This study assessed the safety of sevoflurane anaesthesia using two Komesaroff vaporizers inside the circle with both spontaneous and controlled ventilation. Sevoflurane concentrations were continuously monitored using a mass spectrometer and the anaesthetic depth was easily controlled. Involuntary movements occurred in eight patients and breathholding occurred in five patients after inhalational induction. With continuous monitoring of sevoflurane concentrations, induction and maintenance of anaesthesia using a vaporizer inside the circle is safe during both controlled and spontaneous ventilation. However the high incidence of involuntary movements may limit the feasibility of induction in spontaneously breathing patients.
RussellW.J.Equipment for anaesthesia and intensive care. 2nd ed. Adelaide: W. John Russell, 1997.
2.
MushinW.W., GalloonS.The concentration of anaesthetics in closed circuits with special reference to halothane. III: clinical aspects. Br J Anaesth1960; 32: 324–333.
3.
WrightD., Brosnan, RoystonB., WhiteD.Controlled ventilation using isoflurane with an in-circle vaporizer. Anaesthesia1998; 53: 650–653.
4.
BewleyJ.S., EltringhamR.J., SandersonP.Closed circuit anaesthesia in ventilated patients using the Komesaroff Vaporizer within the circle. Anaesth Intensive Care1998; 26: 558–562.
5.
LiuE.H.C., DharaS.S.Sevoflurane anaesthesia with an Oxford Miniature Vaporizer in vaporizer inside circle mode. Br J Anaesth1999; 82: 557–560.
6.
ThwaitesA., EdmendsS., SmithI.Inhalational induction with sevoflurane: a double blind comparison with propofol. Br J Anaesth1997; 78: 356–361.
7.
YurinoM., KimuraH.A comparison of vital capacity breath and tidal breathing techniques for induction of anaesthesia with high sevoflurane concentrations in nitrous oxide and oxygen. Anaesthesia1995; 50: 308–311.
8.
FredmanB., NathansonM.H., SmithI., WangJ., KleinK., WhiteP.F.Sevoflurane for outpatient anesthesia: a comparison with propofol. Anesth Analg1995; 81: 823–828.
9.
SmithI., DingY., WhiteP.F.Comparison of induction, maintenance, and recovery characteristics of sevoflurane-N2O and propofol-sevoflurane-N2O with propofol-isoflurane-N2O anesthesia. Anesth Analg1992; 74: 253–259.
10.
KharaschE.D., FrinkE.J., ZagerR., BowdleT.A., ArtruA., NogamiW.M.Assessment of low-flow sevoflurane and isoflu-rane effects on renal function using sensitive markers of tubular toxicity. Anesthesiology1997; 86: 1238–1253.
11.
BitoH., IkedaK.Renal and hepatic function in surgical patients after low-flow sevoflurane or isoflurane anaesthesia. Anesth Analg1996; 82: 173–176.
12.
YurinoM., KimuraH.Induction of anesthesia with sevoflurane, nitrous oxide and oxygen: A comparison of spontaneous ventilation and vital capacity rapid inhalation induction (VCRII) techniques. Anesth Analg1993; 76: 598–601.
