Acute septic meningitis, also known as meningitis, is an acute inflammatory reaction of the soft meninges, arachnoid, cerebrospinal fluid and ventricles due to septic bacteria.
A. Diagnostic criteria of septic meningitis
1.More fulminant or acute onset, preferably in infants, children and the elderly.
2. There is a history of sinusitis, open craniosynostosis, septic otitis media, etc. before the disease.
3.Many have fever, severe headache, vomiting, convulsions, severe cases may appear consciousness disorders, psychiatric symptoms, physical examination of the neck tonicity, positive Brønsted’s sign, Kirsch’s sign, etc.
4, blood routine: blood routine leukocytes and neutrophils are significantly elevated.
5, cerebrospinal fluid examination: increased pressure; cloudy or purulent appearance; cell count up to (1000 ~ 10000) × 106 / L, early neutrophils accounted for 85% ~ 95%, later lymphocytes and plasma cells mainly, increased protein mostly 1 ~ 5g / L, sugar and chloride content is reduced, general bacterial culture can be positive.
6, EEG examination: no characteristic changes, showing diffuse slow waves. Early CT or cranial MRI examination can be normal, with the progression of the disease MRI shows subarachnoid space asymmetry, signal increase, irregular enhancement after enhancement, later part of CT or MRI can be seen ventriculitis, subdural effusion and limited brain abscess, etc.
Differential diagnosis
1, viral meningitis: the prodromal phase has flu-like symptoms, manifested as fever, headache, mild systemic toxicity, CSF is dominated by lymphocytosis, protein is mildly or moderately elevated, sugar is normal, and is self-limiting.
2, fungal meningitis: patients often have a history of immunodeficiency, the onset of the disease is insidious, CSF lymphocyte increase is dominant, sugar content is significantly reduced, CSF ink staining can detect new cryptococci.
3, tuberculous meningitis: the onset is more insidious, manifested by a certain degree of impaired consciousness, increased intracranial pressure, seizures and focal neurological signs, typical changes in CSF are mild to moderate increase in lymphocytes, increased protein, decreased sugar and chloride, and positive antacid staining for tuberculosis.
4. Subarachnoid hemorrhage: often starts during activity, with sudden onset of severe headache, vomiting, cervical tonicity and transient loss of consciousness; hemorrhage is seen on CT, and cerebrospinal fluid hemorrhage can confirm the diagnosis, which must be differentiated from trauma or lumbar puncture injury.
Treatment
On the basis of maintaining blood pressure and correcting shock, choose effective antibiotics that can easily cross the blood-cerebrospinal fluid barrier, and then adjust antibacterial drugs according to the results of bacterial culture and drug sensitivity test.
In children and adults, three generations of cephalosporins are the drugs of choice for the treatment of three common types of septic meningitis. Among them, ceftriaxone (ceftazidime) and cefotaxime, and for those with severe allergy to penicillin, chloramphenicol is more appropriate.
In those cases of meningitis caused by impaired immune function, post-neurosurgery, ventricular drainage or severe cranial trauma, ceftazidime (ceftazidime) and vancomycin should be used due to the high potential for pathogenicity of staphylococci or gram-negative bacilli, especially Pseudomonas aeruginosa. This is usually for 10 to 14 days.
For pediatric patients dexamethasone 0.6 mg/(kg?d) should be added for 3 to 5 days to reduce the incidence of hearing impairment and other neurological sequelae. Corticosteroids should also be used in the presence of intracranial hypertension. Dexamethasone 10-20 mg,/d intravenously for 3-5 days.
For increased intracranial pressure, 20% mannitol or tachyphylaxis should be used. Anticonvulsant drugs should be given to those with epileptic seizures.
IV. Prognosis
Untreated septic meningitis is usually fatal. The early use of highly effective broad-spectrum antibiotics has improved the prognosis considerably. The mortality rate of neonatal septic encephalitis has decreased from 50% in the 1970s to less than 10%, but the rate of death and disability remains high in severely ill patients or those who are diagnosed and treated too late.