[Intracranial pressure-volume relationship. Physiology and pathophysiology]
Related Experiment Video
Updated: Jun 23, 2026

A Detailed Protocol for Physiological Parameters Acquisition and Analysis in Neurosurgical Critical Patients
Published on: October 17, 2017
K Zweckberger1, O W Sakowitz, A W Unterberg
1Neurochirurgische Klinik, Universität Heidelberg, Im Neuenheimer Feld 400, 69120 Heidelberg, Deutschland. klaus.zweckberger@med.uni-heidelberg.de
Abstract:
Posttraumatic increase of intracranial pressure (ICP) is a strong prognostic factor for the outcome of patients after traumatic brain injury. After exhausting all compensatory mechanisms ICP increases exponentially, where ICP(norm)=(CSF production*CSF flow resistance)+venous pressure((sinus sagittalis))=10-15 mmHg. The ICP curve is influenced by the compliance (DeltaV/DeltaP) and elasticity (DeltaP/DeltaV) of the brain. Marmarou could demonstrate that the non-linear cranio-spinal pressure-volume relationship describes a logarithmic, mono-exponential, strongly linear relationship between pressure and volume and named this the pressure volume index (PVI=log ICP/DeltaV). The pressure volume index describes the volume necessary to increase ICP by a factor of 10. Additionally to PVI the measurement of volume-pressure response (VPR) was introduced. The continuous intracranial compliance could be determined on the principle of pulsatile volume increases as an equivalent of very small intra-cranial volume increases. However, to ascertain functional status of the injured brain a combination of measurements of different parameters, such as tissue oxygen partial pressure (p(ti)O2), cerebral blood flow (CBF), microdialysis and electrocorticography (ECoG) is recommended.
Related Concept Videos
Increased Intracranial Pressure ll: Pathophysiology
Increased Intracranial Pressure l: Introduction
Cerebral Edema ll: Pathophysiology
Cerebral Edema l: Introduction
Cytotoxic Edema: Pathophysiology
Pressure Relationships in Thoracic Cavity
Breathing Mechanisms
Both intra-alveolar and intrapleural pressures rely on specific lung properties. The ability to breathe—allowing air to enter the lungs during...
