目的：本文描述一件癌症化療時發生Port-A靜脈導管外滲，造成醫療不良事件，運用RCA找出根本原因與改善方案，提供醫護人員注意與防範。材料：成立Port-A化療外滲RCA調查小組，使用「時間序列表」、「改變因素」檢視化療標準流程與實際執行之差異，列出前端因子，依臨床實證進行「原因樹」、「屏障分析」找出根本原因，並建立「改善計畫」。結果：確立3個根本原因；1. Port-A安全角針規格不符，引用錯誤。2. 護理師對第一次化療病人之反應警覺性不夠。3. 未及時通報異常，錯失急救傷害時機。因此修訂化療給藥流程及落實執行。討論：RCA確為院內醫療異常事件根本原因分析檢討改善有效之工具，然對規格不符之醫材與院外廠商協商修正，卻是一項挑戰。
Purpose: The aim of this article was to describe the use of root cause analysis (RCA) for identifying the possible causes of an adverse event involved vesicant extravasation injury from a central venous Port-A catheter, a rare reported, and provide attention & prevention.Methods: As a serious and sentinel event, an investigation team was established. Key participants were identified and an RCA was implemented systematically with a trained facilitator guiding each analysis step. Chronological narratives were tabulated in a timeline sheet. Why tree & Barrier analysis were used to determine the root factors of this event.Results: Three root causes of the extravasation event were identified, which included 1. Port-A needle was not qualify, 2. Nurse was not alert of the potential of extravasation of the patients first time receiving chemotherapy, 3. Reporting of adverse event was slow. Based on the analysis, we implemented action plan to ensure safety in administering chemotherapy. After the improvement measures, we have not had similar event recurred.Discussion: RCA is a useful tool to identify the causes of an adverse event. Subsequent measures can target the causes to prevent or reduce future occurrence of the event. However, implementing the desired changes can be a challenge in which the measure required negotiation of changes outside of our institution.