NORCET 9 Mains - 2025: In Kawasaki disease, coronary artery aneurysm is diagnosed when the median internal diameter is greater than:

NORCET 9 Mains - 2025

Child Health Nursing (Pediatrics)

Easy

Appeared in: NORCET 9 Mains - 2025

Explanation

The standard diagnostic criterion for a coronary artery aneurysm in children under 5 years old with Kawasaki disease is an internal lumen diameter greater than 3 mm.
Kawasaki disease predominantly affects children under 5, making the 3 mm threshold the most relevant and commonly tested value.
Alternative diagnostic criteria include an internal diameter greater than 4 mm for children 5 years or older, a coronary segment 1.5 times the size of an adjacent normal segment, or a Z-score of ≥2.5.

Option A: This value is too low and is not a recognized threshold for diagnosing a coronary artery aneurysm in Kawasaki disease.
Option C: This is the diagnostic threshold for children aged 5 years and older. Since Kawasaki disease is most common in younger children, 3 mm is the more standard answer.
Option D: This value is used in the classification of aneurysm size, typically marking the transition from a small to a medium aneurysm, rather than the initial diagnostic threshold.

Clinical Relevance

Nursing practice connection: Knowing Diagnostic criteria for coronary artery aneurysm in Kawasaki disease helps nurses interpret findings accurately and avoid errors in routine assessment, medication administration, and patient teaching.
Nurses are critical in the early identification of Kawasaki disease symptoms and ensuring prompt administration of Intravenous Immunoglobulin (IVIG). Treatment within the first 10 days of fever reduces the risk of coronary artery aneurysms from about 25% to less than 5%.
Patient and family education is a key nursing responsibility. This includes explaining the disease, the importance of treatment, and the schedule for follow-up echocardiograms (typically at diagnosis, 1-2 weeks, and 4-6 weeks after illness onset) to monitor heart health.
What if? If a child is diagnosed after the 10-day window (e.g., on day 13 of fever), IVIG is often still given, especially if there are signs of ongoing inflammation (like elevated CRP). The goal is to mitigate any further vascular damage, although the risk of aneurysm is higher.

How to Approach the Question

First, identify the key components of the question: 'Kawasaki disease,' 'coronary artery aneurysm,' and 'internal diameter.' This points to a question of diagnostic criteria.
Recall that Kawasaki disease is a pediatric condition, primarily affecting children under 5 years old.
Recognize that diagnostic criteria in pediatrics are often age-dependent. The question does not specify an age, so you should consider the most common patient population.
Evaluate the options based on standard pediatric guidelines. The >3 mm threshold is the specific criterion for children under 5, the most affected group.
Differentiate between the value used for initial diagnosis (>3 mm) and values used for classifying the severity of an already diagnosed aneurysm (e.g., >4 mm for medium, >8 mm for giant).

Concept Tested & Keywords

Concept Tested: Diagnostic criteria for coronary artery aneurysm in Kawasaki disease
Stem keywords: Kawasaki disease, coronary artery aneurysm, internal diameter
Lead-in keywords: greater than

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E6 Nelson Textbook of Pediatrics(2024) — Volume 1 pp. 1546-1548, 1545-1547