title: Choice of volatile anesthetic for the morbidly obese patient: sevoflurane or desflurane.
abstract: OBJECTIVE
  Morbid obesity is associated with significant comorbidities. Desflurane has a low fat-blood solubility coefficient and may be better suited in this population to achieve a rapid emergence; however, sevoflurane has favorable cardiorespiratory properties that might also prove advantageous in the morbidly obese (MO) patient. This study used careful drug titration to determine if emergence differences between sevoflurane and desflurane could be minimized in MO patients.
  
  
  METHODS
  A randomized, prospective blinded study to determine the emergence profiles of desflurane and sevoflurane in MO patients when anesthetic drug titration is used.
  
  
  METHODS
  Operating room of the VA Medical Center, Milwaukee, Wis.
  
  
  METHODS
  Forty American Society of Anesthesiologists II and III, MO patients (body mass index > or = 35 kg/m2), who were scheduled for elective surgery predicted to last for more than 2 hours, were studied.
  
  
  METHODS
  Patients were induced with fentanyl, midazolam, and propofol and maintained with desflurane or sevoflurane, mixed in air and oxygen. Intraoperative bispectral index (BIS) was targeted to 45 to 50 and to 60 in the last 15 minutes of surgery.
  
  
  METHODS
  Intraoperative anesthetic concentration, BIS, and hemodynamics were recorded. During emergence, time to follow command and extubation were noted, with assessments of cognitive function via the Mini-Mental Status Test and psychomotor performance via the Digit Symbol Substitution Test. A blinded observer recorded key recovery events.
  
  
  RESULTS
  Demographic data (age, 61 [36-83] years; body mass index, 38 [35-47] kg/m2), surgical procedures, length of anesthesia (approximately 3.5 hours), adjuvant drugs, and intraoperative BIS, heart rate, and mean arterial pressure were not significantly different. Hemodynamics, time to follow commands and to extubation, and results of Digit Symbol Substitution Test and Mini-Mental Status Test did not differ between anesthetic groups during recovery.
  
  
  CONCLUSIONS
  There were no differences in emergence and recovery profiles in MO patients receiving desflurane or sevoflurane when anesthetic concentration was carefully titrated.
authors.affiliation: Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, WI 53226, USA.
authors.forename: Shahbaz R
authors.initials: SR
authors.lastname: Arain
authors.forename: Christofer D
authors.initials: CD
authors.lastname: Barth
authors.forename: Hariharan
authors.initials: H
authors.lastname: Shankar
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Ebert
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000769:Anesthesia, Inhalation; D018685:Anesthetics, Inhalation; D001279:Atracurium; D015992:Body Mass Index; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D003071:Cognition / Q000187:drug effects; D000077335:Desflurane; D004569:Electroencephalography / Q000187:drug effects; D005260:Female; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D007530:Isoflurane / Q000031:analogs & derivatives* / Q000737:chemistry; D008297:Male; D008738:Methyl Ethers / Q000737:chemistry; D008875:Middle Aged; D003473:Neuromuscular Nondepolarizing Agents; D009767:Obesity, Morbid / Q000150:complications* / Q000503:physiopathology*; D011229:Preanesthetic Medication; D011446:Prospective Studies; D011597:Psychomotor Performance / Q000187:drug effects; D000077149:Sevoflurane
chemical_list: D018685:Anesthetics, Inhalation; D008738:Methyl Ethers; D003473:Neuromuscular Nondepolarizing Agents; D001279:Atracurium; D000077149:Sevoflurane; D000077335:Desflurane; D007530:Isoflurane