Appropriate Location and Equipment

Room equipped with standard ASA monitors

Immediate access to resuscitative drugs and equipment

Equipment checked

Neurostimulators able to deliver a
current of up to 5-mA intensity, frequency of 1 or 2 Hz (1 or 2
impulses per second), impulse duration of 0.1 to 1 msec (0.1 to 0.3
msec for a motor nerve stimulation and 1 msec for a sensory nerve
stimulation)

Insulated needles of 1, 2, 4, and 6 inches (2.5, 5, 10, and 15 cm)

Catheter sets with 2-, 4-, and 6-inch (5-, 10-, and 15-cm) introducer needles

Check nerve stimulator and connecting cables for their proper function.

Skin prep and local infiltrate for needle insertion.

Minimal distance between skin electrode and needle.

After skin puncture, gradually increase the intensity up to 1.5 mA at 0.3 msec.

Search in 3 axes (see picture on page x).

As soon as the first twitch is obtained,
impulse duration (msec) should be decreased to 0.1 msec. Then intensity
(mA) is slowly decreased while approaching the nerve to a minimal
stimulation intensity of 0.5 to 0.3 mA.

Aspirate for blood.

Loss of motor response after injection of 1 mL of local anesthetic and return of the motor response when intensity is increased.

No resistance or pain during injection.

Slow and fragmented injection.