護理師準備對一位大型手術傷口的病人進行無菌換藥，下列哪項措施符合無菌技術原則？
A nurse is preparing to perform sterile dressing changes on a client with a large surgical wound. Which action by the nurse maintains the principles of sterile technique?
- AReach over the sterile field to grab necessary supplies越過無菌區域抓取所需用品
- BConsider the outer 2 inches of the sterile drape as contaminated認為無菌單的外側 2 英吋已受污染
- CKeep the sterile field above waist level✓ 正解保持無菌區域高於腰部水平
- DTurn back on the sterile field while gathering tape在收集膠帶時背對無菌區域
無菌技術的核心在於維持無菌場（sterile field）的完整性。無菌場的定義是：所有位於腰部以上且在視線範圍內的平面皆為無菌區。為何 C 正確？因為低於腰部的視線邊緣不可控，容易發生無意間的污染。為何其他選項錯？越過（reaching）無菌場會導致非無菌物體掉落其中；邊緣（border）的定義是 1 英寸（約 2.5 公分）而非 2 英寸；轉身則意味著視線離開了無菌區，根據原則，若視線離開，則視為已被污染。護理人員在進行無菌操作時，必須時刻保持專注，隨時監控無菌環境的完整性，這是預防醫療照護相關感染（HAI）的最基礎防線。
The core of sterile technique is maintaining the integrity of the sterile field. The sterile field is defined as any surface above the waist within the nurse's line of sight. Why is A correct? Areas below the waist are out of sight and uncontrollable, increasing the chance of inadvertent contamination. Why are the others wrong? Reaching over the field can cause non-sterile objects to drop into it; the border is defined as 1 inch (about 2.5 cm), not 2 inches; turning one's back means the line of sight has left the sterile area, so by principle it must be considered contaminated. During sterile procedures the nurse must remain focused and continuously monitor the integrity of the sterile environment, the most fundamental defense against healthcare-associated infection (HAI).
在美國臨床教學中，無菌邊緣的 1 英寸（1-inch margin）定義非常嚴格且廣泛測試；台灣臨床對此邊緣規定有時會放寬為『邊緣區域』概念，但大型醫學中心皆嚴格執行 1 英寸標準。