Diabetic ketoacidosis (DKA) is a major cause of mortality of children with diabetes mellitus even in developed countries (mortality 1 - 2 %). Bedside laboratory estimations contribute to its more sophisticated therapy. Up to now, bedside monitoring of ketogenesis has been limited to urine dipstick tests based on the nitroprusside reaction (Ketophan, Diaphan). This semiquantitative estimation detects acetoacetate but not beta-hydroxybutyrate (
- OHB) which is the predominant ketone body responsible for acidosis. Authors tested 17 patients (7 boys) age 0.1 - 17.4 years (median 10.7) during initial treatment of newly diagnosed type 1 diabetes mellitus or during therapy of DKA which appeared later in the course of diabetes. Forty-three
-OHB estimations (using bedside system with electrochemical sensor - Optium, Abbot/Medisense) were correlated with parallel results of acid-base balance and with semiquantitative measurement of ketonuria (Diaphan). Levels of
-OHB ranged from 0.0 to 5.7 mmol/L (median 0.8). A significant correlation was found between
-OHB and pH (r = -0.62, p < 0.0001), base excess (BE; r = -0.66, p < 0.0001) and urine ketones (r = 0.79, p < 0.0001). However, individual scattering of values from regress lines suggests that acid-base balance and urine ketones do not optimally determine the severity ofDKAin individual patients, due to other interfering factors. Determination of
-OHB levels in blood using a bedside system opens new option for an early detection of DKA if measured at home or for precision of its therapy at hospital.

        Key words: type 1 diabetes mellitus, diabetic ketoacidosis, children, ketogenesis, beta-hydroxybutyrate