A postoperative client with a NG tube that has drained 2500 mL in 6 hours should be monitored for which electrolyte imbalance?

A postoperative client with a NG tube that has drained 2500 mL in 6 hours should be monitored for which electrolyte imbalance?

• A. Hyperkalemia
• B. Hyponatremia
• C. Decreased potassium level
• D. Hyperchloremia

Answer: (C)

Gastric drainage of large volumes removes a lot of stomach secretions, which are rich in hydrogen, chloride, and potassium. Losing these electrolytes with suction leads to metabolic alkalosis and shifts that promote potassium loss in the kidneys, so serum potassium drops. That’s why a decreased potassium level (hypokalemia) is the most likely imbalance with substantial NG drainage. Hyperkalemia wouldn’t fit since potassium is being lost, not retained; hyperchloremia isn’t typical because losing gastric fluid usually causes chloride depletion, not excess; sodium loss can occur, but the characteristic and most clinically relevant change here is hypokalemia.

Gastric drainage of large volumes removes a lot of stomach secretions, which are rich in hydrogen, chloride, and potassium. Losing these electrolytes with suction leads to metabolic alkalosis and shifts that promote potassium loss in the kidneys, so serum potassium drops. That’s why a decreased potassium level (hypokalemia) is the most likely imbalance with substantial NG drainage. Hyperkalemia wouldn’t fit since potassium is being lost, not retained; hyperchloremia isn’t typical because losing gastric fluid usually causes chloride depletion, not excess; sodium loss can occur, but the characteristic and most clinically relevant change here is hypokalemia.