Optimal Concentration of Remifentanil for NIM Tube Intubation With Low-dose NMBA

"Following a sequential allocation scheme, the predetermined Ce of remifentanil for each patient will be determined by the Dixon up-and-down method. The Ce of remifentanil for the first patient will be 4.0 ng/ml, and then the remifentanil Ce will be increased or decreased in 0.5 ng/ml increments for subsequent patients depending on the success or failure of intubation.~The Ce of remifentanil to provide acceptable intubation at low dose neuromuscular blockade, the primary outcome, will be determined by obtaining seven crossovers of patients with acceptable intubation/unacceptable intubation and then calculating the mean of the midpoint doses for each independent pair of patients. According to previous studies that estimated EC50 by Dixon's up-and-down method, 6-8 failure/success crossover pairs are required, so this study aims to collect independent data of 7 pairs of intubation acceptable/unacceptable patients."