Assessing the efficiency of a pharmacokinetic-based algorithm for target-controlled infusion of ketamine in ponies.

This research investigates the effectiveness of a pharmacokinetic algorithm in predicting ketamine levels and guiding a targeted drug infusion process in ponies. The study also seeks to examine the algorithm’s efficacy in maintaining consistent plasmic concentrations of the drug.

Experiment Overview

• The study revolved around the use of a pharmacokinetic algorithm designed to forecast ketamine plasma levels and regulate a target-controlled infusion (TCI) of ketamine in ponies.
• First, the algorithm was deployed to simulate the pathway of ketamine enantiomers’ plasma concentrations following the administration of an intravenous bolus in six ponies. These simulations were based upon individual pharmacokinetic parameters obtained from a previous experiment.

Target-Controlled Infusion Test

• Using the same pharmacokinetic parameters as in the initial phase, a TCI of S-ketamine was then administered over a course of 120 minutes. The aim was to maintain a concentration of 1 microgram/millilitre in the plasma.
• The actual plasma concentrations of S-ketamine were subsequently determined using arterial samples acquired from the ponies. This was done by adopting the capillary electrophoresis procedure.

Performance and Results

• Based on the research findings, the pharmacokinetic algorithm’s simulation performance, in correlation to single bolus administration, was rather effective.
• During the TCI, S-ketamine plasma concentrations were maintained within the limit of acceptance, which was defined as a wobble and divergence value of less than 20%. On average, the plasma concentration reached 79% (with an interquartile range of 71-90%) of the highest concentration achieved post the initial bolus injection.
• Nevertheless, in three of the ponies included in the study, the steady state concentrations recorded were notably higher than the aimed target. One possible explanation for this discrepancy, as proposed in the study, is that there may have been a miscalculation of the central compartment’s volume.

Conclusion

• Overall, the pharmacokinetic algorithm proved to be proficient in making accurate predictions for the single bolus administration as well as in maintaining constant plasma concentrations.