What are Lundberg waves?
Lundberg (or B) waves, defined as repetitive changes in intracranial pressure (ICP) occurring at frequencies of 0.5 to 2 waves/min, have been attributed to cerebral blood flow fluctuations induced by central nervous system pace-makers or cerebral pressure autoregulation.
What is the normal ICP?
It is normally 7-15 mm Hg in adults who are supine, with pressures over 20 mm Hg considered pathological and pressures over 15 mm Hg considered abnormal. Note that ICP is positional, with elevation of the head resulting in lower values. A standing adult generally has an ICP of -10 mm Hg but never less than -15 mm Hg.
Which intracranial pressure waveforms are most clinically significant?
Simple visual assessment of the ICP waveform for increased amplitude and P2 elevation is clinically relevant and has been found to provide a rough indicator of decreased adaptive capacity.
How do ICP monitors work?
Intracranial pressure (ICP) monitoring is a diagnostic test that helps your doctors determine if high or low cerebrospinal fluid (CSF) pressure is causing your symptoms. The test measures the pressure in your head directly using a small pressure-sensitive probe that is inserted through the skull.
What is P2 ICP?
P2 is the pressure generated within the CSF as a result of the forces generated from both the pulsatile blood vessel and the resistance from the intracranial tissue. The higher the resistance is, the greater the pressure within the CSF and therefore the greater the P2 wave amplitude.
What is Monro Kellie hypothesis?
What finally came to be known as the Monro–Kellie doctrine, or hypothesis, is that the sum of volumes of brain, CSF, and intracranial blood is constant. An increase in one should cause a decrease in one or both of the remaining two.
What is CPP neurology?
Definition/Introduction. Cerebral perfusion pressure (CPP) is the net pressure gradient that drives oxygen delivery to cerebral tissue. It is the difference between the mean arterial pressure (MAP) and the intracranial pressure (ICP), measured in millimeters of mercury (mm Hg).
How do you troubleshoot a dampened ICP waveform?
To troubleshoot a dampened waveform, first examine the drainage tubing distal to the patient for the presence of air bubbles, clots, or tissue. If any are present, flush the tubing away from the patient to remove the debris or change the entire drainage system if necessary.
What does an ICP of 0 mean?
A RAP coefficient close to 0 indicates lack of synchronisation between changes in AMP and mean ICP. This denotes a good pressure–volume compensatory reserve at low ICP (fig 3), where a change in volume produces no or very little change of the pressure.
What is ICP?
Intracranial pressure (ICP) is defined as the pressure within the craniospinal compartment, a closed system that comprises a fixed volume of neural tissue, blood, and cerebrospinal fluid (CSF). From: Cerebrospinal Fluid in Clinical Practice, 2009.
What are the components of ICP waves?
ICP Waves. The ICP wave is produced by pressure transmitted from the arterial pulse to the brain. This wave has 3 components: Normal ICP wave: P1 has the highest pulse pressure, followed by P2 and P3. In disturbed intracranial elastance (i.e. small increases in intracranial volume dramatically increases ICP), P2 pulse pressure is higher than P1.
What is the normal ICP wave number?
Normal ICP wave: P1 has the highest pulse pressure, followed by P2 and P3. In disturbed intracranial elastance (i.e. small increases in intracranial volume dramatically increases ICP), P2 pulse pressure is higher than P1.
How is intracranial pressure waveform (icpw) impairment assessed?
Another method to observe ICC impairment is the intracranial pressure waveform (ICPW) [15] by the alteration of the natural relation of its peaks; P1 (arterial pulsation), P2 (cerebral venous flow, which is secondary to cyclic fluctuations of arterial blood volume, Figure 1), and P3 (aortic valve closure) [21]. Open in a separate window Figure 1
How does intracranial elastance affect ICP waveforms?
In disturbed intracranial elastance (i.e. small increases in intracranial volume dramatically increases ICP), P2 pulse pressure is higher than P1. Another picture to illustrate normal and noncompliant ICP waveforms.