مريض بانسداد أمعاء على أنبوب أنفي معدي على الشفط من ٣ أيام، يأخذ سوائل وريدية بدون بوتاسيوم. صار عنده ضعف في العضلات وانتفاخ أكثر. تخطيط القلب يظهر موجة U. البوتاسيوم ٢٫٧. ما السبب الأرجح؟

A client with bowel obstruction has been on NG suction for 3 days with IV fluids lacking potassium. He now has muscle weakness and more distension. The ECG shows U waves. Potassium is 2.7. What is the most likely cause?

1. An allergy to the NG tube material
2. Excess potassium from IV fluids
3. Potassium lost in gastric aspirate without replacement
4. Acute kidney injury preventing normal potassium excretion

Answer: C) Potassium lost in gastric aspirate without replacement. Gastric suction loses potassium and chloride and causes alkalosis. Hypokalaemia causes weakness, worsens ileus and produces U waves. Replace IV potassium as ordered with monitoring.