What is the ponderal index of a child with weight 2000 g and height 50 cm
First, I need to recall what the ponderal index is. From what I remember, the ponderal index is similar to BMI but adjusted for height cubed. The formula is weight divided by height cubed. But wait, units matter here. The standard formula uses kg for weight and meters for height. The given weight is in grams, so I need to convert that to kilograms. 2000 grams is 2 kg. The height is 50 cm, which is 0.5 meters.
So the formula would be weight (kg) / (height in meters)^3. Plugging in the numbers: 2 / (0.5)^3. Let's calculate that. 0.5 cubed is 0.125. Then 2 divided by 0.125 is 16. So the ponderal index is 16. Wait, but what's the normal range? I think for term infants, the ponderal index around 3.5 to 4.5 kg/m³ is normal. But this is a child with a ponderal index of 16? That seems way too high. Hmm, maybe I made a mistake in the calculation.
Wait, maybe the formula is different. Let me check again. Oh, right, the ponderal index is calculated as weight (kg) / (height in meters)^3. So 2 kg divided by (0.5)^3. 0.5^3 is 0.125. 2 / 0.125 = 16. That's correct. But 16 is extremely high. Maybe the question is about a preterm infant? Because preterm babies can have different indices. But the question states a child, so maybe it's a very small child. Alternatively, perhaps I confused the formula with BMI. BMI is kg/m², but ponderal index is kg/m³. So in this case, the calculation is right. The answer is 16.
Now, the options are not given, but the correct answer is the one that results from this calculation. The user needs the explanation. The core concept is the formula for ponderal index. The correct answer is based on converting units and applying the formula correctly. The wrong options might involve using BMI formula, incorrect unit conversions, or miscalculations. The clinical pearl is to remember the formula and unit conversions. So the correct answer is 16.
**Core Concept**
The **ponderal index** measures body weight relative to height cubed, calculated as *weight (kg) / height (m)³*. It is used to assess body proportionality in infants and children.
**Why the Correct Answer is Right**
For a child weighing **2 kg** (2000 g) and measuring **0.5 m** (50 cm), the calculation is:
2 kg / (0.5 m)³ = 2 / 0.125 = **16 kg/m³**.
This formula adjusts for height cubed, making it more suitable for pediatric populations than BMI (which uses height squared