After colon resection, SIADH can lead to which symptoms?

After colon resection, SIADH can lead to which symptoms?

• A. Fatigue, lethargy, and nausea
• B. Weight gain only
• C. Polyuria only
• D. Hypertension

Answer: (A)

SIADH causes water retention with dilutional hyponatremia. When ADH is inappropriately high after a surgical stress like colon resection, the kidneys hold water, lowering serum sodium and osmolality. This brain-friendly swelling manifests early as fatigue, lethargy, and nausea, and can progress to confusion or seizures if hyponatremia worsens. The combination of fatigue, lethargy, and nausea is a classic presentation of mild-to-moderate hyponatremia from SIADH, making it the best match. Weight gain can occur due to fluid retention but is not the defining, primary symptom set. Polyuria would point toward diabetes insipidus (loss of ADH effect), not SIADH. Hypertension is not a hallmark feature of SIADH-induced hyponatremia.

SIADH causes water retention with dilutional hyponatremia. When ADH is inappropriately high after a surgical stress like colon resection, the kidneys hold water, lowering serum sodium and osmolality. This brain-friendly swelling manifests early as fatigue, lethargy, and nausea, and can progress to confusion or seizures if hyponatremia worsens. The combination of fatigue, lethargy, and nausea is a classic presentation of mild-to-moderate hyponatremia from SIADH, making it the best match.

Weight gain can occur due to fluid retention but is not the defining, primary symptom set. Polyuria would point toward diabetes insipidus (loss of ADH effect), not SIADH. Hypertension is not a hallmark feature of SIADH-induced hyponatremia.