title: The scavenging of volatile anesthetic agents in the cardiovascular intensive care unit environment: a technical report.
abstract: OBJECTIVE
  The use of volatile-based sedation within critical care environments has been limited by difficulties of drug administration and safety concerns over environment pollution and staff exposure in an intensive care unit (ICU) with no scavenging. The aim of this study was to develop a simple scavenging system to be used with the Anesthesia Conserving Device (AnaConDa(®)) and to determine whether or not ambient concentrations of residual anesthetic are within current acceptable limits.
  The scavenging system consists of two Deltasorb(®) canisters attached to the ICU ventilator in series. AnaConDa is a miniature vaporizer designed to provide volatile-based sedation within an ICU. The first ten patients recruited into a larger randomized trial assessing outcomes after elective coronary graft bypass surgery were sedated within the cardiac ICU using either isoflurane or sevoflurane. Sedation was guided by the Sedation Agitation Scale, resulting in an end-tidal minimum anesthetic concentration of volatile agent ranging from 0.1-0.3. At one hour post ICU admission, infrared photometric analysis was used to assess environmental contamination at four points along the ventilator circuit and scavenging system and around the patient's head. All measurements taken within the patient's room were below 1 part per million, which satisfies criteria for occupational exposure.
  
  
  CONCLUSIONS
  This study shows that volatile agents can be administered safely within critical care settings using a simple scavenging system. Our scavenging system used in conjunction with the AnaConDa device reduced the concentration of environmental contamination to a level that is acceptable to Canadian standards and standards in most Western countries and thus conforms to international safety standards. The related clinical trial was registered at                      www.clinicaltrials.gov                                         (NCT01151254).
authors.affiliation: Department of Anesthesia and Pain Management, Toronto General Hospital/University Health Network, ON, Canada.
authors.forename: Thomas
authors.initials: T
authors.lastname: Pickworth
authors.forename: Angela
authors.initials: A
authors.lastname: Jerath
authors.forename: Rita
authors.initials: R
authors.lastname: DeVine
authors.forename: Nazmin
authors.initials: N
authors.lastname: Kherani
authors.forename: Marcin
authors.initials: M
authors.lastname: Wąsowicz
mesh_terms: D018685:Anesthetics, Inhalation / Q000302:isolation & purification*; D002170:Canada; D002244:Carbon; D016292:Procedural Sedation; D003331:Coronary Vessels / Q000601:surgery; D003422:Critical Care; D005374:Filtration; D006801:Humans; D006813:Humidity; D006993:Hypnotics and Sedatives; D007362:Intensive Care Units; D007530:Isoflurane / Q000737:chemistry; D008738:Methyl Ethers / Q000737:chemistry; D016273:Occupational Exposure; D010783:Photometry; D011182:Postoperative Care; D015742:Propofol; D000077149:Sevoflurane; D013055:Spectrophotometry, Infrared; D013903:Thoracic Surgery; D014691:Ventilation
chemical_list: D018685:Anesthetics, Inhalation; D006993:Hypnotics and Sedatives; D008738:Methyl Ethers; D000077149:Sevoflurane; D002244:Carbon; D007530:Isoflurane; D015742:Propofol