Zero-Calibrating External Ventricular Drains: Exploring Practice.

BACKGROUND: Guidelines call for the removal of the nonvented cap (NVC) on the flushless transducer applied to the external ventricular drain (EVD) to zero the device to atmospheric pressure. Some hospitals have abandoned this practice to prevent opening the system to air. No data exist to determine the safest, most effective method of EVD zero-calibration.