Background and aims Ultrasound guided interscalene block is widely practiced for upper extremity surgery. There are two methods of identifying the brachial plexus by interscalene method: transverse sweep and backtracking. The aim of this study was to compare the two methods in an awake patient, the level of patient‘s comfort, acceptance and presence of any symptoms like coughing, choking, vomiting or dyspnea.

Methods 100 patients undergoing upper extremity surgery requiring interscalene block were scanned with SonoSite Edge, high frequency linear probe (6–13Hz) by both the transverse and backtracking method. All patients were subjected to both the methods of scanning and levels of patient‘s comfort parameters were compared. We categorized comfort level into 3 levels: (1) comfortable, (2) mild discomfort, (3) significant discomfort. Also, we recorded associated symptoms including choking sensation, nausea, vomiting, cough and dyspnea.

Results Even though the number of events were smaller in number in transverse sweep method, the backtracking method scored over transverse sweep. Transverse sweep method caused some percentage of nausea (4%), choking (12%), dyspnea (6%) and was statistically worse than the backtracking method. Although comfort levels were not comparable statistically due to lack of enough sub-groups, transverse sweep patients had discomfort ranging from mild to significant compared to the comfortable feeling reported by all, when backtracking method was used.

Conclusions The acceptance of backtracking method was better than transverse sweep method while performing ultrasound guided interscalene block in awake patients.