Septic meningitis is a common purulent infection of the central nervous system and remains one of the diseases with high morbidity and mortality rates worldwide. It usually starts acutely, with fulminant cases being so severe that death can occur within 24 hours if not rescued in time.
I. What is septic meningitis?
The most common causative agents of septic meningitis are pneumococcus, diplococcus meningitidis and Haemophilus influenzae type B. Knowing the pathogenic bacteria at different ages helps to select different antibiotics empirically. However, in clinical work, because many patients have been given antibiotics when doing lumbar puncture, the bacteria often cannot be cultured when doing culture, so not all septicemia can be clearly stated which bacteria are causing it, but do not worry, even if the bacteria cannot be cultured, the doctor can also give appropriate treatment according to clinical experience.
What are the signs of septic meningitis?
Parents should be alert if they notice the following signs in their child and seek medical attention from a regular hospital.
1. Symptoms of infection
There may be symptoms of general respiratory tract infection.
2. Meningeal irritation signs
The symptoms are cervical tonicity (commonly known as stiff neck), positive Kernig’s sign and Brudzinski’s sign. In infants and young children (under 2 years old), the symptoms of meningitis are often atypical because the skull sutures and fontanelle are not closed, manifesting as high fever, vomiting, refusal to eat, crying and restlessness, and even convulsions, although there are no signs of meningeal irritation, but the fontanelle is full to help diagnose.
3.Symptoms of increased intracranial pressure
The symptoms are severe headache, vomiting, and impaired consciousness. If the intracranial pressure increases significantly, brain herniation may be formed, which is life-threatening.
4.Focal symptoms
Some patients may show symptoms of focal neurological impairment, such as hemiplegia, aphasia, facial nerve palsy, motoneuropathy, etc.
5.Other symptoms
Some patients have more specific clinical features, such as the rash that appears during meningococcal meningitis (also known as epidemic meningomyelitis) bacteremia, which starts as a diffuse red maculopapular rash and rapidly turns into skin petechiae, mainly on the trunk, lower extremities, mucous membranes, and conjunctiva, and occasionally on the palms of the hands and soles of the feet. The pathogenic infection may lead to fulminant outbreaks with a high mortality rate.
In addition, it should be noted that some infants and children with atypical clinical symptoms, mild fever, or even good spirit, without convulsions and obvious cranial symptoms, may still have intracranial infection, which requires a comprehensive clinical judgment. We once saw a case of a child who had the disease for 40 days before it was diagnosed as septic meningitis, resulting in prolonged illness, difficult treatment, and many complications.
What tests can be done to confirm the diagnosis of septic meningitis?
Lumbar puncture is the only way to confirm the diagnosis. Lumbar puncture can not only diagnose the presence of encephalitis (or meningitis), but also distinguish the nature of the infection.
Do I need a cranial CT or MRI?
No. Imaging tests are of little significance for diagnosis and differential diagnosis. Some patients show enhanced signal in the meninges and cerebral cortex after enhancement, but the absence of enhancement does not exclude the diagnosis. Some families worry about the risk of lumbar puncture and are reluctant to do it, hoping to determine the presence of intracranial infection by cranial CT or MRI, which is incorrect.
However, cranial imaging should still be done. The real significance of the examination is to understand the central nervous system complications of meningitis, such as brain abscess, cerebral infarction, hydrocephalus, subdural fluid (or pus accumulation), etc. Also some intracranial hemorrhages or intracranial occupancies can present with symptoms similar to encephalitis and need to be excluded. We have diagnosed children with pyogenic meningitis with multiple brain abscesses.
What is the treatment?
The most important thing is antimicrobial therapy (if the choice of antibiotics is inappropriate or the dose is insufficient, it may lead to the failure of treatment).
The principle is to use antibiotics that can cross the blood-brain barrier early and in sufficient quantity, and to combine therapy if necessary, usually using broad-spectrum antibiotics before determining the pathogenic bacteria, and choosing the corresponding sensitive antibiotics if the pathogenic bacteria are clear.
The first choice of broad-spectrum antibiotics is ceftriaxone of three generations of cephalosporins, in addition, for drug-resistant bacteria may be used meropenem, vancomycin, chloramphenicol, etc., especially with chloramphenicol must pay attention to the occurrence of bone marrow suppression.
2.Hormone therapy
Hormone can inhibit the release of inflammatory cytokines and reduce the occurrence of hydrocephalus. It can be considered for patients with severe disease and no obvious contraindication to hormone. Dexamethasone 0.6mg/kd.d is usually given in 4 doses for about 3 days, which should not be too long.
3.Symptomatic supportive treatment
Those with high cranial pressure can be dehydrated to lower cranial pressure, those with hyperthermia use physical cooling or use antipyretic agents, and those with convulsions are given anti-convulsive treatment.
VII. What is the prognosis of chemoencephalitis? Will there definitely be sequelae?
Although the death rate and disability rate are high, the prognosis is closely related to the pathogenic bacteria, the condition of the body and the early and effective application of antibiotic treatment. With active treatment, most children can be cured, but a few patients may be left with sequelae such as mental retardation, epilepsy and hydrocephalus. Children with long coma and many convulsions during the course of the disease are likely to have sequelae.