Evaluation the Intracranial Volume Pressure Response in Increased Intracranial Pressure

Study Overview
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Brief Summary
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The purpose of this study is to discover a mathematic equation to express the intracranial pressure-volume (P-V) curve and a single indicator to reflect the status of the curve.

Detailed Description
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Monitoring of intracranial pressure (ICP) has been used in the management of patients with increased ICP, or in whom increased ICP was suspected. ICP depends on the relative constancy of total volume inside the skull, comprising cerebrospinal fluid (CSF), blood, and brain tissue. The changes of CSF volume affect the ventricular fluid pressure and defined it as volume pressure response (VPR). The shape or curve of the intracranial volume-pressure (V-P) relationship is well known in daily neurosurgical practice. If the P-V curve can be expressed by mathematic manner, then there should be an indicator to reflect the status of the curve. This study is conducted in order to understand the difference of each P-V curve in patients with increased intracranial pressure. The individual VPR values have been tested with three mathematical models (linear, parabolic and exponential regression equation).

Official Title
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Evaluation of the Intracranial Volume Pressure Relationship in Increased Intracranial Pressure Patients by a Mathematic Manner

Conditions
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Brain Injury, Intracranial Hypertension

Intervention / Treatment
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* Other: drainage of cerebrospinal fluid (CSF)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients with severe brain damage Underwent bilateral external ventricular drainage (EVD) Exclusion Criteria: -

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| All subjects act as their own contral<br> | Other: drainage of cerebrospinal fluid (CSF)<br>* Once the ICP exceed 20-25 mmHg, 1 ml of CSF was withdrawn from EVD and the corresponding change of ICP value was recorded. The withdrawn drainage of CSF continued until the final ICP value declined to 10 mmHg.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| intracranial pressure | The ICP values were obtained from the bedside ICU monitor. Once the ICP values exceed 20-25 mmHg, 1 ml of CSF was withdrawn from EVD and the corresponding change of ICP value was recorded. The withdrawn drainage of CSF continued until the final ICP value declined to 10 mmHg and the whole drainage procedure was completed within one minute. | one minute. | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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pressure-volume curve, intracranial pressure, volume pressure response, pressure-volume relationship, mathematical model