What triad of symptoms is highly indicative of meningitis?
Headache, neck stiffness, pyrexia/fever
Organisms that can cause meningitis
Commonly:
- Neisseria meningitides (meningococcus)
- Streptococcus pneumoniae (pneumococcus)
Less commonly:
- Haemophilus influenzae
- Listera monocytogenes
- If immunocompromised (e.g. HIV positive, organ transplant, malignancy): cytomegalovirus (CMV), cryptococcus (?), tuberculosis (TB)
Differentials for meningitis
- Malaria (?)
- Encephalitis (unlike meningitis, causes confusion, disorientation, drowsiness, seizures and changes in personality/behaviour, such as feeling agitated)
- Septicaemia
- Subarachnoid haemorrhage (SAH)
- Dengue (?)
- Tetanus
Early features of meningitis
- Headache
- Leg pain
- Cold hands/feet
- Abnormal skin colour (?)
Later signs of meningitis
- Meningism: neck stiffness, Kernig’s sign, photophobia
- Reduced level of consciousness, coma
- Seizures (20% of individuals) +/- focal neurological signs, opisthotonus
- Petechial/purpuric rash (non-blanching; may only be 1-2 spots, or none)
What is Kernig’s sign?
- One of the physically demonstrable symptoms of meningitis
- Pain and resistance on passive knee extension with a fully flexed hip
Signs of galloping sepsis
- Slow cap refill (>2s after pressing nail bed for 5s)
- Disseminated intravascular coagulation (DIC)
- Decreased BP
- Pyrexia and tachycardia or normal temperature and pulse
What is disseminated intravascular coagulation (DIC)?
A condition in which small blood clots develop throughout the bloodstream, blocking small blood vessels. The increased amount of clotting depletes stores of platelets and clotting factors, resulting in excessive bleeding.
What is opisthotonus?
Spasm of back muscles, causing arching of the body with neck hypertension (if a person with opisthotonus lies on their back, only the back of their head and heels touch the surface they are on)
What is the difference between a petechial and purpuric rash?
Both are due to capillary haemorrhage. Petechiae are non-blanching spots <2 mm in size, whereas purpura, a collection of petechiae, are >2 mm in size.
What test can be done to determine whether petechiae/purpura are non-blanching, so indicative of invasive of meningococcal disease?
Glass test (a clear glass tumbler is placed against the rash, and if it does not disappear with pressure, then this indicates septicaemia)
What investigations should be carried out?
- FBC (low WCC —> immunocompromised, get help)
- U&Es
- LFTs
- Coagulation screen (clotting)
- Glucose
- Blood culture
- Throat swabs (1 for bacteria, 1 for virology)
- Serology (e.g. for EBV, HIV)
- Lumbar puncture (send CSF for MC&S, Gram stain, protein, glucose, virology/PCR and lactate)
- (In aseptic meningitis, which is usually self-limiting, do CSF PCR -enteroviruses (e.g. Coxsackie A & B, echoviruses) predominate, then herpes simplex type 2 (HSV2) followed by HSV1)
- CXR (signs of TB —> TB meningitis)
- Urine pneumococcal antigen
When is lumbar puncture done, before or after CT? What are it’s contraindications?
Usually done after CT, but can proceed if GCS is 15, and there no signs of raised ICP or focal neurological signs
Contraindications:
- Signs of raised ICP (e.g. focal neurological signs, papilloedema)
- Uncorrected coagulopathy
- Signs of infection at the lumbar puncture site
- Acute spinal cord trauma
- Middle ear pathology (?)
In the context of lumbar puncture, what is a normal CSF opening pressure (patient is in the lateral decubitus position)? What is it in meningitis?
- Normal: 7-18 cm
- Meningitis: typically 14-30 cm, but can be >40 cm
What come first in the management of suspected bacterial meningitis?
Prior to admission: If 2 of headache/neck stiffness/pyrexia/altered mental state, and not yet in hospital (e.g. GP), benzylpenicillin (1.2g IM/IV)
On admission:
- IVI and fluid resuscitation
- Cefotaxime* 2g/6h (qds)
- If immunocompromised, get help
- For Listeria monocytogenes or if >55, add ampicillin 2g/6h (qds)
*Or other 3rd generation cephalosporin, e.g. ceftriaxone 2g/12h IV (bds)
In the management of suspected bacteria meningitis, treatment depends on whether the patient has predominantly meningitic or additional septicaemic signs.
What are the septicaemic signs of meningitis?
- Slow cap refill
- Cold hands/feet (before BP falls)
- Rash
In the management of suspected bacteria meningitis, treatment depends on whether the patient has predominantly meningitic or additional septicaemic signs.
What are the meningitic signs of meningitis?
- Neck stiffness
- Photophobia
Following initial treatment with cefotaxime or ceftriaxone +/- ampicillin on admission, what are the next steps in managing a patient with suspected bacterial meningitis and predominantly meningitic signs?
- Dexamethasone 4-10mg/6h (qds) IV
- Lumbar puncture if no signs of shock or raised ICP (2g cefotaxime IV immediately after)
Cefotaxime type of drug
3rd generation cephalosporin antibiotic
Ceftriaxone type of drug
3rd generation cephalosporin antibiotic
Ampicillin type of drug
Broad-spectrum antibiotic
Dexamethasone type of drug
Corticosteroid (systemic, glucocorticoid)
Benzylpenicillin type of drug
Penicillin antibiotic
In a patent with suspected bacterial meningitis, what should be co-administered if there is also concern of encephalitis?
IV antivirals
