Patients

How is ICP monitored?

In case of brain injuries, a patient is treated in the Intensive Care Unit (ICU) of the hospital. He/she may get an external drainage system. These systems ensure aseptic CSF excess shunting from the ventricular cavities or the lumbar sub-arachnoid spaces towards a drainage bag.

Using an external pressure transducer allows only temporary measurement of ICP. Indeed, when measuring ICP, the external CSF drainage needs to be stopped temporarily.

An external drainage system includes four main elements:

  • a catheter implanted in patient's brain, more specifically in a ventricle
  • a tubing, connecting the catheter to the collecting bag, with features allowing control over CSF flow and CSF access
  • a collecting bag for CSF flow monitoring
  • a fixation system

The external drainage has two main objectives: to control ICP by removing CSF and to get an access to CSF for cytology and chemistry. External drainage tubing can also be used to measure ICP: external pressure transducer inserted into's patient line.

Using an external pressure transducer allows only temporary measurement of ICP. Indeed, when measuring ICP, the external CSF drainage needs to be stopped temporarily.

It is also possible to measure ICP thanks to a dedicated monitoring system with an internal pressure sensor which is connected to an ICP monitor.

A pressure-sensor tipped catheter is inserted into the brain of the patient, through a small hole in the cranium. The other extremity of the catheter is connected to a monitor, which displays the ICP values. These ICP values have to meet the alarm threshold criteria entered in the system. Otherwise, the monitor will emit a warning signal. A treatment will be given to patient depending on ICP values and medical recommandations.



The ICP measurement can be made from three different implantation sites for the pressure-sensor tipped catheter:

  • Subdural: associated with the drainage of a subdural hematoma
  • Parenchymal: in the brain tissues, into the parenchyma
  • Intra-ventricular: into a catheter which also allows CSF external drainage.

The ICP sensor can also be associated to a thermistor for intra-cranial temperature (ICT) measurement