病人裝有胸管並連接到水封式引流系統。護理師觀察到水封瓶內的水位隨病人的呼吸而起伏。護理師對此發現的最佳解釋為何？
A client has a chest tube connected to a water-seal drainage system. The nurse observes that the water level in the water-seal chamber fluctuates with the client's respirations. What is the nurse's best interpretation of this finding?
- AThe system is functioning normally (tidaling).✓ 正解系統運作正常（潮汐現象）
- BThe lung has fully re-expanded and the tube can be removed.肺部已完全復張，可以拔除引流管
- CThe suction pressure is too high for the client.抽吸壓力對個案而言過高
- DThe system has an air leak that needs immediate repair.系統有空氣洩漏，需要立即修復
胸管水封瓶內水位的起伏（Tidaling）是正常的生理現象。這代表胸腔與引流瓶之間的管路是通暢的，且隨著病人呼吸時胸內壓的改變（吸氣時壓力更負，水位上升；呼氣時水位下降），水位會產生規律波動。如果波動停止，通常意味著肺部已完全復張、管路受壓阻塞或是出現了問題。空氣洩漏（D）通常表現為水封瓶內的持續氣泡而非起伏。及時正確判讀引流系統的物理徵兆是預防術後呼吸系統風險的基本功。此題考查的是對正常與異常臨床表徵的區別。
Fluctuation of the water level in the water-seal chamber, known as tidaling, is a normal finding that indicates the chest tube is patent and responsive to intrapleural pressure changes. Continuous bubbling would suggest an air leak, while cessation of tidaling may indicate lung re-expansion or obstruction.
美國 NCLEX 非常喜歡考胸管引流系統的判讀（Tidaling vs Bubbling）。在台灣，臨床護理師對此亦有訓練，但美國 RN 更有可能在發現停止起伏時，依程序進行初步檢查（如檢查管路有無受壓）後直接向醫師報告肺復張的可能性。