critical care medicine
Monitoring and Testing the Critical Care Patient
Intracranial Pressure (ICP) Monitoring
Intracranial pressure monitoring is standard for patients with severe closed head injury and is occasionally used for some other brain disorders, such as in selected cases of Hydrocephalus and Several types of intracranial pressure monitors are available. Extraventricular drain (EVD) is the most useful method; a catheter is placed through the skull into a cerebral ventricle (ventriculostomy catheter). This device is preferred because the catheter can also drain cerebrospinal fluid (CSF) and hence decrease intracranial pressure. However, the EVD is also the most invasive method, has the highest infection rate, and is the most difficult to place. Occasionally, the EVD becomes occluded due to severe brain edema. Other types of intracranial devices include an intraparenchymal monitor, subarachnoid bolt, subdural bolt, and an epidural bolt inserted between the skull and the dura through which a pressure sensor is passed. Of these, the intraparenchymal monitor is more commonly used. All intracranial pressure devices should usually be changed or removed after 5 to 7 days because infection is a risk. 