Author/Editor		Križmarić, Miljenko; Manohin, Aleksander
Title		Analiza pretokov dihalne zmesi skozi krožne anestezijske dihalne sisteme in njihov vpliv na izsušenost zrnc absorberja CO2
Translated title		The analysis of fresh gas flow in a circle anaesthetic breathing system, and its influence on CO2 abrorbent desiccation
Type		članek
Source		Zdrav Vestn
Vol. and No.		Letnik 81, št. 4
Publication year		2012
Volume		str. 341-8
Language		slo
Abstract		Background: If at the end of anaesthesia, the gases on the anaesthetic machine are not turned off, they continue to flow through the breathing circuit and may dry out the carbon dioxide absorbent in the absorber. At the beginning of the next anaesthetic procedure, the desiccated absorbent decomposes the volatile anaesthetic, resulting in the formation of toxic gas mixtures, which are dangerous for the patient. In such circumstances, the measured level of the volatile anaesthesic in the breathing circuit differs from the selected value. In the paper, we analyse potentially dangerous possible directions of continuous flow of fresh gas mixture in different anaesthetic breathing circuits. Methods: In the first part of the study, we simulated the continuous flow of gases in a Sulla anaesthesia machine using an experimental method in a simulation setting. In the second part, we analysed whether a retrograde flow through the absorber was possible in a convential anaesthetic breathing circuit and in the Fabius GS, Cato, Julian and Primus circuits with the Y-piece connector open or closed. Information on users' requests for maintenance services due to discrepancies between the desired and measured levels of the volatile anaesthetic in the breathing circuit were obtained from the manufacturer's local servicing agent. Results: In a Draeger ISO 8 circle system (Sulla anaesthetic machine) with a standard gas supply connector, a retrograde flow is not possible. If the Y-piece connector is left open, the gases are vented to the outside via the absorber and the inspiratory tube. If the Y-piece connector is closed or open, the absorbent in the canister dries because of the continuous flow of gas. A retrograde flow is possible only in those Sulla anaestheticmachines where the fresh gas inlet is located below the inspiratory valve. (Abstract truncated at 2000 characters).
Descriptors		ANESTHESIA, GENERAL ANESTHESIA, CLOSED-CIRCUIT CARBON DIOXIDE DESICCATION