A previously healthy 25 year old female was admitted with low GCS and a fever. She had a 24 history of viral symptoms including sore throat and a headache. On admission she had a GCS of 3, temperature of 38.9°C and raised inflammatory markers. She was intubated but did not require vasopressor support. A CT brain showed diffuse cerebral swelling, effacement of the sulci, sylvian fissures, basal cisterns and 3rd/4th ventricles, and early cerebellar tonsillar herniation. Lumbar puncture was not performed due to CT appearances. She was commenced on intravenous (IV) ceftriaxone 2g twice daily, IV acyclovir 800mg three times daily, and IV dexamethasone 10mg four times daily. Unfortunately, her pupils remained fixed and dilated on sedation hold 36 hours later, and she was making no respiratory efforts. She subsequently became a DBD organ donor.
What is the evidence for dexamethasone in bacterial meningitis?