Introduction
Bacterial meningitis refers to inflammation of the leptomeninges as a result of bacterial infection.
This condition occurs more frequently in
Late-Onset Sepsis compared to Early-Onset Sepsis. See Sepsis.
It is associated with high mortality
because early diagnosis is usually difficult since the early features are non-specific.
Clinical Features
The early, non-specific features include:
- fever, vomiting, poor feeding and poor activity.
The late features are more specific and these include:
- hypothermia, tone abnormalities, particularly, hypertonia, high-pitched cry, setting-sun eye appearance, opisthotonus, bulging and tense anterior fontanelle, seizures, apnea and altered sensorium.
Investigations
A lumbar tap for cerebrospinal fluid
analysis is mandatory. Skip it if the infant has cardio-respiratory instability.
Inability to carry out this important
investigation must not be a reason to
delay empirical antibiotic therapy.
Meningitis is diagnosed with cell count
greater than 30/mm’, pleocytosis with
polymorphonuclear cells, protein greater
than 150mg/dl and glucose less than 50% of simultaneously assayed blood glucose.
Neuro-imaging studies are required if:
- fever persists or recurs
- seizures recur after initial control
- occipito-frontal circumference is increasing. It will be necessary to exclude subdural and intra cerebral collections.
Treatment
The empirical antibiotic therapy should
be tailored to the local pattern of bacterial aetiology of neonatal meningitis.
Staphylococcus aureus, Streptococcus
pneumoniae and the Gram-negative bacilli are frequently encountered.
Therefore, the recommended antibiotics
include a combination of intravenous
third generation cephalosporin:
- Ceftriaxone 50mg/kg 12-hourly
or
- Cefotaxime 50mg/kg 6-hourly
and
- Gentamicin 2.5mg/kg 12-hourly.
Intravenous ampicillin 50mg/kg 6
hourly may be useful in places where
resistance of organisms to the drug is not
remarkable and in known cases of Listeria monocytogenes infection.
The duration of antibiotic therapy is 14
days for Gram-positive organisms and 21
days for Gram-negative organisms.
Phenobarbitone is recommended through the intravenous route for seizures; 15mg/kg loading dose followed up with 2.5mg/kg 12-hourly maintenance doses.
The loading dose could be repeated at 10mg/kg when seizures are difficult to control.
Fluid therapy: The current body of
evidence is not in favour of fluid
restriction for all infants.
Critically-ill infants tend to be dehydrated from poor feeding or vomiting and fluid restriction is likely to be harmful – risk of shock and renal shut-down in such babies.
More important is the need to avoid over
hydration (in lieu of the risk of cerebral
edema) and that could be achieved by
stringent administration of not more than the recommended maintenance fluid requirement.
Corticosteroids: Unlike in older infants and children, corticosteroids are presently not recommended for use in neonatal meningitis for lack of evidence of usefulness.
Support care:
Fluid and caloric balance, blood transfusion for severe anaemia, oxygen therapy and ventilators supports for hypoxaemia.