[Animal experiments to study placental passage of Sombrevin and Hexobarbital and their concentrations in various foetal organ systems (author's transl)].

Studies were conducted into 55 rabbits and their 327 foetuses to measure the two intravenously applied anaesthetics, Sombrevin and Hexobarbital, for their passage through the placenta and for the concentrations which eventually settle in various organ systems of the foetuses. Fast placental passage, but in different concentrations, was established for either anaesthetic. Sombrevin was found to reach the foetal organism only in low quantity and for short-time retention, whereas Hexobarbital passed the placental barrier in much higher concentration to stay detectably for a longer period of time in the foetal blood. While Sombrevin was not recordable from foetal organs, its intraplacental buildup reached higher concentrations. Relatively high concentrations of Hexobarbital were recordable from both the placenta and vital foetal organs. The conclusions so far derived from those animal experiments seem to suggest a superiority of Sombrevin over Hexobarbital and regard to applicability to obstetric anaesthesia.