The Safe Depth of Coracoid Infraclavicular Brachial Plexus Block in Taiwan

Abstract

Pneumothorax is a major complication caused by too deep puncture while performing infraclavicular block. The coracoid block provides a safer and easer approach than classic infraclavicular block. Our purpose was to design a prospective study in volunteers to evaluate the safe depth of the coracoid block by ultrasound guidance. Ultrasound examinations were performed in 41 volunteers in bilateral infraclavicular regions. The center of ultrasound probe was placed at the landmark puncture point 2 cm below and 2 cm medial to coracoid process. After identifying the neurovascular bundle, we try to identify pleura. Measured distances including skin to upper periphery of brachial plexus and skin to pleura were recorded. Safe depth was defined as vertical distance from skin to pleura. Demographic data was applied to correlate with the safety depth. Our results revealed that the mean depth from skin to plexus was 1.88±0.51cm. Pleura were identified in 84% ultrasound examinations. The mean safe depth was 3.49±0.63cm and positively correlated to both body weight and body mass index(both p＜0.001). In conclusion, safe depth of coracoid block was 3.49 cm within our demographic range and too deep puncture may result in pneumothorax. Ultrasound guidance is suggested whenever performing coracoid infraclavicular block