 Welcome back to meningitis and encephalitis part two. In this section, we discuss the investigations in treatment. Since meningitis, and particularly bacterial meningitis, has high mortality and morbidity, we want to often treat first before we begin the investigations. And therefore, let's talk about treatment. In terms of treatment, the general treatment for any patient in the emergency department again goes back to ABC. If the patient has decreased level of consciousness than they need in airway, we might have to intubate the patient first. Oxygen should be given to the patient who is hypoxic. For circulation, IV fluids should be given. We will add vasopressors if the patient is persistently hypotensive. The main treatment is antibiotics for meningitis and antivirals for encephalitis. Even though some meningitis would turn out to be not bacteria in origin, we still want to start them on antibiotics. Since the mortality, morbidity for bacterial meningitis is so high. Antibiotic choice for meningitis can include a third generation cephalosporin, vancomycin, and depending on the age group, ampicillin. It's best to check with your staff about the specific one that you want to use. For encephalitis, the choice of antiviral is usually acyclovir. There are also other adjunct treatment. For seizures, we often use benzodiazepines. For fever control, antibiotics. For patients with suspected bacterial meningitis, sometimes dexamethasone is given with the first dose of antibiotics. It is best to discuss with your staff. Again, if you are suspicious that your patient might have meningitis or encephalitis, we would want to initiate treatment first and then we will start to investigate. Let's talk about investigations. They include routine blood work, imaging such as CT, and a lumbar puncture. For blood work, it will be important to find out the patient's CBC, electrolytes, and renal function. We can order a lactate if the patient looks septic. A CT scan of the head is needed if the patient has one of two things. Decrease level of consciousness or focal neurological findings. The aim of the CT is to rule out any abscesses or mass. Sometimes MRI is used in patients with suspicion for encephalitis. In MRIs, they can sometimes see changes in the temporal lobes. The main diagnostic tool, however, is a lumbar puncture. A few tubes of CSF fluid should be obtained. These are what we should send it for. One tube should be sent for glucose and protein. A tube is sent for cell counted differential. A tube for gram stain and culture. And a fourth tube can be sent for viral PCR if we are suspicious of a viral cause. Once the CSF is obtained, this is how we can interpret the results. In bacteria meningitis, we will see high white blood cell count, with high percentages of neutrophils, low glucose, and high protein. The gram stain and culture might show the bacteria. However, that percentage gets a bit lower since we have pretreated the patient with antibiotics. We still like that because the patients do better with early antibiotics. In viral meningitis or encephalitis, this is what we'll see. Low protein, normal glucose, high white blood cell count, with mostly monocytes. The gram stain and culture are negative for bacteria. The viral PCR might be positive. For patients with bacterial meningitis, prophylaxis for household contacts needs to be done. They include those who eat and sleep in the same dwelling. There are different drugs we can use. They include ceftriaxone, suprafloxacin, or revampin. In summary, we discussed the investigation and treatment of patients with suspected meningitis and encephalitis. Remember, we're always treat before we investigate. They include attending the patient's ABC, antibiotics for meningitis, and antivirals for encephalitis. For investigation, we may have to image patients who have focal neurological findings or decreased the level of consciousness. And the main diagnostic tool is a lumbar puncture. We hope this has been a useful overview for you. Thank you for watching.