title: Comparison of effect-site concentration of remifentanil for tracheal intubation with the lightwand and laryngoscopy during propofol target-controlled infusion.
abstract: BACKGROUND
  Target-controlled infusion (TCI) of propofol and remifentanil can provide satisfactory intubating conditions without a neuromuscular blocking agent. We compared the effect-site concentration of remifentanil required for intubation with the lightwand and the Macintosh laryngoscope during propofol TCI without a neuromuscular blocking agent in adult patients.
  
  
  METHODS
  Forty-nine patients were randomly assigned to the lightwand group (n = 25) or the direct laryngoscope group (n = 24). Anesthesia was induced by propofol TCI with an effect-site concentration of 5.4 µg/ml. Two minutes after start of propofol TCI, remifentanil was administered at the predetermined effect-site concentration. The effect-site concentration of remifentanil was determined using Dixon's up-and-down method (0.5 ng/ml as a step size). The first patient in each group was tested at 4.5 ng/ml of remifentanil. Tracheal intubation was performed 2 min after the start of remifentanil TCI. Acceptable intubation was defined as an excellent or good intubating conditions.
  
  
  RESULTS
  Using a modified Dixon's up and down method, the EC50 ± SD of remifentanil in the lightwand and laryngoscope groups was 4.75 ± 0.71 ng/ml and 5.08 ± 0.52 ng/ml, respectively; there was no statistically significant difference between the groups (P = 0.373).
  
  
  CONCLUSIONS
  The effect-site concentration of remifentanil for acceptable intubation with the lightwand and Macintosh laryngoscope in 50% of adults did not differ during propofol TCI without a neuromuscular blocking agent.
authors: Department of Anesthesiology and Pain Medicine, Ajou University School of Medicine, Suwon, Korea.
authors: Jin-Soo
authors: JS
authors: Kim
authors: Dae-Hee
authors: DH
authors: Kim
authors: Sang-Kee
authors: SK
authors: Min
authors: Kyung-Mi
authors: KM
authors: Kim
authors: Jong-Yeop
authors: JY
authors: Kim