Intracranial Pressure Monitoring

Intracranial pressure (ICP) is the pressure of cerebrospinal fluid (CSF) inside the head. This pressure is affected by different factors. It goes up when the heart is beating and down when it is resting. It falls when we breathe in and goes up when we breathe out.

Our brain is enclosed in a boney container (the skull), so it can not swell when it is injured like other tissues in our body. If the brain tries to swell like an ankle does when we sprain it, the pressure in our head must go up. If the rise in pressure inside the head gets higher than our blood pressure, it stops the blood supply to the brain. A high pressure after a brain injury affects how well the brain will work following recovery.

It is necessary to follow an injury to the brain to:

  • Monitor the pressure.

  • Be ready to treat pressures which will eventually lead to permanent brain damage.

Non-invasive methods used are those in which nothing is put into the head to measure pressure. Invasive measures use monitors which are put inside the skull to directly measure the pressures. Your caregiver will discuss these with you. ICP monitoring helps manage conditions with prolonged elevations of intracranial pressure. Monitoring helps in selecting the best treatment and helps determine if you are at risk for developing injury from the increased pressure. ICP monitoring can be alone or done along with a drain to remove CSF if the pressure is elevated. It also helps determine if there has been brain death. This happens when the pressure in the brain is greater than the blood pressure.

DIAGNOSIS

  • Caregivers for head injuries can tell the pressure is elevated by physical things that are happening to the patient.

  • The monitoring is done to tell how much the pressure is elevated and is used as a guide for treatment.

TREATMENT

The best treatment for increased ICP is the removal of the cause. Some of the causes of brain swelling are due to:

  • Liver failure.

  • Infection.

  • Injury (trauma).

  • Tumors.

  • Water on the brain (hydrocephalus).

  • Blood collection (hematomas).

Other treatments include adjusting the breathing machine (ventilator) if one is present and medications which can be used to lower the pressure. Sometimes a flap of skull bone is removed to allow the brain to swell. The three main invasive means used to monitor the pressure in the head include:

  • Putting a thin plastic catheter through a drilled hole (burr hole) into one of the fluid filled spaces (ventricles) in the brain.

  • Placing a hollow screw or bolt in the space between the brain and its coverings and the skull.

  • Placing a small pressure sensor through a burr hole just below the bone in the skull. This does not go through the membranes covering the brain so it does not provide treatment such as fluid removal like the catheter, screw and bolt can.

RISKS AND COMPLICATIONS

  • Infection.

  • Failure of procedure.

  • Anesthesia risks if a general anesthetic is used.

  • Bleeding.

  • Brain tissue injury with lasting neurologic problems.

This is a procedure that will be discussed with you or your family and the best possible treatment will be recommended for you.