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Journal of Clinical Monitoring and Computing

, Volume 28, Issue 2, pp 117–121 | Cite as

End-tidal versus manually-controlled low-flow anaesthesia

  • Umberto Lucangelo
  • Giuliana Garufi
  • Emanuele Marras
  • Massimo Ferluga
  • Federica Turchet
  • Francesca Bernabè
  • Lucia Comuzzi
  • Giorgio Berlot
  • Walter A. Zin
Original Research

Abstract

During low-flow manually-controlled anaesthesia (MCA) the anaesthetist needs constantly adjust end-tidal oxygen (EtO2) and anaesthetic concentrations (EtAA) to assure an adequate and safe anaesthesia. Recently introduced anaesthetic machines can automatically maintain those variables at target values, avoiding the burden on the anaesthetist. End-tidal-controlled anaesthesia (EtCA) and MCA provided by the same anaesthetic machine under the same fresh gas flow were compared. Eighty patients were prospectively observed: in MCA group (n = 40) target end-tidal sevoflurane (1 %) and EtO2 concentrations (≥35 %) were manually controlled by the anaesthetist. In EtCA group (n = 40) the same anaesthetic machine with an additional end-tidal control feature was used to reach the same targets, rendering automatic the achievement and maintenance of those targets. Anaesthetic machine characteristics, amount of consumed gases, oxygen and sevoflurane efficiencies, and the amount of interventions by the anaesthetist were recorded. In EtCA group EtAA was achieved later (145 s) than in MCA (71 s) and remained controlled thereafter. Even though the target expired gas fractions were achieved faster in MCA, manual adjustments were required throughout anaesthesia for both oxygen and sevoflurane. In MCA patients the number of manual adjustments to stabilize EtAA and EtO2 were 137 and 107, respectively; no adjustment was required in EtCA. Low-flow anaesthesia delivered with an anaesthetic machine able to automatically control EtAA and EtO2 provided the same clinical stability and avoided the continuous manual adjustment of delivered sevoflurane and oxygen concentrations. Hence, the anaesthetist could dedicate more time to the patient and operating room activities.

Keywords

Anaesthesia, inhalation Anaesthetics, sevoflurane Human experimentation Anaesthetic machines, mechanical 

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Copyright information

© Springer Science+Business Media New York 2013

Authors and Affiliations

  • Umberto Lucangelo
    • 1
    • 2
  • Giuliana Garufi
    • 1
  • Emanuele Marras
    • 1
  • Massimo Ferluga
    • 1
  • Federica Turchet
    • 1
  • Francesca Bernabè
    • 1
  • Lucia Comuzzi
    • 1
  • Giorgio Berlot
    • 1
  • Walter A. Zin
    • 3
  1. 1.Department of Perioperative Medicine, Intensive Care and Emergency, Cattinara HospitalTrieste University School of MedicineTriesteItaly
  2. 2.Department of Industrial Engineering and Information TechnologyUniversity of TriesteTriesteItaly
  3. 3.Carlos Chagas Filho Institute of BiophysicsFederal University of Rio de JaneiroRio de JaneiroBrazil

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