Serial changes in plasma ketone concentrations in patients with acute brain injury

Abstract

Objective

Acute brain injury (ABI) is a catastrophic event, leading to disruption of the normal cerebral metabolic pathways and a subsequent cerebral energy deficit. Ketones (beta-hydroxybutyrate (BHB) and acetoacetate) may represent an alternative metabolic substrate with the potential to improve cerebral energy supply and decrease injury. The purpose of this study was to evaluate baseline ketone concentrations in the ABI population.

Methods

Thirty-eight patients with ABI were enrolled into the study and followed for up to 7 days. We collected arterial blood samples immediately after admission and daily to measure the levels of BHB and acetoacetate. Where possible, matching cerebrospinal fluid (CSF) specimens were also collected.

Results

During the study period, plasma BHB levels were increased initially but normalized by day 3 while acetoacetate levels remained within the normal range. The change in BHB was significant. There were 30 observations in 10 patients where BHB could be measured in both blood and CSF. When the data were averaged over patients there was a weak correlation between blood and CSF BHB (Spearman’s ρ = 0.62, p = 0.054).

Conclusion

Blood ketone concentrations remain low within the ABI population. An external source of ketones will be required to increase blood concentrations to clinically relevant levels.

Keywords:

• Ketones
• acute brain injury
• traumatic brain injury
• beta-hydroxybutyrate
• stroke
• subarachnoid haemorrhage

Notes on contributors

Hayden White is an associate professor with Griffiths University. His research includes examining the deficit and impact of substrate supplementation on acute brain injury.

Balasubramanian Venkatesh is a Professor of Intensive Care at University of Queensland. His research includes monitoring modalities in neurotrauma and the impact of corticosteroids in sepsis.

Mark Jones is a Phd scholar and statistician with the School of Public Health, University of Queensland.

Hesly Fuentes is completing his Intensive Care Fellowship in Australia.

All authors contributed towards concept, design, manuscript preparation, manuscript editing and manuscript review. The authors are in agreement with the content of manuscript.