Meningitis is an inflammation of the membranes covering the brain and the spinal cord (meninges).
It is an endemic infection and usually occurs in the tropics, where there is low humidity. In Ghana, it mainly occurs in the Northern and Upper regions during the harmattan season.
Causes Of Meningitis
The cause of Meningitis can be bacterial, viral or fungal.
1. Bacteria causes of meningitis are Neisseria Meningitidis, Haemophilus Influenzae, and Streptococcus Pneumoniae.
3. Fungal causes include Cryptococcus neoformans.
Predisposing Factors To Meningitis
Below are the predisposing factors to meningitis;
- Brain and spinal cord injuries/surgeries
- Upper respiratory tract infections
- Middle ear infections
- Immuno-compromised state, eg. HIV
- Systemic infections
- Post-surgical infections
- Meningeal infections
- Anatomic defects
- Toxins such as intrathecal drugs
Types Of Meningitis
This is usually caused by bacteria from upper respiratory tract infections.
2. Tuberculous meningitis
It is caused by tubercle bacilli. The onset is gradual, and recovery is also prolonged. It only responds to tuberculous drugs.
3. Meningococcal meningitis
It is caused by Neisseria meningitides. It is very fatal and spreads by droplet infection.
4. Viral meningitis
It is also known as aseptic meningitis as it is not associated with pus formation. The commonest viruses implicated are; the measles virus (morbillivirus), the virus that causes mumps (paramyxovirus).
5. Fungal meningitis
The common one is cryptococcal commonly found in immunocompromised patients.
6. Meningism/sterile meningitis:
It is caused by meningeal irritations that arise from certain systemic conditions. It is not necessarily an inflammation of the meninges but rather an irritation.
Pathophysiology of meningitis
Meningitis start as an infection of the oropharynx or nasopharynx.
The organism enters the bloodstream and crosses the blood-brain barrier and triggers an inflammatory reaction in the meninges.
There is scarring of the structures within the ventricles leading to an abnormal increase in the production of cerebrospinal fluid. This increases intracranial pressure (ICP).
Bacterial meningitis starts as an infection of the oropharynx and is followed by septicemia. This extends to the meninges of the brain and upper region of the spinal cord.
In bacterial meningitis, purulent secretions produced quickly spread to other areas of the brain through the CSF and cover the cranial nerves and other intracranial structures.
If this process extends into the brain parenchyma, cerebral edema and increased ICP become problems.
Bacterial meningitis is considered a medical emergency. Untreated bacterial meningitis has a mortality rate of almost 100%.
The prognosis of bacterial meningitis depends on the causative organism, the severity of infection and illness, as well as the timeliness of treatment.
Clinical Manifestations Of Bacterial Meningitis
- Severe headache (which is unrelenting). It results from meningeal irritation.
- Fever remains high throughout the course of the illness.
- Memory impairment
- Nuchal rigidity (stiff neck. Any attempt at flexion of the neck is difficult bcos of spasms in the muscles of the neck. Forceful flexion produces severe pain).
- Positive Kernig’s sign (when lying with the thigh flexed on the abdomen, the patient cannot completely extend the leg).
- Positive Brudzinski’s sign: flexing the patient’s neck produces flexion of knees and hips. Passive flexion of the lower extremity of one side produces a similar movement for opposite extremity.
- Photophobia (extreme sensitivity to light)
- Increased ICP.
Signs of increased ICP include focal motor deficits, widened pulse pressure and bradycardia, respiratory irregularity, headache, vomiting and depressed levels of consciousness.
A rash can be a striking feature. N. meningitides infection produces skin lesions ranging from petechial rash with purpuric lesions to large areas of ecchymosis.
Manifestations Of Meningococcal Meningitis
In about 10% of patients, there is a fulminating infection with signs of overwhelming septicemia.
- Abrupt onset of high fever
- Extensive purpuric lesions (over face and extremities).
- Shock and signs of disseminated intravascular coagulopathy (DIC).
- Death may occur within a few hours of the onset of the infection.
Some other neurologic signs and symptoms include:
- Flexing of the neck is impossible due to muscle spasm.
Symptoms Of Meningitis In Children:
- Irritability and restlessness
- Refusal to eat or poor sucking
- Vomiting, drowsiness and a weak cry
- Focal or generalized convulsions
- Bulging fontanel
- The neck may be retracted and back arched
Assessment And Diagnostic Findings
- Lumbar puncture for culture and sensitivity of CSF and blood. CSF flows under enormous pressure and is bloody or cloudy. Also, the presence of antigens supports a diagnosis of bacterial meningitis.
- Neurologic signs and symptoms
- History taking
- Blood film to rule out malaria
- Throat and nose swab
- Magnetic resonance imaging (MRI)
- CT scan
- Chest X-ray
Prevention Of Meningitis
- Health education of the general public on personal hygiene is vital.
- Education on the need to avoid overcrowding
- Close contacts should be given antimicrobial prophylaxis (ciprofloxacin, rifampicin, ceftriaxone).
- Contacts shd be observed and treated immediately if fever or other signs and symptoms of meningitis develop.
- Contacts should be vaccinated
- Children should be immunized against Hemophilus influenza infection to prevent meningitis.
- Educate on the need to avoid direct contact with infected persons.
The main drugs used to treat this condition are antibiotics, analgesics, and anticonvulsants.
Antimicrobial therapy: Penicillin antibiotics (e.g. Piperacillin or Ampicillin), or one of the cephalosporins eg. Ceftriaxone sodium, cefotaxime sodium.
The treatment for cryptococcal meningitis is intravenous administration of amphotericin B. It may be used with 5-fluorocytosine.
Vancomycin hydrochloride alone or in combination with rifampicin may be used if resistant strains of bacteria are identified.
Dexamethasone may be beneficial as an adjunct therapy for acute bacterial meningitis and pneumococcal meningitis.
Fluid volume expanders are used to treat dehydration and shock.
Diazepam (valium) or phenytoin (Dilantin) is used to control seizures.
An osmotic diuretic such as mannitol is used to treat cerebral edema.
Nursing Management Of Meningitis
Prognosis depends mainly on the supportive care provided.
Monitor vital signs constantly. Determine oxygenation from arterial blood gas values and
Give oxygen to maintain arterial partial pressure of oxygen.
Prevent shock which precedes cardiac or respiratory failure.
Note: generalized vasoconstriction, cyanosis, and cold extremities.
Reduce high fever (by tepid sponging) to decrease the load on the heart and brain for oxygen demands.
Frequent assessment of neurologic status is indicated to detect early manifestations of Increasing ICP and seizures.
Maintain adequate fluid and electrolyte balance by; Rapid intravenous fluid replacement. But care shd be taken not to overhydrate pt bcos of risk of fluid overload and cerebral edema
Assess clinical status continuously, maintain skin and oral hygiene, promote comfort and protect the patient during seizures and while comatose.
Implement infection control precautions and respiratory isolation until 24 hrs after the start of antibiotic therapy (oral and nasal discharges are considered infectious).
Prevent complications associated with immobility such as pressure sores and pneumonia.
Inform the family about the patient’s condition and permit the family to see the patient at appropriate intervals.
Provide emotional support by reassuring the patient and relatives.
Keep accurate intake and output chart.
Disinfect discharges from the nose and all other articles before disposal
Observe for convulsive attacks and fits, the time they occur, and their duration.
A nasogastric tube is passed, and a fluid diet is given if the patient cannot feed.
When the patient is able, start with copious fluids, then to a soft diet, and gradually increase to a normal diet. Meals should be nutritious and well balanced.
Nurse patient in a dark ventilated and quiet environment.
Provide side rails because the pt is restless, irritable and delirious and as such can easily fall.
- Paralysis of any part of the body
- Blindness and deafness
- Impaired speech