Excessive secretion of vasopressin is responsible for which of the following disorder?

Appeared in: RAK Nursing Officer - 2019

Explanation

Syndrome of Inappropriate Antidiuretic Hormone (SIADH) is characterized by excessive secretion of vasopressin (also known as ADH).
This excess ADH causes the kidneys to retain too much free water.
The retained water leads to dilutional hyponatremia (low serum sodium) and concentrated urine.
Key clinical findings include low urine output, high urine specific gravity, and low serum sodium despite a normal or increased fluid volume.

Option A: Diabetes Insipidus is caused by a deficiency of vasopressin (ADH) or the kidneys' inability to respond to it, leading to excessive water loss.
Option C: Cushing's syndrome results from excessive levels of the hormone cortisol, not vasopressin. It is related to the adrenal cortex or pituitary gland overproducing ACTH.
Option D: Addisonian crisis is an acute, life-threatening condition caused by adrenal insufficiency, meaning a severe lack of cortisol and aldosterone.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Endocrine Disorders: Vasopressin (ADH) Imbalance as background academic context rather than a clinical decision trigger.
Nurses must closely monitor fluid status, serum sodium levels, and neurological status in patients with SIADH, as severe hyponatremia can lead to cerebral edema, seizures, and coma.
Key nursing interventions for SIADH include fluid restriction, daily weights, and implementing seizure precautions.
What if? If a patient presented with high urine output, intense thirst, and a high serum sodium level, the nurse would suspect Diabetes Insipidus (ADH deficiency) instead of SIADH, and anticipate orders for vasopressin replacement therapy and hydration.

How to Approach the Question

First, identify the key terms in the question: "excessive secretion" and "vasopressin".
Recall that vasopressin is also known as Antidiuretic Hormone (ADH), which helps the body retain water.
Consider the effect of "excessive" ADH. An 'antidiuretic' stops urination, so too much of it would cause the body to hold onto too much water.
Evaluate the options based on this understanding. SIADH is the 'Syndrome of Inappropriate Antidiuretic Hormone', which directly relates to excess ADH.
Differentiate this from Diabetes Insipidus, which is the opposite condition (ADH deficiency). Rule out Cushing's and Addison's as they relate to adrenal hormones (cortisol/aldosterone), not vasopressin.

Concept Tested & Keywords

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E6 Pathology- ROBBINS & COTRAN PATHOLOGIC BASIS OF DISEASE 10TH Ed pp. 1073-1075, 1072-1074

E6 Nelson Textbook of Pediatrics(2024) — Volume 2 p. 1179-1181

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Attempt every question from this paper in a timed mock, then review the full solution for each one.