Automatic control of desflurane concentration in surgical procedures using laparoscopic technique

Abstract

Currently computer programs are known to predict what value of desflurane concentration will be required during general anesthesia. None of them are coupled with the vaporizer of this anesthetic. The authors of the article presented the possibilities of automating the selection of desflurane concentration for vaporizers equipped with an adjustable knob during the conduction phase of balanced anesthesia. The value of the delivered concentration of the volatile anesthetic should be such as to ensure the hemodynamic stability of the anesthetized patient. The above-mentioned solution is based on the values of circulatory parameters such as: mean blood arterial pressure (MAP) and heart rate (HR). The proposed system is equipped with limiters containing upper and lower limits to prevent decrease or excessive deepening of anesthesia which resulting in hemodynamic instability. The system also reacts to rapid changes in blood circulation values adjusting the concentration of anesthetic to the strength of the surgical stimulus and the circulatory response to the course of anesthesia and the surgical procedure. The authors of the article showed the usefulness of automating the selection of desflurane concentration in low-flow anesthesia. The algorithm controlling the setting of the desflurane vaporizer knob does not bind the input and output spaces with mathematical relationships.

Comparison of Manual Mode With Automatic Gas Control Mode for Sevoflurane Consumption in Maquet Flow-I Anesthesia Machine

“…The decrease sevoflurane consumption reduces cost of purchasing it as well as additional benefits of low oxygen utilization. This mode allows majority of exhaled gas to be rebreathed after carbon dioxide removal 18 .…”