Factors Affecting the Performance of Circle Systems Used Without Carbon Dioxide Absorption

  • C. M. Conway
  • C. Schoonbee
Part of the European Academy of Anaesthesiology book series (ANAESTHESIOLOGY, volume 1)


A circle system with an attached ventilator has been used to ventilate a model lung. The reservoir bag of the system was replaced by a length of corrugated tubing attached to the ventilator outlet. A small constant flow of carbon dioxide entered the lung and tidal carbon dioxide concentrations were measured at various combinations of fresh gas flow (VF), tidal volume (VT), and respiratory frequency (f). Two separate forms of circle geometry were studied.


Tidal Volume Respiratory Frequency Model Lung Separate Form Corrugate Tubing 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


  1. Snowdon SL, Powell DL, Fadl ET, Utting JE (1975) The circle system without absorber. Use with controlled ventilation. Anaesthesia 30: 323–332PubMedCrossRefGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 1981

Authors and Affiliations

  • C. M. Conway
  • C. Schoonbee

There are no affiliations available

Personalised recommendations