Bergmann H
Anaesthesist. 1986 Oct;35(10):587-94.
With mainly clinical needs in mind, the technical and functional details of current anaesthesia equipment are discussed, as well as potential future developments. The following topics are discussed in detail: delivery of narcotic gases, dosimetry of both gaseous and volatile anaesthetics, the patterns of anaesthesia systems, mechanical ventilation during anaesthesia and intra-operative monitoring. As for the narcotic gases, plain air might become more important than ever before. The importance of helium has so far not been clearly assessed. The safety measures of the German Industry Norm (DIN) 13252 should become more widely known and be fully accepted: colour codes, non-interchangeable dimensions, oxygen bypass and oxygen-failure alarms, and automatic cut-off and alarm if the concentrations of nitrous oxide are too high. The delivery of a hypoxic gas mixture should be detectable whatever the cause might be and not only in cases when the oxygen-supply pressure is too low. Special attention should be given to the interactions between man and machines to exlude difficulties arising from "inhuman engineering". Concerning the rotameters, uniform serial attachment of these controllers of gaseous flow should be aimed at. The ranges (low flow, high flow), accuracy of the meter (+/- 3%) and DIN safety measures (different shape of button switches, etc.) should be kept in mind; a gas proportioning and mixing device that would strictly exclude the possibility of too-low oxygen concentrations would be very advantageous. The vaporizers for volatile anaesthetics should work independently of external physical variables and also fulfil the DIN safety programme.(ABSTRACT TRUNCATED AT 250 WORDS)