EVD management strategies for institutions with a single approach. (A) There is no difference in use of intermittent vs. continuous drainage for unsecured and secured aneurysms (p=0.15). (B) Default EVD levels for institutions using a continuous drainage strategy. Mean level 18 cm H2O for unsecured (N=29) and 11 cm H2O for secured (N=34, p<0.0001). Dotted line at 20 cm H2O. (C) Use of a minimize vs. enhance drainage strategy is significantly different between unsecured and secured aneurysms (p<0.0001). Minimize drainage group includes intermittent plus continuous with the EVD ≥ 20 cm H2O. Enhance drainage only includes continuous with EVD <20 cm H2O. (D) Proportion of rapid (8/36, 22%) and gradual (28/36, 78%) weans. N=36 centers for (A), (C), and (D).