Eran Elinav, MD Zvi Ackerman, MD Nathan P. Gottehrer, MD Samuel N. Heyman, MD ness. On arrival, the patient’s examination revealed hypoventilation and a Glasgow Coma Scale score of 3. He was intubated and mechanically ventilated and recovered within several hours. Serum GHB returned at 336.1 mg/L, urine GHB returned at 5,293.3 mg/L. Serum B-OH-B was 0 mmol/L. Urine was not tested for BOH-B. The B-OH-B assay (Abbott Laboratories, MediSense products, Abbott Park, IL) is conducted as follows: whole blood (5 μL, sodium or lithium heparin tube) is added to a test strip on which B-OH-B in blood reacts with beta-hydroxybutyrate dehydrogenase on the test strip, producing an electric current that is measured and converted to the measured units, mmol/L. Normal levels Beta-Hydroxybutyrate Assay Does Not CrossReact With GammaHydroxybutyrate