Avoidance of phrenic nerve paresis during continuous supraclavicular regional anaesthesia*

Abstract
This study sought to determine whether it is possible reliably to avoid phrenic nerve block using the bent needle technique for continuous supraclavicular brachial plexus anaesthesia. In a prospective study, 100 patients undergoing a variety of upper extremity surgical procedures were studied. Ultrasound examinations of the patients' diaphragms were performed after insertion of an anaesthetic block, and were repeated a day later with the analgesic block working. Three phrenic nerve blocks were detected in different patients. Factors were identified in all three cases that we think contributed to the phrenic nerve blocks. We think it is possible to provide continuous supraclavicular regional anaesthesia and analgesia for a wide range of upper extremity operations without phrenic nerve blockade.