During examination of a 6-month-old infant with suspected hydrocephalus, the physician percusses the skull and notes a distinct sound. Which of the following findings is most closely associated with Macewen's sign?

1. A

   Crack pot sound on percussion of skull

2. B

   Clubbing of fingers

3. C

   Pleural effusion

4. D

   Ascites

Appeared in: JIPMER Nursing Officer-2024

Explanation

• Macewen's sign is the term for the 'cracked pot' sound heard upon percussion of an infant's skull.
• This sound is generated because increased intracranial pressure (ICP), commonly from hydrocephalus, has caused the cranial sutures to separate.
• The separated bones and underlying fluid create a resonant, hollow sound when tapped.
• It is a classic and specific sign of increased ICP in infants whose skull bones have not yet fused.

Why Other Options Were Wrong

• Option B: Clubbing of fingers is a sign of chronic hypoxia, not increased intracranial pressure. It involves changes to the nail beds due to long-term low oxygen levels.
• Option C: Pleural effusion is the accumulation of fluid around the lungs in the pleural space. It is a thoracic finding, unrelated to the head or neurological system.
• Option D: Ascites is the accumulation of fluid within the abdominal cavity. It is a sign of systemic conditions like liver failure or heart failure, not a neurological issue like hydrocephalus.

Related Visual

• Visual 1: Diagram: An illustration showing the technique of percussing an infant's skull at the junction of the parietal, frontal, and temporal bones to elicit Macewen's sign.
• Visual 2: Illustration: A comparison of a normal infant's head and an infant with hydrocephalus, highlighting features like a bulging fontanel, prominent scalp veins, and the 'setting-sun' eye sign.

Clinical Relevance

• Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Identification of Macewen's sign as a clinical finding in infantile hydrocephalus as background academic context rather than a clinical decision trigger.
• Recognizing Macewen's sign is a critical nursing assessment skill in pediatrics, as it can be an early indicator of dangerously high intracranial pressure requiring urgent medical intervention.
• A nurse's role includes serial measurement of head circumference, palpating fontanels, and observing for behavioral changes (irritability, lethargy), which are all part of monitoring for developing hydrocephalus or shunt malfunction.
• What if? If an infant post-ventriculoperitoneal (VP) shunt placement suddenly develops a positive Macewen's sign, irritability, and vomiting, the nurse should suspect acute shunt malfunction. The priority action is to notify the neurosurgeon immediately and prepare for emergency diagnostic imaging and possible surgical revision, as this is a life-threatening emergency.

How to Approach the Question

• First, identify the core concept in the question stem: 'Macewen's sign' in the context of 'hydrocephalus' and 'percussion of the skull'.
• This is a direct recall question. Access your knowledge of pediatric physical assessment findings.
• Recall the definition of Macewen's sign. It is specifically known as the 'cracked pot' sound.
• Evaluate the options. Option A directly provides the classic description of the sign.
• Eliminate the other options by recognizing they describe signs related to other body systems (respiratory, cardiac, gastrointestinal/hepatic) and are not associated with hydrocephalus or skull percussion.

Concept Tested & Keywords

• Concept Tested: Identification of Macewen's sign as a clinical finding in infantile hydrocephalus.
• Stem keywords: 6-month-old infant, hydrocephalus, percusses the skull, Macewen's sign
• Lead-in keywords: most closely associated with
• Clinical cues: The patient's age (6 months) is significant because the cranial sutures are not yet fused, allowing for the development of Macewen's sign.

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QnQPZqBoiGbjFfHjsEA16A

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