In a person on hunger strike from past three days which of the following urinary tests would give a positive… - HP CHO -9 October 2022

HP CHO -9 October 2022

Biochemistry & Nutrition

Hard

Appeared in: HP CHO -9 October 2022

Explanation

After 2-3 days of starvation, the body's glycogen stores are depleted, forcing it to metabolize fat for energy.
The breakdown of fatty acids produces acidic byproducts known as ketone bodies (acetone and acetoacetic acid).
These ketone bodies accumulate in the blood and are subsequently excreted in the urine, a condition called ketonuria.
Rothera's test is a specific chemical test that detects the presence of ketone bodies in urine, yielding a positive result (a purple ring) in this state.

Option A: Benedict's test detects reducing sugars like glucose. In starvation, blood glucose is conserved and levels are low, so there is no glucose in the urine (glucosuria).
Option B: Barfoed's test is a specific biochemical lab test used to distinguish monosaccharides from disaccharides. It has no clinical application in assessing a patient's metabolic state during starvation.
Option D: The Biuret test detects proteins. While prolonged and severe starvation eventually leads to muscle breakdown, significant protein in the urine (proteinuria) is not an early finding and typically suggests underlying kidney disease.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Biochemical changes and urinary findings during starvation as background academic context rather than a clinical decision trigger.
Nurses frequently use urine dipsticks, which include a reagent pad for ketones, for rapid bedside assessment of metabolic status in patients with diabetes, prolonged vomiting, or poor nutritional intake.
Recognizing ketonuria is vital for differentiating between physiological starvation ketosis and diabetic ketoacidosis (DKA), a life-threatening emergency characterized by hyperglycemia, ketosis, and metabolic acidosis.
What if? If the patient on the hunger strike also had a history of Type 1 Diabetes, a positive ketone test would be a critical finding. It would necessitate an immediate blood glucose check to rule out DKA, as the stress of starvation can trigger this dangerous condition even with low food intake.

How to Approach the Question

First, identify the key clinical scenario: a person on a hunger strike for three days. This signifies a state of starvation.
Next, recall the body's metabolic response to starvation. After initial glycogen stores are depleted (within about 24-48 hours), the body begins to metabolize fat for energy.
Understand the byproduct of fat metabolism. The breakdown of fatty acids produces ketone bodies.
Connect the byproduct to its excretion route. Excess ketone bodies are eliminated from the body via the urine (ketonuria).
Finally, evaluate the given options to find the test that specifically detects this byproduct. Rothera's test is for ketones, Benedict's is for sugar, and Biuret is for protein. Therefore, Rothera's test will be positive.

Concept Tested & Keywords

Concept Tested: Biochemical changes and urinary findings during starvation
Stem keywords: hunger strike, three days, urinary tests, positive reaction
Lead-in keywords: which of the following
Clinical cues: The 3-day duration is a key cue, indicating that the body has moved beyond using its initial glycogen stores and is now in a state of ketosis.
Negative lead-in flag: false

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E6 Biochemistry U Satyanarayana— Part 2 (pp 421-820 of 840) p. 367-369

E6 Pathology-Vandana Puri & Kavita Gaur Textbook of Pathology and Genetics p. 449-451