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meningitis(men-en-jit'is) (-jit'i-dez?) plural.meningitides [ meningo- + -itis]
Meningitis may result from infection with bacteria, viruses, mycobacteria, fungi, amebas, or noninfectious sources, such as chemical irritation. Occasionally, infectious meningitis follows head trauma or sinus or ear infection. It also may result from the spread of blood-borne infection.
The symptoms of meningitis include fever, chills, headache, stiff neck, altered mental status, vomiting, and photophobia. Many patients with meningitis present with only two or three of these clinical indicators. Acute bacterial meningitis and meningitis caused by some fungi and amebas may also cause rapid deterioration in mental status, seizures, shock, and death.
Cerebrospinal fluid (CSF) must be examined. A cell count to assess the level of inflammation, a Gram stain to look for infectious organisms, measurement of spinal fluid pressure, and levels of bacterial antigens, glucose, lactate, and protein are typically obtained. CSF may appear milky-white due to the large numbers of white blood cells present.
All children in the U.S. are now vaccinated against H. influenzae type b (Hib) and pneumococcus (Prevnar) as primary prevention against the disease. Meningococcal polysaccharide vaccines are highly effective in preventing the disease during epidemic outbreaks with this organism. Close family contacts of patients with meningococcal meningitis, day care center contacts of infected children, or any persons (including health care workers) with direct contact with the saliva of infected patients are to be treated with antibiotics to prevent disease transmission.
Definitive treatment depends on identification of the underlying causes, but empirical therapies for infectious meningitis must be given immediately, hours before the causative agent is identified. Dexamethasone is administered intravenously before starting antibiotic therapy for best response to reduce the incidence of deafness in children (a common complication) and to help prevent death in adults with pneumococcal meningitis. The evolution of penicillin-resistant strains of pneumococci has altered traditional empirical treatments. Third-generation cephalosporins, ampicillin and gentamicin, chloramphenicol, or vancomycin plus rifampin have been given, depending on the patient's age, level of immune function, or clinical presentation. Antibiotic therapy is usually administered intravenously for 2 weeks, then orally for a prescribed period for bacterial infections. Viral meningitis treatment is supportive; recovery usually is complete (within 7 to 10 days). Antipyretic analgesics relieve headache and fever.
Specific measures for coexisting conditions and for shock and other complications (disseminated intravascular coagulation, metabolic acidosis, or seizures) should be initiated when indicated. Supportive therapies include bed rest, a dimly lit room, and reduced sensory stimulation. Standard precautions apply, and airborne/droplet precautions are initiated if nasal cultures are positive. Neurologic function is closely monitored for changes in level of consciousness, signs of increasing intracranial pressure (ICP), and indications of cranial nerve involvement. Fluid and electrolyte balance is monitored, and fluids are provided in quantities to prevent or treat dehydration while avoiding fluid overload and resultant cerebral edema. The patient is assessed for adverse effects of antibiotic therapy with peak and trough blood levels assessed to ensure therapeutic levels and avoid toxic overdose. The patient is repositioned carefully and assisted with range-of-motion exercises to prevent skin, muscle, and joint complications. Frequent mouth care is provided and adequate nutrition and elimination are maintained. Small frequent meals, nasogastric or parenteral feedings are provided as required. Constipation is prevented by stool softeners or mild laxatives to prevent straining, which could increase ICP. Basic explanations, realistic reassurance, and support are provided, with reorientation if delirium or confusion is present. Questions from the patient and family should be answered honestly, with reassurance that behavioral changes usually resolve.
The patient with infectious meningitis may need monitoring in an ICU. Patients with neurologic deficits that appear to be continuing should be referred to a rehabilitation program once the acute phase of illness has ended. To help prevent meningitis, patients with chronic sinusitis or other chronic infectious or inflammatory illnesses should be taught the importance of proper hand hygiene and of following through with prescribed treatments. Sterile techniques should be strictly enforced when treating patients with head wounds, skull fractures, or lumbar puncture, ventricular shunting, or other invasive therapies.
acute aseptic meningitis
Patients report fever, headache, stiff neck, malaise, and sometimes altered mental status or photophobia.
Treatment is supportive, with antipyretics and pain-relieving medications administered as prescribed. The virus can be spread by direct contact with saliva, sputum, mucus, or stools of an infected person. Standard precautions apply, with droplet precautions if nasal cultures are positive; contaminated articles are disposed of by double bagging. Neurological status is monitored for changes in level of consciousness and for increases in intracranial pressure. Personal hygiene is provided, and measures to prevent complications due to immobility are implemented. Gentle position changes are performed to reduce excessive stimulation. Artificial airway, suction, and oxygen are readily available. A quiet, dark atmosphere is provided, and siderails are padded to reduce the risk of injury. Prescribed analgesics are administered, and cool compresses are applied to the forehead to relieve headache. Intravenous fluids or tube feedings are administered as ordered, and intake and output are monitored. Assessments are made for complications such as shock, respiratory distress, and disseminated intravascular coagulation.
Since mosquitoes can spread some viruses that cause meningitis, avoiding mosquito bites during the warm months of the year by wearing insecticides (DEET) and barrier protection, and eliminating standing pools of water, where mosquitoes breed, may help prevent the disease. The public should be made aware of meningitis symptoms (fever, headache, stiff neck, altered levels of consciousness) and the importance of prompt attention for any patient suspected of meningitis.
Treatment options include amphotericin B, often with flucytosine. Fluconazole and/or related antifungals are sometimes used for maintenance therapy.