Beta hydroxybutyric acid
A positional isomer of hydroxybutyric acid. Commonly, referred to as the ionised form, β-hydroxybutrate (IUPAC: 3-hydroxybutrate).
It is one of the 'ketone bodies' seen in ketoacidosis, in particular, that caused by alcoholic ketoacidosis. Ketone bodies typically exist in chemical equilibrium, but in alcoholic ketoacidosis, the depletion of NAD+ by alcohol metabolism favours β-hydroxybutyrate over acetoacetate or acetone.
It may not be detected by urine dipstick which generally detects acetoacetate. Chemical or toxicological analysis can be performed using enzymatic or other physico-chemical methods such as gas chromatography-mass spectrometry. The latter is probably preferrable in post-mortem material.