Closed circuit anaesthesia in ventilated patients using the Komesaroff vaporizer within the circle

• Published in: Anaesthesia and intensive care Vol. 26; no. 5; pp. 558 - 562
• Main Authors: BEWLEY, J. S, ELTRINGHAM, R. J, SANDERSON, P
• Format: Journal Article
• Language: English
• Published: Edgecliff Anaesthesia and Intensive Care 01-10-1998; Sage Publications Ltd
• Subjects: Adult; Anesthesia; Anesthesia, Closed-Circuit - instrumentation; Anesthesia. Intensive care medicine. Transfusions. Cell therapy and gene therapy; Anesthesia: equipment, devices; Anesthetics, Inhalation; Biological and medical sciences; Elective Surgical Procedures; Halothane; Humans; Isoflurane; Medical sciences; Nebulizers and Vaporizers; Respiration, Artificial; Volatile compound; Performance evaluation; Human; Halothane; General anesthesia; Artificial ventilation; Vaporizer; Closed circuit; Isoflurane; General anesthetic; Apparatus; Anesthetic circuit; Halogen Organic compounds
• ISSN: 0310-057X; 1448-0271
• DOI: 10.1177/0310057x9802600513

A study was undertaken to assess the performance of the Komesaroff vaporizer, placed within the circuit, in ventilated patients during maintenance of closed circuit anaesthesia with halothane or isoflurane. Following intravenous induction, anaesthesia was maintained by inhalation. This was achieved using a conventional vaporizer outside the circle for the first 10 minutes to manage the fast uptake phase. The fresh gas flow was then reduced to the basal oxygen requirement with the Komesaroff vaporizer within the circle maintaining inhalational anaesthesia. Complete isolation of the circuit was achieved by returning all anaesthetic gases to the circuit following analysis and using a bag-in-bottle ventilator. The Komesaroff vaporizer dial was positioned at between the first and second division and end-tidal volatile anaesthetic agent levels were measured. This study demonstrated that at dial positions 1 or 1.5 with either agent, the end-tidal volatile concentration plateaued at clinically acceptable levels. The Komesaroff vaporizer can therefore be used safely in ventilated patients to maintain closed circuit anaesthesia provided clinical observation and monitoring are meticulous.