Adaptive pharmacokinetic and pharmacodynamic modelling to predict propofol effect using BIS-guided anesthesia.
Propofol is widely used for hypnosis induction and maintenance of general anesthesia. Its effect can be assessed using the bispectral index (BIS). Many automatic infusion systems are based in pharmacokinetics (PK) and pharmacodynamics (PD) models to predict the response of the patient to the drug. However, all these models do not take into account intra and inter-patient variability. An adjusted intraoperative drug administration allows faster recovery and provides post-operative side-effect mitigation



BIS evolution and surgery-recorded propofol infusion data of a group of 60 adult patients (30 males/30 females) with ASA I/II physical status were used to test a real time PK/PD compartmental model. This new algorithm tunes three model parameters (ce50, γ and ke0), minimizing a performance function online.



The error in the BIS signal predicted by the real time PK/PD model was smaller than the error measured with fixed parameter equations. This model shows that ce50, γ and ke0 change with time and patients, given a mean (95% confidence interval) of 3.89 (3.52-4.26)mg/l, 4.63 (4.13-5.13) and 0.36 (0.31-0.4)min(-1), respectively.



The real time PK/PD model proposed provides a closer description of the patient real state at each sample time. This allows for greater control of the drug infusion, and thus the quantity of drug administered can be titrated to achieve the desired effect for the desired duration, and reduce unnecessary waste or post-operative effects.
Department of Industrial Engineering, Universidad de La Laguna (ULL), 38200 La Laguna, Tenerife, Spain.
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Martín-Mateos
Department of Computer Science and Systems Engineering, Universidad de La Laguna (ULL), 38200 La Laguna, Tenerife, Spain. Electronic address: jamendez@ull.edu.es.
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Méndez Pérez
Department of Anesthesiology and Reanimation, Hospital Universitario de Canarias (HUC), 38320 La Laguna, Tenerife, Spain.
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Reboso Morales
Department of Industrial Engineering, Universidad de La Laguna (ULL), 38200 La Laguna, Tenerife, Spain.
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Gómez-González
D000328:Adult; D000758:Anesthesia / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008954:Models, Biological; D015742:Propofol / Q000008:administration & dosage* / Q000493:pharmacokinetics*
D015742:Propofol
Anesthesia modelling; Bispectral Index; Compartmental model; Pharmacokinetics and pharmacodynamics model; Propofol; Real time