ICP – All Sensors | Put the Pressure on Us

Welcome to All Sensors “Put the Pressure on Us” blog. This blog brings out pressure sensor aspects in a variety of applications inspired by headlines, consumer and industry requirements, market research, government activities, and you.

Pressure on the Brain (Part 2)

Dynamic pressure measurements allow physicians to characterize and evaluate higher levels of intracranial pressure (ICP) including intracranial hypertension (ICH).

Figure 1. A dynamic pressure measurement to diagnose increased ICP.
Source: Science Alert.

Maintaining an appropriate cerebral perfusion pressure (CPP) is essential in managing patients with intracranial pathology, including a traumatic brain injury. CPP, which drives oxygen delivery to cerebral tissue, is a function of ICP and the mean systemic arterial pressure (MAP) (blood pressure (BP) measurements). It is calculated by the following equation:

CPP = MAP − ICP

Where MAP = (1/3 systolic BP) + (2/3 diastolic BP)

Normal CPP lies between 60 and 80 mm Hg.

Some of the underlying causes of increased ICP including an infection, high blood pressure, tumor or stroke can be treated to reduce the pressure. However, since increased intracranial pressure is an emergency health concern, additional treatment might include:

- - Medicine to reduce swelling
  - Draining extra cerebrospinal fluid or bleeding around the brain
  - In rare instances, removing part of the skull to ease swelling

Do you have a pressure sensing question? Let us know and we’ll address it in an upcoming blog.
Email us at [email protected]

Pressure on the Brain (Part 1)

A brain injury or several different medical conditions can cause higher pressure than normal inside the skull. The increased intracranial pressure (ICP) can lead to a headache and even injure the brain or spinal cord. Besides a headache, other common symptoms of an increased ICP include:

- - Blurred vision
  - Vomiting
  - Changes in behavior
  - Weakness or problems with moving or talking
  - Lack of energy or sleepiness

In addition to a brain or head injury, other causes of increased ICP are:

- - Excessive cerebrospinal fluid (the fluid around the brain and spinal cord)
  - Bleeding into the brain
  - Swelling in the brain
  - Aneurysm
  - Brain tumor
  - Infections such as encephalitis or meningitis
  - Hydrocephalus (water on the brain)
  - High blood pressure

The normal range for ICP varies with age with young children and infants having lower levels. A normal adult ICP is defined as 5 to 15 mm Hg (7.5–20 cm H₂O). ICP values of 20 to 30 mm Hg represent mild intracranial hypertension (ICH) with ICP values greater than 20 to 25 mm Hg requiring treatment in most circumstances. Sustained ICP values of greater than 40 mm Hg indicate severe, life-threatening ICH.

One of the diagnostic techniques for increased ICP is a spinal tap or lumbar puncture to measure the pressure of cerebrospinal fluid

Figure 1. Draining excessive cerebrospinal fluid can reduce ICP. Source: Johns Hopkins Medicine.

Part 2 will provide additional details of ICP’s relationship to blood pressure and potential treatments.

Do you have a pressure sensing question? Let us know and we’ll address it in an upcoming blog.
Email us at [email protected]