[Pharmacokinetics of thiopental in women and newborn infants]

Abstract

Plasma thiopentone concentrations after a single intravenous dose were determined by high pressure liquid chromatography in female surgical patients (n = 13), in pregnant women at term (n = 13) and in neonates (n = 13). In pregnant women, the apparent volume of distribution (Vd = 10.02 +/- 3.26 l X kg-1), plasma clearance (Cl = 22.03 +/- 7.55 l X h-1) and elimination half-life (t 1/2 (3) = 21.71 +/- 11.12 h) were significantly greater than in the surgical patients (Vd = 4.22 +/- 1.16 l X kg-1; Cl = 12.49 +/- 3.50 l X h-1; t 1/2 (3) = 13.79 +/- 3.09 h). Elimination half-life in neonates (t 1/2(e) = 17.9 +/- 9.7 h) was not different from half-life in mothers or in the surgical group. At delivery, the simultaneous concentrations were 5.3 +/- 1.3 mg X l-1 in venous blood and 3.8 +/- 1.6 mg X l-1 in cord venous blood. Apgar score was 10 in eleven neonates. For two babies, an Apgar score at 6 was explained by a uterine incision-to-delivery time interval greater than 2 min.