At the end of this presentation, attendees should be able to:

- Understand the distinction between hypoperfusion and true ischaemia.

- Compare the use of 15 Oxygen positron emission tomography to help distinguish between the two

- Understand the spatial and temporal variations in ischaemia following TBI

- Discuss the heterogeneity of mechanisms causing energy failure in TBI

- Understand how common bedside interventions impact on ischaemia in TBI

- Understand the relation of abnormal acute physiology to tissue outcomes