Hello, we're going to talk about some of the areas of the brain and devices that we're able to use to monitor intracranial pressure. Our earlier Camtasia, we talked about our physical assessment. of the neurologically impaired patient. This kind of goes along with the physical assessment.
This is also a way that we're able to monitor these patients if they have an increased intracranial pressure. Some of the areas areas of the brain that we're able to assess for intracranial pressure is the interventricular space, the subarachnoid space, the epidural space, and the intraparachymal space. And we'll discuss the devices that you can use in each of these spaces in just a minute.
But all of the devices are inserted through a burr hole, also known as a keyhole craniotomy, that is placed in the skull using a twist. twist drill. And then most of these devices that we insert are connected to an electronic transducer that converts the intracranial pressure into electrical impulses and allows that information to be viewed on a monitor. One of the first devices that we'll talk about is the interventricular catheter.
It's a small tube that's inserted into the anterior horn of the lateral ventricle of the non-dominant cerebral hemisphere. advantages of the interventricular catheter is that it allows for an accurate monitoring of the intracranial pressure but it also allows you access to this cerebral spinal fluid. So if you need to drain some of the cerebral spinal fluid or you need to sample it or send it off for testing, you're able to do that with the intraventricular catheter. However, some of the disadvantages to this intraventricular catheter is that it's a potential site for infection and it is the most invasive method for monitoring ICP.
The second instrument that we'll talk about is the subarachnoid bolt or screw. It's a hollow device that's placed in the subarachnoid space for a direct pressure measurement. of this system is that you cannot access the cerebral spinal fluid and it can't be drained from this area.
This is only a way to monitor you can't actually treat an increased intracranial pressure with this unlike the intraventricular catheter whereas you can treat an increase in intracranial pressure by draining some of the CSF. One of the advantages to the subarachnoid bolt is that it's easy to place and it can be used with small or collapsed ventricles. One of the disadvantages of this device though is that it can be used with small or collapsed ventricles.
is it's less accurate at high levels of intracranial pressure and it may become occluded by blood or tissue. The third device we'll talk about is the subdural or epidural catheter and the difference being whether it's above the dura or underneath the dura. The epidural catheter is placed between the skull and the dura, leaving the dura intact.
And not leaving the dura intact. And then the subdural catheter is placed under the dura. Again, one of the advantages to it is it is less invasive than the two above it. It is quick and easy to be placed and there is a decreased risk for infection with these. one of the disadvantages is again that it does not provide access to the CSF for sampling or drainage and then the last device that we'll talk about is the transducer tipped catheters and these catheters are used again for monitoring intracranial pressure they can be placed in the subdural the subarachnoid in in the ventricle or directly into the brain tissue so it can be placed in several areas of the brain.
And that is one of the advantages to this catheter. It is easily transported and again one of its biggest disadvantages is that you have no access to the CSF for sampling or drainage. This is just strictly for monitoring.
And you can see in these two slides, the slide to your left is the intraventricular catheter. And this is actually the intraventricular drain. You can see where they've put the catheter in. They've got the drain level, the zero line level with the ear.
And then there's a collection bag. So as the intracranial pressure increases, it will force the CSF out of the brain and into the collection device. That is one way that we can relieve some of the pressure on the brain. And then your figure to the right, that figure 42-1, just kind of shows you where some of these devices lie in the brain, whether it's the epidural catheter or the subarachnoid bolt.
It just kind of shows you where the dura and the arachnoid spaces are and the relationship of the rice to that space. I tried to pull out some other pictures of the layers of the brain so maybe you would have a little better understanding of where they sit. In your bottom right corner you can also see what that epidural hematoma which is bleeding between the dura matter and the skull and the subdural hematoma look like which is bleeding between the arachnoid matter and the dura matter.
In both facilities here that we use, Medical Center and Flowers, both of them are currently using this Camino monitoring system that you see to your left. And again, if you can see the screen, that's where it's taken. the increased intracranial pressure and it's converted it to a electrical impulse that you can read on the screen.
The right is just an example of a strip or what you might see on the monitor and what you want to see is the want to see on the monitor is exactly that. We have the peaks, the three peaks in a row, a P1, a P2, and a P3. As your intracranial pressure increases, that goes from being three distinct peaks to more of just a hill or a mountain.
And that's an indication that your intracranial pressure is rising. I hope this is just a little bit of helpful information on some of the ways that we can monitor intracranial pressure at bedside. Thank you.