Which of the following is a sign of severe dehydration in an infant?

Appeared in: AIIMS Delhi NO-2016

Explanation

Sunken fontanels are a classic and significant sign of fluid volume deficit in infants whose cranial sutures have not yet closed.
Severe dehydration causes a substantial loss of extracellular fluid, which includes the fluid within the intracranial space.
This reduction in intracranial volume and pressure causes the soft, membranous fontanel to physically depress or sink inwards.
Among the given options, markedly sunken fontanels are one of the most specific indicators for severe dehydration.

Option B: In severe dehydration, the body shunts blood from the periphery to vital organs, leading to poor circulation and cool, clammy, or mottled skin.
Option C: A moist tongue and mucous membranes are signs of adequate hydration.
Option D: While decreased tears are a sign of dehydration, they are more characteristic of mild to moderate dehydration. In severe dehydration, tears are typically absent altogether.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Clinical assessment of dehydration in infants as background academic context rather than a clinical decision trigger.
Accurate and rapid assessment of dehydration in infants is a critical nursing skill, as their condition can deteriorate quickly. Recognizing severe signs like sunken fontanels prompts immediate intervention, often involving intravenous fluid resuscitation.
Nurses must educate caregivers on early signs of dehydration (e.g., fewer wet diapers, thirst, irritability) to prevent progression to a severe state.
Daily weight is the single most accurate objective measure to monitor fluid status in infants. A weight loss of over 10% is indicative of severe dehydration.

How to Approach the Question

First, identify the key terms in the question: 'severe dehydration' and 'infant'. This sets the context for a serious condition in a vulnerable population.
Evaluate each option based on the pathophysiology of dehydration. Think about what happens to the body when it loses a significant amount of fluid.
Consider the options in terms of severity. Some signs appear early (mild dehydration), while others only manifest in severe states.
For 'Warm skin', recall that shock from fluid loss causes peripheral shutdown, leading to cool skin.
For 'Moist tongue', recognize this is the opposite of a dehydration sign.
Differentiate between 'decreased tears' (moderate) and 'absent tears' (severe).

Concept Tested & Keywords

Concept Tested: Clinical assessment of dehydration in infants
Stem keywords: sign, severe dehydration, infant
Lead-in keywords: Which
Clinical cues: The patient is an infant, which makes signs like fontanel assessment particularly relevant.

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E6 Ghai Essential Pediatrics(pp 26-904 of 913) p. 311-313

E6 Nelson Textbook of Pediatrics(2024) — Volume 2 p. 152-154

E6 Nelson Textbook of Pediatrics(2024) — Volume 1 p. 574-576

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