Physiological and biochemical principles underlying volume-targeted therapy--the "Lund concept"

Area of Science:

• Neuroscience
• Physiology
• Neurosurgery

Background:

• Sustained increase in intracranial pressure (ICP) management is controversial.
• The blood-brain barrier (BBB) normally restricts fluid exchange via hydrostatic and osmotic pressures.
• Pathophysiological conditions can disrupt the BBB, altering fluid dynamics and ICP.

Purpose of the Study:

• To discuss the volume-targeted therapy (Lund concept) for managing intracranial pressure.
• To explain the physiological mechanisms of fluid exchange across the BBB.
• To review experimental and clinical evaluations of the Lund concept.

Main Methods:

• Focus on physiological volume regulation of intracranial compartments.
• Analysis of transcapillary fluid exchange driven by hydrostatic and osmotic pressures.
• Evaluation of the Lund concept using intracerebral microdialysis in experimental and clinical studies.

Main Results:

• The intact BBB maintains low transcapillary fluid exchange due to high osmotic pressure and low permeability.
• Disruption of the BBB alters fluid exchange, making it sensitive to hydrostatic pressure gradients.
• High cerebral perfusion pressure can increase intracerebral water content and ICP when BBB is compromised.

Conclusions:

• The Lund concept provides a volume-targeted approach to ICP management.
• This therapy leverages physiological principles of fluid regulation.
• Clinical experiences with the Lund concept have been favorable.