台灣區喙突鎖骨下臂神經叢阻斷術安全深度之探討

The safe depth of coracoid infraclavicular brachia! plexus block in Taiwan

氣胸是鎖骨下臂神經叢阻斷術下針過深所產生的嚴重併發症，喙突鎖骨下臂神經叢阻斷術，比傳統鎖骨下臂神經叢阻斷術更為安全而簡便。本研究目的是以超音波檢查，分析此術之安全深度。徵求41名健康自願者，接受超音波儀器檢測左右兩側鎖骨下區域，超音波探頭置於喙突內側2公分下方2公分之解剖標紀定位點。在超音波檢查確認神經血管叢之後，確認肋膜是否可見，紀錄體表至臂神經叢上緣與體表至肋膜之距離，後者定義為安全深度。分析人口學資料與安全深度之相關性。結果如下：體表至臂神經叢上緣，平均深度為1.88±0.51公分，肋膜可確認之比例為84%，平均安全深度3.49±0.63公分。安全深度則與體重及身體質量指數成正相關。在本研究的人口學資料範圍內，喙突鎖骨下臂神經叢阻斷術垂直安全深度為3.49公分，過深則有氣胸之危險。建議在超音波指引下操作此街，確保安全。

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 brachia! 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.Slcm. 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 .