title: The concentration of desflurane preventing spectral entropy change during surgical stimulation: A prospective randomized trial.
abstract: OBJECTIVE
  To determine the concentration of desflurane necessary to blunt changes in spectral entropy during surgical incision when two different target-controlled effect-site concentrations of remifentanil (1 and 3ng/ml) were infused.
  
  
  METHODS
  Prospective, randomized controlled study.
  
  
  METHODS
  Operating room of a university hospital.
  
  
  METHODS
  Forty-two patients undergoing general anesthesia for elective surgery were enrolled and randomly allocated to the R1 (1ng/ml of remifentanil, n=21) or R3 (3ng/ml of remifentanil, n=21) group. After at least a 10-min administration of target-controlled remifentanil concentration and predetermined end-tidal desflurane following endotracheal intubation, changes in spectral entropy in response to surgical incision were evaluated.
  
  
  METHODS
  Concentration of desflurane necessary to blunt changes in spectral entropy during surgical incision for each group was determined using Dixon's up-and-down method. Hemodynamic variables including mean arterial pressure (MAP) and heart rate (HR) were measured.
  
  
  RESULTS
  Concentration of desflurane necessary to blunt changes in spectral entropy during surgical incision in 50% of patients (EC50) was 4.1% (95% CI: 3.5-4.7%) for the R1 group and 3.4% (95% CI: 3.0-3.8%) for the R3 group (P=0.033). Additionally, the calculated EC95values using the logistic regression analysis for the R1 and R3 groups were 5.8% (95% CI: 5.0-10.8%) and 5.1% (95% CI: 4.3-10.6%), respectively. MAPs and HRs were significantly higher in the R1 than in the R3 group after surgical incision.
  
  
  CONCLUSIONS
  Desflurane 4.1% with remifentanil 1ng/ml and desflurane 3.4% with remifentanil 3ng/ml significantly blunt the change in spectral entropy after surgical incision in 50% of patients.
authors.affiliation: Zero Pain Clinic, Seoul, South Korea.
authors.forename: Sun-Sook
authors.initials: SS
authors.lastname: Han
authors.affiliation: Department of Anesthesiology & Pain Medicine, Seoul National University College of Medicine, Seoul, South Korea; Department of Anesthesiology & Pain Medicine, Seoul National University Bundang Hospital, Seongnam-si, Gyeonggi-do, South Korea.
authors.forename: Sunghee
authors.initials: S
authors.lastname: Han
authors.affiliation: Department of Anesthesiology & Pain Medicine, Seoul National University College of Medicine, Seoul, South Korea; Department of Anesthesiology & Pain Medicine, Seoul National University Bundang Hospital, Seongnam-si, Gyeonggi-do, South Korea.
authors.forename: Byung-Gook
authors.initials: BG
authors.lastname: Kim
authors.affiliation: Department of Anesthesiology & Pain Medicine, Seoul National University College of Medicine, Seoul, South Korea.
authors.forename: Dong-Ho
authors.initials: DH
authors.lastname: Kim
authors.affiliation: Department of Anesthesiology & Pain Medicine, Seoul National University College of Medicine, Seoul, South Korea; Department of Anesthesiology & Pain Medicine, Seoul National University Bundang Hospital, Seongnam-si, Gyeonggi-do, South Korea. Electronic address: jinaryu74@gmail.com.
authors.forename: Jung-Hee
authors.initials: JH
authors.lastname: Ryu
mesh_terms: D000328:Adult; D000768:Anesthesia, General / Q000379:methods; D018685:Anesthetics, Inhalation / Q000008:administration & dosage*; D001794:Blood Pressure / Q000187:drug effects; D000077335:Desflurane; D017558:Elective Surgical Procedures / Q000009:adverse effects; D004569:Electroencephalography; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D006993:Hypnotics and Sedatives / Q000008:administration & dosage*; D058926:Intraoperative Awareness / Q000517:prevention & control*; D064795:Intraoperative Neurophysiological Monitoring; D007530:Isoflurane / Q000008:administration & dosage / Q000031:analogs & derivatives*; D008297:Male; D008875:Middle Aged; D010880:Piperidines / Q000008:administration & dosage*; D011446:Prospective Studies; D000077208:Remifentanil
chemical_list: D018685:Anesthetics, Inhalation; D006993:Hypnotics and Sedatives; D010880:Piperidines; D000077335:Desflurane; D007530:Isoflurane; D000077208:Remifentanil
keywords: Desflurane; Hemodynamic response; Remifentanil; Spectral entropy; Surgical stimulation