RESUMEN
Background and Objectives - A simplifield method is proposed to calculate intravenous sufentanil infusion rate based on the finite-differnces method, also know as Euler method. Methods - Softwares were elaborated for sufentanil, using the Bovill pharmacokinetic atributes (SUFENTIL and SUFENTAV) or the Hudson pharmacokinetic atributes (SUFENHUD and SUFENHUV). SUFENTIL and SUFENTAV were used to calculate the concentration on the drug at each 25"(seconds) after patient's sex, weight and age information followed by "bolus" amount and infusion rate. Such softwares execute only simulation. The other softwares (SUFENTAV and SUFENHUV) were used to calculate the necessary infusion rates to appoximately maintain constant plasma level following bolus infection. Results - The results obtained with these two softwares (SUFENTIL and SUFENHUD) were compared with the STANPUMP software (S. Shafer, Palo Alto-USA) and showed similar results. The infusion rates obtained by SUFENTAV were used in 18 adul patients and those obtained by SUFENHUV were usedin 9 adult patients. the doses ised in thse patients were usewere used in the SUFENTIL and SUFENHUD softwares and also compared with a simulation of sufentanil plasma concentration obtained from STANPUMP. The results obtained with the different methods were similar, except for the initial moments of the infusion, when the sufentanil plasma concentration is more dependent of the bolus administration. Conclusions - The simplified methods (SUFENTAV and SUFENHUD) are as accurate as the CACI method (Computadorized Assisted Continuous Infusion)