title: The optimal effect-site concentration of remifentanil for lightwand tracheal intubation during propofol induction without muscle relaxation.
abstract: OBJECTIVE
  To determine the most suitable effect-site concentration of remifentanil during lightwand intubation when administered with a target-controlled infusion (TCI) of propofol at 4.0 μg/mL without neuromuscular blockade.
  
  
  METHODS
  Prospective study using a modified Dixon's up-and-down method.
  
  
  METHODS
  Operating room of an academic hospital.
  
  
  METHODS
  28 ASA physical status 1 and 2 patients, aged 18-65 years, scheduled for minor elective surgery.
  
  
  METHODS
  Anesthesia was induced by TCI propofol effect-site concentration to 4.0 μg/mL, and the dose of remifentanil given to each patient was determined by the response of the previously tested patient using 0.2 ng/mL as a step size. The first patient was tested at a target effect-site concentration of 4.0 ng/mL of remifentanil. If intubation was successful, the remifentanil dose was decreased by 0.2 ng/mL; if it failed, the remifentanil dose was increased by 0.2 ng/mL. Successful intubation was defined as excellent or good intubating conditions.
  
  
  RESULTS
  The remifentanil effect-site concentration was measured. The optimal effect-site concentration of remifentanil for lightwand tracheal intubation during propofol induction using 2% propofol target effect-site concentration to 4 μg/mL was 2.16 ± 0.19 ng/mL. From probit analysis, the effect-site concentration of remifentanil required for successful lightwand intubation in 50% (EC50) and 95% (EC95) of adults was 2.11 ng/mL (95% CI 1.16-2.37 ng/mL) and 2.44 ng/mL (95% CI 2.20-3.79 ng/mL), respectively.
  
  
  CONCLUSIONS
  A remifentanil effect-site concentration of 2.16 ± 0.19 ng/mL given before a propofol effect-site concentration of 4 μg/mL allowed lightwand intubation without muscle relaxant.
authors: Department of Anesthesiology and Pain Medicine, Inha University, College of Medicine, Incheon, 400-103, South Korea.
authors: Jeong Uk
authors: JU
authors: Han
authors: Sangyun
authors: S
authors: Cho
authors: Woo Jae
authors: WJ
authors: Jeon
authors: Jong Hoon
authors: JH
authors: Yeom
authors: Woo Jong
authors: WJ
authors: Shin
authors: Jae Hang
authors: JH
authors: Shim
authors: Kyoung Hun
authors: KH
authors: Kim
mesh_terms: D000328:Adult; D018686:Anesthetics, Intravenous / Q000008:administration & dosage / Q000493:pharmacokinetics* / Q000627:therapeutic use; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D007442:Intubation, Intratracheal / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010880:Piperidines / Q000008:administration & dosage / Q000493:pharmacokinetics* / Q000627:therapeutic use; D015742:Propofol / Q000008:administration & dosage / Q000493:pharmacokinetics* / Q000627:therapeutic use; D011446:Prospective Studies; D000077208:Remifentanil
chemical_list: D018686:Anesthetics, Intravenous; D010880:Piperidines; D000077208:Remifentanil; D015742:Propofol