A Comparison of Consumption and Recovery Profiles According to Anaesthetic Circuit Mode using a New Multifunctional Closed-Circuit Anaesthesia System during Desflurane Anaesthesia: A Clinical Study

Abstract

This clinical study compared induction time, consumed anaesthetic dose, and haemodynamic and recovery profiles when using a new type of multifunctional anaesthesia machine (Zeus) in semi-closed or closed circuit modes. Sixty female patients undergoing gynaecological surgery were randomly assigned to three groups and received desflurane anaesthesia through a semi-closed circuit (SCC) at fresh gas flow rates of 4 l/min (SCC 4 l/min) or 2 l/min (SCC 2 l/min), or through a closed circuit (CC). Anaesthesia was maintained at the minimum alveolar concentration for blocking the adrenergic response to painful stimulus (MAC(BAR)) (4.6% end-tidal desflurane) during each operation. The time required to reach MAC(BAR) was significantly shorter and the dose of desflurane was significantly smaller in the CC group compared with the other groups. There were no differences in haemodynamic and recovery profiles between the groups. It is concluded that the CC mode allowed a faster and more reliable induction, lower anaesthetic consumption and stable haemodynamic and recovery profiles.

The effect of fresh gas flow rate and type of anesthesia machine on time to reach target sevoflurane concentration

“…Kern et al [7] reported that, in toddlers and newborns, the time to target concentration shortens at high FGF rates, at small internal volumes of the AM, and at high minute ventilations. In the present study, the Primus ® [7, 12], Perseus ® [13], and Zeus ® (Zeus ® -F and Zeus ® -A) [5, 6, 14, 15] differed in the following ways: (1) type of ventilator, (2) internal volume, (3) proximity of the fresh gas inlet to the patient, (4) presence of the decoupling system, (5) type of vaporizer, and (6) involvement of TCA (Table 1). …”

“…In the Primus ® and Zeus ® -F, the times to target sevoflurane concentration were longer than needed with Perseus ® , because (1) the fresh gas inlets were not close to the patient in either Primus ® or Zeus ® , (2) Primus ® has a large internal volume, (3) Primus ® has a decoupling system, and (4) Zeus ® has two modes of vaporization with the direct injection of volatile anesthetics (DIVA; Table 1) [5, 6, 12–14, 17]. The Primus ® and Perseus ® use a semi-closed circuit system and a bypass vaporizer (out-of-circle vaporization), whereas Zeus ® is the multifunctional system that can operate a semi-closed circuit system (out-of-circle vaporization) or closed-circuit system (in-circle vaporization) using the DIVA vaporizer.…”

Target-controlled inhalation anaesthesia: A cost-benefit analysis based on the cost per minute of anaesthesia by inhalation

“…Lortat Jacob et al observed a 65% reduction in the consumption of desflurane and a 50% reduction for fresh gas with the Zeus® machine from Drager [3]. Park et al demonstrated a 5-fold reduction in halogenated agent consumption with the Zeus® TCIA system as compared to its standard use with manual adjustment and a 2 l.min-1 fresh gas flow [6]. Others observed smaller reductions [7].…”

A closed-circuit anesthesia ventilator facilitates significant reduction in sevoflurane consumption in clinical practice

“…Nevertheless, studies evaluating the Dräger Zeus Ò Infinity Ò Empowered (IE) ventilator -the only closed-circuit ventilator available in North Americahave generated mixed results. [1][2][3][4][5] Most studies evaluating the closed-circuit machine and semi-closed-circuit machines have compared the automated mode of the Zeus IE with the traditional semi-closed-circuit run by the anesthesiologist under optimal conditions. Our goal was to investigate whether the closed-circuit ventilator offers a reduction in the consumption of volatile agent without requiring anesthesiologists to change their practice habits.…”