External ventricular drain (EVD) placement carries a 9-22% risk of meningitis or ventriculitis. Risk factors include recent neurosurgery, intraventricular hemorrhage, CSF leak, steroids, prolonged use, catheter irrigation, and frequent CSF sampling. Best practices include a single preoperative antibiotic dose, aseptic technique, minimizing CSF sampling, limiting drain manipulation, avoiding routine drain exchange, and avoiding ongoing antibiotics (PMIDs 28962814, 33395081). MedThreads