Background: Desiccation of the carbon dioxide (CO2) absorbent in an anaesthetic breathing system results in a discrepancy between the desired (selected) and actual (measured) levels of volatile anaesthetic; the measured value is lower than the selected value, which may make the induction of anaesthesia difficult. Moreover, because of a complicated interaction between the absorbent and the anaesthetic agent, toxic gases are formed within the system, which cannot be detected by standard monitoring during anaesthesia. The aim of this study was to check if the personnel responsible for changing the absorbent are aware of this problem, and to provide guidelines for its prevention.
Method: A descriptive pilot study was conducted on a sample of 25 anaesthesia nurses from five Slovene hospitals performing surgical procedures under general anaesthesia. Data was gathered with an open-type questionnaire.
Results: We found that 92 % of the study participants had noticed discrepancies between the selected and measured levels of anaesthetic agent in the breathing system, which ranged between 10 % and 50 %. A large proportion of the nurses (64 %) did not consider CO2 absorber to be a possible source of the observed discrepancies. Only one nurse knew that the problem was caused by absorbent desiccation. Guidelines for absorbent replacement vary among hospitals, and so absorbents are changed at different intervals.
Conclusion: The majority of nurses in our study were not aware that absorbent desiccation can significantly reduce the level of volatile anaesthetics in the breathing system. The problem can be prevented by adopting appropriate guidelines, which guarantee that absorbents are changed regularly as required.