulging fontanelle, status epilepticus, focal neurological signs or seizures
Significant respiratory distress
Bile-stained vomiting
Severe dehydration or shock
What is included in a septic screen?
Blood cultures FBC inc WCC CRP Urine sample Consider: CXR, LP, rapid antigen screen, meningococcal/pneumococcal PCR, PCR for viruses in CSF
When is the threshold low for performing a septic screen?
younger the child the lower the threshold
Define shock
circulation is inadequate to meet demands of tissues
What are the early clinical signs of shock?
compensated
tachypnoea tachycardia decreased skin turgour sunken eyes and fontanelle delayed cap refill (>2secs) mottled, pale, cold skin core-peripheral temp gap decreases urinary output
What are the late clinical signs of shock?
uncompensated
acidotic breathing bradycardia confusion/depressed cerebral state blue peripheries absent urine output hypotension
Which abx are given in the first 6-8 weeks of life for sepsis?
ampicillin + one of the following: gentamycin, cefotaxime, ceftriaxone
What abx are given to older infants and children?
3rd gen cephalosporin
How is sepsis treatment escalated?
- provide abx cover
- fluid resuscitation
- if no improvement or - progression of shock
- paediatric ICU
- poss tracheal intubation and mechanical ventilation
- invasive monitoring of BP
- inotrophic support
- correct haematological, biochemical and metabolic derangements
- support for renal or liver failure
