Association of External Ventricular Drain Wean Strategy with Shunt Placement and Length of Stay in Subarachnoid Hemorrhage: A Prospective Multicenter Study

Background: Survivors of aneurysmal subarachnoid hemorrhage (SAH) face a protracted intensive care unit (ICU) course and are at risk for developing refractory hydrocephalus with the need for a permanent ventriculoperitoneal shunt (VPS). Management of the external ventricular drain (EVD) used to provide temporary cerebrospinal fluid diversion may influence the need for a VPS, ICU length of stay (LOS), and drain complications, but the optimal EVD management approach is unknown. Therefore, we sought to determine the effect of EVD discontinuation strategy on VPS rate. Methods: This was a prospective multicenter observational study at six neurocritical care units in the United States. The target population included adults with suspected aneurysmal SAH who required an EVD. Patients were preassigned to rapid or gradual EVD weans based on their treating center. The primary outcome was the rate of VPS placement. Secondary outcomes were EVD duration, ICU LOS, hospital LOS, and drain complications. Results: A rapid EVD wean protocol was associated with a lower rate of VPS placement, including a delayed posthospitalization shunt, in an adjusted Cox proportional analysis (hazard ratio 0.52 [p = 0.041]) and adjusted logistic regression model (odds ratio 0.43 [95% confidence interval 0.18–1.03], p = 0.057). A rapid wean was also associated with 2.1 fewer EVD days (p = 0.007) and saved an estimated 2.5 ICU days (p = 0.049), as compared with a gradual wean protocol. There were fewer nonfunctioning EVDs in the rapid group (odds ratio 0.32 [95% confidence interval 0.11–0.92]). Furthermore, we found that the time to first wean and the number of weaning attempts were important independent covariates that affected the likelihood of receiving a VPS and the duration of ICU admission. Conclusions: A rapid EVD wean was associated with decreased rates of VPS placement, decreased ICU LOS, and decreased drain complications in survivors of aneurysmal SAH. These findings suggest that a randomized multicentered controlled study comparing rapid vs. gradual EVD weaning protocols is justified.