運用根本原因分析品質改善手法 (root cause analysis, RCA)，回溯性分析2 件給藥疏失的醫安異常案件，藉由時間序列描述事件發生的經過後，RCA 小組成員依工作因素、個人因素及設備資源因素分類，利用給藥疏失因果圖及魚骨圖分析，歸納出主要導致系統失誤的近端原因為：(1) 高警訊輸液給藥作業規範中，對給藥劑量、給藥速度及給藥途徑流程細節訂定不夠慎密；(2) 新進護理人員對投與輸液流程不熟悉；(3) 個人疏忽；(4) 高濃度potassium chloride (KCl) 原液未先稀釋後投與等4 項。再由小組人員反覆腦力激盪與現場觀察後，制定出改善方案，並經藥委會決議同意：臨床停止使用高濃度KCl 原液，但需備妥已經稀釋完成之商業配方，才能讓臨床有足夠藥品治療特殊病患，以降低給藥錯誤案件發生。經過執行改善措施後，高濃度KCl給藥疏失異常事件通報件數，從改善前1 年發生2 次，減少到改善後1 年未再發生。

There were two high-alert medication error of potassium chloride happened in the acute care setting in 2015. Therefore, we used the method of root cause analysis (RCA) to improve the quality of care. We defined the true causes of these medication errors as follow: (1) the policy and procedure is not adequate for the clinical stuff; (2) the new nursing stuff was not familiar with the hospital policy and procedure; (3) personal negligent; (4) the high-alert medication of potassium chloride was not diluted before admistration. Therefore, we changed the hospital policy and procedure regarding high-alert medication of potassium chloride, and the pharmacists were no long to provide high-alert medication of potassium chloride to the floor instead of commercial products. After this intervention, there is no patient safety report regarding high-alert medication of potassium chloride.