Is nerve stimulation needed during an ultrasound‐guided lateral sagittal infraclavicular block?

Abstract

The objective of the study was to evaluate the influence of ultrasound (US) guidance alone vs. neurostimulation (NS) and US (NSUS) guidance techniques on block performance time and block success rate for the lateral sagittal infraclavicular block (LSIB). In a randomized and prospective manner, 110 adult patients scheduled for distal upper limb surgery were allocated to the US or the NSUS groups. In the US group, a local anesthetic (LA) was administered only with US guidance to produce a 'U'-shaped distribution around the axillary artery. In the NSUS group, LA was administered under US guidance only after electrolocation of one of the median, ulnar or radial nerve-type responses. A total of 30 ml of LA (10 ml of levobupivacaine 5 mg/ml and 20 ml of lidocaine 20 mg/ml) was administered in both groups. Sensory block was tested at 10 min intervals for 30 min. Successful block was defined as analgesia or anesthesia of all five nerves distal to the elbow. Block success rate was 94.5% in both groups. Block performance time was significantly shorter in the US than the NSUS group (157 +/- 50 vs. 230 +/- 104 s) (P=0.000). Block onset time was similar in both groups (12.5 +/- 4.8 in the US vs. 12.8 +/- 5.4 min in the NSUS groups). There were two arterial punctures in the NSUS group. During LSIB performance US guidance alone produces block success rate identical to both US and NS guidance yet with a shorter block performance time.