The skin usually begins to appear jaundiced when plasma concentration of bilirubin rises __________ than normal.

Appeared in: NIA - 29 January 2023

Explanation

Clinical jaundice becomes visible when serum bilirubin levels exceed the normal range by approximately three times.
Normal total serum bilirubin is typically below 1.0 mg/dL.
Visible yellowing of the sclera (scleral icterus), the first sign of jaundice, appears when bilirubin levels reach at least 2.0 to 3.0 mg/dL.
This level (e.g., 3.0 mg/dL) is three times the upper limit of the normal range (1.0 mg/dL).

Option A: A twofold increase (approximately 2.0 mg/dL) is the lower limit for visible jaundice and may not be apparent in all individuals. This is often referred to as subclinical or latent jaundice.
Option C: A fourfold increase (around 4.0 mg/dL) indicates moderate jaundice, which is clearly visible but is not the point at which it begins to appear.
Option D: A fivefold increase (around 5.0 mg/dL) represents significant hyperbilirubinemia where jaundice is pronounced, not just beginning.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Threshold for clinical jaundice based on serum bilirubin levels as background academic context rather than a clinical decision trigger.
Nurses must assess for jaundice by inspecting the sclera and skin in natural light, as fluorescent lighting can mask early signs.
Early detection of jaundice is crucial as it is a key sign of underlying conditions like liver disease, hemolysis, or biliary obstruction, requiring further investigation.
What if? If the patient has dark skin, the nurse should focus assessment on the sclera, hard palate, and under the tongue, as yellowing of the skin is less reliable and may be missed.

How to Approach the Question

First, identify the core of the question: it asks for the multiple of the normal bilirubin level at which jaundice becomes visible.
Recall the normal range for total serum bilirubin in adults, which is generally less than 1.0-1.2 mg/dL.
Recall the threshold for clinically visible jaundice. This typically occurs when levels reach 2.0 to 3.0 mg/dL.
Calculate the ratio by dividing the jaundice threshold by the normal level (e.g., 3.0 mg/dL ÷ 1.0 mg/dL = 3).
Compare this calculated multiple to the given options.
Select the option that best matches the calculated ratio, which is '3 times'.

Concept Tested & Keywords

Concept Tested: Threshold for clinical jaundice based on serum bilirubin levels.
Stem keywords: jaundice, plasma concentration, bilirubin
Lead-in keywords: rises
Negative lead-in flag: false

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E6 Medicine Harrison 22e Part 1 p. 361-363

Practise the full NIA - 29 January 2023

Attempt every question from this paper in a timed mock, then review the full solution for each one.