Stealing-like phenomenon with interscalene nerve block and its influence on the regional blood flow during shoulder arthroscopic surgery

Background Hypotensive anesthesia during shoulder arthroscopy is mandatory. Hypotension in the supine or decubitus position is safe and effective for reducing blood losses and for maintaining a clear surgical field. However, in the beach chair position, major complications have been reported. The current study claims that the alignment of the vessel in these regions favor a stealing-like phenomenon associated with interscalene block. This phenomenon has a good impact on the surgical field. Results There was a significant change in the peak systolic velocity between the two populations with values of 57±5 in group I versus 90±12 in group G, with a clearer surgical field in group I than in group G. The need for the intraoperative adjuvant analgesics was higher in group G (29 patients) compared with group I (10 patients) as was the pain score at early postoperative intervals of 6 and 12 h. Conclusion The distribution of blood vessels in this region favors a stealing-like phenomenon may be because of the associated vasoplegic effect with the interscalene nerve block, yielding a favorable surgical field without deliberate hypotension.