Inhalation sedation with the ‘Anaesthetic conserving device’ for patients in intensive care units: A literature review

Abstract

Background. The Anaesthetic Conserving Device is a modified heat and moisture exchanger that enables the application of inhalation sedation with existing ventilators in intensive care units. The following review describes the advantages of inhalation sedation using the Anaesthetic Conserving Device in comparison to standard intravenous sedation for patients in intensive care units and highlights the technical aspects of its functioning. Methods. The literature search was limited to PubMed, Sage Journals and CINAHL databases, using the terms »anaesthetic conserving device«, »volatile anaesthetic reflection filter«, »AnaConDa« independently and in connection with the terms »sedation« and »intensive care unit«. Included are articles published up until December 2014. Results. Use of inhalation sedation with the Anaesthetic Conserving Device enables faster transition to spontaneous breathing and a shorter awakening time than with intravenous sedation. Even short-term inhalation sedation of patients after open heart procedures has a cardioprotective effect and reduces troponin T values. Despite increased concentrations of inorganic fluoride in serum after sevoflurane exposure, no clinical studies to date have shown its nephrotoxic effect, even after long-term (48 h) sedation. The Anaesthetic Conserving Device is accurate in maintaining target values of volatile anaesthetics. However, increased dead space volume was found in several studies, exceeding the internal volume of the Anaesthetic Conserving Device. Conclusion. Results to date show that inhalation sedation with the Anaesthetic Conserving Device may be an effective and safe alternative to existing protocols of intravenous sedation for patients requiring intensive treatment.