Objective: To examine the clinical impact of a management protocol for external ventricular drains (EVD).
Patients and methods: All patients with EVDs over a six-month period were reviewed retrospectively. Data concerning the indications for EVD placement, antibiotics and cerebrospinal fluid (CSF) analyses were collected. A restrictive antibiotic protocol (e.g. intravenous cephalothin 1g 6-hourly for 24 hours, unless other antibiotics were prescribed for a documented pre-existing infection) was introduced for all patients requiring placement of an EVD during the following six months and all patients were observed prospectively. Daily CSF samples were collected under sterile conditions and examined for organisms, cells, glucose and protein and sent for microbiological culture. External ventricular drains were removed after five days and replaced if further monitoring or CSF drainage was required. Adherence to the protocol and the incidence of ventriculitis was determined.
Results: Twelve patients with EVDs were identified during the 6 month pre-protocol period and 15 patients with EVDs were identified during the 6 month post-protocol period. There was no significant difference between the total (72 vs 88 days) and mean (6 vs 5.9 days) drain placement times between the two groups. There was no significant difference between the mean numbers of CSF samples in the two groups. CSF aspirates were not analysed in 35/72 samples (49%) in the pre-protocol group compared with 45/88 (51%) samples in the post-protocol group. Positive CSF Gram-stains were found in 3/12 (25%) patients in the pre-protocol group and in 0/15(0%) in the post-protocol group. Positive CSF cultures decreased significantly in the post-protocol group (17 vs 5, p = 0.0009). Prophylactic antibiotics were prescribed in 5/12 (42%) patients in the pre-protocol group compared with 12/15 (80%) patients in the post-protocol group.
Conclusions: The protocol was associated with a statistically significant improvement in compliance with antibiotic prescription and reduction in the incidence of positive CSF cultures.