Intracranial pressure monitoring equipment is used to measure the pressure exerted on the skull. If the brain swells and intracranial pressure increases beyond a certain limit, it could lead to permanent brain damage. Intracranial pressure is measured in two ways – It can be measured using a hollow catheter, or a hollow bolt. The catheter is placed into the fluid-filled void in the lateral ventricle of the brain to check the pressure of the cerebrospinal fluid.. Alternatively, the surgeon could use the subdural bolt method. In this method of intracranial pressure monitoring, a hollow screw is drilled through the skull into the subdural space. In both cases, the device is inserted by a surgeon in the Intensive Care Unit (ICU) or the Operating Room. The patient will be medicated while the monitoring equipment is inserted, to keep them comfortable. The probe is removed once swelling decreases and is deemed unlikely to recur.