Optimizing oxygen delivery to the injured brain

Area of Science:

• Neurocritical care
• Brain injury pathophysiology
• Oxygen transport physiology

Background:

• Hypoxia and hyperoxia are key mediators of secondary brain injury.
• Optimizing oxygen delivery is a critical goal in neurocritical care, especially for traumatic brain injury.
• Current management strategies are evolving to include oxygenation endpoints.

Purpose of the Study:

• To review clinical strategies for optimizing oxygenation in acutely brain-injured patients.
• To integrate physiologic principles with available clinical data.
• To guide management of oxygen delivery in neurocritical care.

Main Methods:

• Review of clinical strategies and physiologic principles.
• Analysis of data from a phase II randomized trial.
• Examination of published clinical protocols for oxygen delivery.

Main Results:

• A protocolized approach reduced brain hypoxia duration and showed a trend towards lower mortality in severe traumatic brain injury.
• Protocols focus on increasing oxygen supply (MAP, ICP, oxygen carrying capacity, vasoreactivity) and decreasing demand (sedation, coma, hypothermia).

Conclusions:

• Interest in brain tissue oxygenation as a resuscitative endpoint is growing.
• Many therapies are based on physiologic principles with limited robust clinical evidence.
• Clinicians must balance potential benefits of oxygenation therapies against associated risks.