Letters to the Editor: Letter to the Editor
The recent report by Meiser et al1 that detailed the use of the AnaConDa device (Sedana Medical, Uppsala, Sweden) to allow for inhaled isoflurane to be used for sedation in patients on extracorporeal membrane oxygenation is an interesting report that adds further credence to the potential value of volatile anesthetics in the intensive care unit setting. However, although these investigators appear to have shown success in using this technique in these challenging patients, volatile anesthetic use in the intensive care unit setting is not without limitations. Indeed, one of the complications of using volatile agents for sedation is the risk for potential contamination of the surrounding environment. Indeed, their case report mentions that a closed system for endotracheal tube suctioning was used to minimize workplace contamination. However, inherent in using the AnaConDa device with conventional ventilators is that the waste gases have to be scavenged by either a hospital-based vacuum system (which is not necessarily designed to handle these agents)2,3 or they require the use of a specially designed scavenging system, which has been previously reported.4 Indeed, a simple scavenging system has been described by integrating Deltasorb (Blue-Zone, Concord, Ontario, Canada) canisters between the ventilator’s expiration port and the wall outlet suction.4 Accordingly, if one is going to be considering the use of the AnaConDa for volatile-based sedation in extracorporeal membrane oxygenation patients, which typically require longer term sedation that can increase the risk of environmental contamination, then using a designated scavenging system might be beneficial to consider.
Hilary P. Grocott, MD, FRCPC, FASEDepartment of Anesthesiaand Perioperative MedicineUniversity of ManitobaWinnipeg, Manitoba, Canadahgrocott@sbgh.mb.ca
1. Meiser A, Bomberg H, Lepper PM, Trudzinski FC, Volk T, Groesdonk HV. Inhaled sedation in patients with acute respiratory distress syndrome undergoing extracorporeal membrane oxygenation. Anesth Analg. 2017;125:1235–1239.
2. Dain SL. Anesthesia scavenging in critical care areas: beware of possible hazards and questionable efficacy. Can J Anaesth. 2017;64:96–97.
3. Jerath A, Wąsowicz M. In reply: a nesthesia scavenging in critical care areas: beware of possible hazards and questionable efficacy. Can J Anaesth. 2017;64:98–99.
4. Wong K, Wasowicz M, Grewal D, et al. Efficacy of a simple scavenging system for long-term critical care sedation using volatile agent-based anesthesia. Can J Anaesth. 2016;63:630–632.