Sufentanil en anesthésie balancée: Intérêt de prédire les concentrations pour optimiser les doses

During balanced anaesthesia sufentanil may be difficult to use, as the required doses change over time depending on the patient and the noxious stimuli. Patient adjustment may be improved by using pharmacokinetic simulations that predict the concentration achieved in the body. In the first case report, sufentanil was given manually as repeated boluses, then by infusion. As haemodynamic status remained unstable, a simulation of the sufentanil concentration time course was started during the case. It showed that instability had pharmacokinetic explanation and allowed to determine the adequate sufentanil concentrations (0.30-0.40 ng·mL^-1+ N₂O + isoflurane 0.8-1 vol% for abdominal surgery). However, adjusting the doses manually required numerous human actions. In the second case, sufentanil was given as a computer-controlled infusion. The adequate concentrations were determined (0.15-0.20 ng·mL^-1+ N₂O + isoflurane 0.4 vol% for peripheral surgery in an aged cardiac patient). They were maintained with a limited number of human actions and resulted in satisfactory haemodynamic stability.