病人的 NG tube 接低壓間歇吸引。病人出現肌肉無力和低血鉀。最可能出現哪種酸鹼失衡？
A nurse is caring for a client with a nasogastric tube to low intermittent suction. The client develops muscle weakness and hypokalemia. Which acid-base imbalance is likely?
- ARespiratory Alkalosis呼吸性鹼中毒
- BMetabolic Acidosis代謝性酸中毒
- CMetabolic Alkalosis✓ 正解代謝性鹼中毒
- DRespiratory Acidosis呼吸性酸中毒
鼻胃管（Nasogastric tube, NG tube）接低壓間歇吸引（low intermittent suction）會持續將胃液從體內移除。胃液含有大量的鹽酸（Hydrochloric acid, HCl），其主要成分是氫離子（H+）和氯離子（Cl-）。當這些酸性物質被大量吸出體外時，身體會喪失大量的氫離子，導致體液的酸度降低，pH值升高，進而引發代謝性鹼中毒（Metabolic Alkalosis）。同時，胃液中也含有鉀離子，持續吸引可能導致鉀離子流失，或因代償機制（腎臟排出氫離子以保留鉀離子）而加劇低血鉀（Hypokalemia）。肌肉無力是低血鉀的典型症狀之一。護理師需了解 NG tube 吸引的潛在併發症，並能正確判斷酸鹼失衡類型。
A nasogastric (NG) tube connected to low intermittent suction continuously removes gastric contents from the body. Gastric juice contains a large amount of hydrochloric acid (HCl), composed mainly of hydrogen ions (H+) and chloride ions (Cl-). When these acidic substances are removed from the body in large quantities, the body loses considerable hydrogen ions, decreasing acidity and raising the pH, which leads to metabolic alkalosis. In addition, gastric juice also contains potassium ions; continuous suction may cause potassium loss, or the compensatory mechanism (kidneys excreting hydrogen ions to retain potassium) may worsen hypokalemia. Muscle weakness is a classic symptom of hypokalemia. The nurse must understand the potential complications of NG suction and correctly identify the type of acid-base imbalance.
鼻胃管吸引的護理原則及對酸鹼平衡的影響，在美國和台灣的教學內容和臨床實踐中是完全一致的。護理師都必須了解胃液流失導致代謝性鹼中毒和低血鉀的風險，並密切監測病人的電解質和酸鹼值。在美國，護理師會更強調對低血鉀症狀（如肌肉無力、心律不整）的早期辨識，並依醫囑補充電解質。台灣的臨床做法也相同，但可能在醫師開立電解質補充醫囑的時機上略有差異。