A novel device for target controlled administration and reflection of desflurane – the Mirus^™

Abstract

The Anaconda™ system is used to deliver inhalational sedation in the intensive care unit in mainland Europe. The new Mirus™ system also uses a reflector like the Anaconda; however, it also identifies end-tidal concentrations from the gas flow, injects anaesthetics during early inspiration, controls anaesthetic concentrations automatically, and can be used with desflurane, which is not possible using the Anaconda. We tested the Mirus with desflurane in the laboratory. Compared with an external gas monitor, the bias (two standard deviations) of the end-tidal concentration was 0.11 (0.29)% volume. In addition, automatic control was reasonable and maximum concentration delivered was 10.2%, which was deemed to be sufficient for clinical use. Efficiency was > 80% and was also deemed to be acceptable, but only when delivering a low concentration of desflurane (≤ 1.8%). By modifying the reflector, we improved efficiency up to a concentration of 3.6%. The Mirus appears to be a promising new device for long-term sedation with desflurane on the intensive care unit, but efficiency must be improved before routine clinical use becomes affordable.

AnaConDa™ and Mirus™ for intensive care sedation, 24 h desflurane versus isoflurane in one patient

“…In our previous bench study, we found a high accuracy and precision of the end-tidal concentrations displayed by the Mirus™ (Bomberg et al 2014 ). However, there was a swing of 20 % around the target concentration with a periodicity of 2.6 min which may be criticized.…”

“…In our previous bench study, mean inspiratory concentrations during desflurane injections were only 134 % (SD 12 %) of the preceding end-tidal concentration (Bomberg et al 2014 ). This is unlikely to elicit sympathetic activation as described in the literature (Ebert et al 1998 ; Weiskopf et al 1994 ).…”

Malignant hyperthermia: a review

“…Another potential risk factor is the use of inhalational sedation devices postoperatively in the intensive care unit (ICU) for a range of different conditions [ 25 – 28 ]. Patients susceptible to MH also resident in the ICU may be at risk from such exposure, although administration of sevoflurane via the AnaConDa® device was found to be safe for healthcare workers with the caveat that a gas extraction system should be used in conjunction with such devices to reduce occupational exposure [ 29 ].…”

Environmental safety: Air pollution while using MIRUS™ for short‐term sedation in the ICU

“…AnaConDa™ and MIRUS™ reflect VA and can be used with standard ICU ventilators. Both systems deliver isoflurane (ISO) and sevoflurane (SEVO), but MIRUS™ can also be used with desflurane (DES), which might be useful for short‐term sedation …”