How Do Health Care Professionals Diagnose Meningitis in Adults?
Rapid evaluation and entry into the emergency department begin upon arrival when you are identified as possibly having meningitis.
Often, you are placed in an isolation room to protect staff and others from infection. Additionally, a mask may be placed over your nose and mouth to further prevent the spread of infection.
- Examination: The doctor performs an early examination to determine if help is needed with breathing or blood pressure. The doctor then checks your blood pressure, pulse, and temperature.
- Testing: Once the doctor examines you and learns of your symptoms, further evaluation depends on the doctor's assessment of the likelihood of meningitis. If the doctor suspects bacterial meningitis, he or she may order the following:
- Antibiotics may be given early in the evaluation.
- A CT scan may be performed. This can sometimes determine if the brain is infected or has an abscess.
- Blood is drawn to check the white and red blood cell counts.
- A chest X-ray film may be obtained to look for signs of pneumonia or fluid in the lungs.
- Other tests may be performed to look for other sources of infection.
- Spinal tap: A spinal tap, or lumbar puncture, is necessary to diagnose meningitis. The results of the spinal tap are essential to help the doctor determine both the presence and then the type of meningitis. Correctly diagnosing meningitis is absolutely essential to guide treatment decisions. If you are too sick for a spinal tap, you will be treated with antibiotics on the assumption that you have meningitis. The spinal tap will be done when your condition improves.
- Cerebrospinal fluid is obtained through a spinal tap. This fluid surrounds and cushions the brain and the spinal cord. The fluid is analyzed in the lab for things like the presence of white and red blood cells and protein and glucose (sugar) levels. The doctor then interprets the test results to determine if meningitis is present. The test results can also indicate if the meningitis is due to a bacterial infection, fungal infection, or a virus.
- To obtain the fluid, you are given an injection of lidocaine (Anestacaine, UAD Caine, Xylocaine HCl, Xylocaine-MPF), a local anesthetic similar to Novocaine used by dentists. A small needle is placed in the lower back, around the small of the back, to obtain the fluid.
- Although the spinal tap can sometimes be uncomfortable, it is generally not very painful. The main complications of the procedure are headache, which occasionally occurs, and infection, which is extremely rare.
- Because the results of the spinal tap can take up to several hours to return, the treatment often begins before the results are available. The doctor focuses early treatment on a medical opinion of the most likely cause based on your symptoms and physical examination findings.