背景：周邊靜脈注射是臨床普遍的處置。雖然美國疾病管制中心指引，建議不須常規三天重置周邊靜脈留置針，但台灣海島型氣候是否可依循指引建議，實需本土性實證研究探討之。目的：探討96小時與72小時更換周邊靜脈留置針的效應，提出更換周邊靜脈留置針最佳時機之實證照護依據。方法：研究採隨機控制試驗（randomized controlled trial），方便取樣南部某醫學中心耳鼻喉科病房手術住院病人，以隨機區集（randomized block）方式將個案分派至96小時與72小時組各71人。以卡方檢定與獨立t檢定比較兩組靜脈炎、注射處感染、血流感染、留置針阻塞之發生率，與衛材成本、護理時數耗用之差異。結果：兩組靜脈炎、注射處感染、血流感染與留置針阻塞之發生率並無顯著差異（p＞.05），96小時組顯著減少152.72元／人的醫療衛材成本（p＜.0001）與174.23秒／人的護理時數（p＜.0001）。結論／實務應用：三班常規評估靜脈注射部位，在無感染症狀的情況下，96小時是較佳的周邊靜脈留置針更換時機。

Background: Peripheral intravenous injection is a common clinical procedure. According to U.S. Centers for Disease Control guidelines, there is no need to replace peripheral catheters routinely every three days. However, local evidence‐based research is needed to determine whether these guidelines are appropriate for Taiwan's island climate. Purpose: This study explores the effects of routine replacement of peripheral intravenous catheters every 96 hours versus every 72 hours, attempting to provide evidence‐based information on optimal timing for replacing peripheral intravenous catheters. Methods: A randomized controlled trial design was adopted. Using convenience sampling, surgical otolaryngology inpatients of a medical center in southern Taiwan were recruited. A randomized block design assigned 71 participants to the 96‐hour group and to the 72‐hour group, respectively. A chi‐square test and independent t test were used to compare the differences in the incidence of phlebitis, injection site infections, bloodstream infections, and catheter occlusion as well as the materials costs and nursing hours per patient day between the two groups. Results: There were no significant differences between the groups with respect to the incidence of phlebitis, injection site infections, bloodstream infections, or catheter occlusion (p ＞ .05). The 96‐hour group had a significant NT$ 152.72/person reduction in medical material costs (p ＜ .0001) and a significant 174.23 seconds /person reduction in nursing hours per patient day (p ＜ .0001). Conclusions/Implications for Practice: The results of this study suggest that for cases in which no infection signs at the intravenous injection sites are detected by routine assessment for more than three shifts during one day, the optimal replacement interval for peripheral intravenous catheters is 96 hours.