D. Breilh(1) , C. Pobel(1) , C. Roth(2) , M.C. Saux(1) , G.Janvier(2)
Laboratory of Clinical Pharmacokinetic, Bordeaux II University, France(1)
Anaesthesiology ward, Haut-Leveque hospital, Bordeaux II University, France(2)
10 patients were investigated. Their average characteristics are:
age 65
8.7 years, weight 75.7
9.9 kg. They were given an
average total dose of 409
69.67 mg/kg of sufentanyl during
anaesthesia: 6 mg/kg from induction to sternotomy (one or several
bolus), and 1 mg/kg in continue with an electric seringe to
increase the duration of anaesthesia. Blood samples mean is
18
2.7 per patient (extreme: 15-23) and blood sampling was
done between 0 and 18 hours after anaesthesia was induced and
depends on the duration of the operation.
Pharmacological effects studied are haemodynamic as the mean arterial blood pressure (MAP) was taken in each patient when blood samples were taken. The PK/PD model is a two-compartment pharmacokinetic model, whose central compartment is linked to the effect compartment. The sigmoid Emax model (Hill's equation) as well as a linear model have been used for studying the relationship between the effect (E%) and the concentration in the effect compartment. Results (on model plasma concentration):
The values of parameters (K10, K12, K21) are similar between the Emax model and the linear model. The biophase can be put on the central level with these results. This is interesting as far as the MAP is a very easy parameter to follow in anaesthesia and is a means of controlling the quality of anaesthesia.