Comparison of nerve stimulation vs. ultrasound-guided lateral sagittal infraclavicular block

A nerve stimulation-guided lateral sagittal infraclavicular block (LSIB) has been proven to be an effective block. The purpose of this study was to evaluate whether the use of ultrasound (US) guidance would further improve the block quality of LSIB.

In a prospective manner, 80 adult patients scheduled for hand, wrist and forearm surgery were randomly allocated to US or nerve stimulation (NS) groups. A needle was inserted into a sagittal plane, 20 degrees dorsally, until muscle twitches were observed in synchrony with the stimulation. In the US group, the block was performed using the same puncture site but under ultrasonic guidance. The final position of the needle was verified with the use of a nerve stimulator. A local anesthetic mixture of 20 ml of levobupivacaine, 5 mg/ml and 20 ml of lidocaine and 20 mg/ml with 5 microg/ml epinephrine (total 40 ml) was administered in both groups.

The block was successful in 37 patients in the NS group and 38 patients in the US group. Block efficacy was better in the US group than the group NS in radial nerve distribution at 20 min (P<0.05). In the US group, there was a slight tendency toward better block density in other nerve areas also but these differences were not significant. Vascular puncture was noted in three patients in the NS group and none in the US group.

The block success rate was high and comparable in both groups. There was a trend toward improved block quality in the US group, although not significant.