Hemorrhagic complications of external ventricular drainage.

OBJECTIVE: Despite the widespread use of external ventricular drainage (EVD), the frequency of associated hemorrhagic complications remains unclear. This retrospective study examined the frequency of hemorrhagic complications of EVD and attempted to discern associated risk factors.
METHODS: Treatment records from 160 patients admitted during a 2.5-year period who required EVD placement were reviewed. Indications for placement of EVD included acute complications of cerebrovascular disease (n = 94), traumatic brain injury (n = 36), primary hydrocephalus (n = 16), and tumor (n = 14). Patients received either a 3.0 or 2.5-mm outer diameter ventricular catheter (n = 82 and 78, respectively). Postinsertion computed tomographic scans were obtained within 24 hours on all patients and were analyzed for any new hemorrhage related to the ventricular catheter. Patient age, sex, catheter type, and dimensions of hemorrhage were also analyzed.
RESULTS: The incidence of EVD-related hemorrhage was 33 +/- 0.04%. However, the incidence of detectable change in the clinical neurological examination was 2.5%. A significant proportion of EVD-related hemorrhages were small (<4 cm), punctate, intraparenchymal hematomas. Patients with cerebrovascular disease exhibited an increased incidence (39%) of hemorrhage. The mean volume of intraparenchymal hemorrhage was larger in patients who received the 2.5-mm ventricular catheter, as well as those admitted for cerebrovascular disease.
CONCLUSION: Hemorrhagic complications of EVD placement are more common than previously suspected. Admitting diagnosis seems to have an effect on the development of an associated hemorrhage and its size. Catheter gauge has an effect on hematoma volume. Most of the hemorrhages seen on postinsertion computed tomographic scans do not cause detectable changes in the clinical examination.