WHO ORS has –
WHO ORS is a standard solution used to prevent and treat dehydration caused by diarrhea. The standard composition includes sodium chloride, sodium bicarbonate, potassium chloride, and glucose. The key here is to recall the exact concentrations. The WHO recommends specific amounts per liter. Let me recall: sodium is 75 mmol/L, potassium is 20 mmol/L, chloride is 65 mmol/L, and glucose is 75 mmol/L. The osmolarity is around 245 mOsm/L.
Wait, sometimes there's confusion between different formulations. The newer ORS (from 2002) has lower osmolarity, which is 245 mOsm/L compared to the older 311 mOsm/L. The components are adjusted to reduce the sodium and glucose content. So if the question is about the osmolarity or the specific concentrations of each component, the correct answer would be based on the 2002 WHO guidelines.
Now, considering the options are missing, but the correct answer is supposed to be filled in. Let's assume that the correct answer is option C, for example. But since the user didn't specify, I need to make sure the explanation covers the standard components and concentrations.
The core concept is the composition of WHO ORS. The correct answer would detail the exact amounts of each solute. The incorrect options might have wrong concentrations, like higher sodium or different osmolarity. For example, an option might have sodium at 90 mmol/L instead of 75, making it incorrect. Another might use sodium citrate instead of bicarbonate.
Clinical pearls include the fact that the 2002 WHO ORS has lower osmolarity to reduce stool output and improve absorption. Students should remember the key components and their concentrations to avoid mixing up with other solutions like Ringer's lactate or other ORS formulations.
Putting this all together, the explanation should highlight the exact composition, why other options are wrong (like higher concentrations or different components), and the importance of the 2002 update. The correct answer would be the option that lists the correct concentrations as per the latest WHO guidelines.
**Core Concept**
WHO Oral Rehydration Solution (ORS) is a standardized solution for managing dehydration, containing precise concentrations of electrolytes (Na⁺, K⁺, Cl⁻) and glucose to optimize fluid absorption via the sodium-glucose cotransport mechanism in the small intestine. The 2002 WHO updated formulation has **lower osmolarity (245 mOsm/L)** compared to the older version (311 mOsm/L).
**Why the Correct Answer is Right**
The 2002 WHO ORS contains **75 mmol/L NaCl, 20 mmol/L KCl, 10 mmol/L NaHCO₃, and 75 mmol/L glucose**. This formulation reduces osmolarity