title: 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.
authors: a Department of Intensive Care, Logan Hospital , Griffiths University , Brisbane , Australia.
authors: Hayden
authors: H
authors: White
authors: b Critical Care Medicine, Princess Alexandra & Wesley Hospitals , University of Queensland , Brisbane , Australia.
authors: Balasubramanian
authors: B
authors: Venkatesh
authors: c Faculty of Medicine and Biomedical Sciences, School of Public Health , University of Queensland , Brisbane , Australia.
authors: Mark
authors: M
authors: Jones
authors: d Princess Alexandra Hospital , Brisbane , Australia.
authors: Hesly
authors: H
authors: Fuentes
mesh_terms: D020155:3-Hydroxybutyric Acid / Q000097:blood* / Q000134:cerebrospinal fluid; D000090:Acetoacetates / Q000097:blood* / Q000134:cerebrospinal fluid; D000328:Adult; D000368:Aged; D001930:Brain Injuries / Q000097:blood* / Q000134:cerebrospinal fluid; D005260:Female; D015600:Glasgow Coma Scale; D006801:Humans; D007362:Intensive Care Units; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D013223:Statistics as Topic; D013997:Time Factors
chemical_list: D000090:Acetoacetates; C016635:acetoacetic acid; D020155:3-Hydroxybutyric Acid
keywords: Ketones; acute brain injury; beta-hydroxybutyrate; stroke; subarachnoid haemorrhage; traumatic brain injury