1. An I-gel mask is inserted for the mechanical ventilator of the patient who is sedated with propofol.
2. For the ultrasound-guided obturator nerve (ON) block, and needle tip gradually advanced to the anterior branch of the ON. The current intensity for the stimulation of ON starts at 1.0 mA (using the sequential electrical nerve stimulation mode), and the needle is advanced gradually to the location where the contraction of the adductor longus muscle (ALM) occurs at 0.3-0.5 mA.
3. After fixing the needle in that position, measure the current intensity.
4. Then, rocuronium (0.6 mg/kg) is administered under quantitative neuromuscular-blockade monitoring.
5. When the train-of-four count becomes 0, the current intensity is increased until the contraction of the ALM occurs.
6. The current intensity is measured when the contraction of the ALM occurs.

After measuring the initial current intensity, quantitative neuromuscular blockade monitoring is applied, and rocuronium (0.6 mg/kg) is administered.

The current intensity for the stimulation of the obturator nerve starts at 1.0 mA (using the sequential electrical nerve stimulation mode), and the needle is advanced gradually to the location where the stimulus response occurs at 0.3-0.5 mA. After fixing the needle position in a position where contraction of the adductor longus muscle responds to the minimum current intensity, measure the current intensity.

After administration of rocuronium (0.6 mg/kg), when the train-of-four count becomes 0, the current intensity for the stimulation of the obturator nerve is increased until the contraction of the adductor longus muscle occurs. The current intensity is measured when the contraction of the adductor longus muscle occurs.

After administration of rocuronium (0.6 mg/kg), the quantitative neuromuscular blockade monitoring using train-of-four is observed with 12 seconds interval. At each time point, the current intensity for the obturator nerve is increased until the contraction of the adductor longus muscle occurs. The current intensity at each time point is measured.