護理師正在查看一位持續嘔吐病人的動脈血氣分析 (ABG) 結果：pH 7.50, PaCO2 48 mmHg, HCO3 34 mEq/L。護理師應如何判讀？
The nurse is reviewing the arterial blood gas (ABG) results for a client with persistent vomiting: pH 7.50, PaCO2 48 mmHg, HCO3 34 mEq/L. How should the nurse interpret these results?
- ARespiratory alkalosis, partially compensated呼吸性鹼中毒，部分代償
- BMetabolic alkalosis, partially compensated✓ 正解代謝性鹼中毒，部分代償
- CMetabolic acidosis, uncompensated代謝性酸中毒，未代償
- DMetabolic alkalosis, fully compensated代謝性鹼中毒，完全代償
判讀 ABG 的三步驟：1. pH 7.50 高於正常 (7.35-7.45)，屬於鹼中毒。2. HCO3 34 高於正常 (22-26)，與 pH 變動方向一致，確認為代謝性鹼中毒。3. PaCO2 48 高於正常 (35-45)，這代表呼吸系統試圖保留 CO2 來降低 pH 值，這是一種代償反應。由於 pH 值尚未回到正常範圍（仍是 7.50），因此稱為「部分代償」。臨床上，持續嘔吐會導致胃酸（H+）大量流失，是代謝性鹼中毒的經典原因。護理師需監測病人呼吸頻率是否下降（代償表現）以及是否有低血鉀風險。此題考驗對酸鹼失衡機轉的深入理解，以及對代償階段的精確區分。
Three steps for ABG interpretation: 1. pH 7.50 is above the normal range (7.35–7.45), indicating alkalosis. 2. HCO3 of 34 is above normal (22–26) and changes in the same direction as the pH, confirming metabolic alkalosis. 3. PaCO2 of 48 is above normal (35–45), indicating that the respiratory system is retaining CO2 in an attempt to lower the pH—a compensatory response. Because the pH has not yet returned to the normal range (still 7.50), this is termed 'partially compensated.' Clinically, persistent vomiting results in significant loss of gastric acid (H+) and is a classic cause of metabolic alkalosis. The nurse should monitor for a decreased respiratory rate (a compensatory finding) and for the risk of hypokalemia. This question tests deep understanding of acid-base disturbance mechanisms and the precise distinction between compensation stages.
在美國 NCLEX 考試中，ABG 判讀是必考的評估技能，護理師需具備獨立分析能力；台灣臨床上護理師同樣需具備判讀能力，但臨床決策（如調整呼吸機參數）通常需依據醫師或呼吸治療師的具體指令。