Which one of the following types of undernutrition is indicated by Z-score below -3 SD of the median WHO chil… - ESIC Nursing Officer-7July 2024

ESIC Nursing Officer-7July 2024

Applied Nutrition & Dietetics

Easy

Appeared in: ESIC Nursing Officer-7July 2024

Explanation

Severe Acute Malnutrition (SAM) is formally diagnosed when a child's weight-for-height Z-score is below -3 standard deviations (SD) from the WHO growth standard median.
This criterion signifies severe wasting, which is a hallmark of SAM and indicates a recent and severe process of weight loss or failure to gain weight.
SAM is the most critical and life-threatening form of undernutrition, requiring immediate therapeutic feeding and medical care to prevent mortality.
In addition to the Z-score, a mid-upper arm circumference (MUAC) of less than 11.5 cm or the presence of bilateral pitting edema are also independent criteria for diagnosing SAM.

Option A: Underweight is a composite measure based on weight-for-age. It does not distinguish between acute malnutrition (wasting) and chronic malnutrition (stunting), making it a less specific indicator for this severe condition.
Option B: Stunting refers to impaired linear growth (low height-for-age) and is an indicator of chronic or long-term undernutrition. A Z-score below -3 SD in this category indicates severe stunting, not acute malnutrition.
Option C: While a weight-for-height Z-score below -3 SD is technically 'severe wasting,' Severe Acute Malnutrition (SAM) is the broader, official diagnostic category that encompasses severe wasting. SAM is the more complete and clinically used term.

Visual 1: Chart - A chart illustrating the WHO Z-score classifications for stunting, wasting, and underweight. It should clearly mark the thresholds for normal, moderate (below -2 SD), and severe (below -3 SD) malnutrition.
Visual 2: Diagram - An infographic showing the three independent criteria for diagnosing Severe Acute Malnutrition (SAM): WHZ less than -3 SD, MUAC less than 11.5 cm, and the presence of bilateral pitting edema.
Visual 3: Photo - A clinical photograph demonstrating how to check for bilateral pitting edema by pressing a thumb on the top of a child's foot for a few seconds to see if an indentation remains.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Classification of childhood undernutrition using WHO Z-scores as background academic context rather than a clinical decision trigger.
Nurses play a crucial role in community and hospital settings in screening children for malnutrition using anthropometric measurements (weight, height, MUAC) and checking for clinical signs like edema.
Early and accurate identification of SAM is a critical nursing responsibility because these children have a significantly higher risk of death (up to 9 times higher) from common infections like pneumonia and diarrhea.
A child with SAM requires urgent referral for specialized care, which includes therapeutic feeding with products like Ready-to-Use Therapeutic Food (RUTF), and management of medical complications such as hypoglycemia, hypothermia, and infections.

How to Approach the Question

First, identify the key data point in the question: 'Z-score below -3 SD'. This is a specific, quantitative measure.
Next, recall the main classifications of undernutrition: underweight (weight-for-age), stunting (height-for-age), and wasting (weight-for-height).
Differentiate between acute (wasting) and chronic (stunting) malnutrition. A very low Z-score often points towards a severe, acute condition that poses an immediate threat to life.
Remember that 'Severe Acute Malnutrition' (SAM) is a specific clinical diagnosis defined by the WHO using three distinct criteria.
Evaluate the options. A Z-score below -3 SD for weight-for-height is the definition of severe wasting, which is a primary criterion for diagnosing SAM. Therefore, SAM is the most accurate and comprehensive answer.

Concept Tested & Keywords

Concept Tested: Classification of childhood undernutrition using WHO Z-scores.
Stem keywords: undernutrition, Z-score, below -3 SD, WHO child growth standards
Lead-in keywords: Which one
Clinical cues: Age/sex group narrows the expected diagnosis, intervention, or normal reference range.

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