Sufentanil pharmacokinetics in pediatric cardiovascular patients

The pharmacokinetics of sufentanil were studied in 28 pediatric patients undergoing cardiovascular procedures. Patients were divided into four groups on the basis of age: neonates (0-1 month, n = 9), infants (1-24 months, n = 7), children (2-12 yr, n = 7), and adolescents (12-18 yr, n = 5). Sufentanil 10-15 micrograms/kg, was administered by IV bolus and plasma concentrations measured for up to 20 hr. A tri-exponential equation best described the time-concentration data in all patients. Clearance rate (Cl) was 6.7 +/- 6.1 ml.kg-1.min-1 (+/- SD) in neonates, which was significantly lower than the values of 18.1 +/- 2.7, 16.9 +/- 3.2, and 13.1 +/- 3.6 ml.kg-1 min-1 observed in infants, children, and adolescents, respectively. The volume of distribution at steady state (Vdss) was 4.15 +/- 1.0 L/kg in neonates, significantly greater than the values of 2.73 +/- 0.5 and 2.75 +/- 0.5 L/kg observed in children and adolescents, respectively. The elimination half-life (T1/2 beta) was 783 +/- 346 min in neonates, significantly longer than the values of 214 +/- 41, 140 +/- 30, and 209 +/- 23 min observed in infants, children, and adolescents, respectively. The plasma concentration of sufentanil at the time of additional anesthetic supplementation to suppress hemodynamic responses to surgical stimulation was 2.51 ng/ml in neonates, significantly higher than the levels of 1.58, 1.53, and 1.56 ng/ml observed in infants, children, and adolescents, respectively. The authors conclude that age-related differences in pharmacokinetic and pharmacodynamic properties of sufentanil are evident in pediatric patients with major cardiovascular disease who are undergoing cardiovascular surgery.