Different Volatile Anaesthetics and the Depth of Long Term ICU Sedation

Depth of Long Term ICU Sedation Under 0,5 MAC Isoflurane, Sevoflurane or Desflurane Using MIRUS, an Automated Delivery System for Volatile Anaesthetics

The MIRUS system (TIM, Andernach, Germany) as well as the AnaConDa uses a reflector to conserve volatile anaesthetics (VA). Both systems can be paired with ICU ventilators, but MIRUS features an automated control of end-tidal VA concentrations (etVA). We compare depth of 0.5 MAC inhalational long-term sedation with Isoflurane (ISO), Sevoflurane (SEVO) or Desflurane (DES).

The study was approved by the appropriate Institutional Review Board. Thirty ASA II-IV patients, undergoing elective or emergency surgery under general anaesthesia were included and randomized into three equal groups: ISO, SEVO or DES. We used MIRUS, a gas delivery system with a VA reflector, just like AnaConDa, that can be paired with common ICU ventilators. Additionally, MIRUS features the unique ability to maintain the end-tidal concentration (etVA) in target by automatically adjusting the delivery rate. Every 8 hours, the RASS was assessed by the nurse. The log of the EEG-Narcotrend Index (NI) was also included in the study.

Inclusion Criteria:

• Signing of the informed consent document (patient or relatives).
• Patient age 18 years or older.
• ASA I-III

Exclusion Criteria:

• ASA IV patients
• Epidural or spinal analgesia
• Allergy or known hypersensitivity to any of the study drugs
• Patients with known or suspected genetic susceptibility to malignant hyperthermia
• Previous participation in this trial
• Participation in another clinical trial within 4 weeks prior to selection.
• Pregnant women