病患自控止痛法（PCA）的安全性探討及風險管理

The Safety and Risk Management of Patient-Controlled Analgesia (PCA)

病患自控止痛法（PCA）已是目前普遍被使用做為手術後止痛的方法，理論上止痛效果好、副作用少、是安全及理想的方法，然而若使用不當或PCA幫浦設計不良或機械故障使輸出不正確的藥量時，都可能發生致命性的危險。不管是PCA或是傳統的止痛方法，使用成癮性止痛藥都有相同的副作用，我們回顧本院開院至今的11年間使用PCA的經驗，對所有使用PCA做手術後止痛的11589位病人，探討並分析在使用PCA期間、PCA引起的副作用及併發症的原因及種頰，以評估PCA使用的安全性。結果顯示醫生之副作用或併發症有噁心、嘔吐、嗜睡、頭暈、皮膚癢、止痛效果不足、尿液滯留、呼吸抑制等，而較具危險性的呼吸抑制的發生率為0.12%，但使用Naloxone拮抗即可處理，無因PCA致死的病例，引起這些副作用的原因可分人為及器械因素，而所發生的問題大部份是人為因素引起的，致於幫浦故障導致藥物不正常或過量輸出、並影響安全的情況沒有發生過，顯示目前本曉所使用的PCA機種是可靠的。PCA之安全性，與很多因素有關，包括使用PCA的作業流程、醫護人員和病人或家屬對PCA的瞭解、術後的照護等都息息相關，能安全的使用PCA渡過11個年頭的經驗，我們認為與本院所使用PCA的特色有關，包括1）使用單一濃度morphine 1 mg/ml）止痛藥，2）止痛藥物單純化，3）醫師每天前視病人，並調整藥量，4）使用單一PCA機種（Baxter APII），5）教導病人及家屬正祖輩使用PCA幫浦，6）訓練本科護士熟識PCA幫浦，7）教育病房護士認識PCA，可能發生的併發症，何時應通知麻醉科人員及馬上處理，8）舉辦全院護士對疼痛認識的教育課程。雖然這些都是很簡單的方法，然而對防止錯誤事件的發生很有幫助。

Patient-controlled analgesia (PCA) refers to a process where patients can determine when and how much medication they receive. It offers advantages which are more effective analgesia and fewer side effects than traditional analgesia theoretically. However, medical errors can occur which may dangerous and even fatal unless PCA is used appropriately. It is important to understand the factors that threaten patient safety with the use of PCA pumps. The aim of this study was to investigate the safety of the PCA pumps and the medical errors with PCA for post-operative pain control at Jen-Ai hospital in the past eleven years. It was a retrospective study; the patients who received PCA for post-operative pain control were enrolled to the study during the period from April 1'' 1995 to Sept. 30th 2005. The causes and the types of side effects and complications induced by PCA as well as the safety of PCA were analyzed and evaluated. During the study period, 11589 patients were enrolled to the study. The result showed that the common side effects induced by PCA contained inadequate analgesia, nausea and vomiting, drowsiness, dizziness. The incidence of serious complication, respiratory depression which needed naloxone to reverse the effect of narcotics, was 0.12% and no fatal cases attributed by PCA were noted in the study. The causes of these side effects could be divided by human-related factors and equipment-related factors. Most of the problems were caused by human-related factors. There was no mortality due to drug overdose which attributed by pump malfunction. It revealed that the PCA pump (Baxter AP 11) we employed was safe and reliable. Although PCA has considerable potential to improve pain management for patients, but patients receiving opioids in this manner may also develop some complications and even life threatening events as conventional analgesia. Since errors can occur inevitably unless PCA is used appropriately. Some factors must be considered to reduce the risk of PCA when PCA used for pain control. We always pay attention to consider the following situations, it includes use single concentration of drug, simplify the analgesics, no PCA proxy, teach the patients and their family to use the PCA pump correctly, follow up the patient everyday during the period of PCA, increase the ability of nursing care by adequate staff and nurse training. We conclude that these are the effective ways to increase the safety of PCA and therefore no mortality attributed by PCA at our hospital in the past eleven years.