Question

a) hyponatraemia occurs when serum sodium levels drop too much. Why do you think drinking

deionized water would result in low blood sodium levels?

b) What could have the individual added to her water to prevent this from happening, and why

would this have prevented hyponatraemia? Incorporate your knowledge of concentration

gradients and diffusion.

c) Over-hydration can be treated if caught in its early stages. What do you think would be the

quickest way to restore the patient's serum sodium levels?

Answer 1

In deionised water the ions are removed . Both the anions and cations are removed. Sodium ions , calcium, magnesium, iron etc are the cations removed. Since the sodium ion is removed drinking deionised water will not supply the ion and at the same time blood will remain over hydrated and will lead to hyponatremia.

Drinking too much water can lead to over hydration and hyponatremia and if it is deionised water then the situation will be worsened. When you drink too much deionised water , water will diffuse in to brain and will cause swelling of brain and edema in brain. This is is because the blood is hypotonic now compared to brain so water enters in to the brain. Thus hyponatremia conditions can be prevented by drinking electrolyte included water.

As mentioned above over hydration will lead to hyponatremia and can further lead to brain swelling, seizure, coma and death. Over hydration mainly happens due extreme excecise, sports persons. This happens because the sodium salt will be lost in sweat and at the same time individual drinks plenty of water. This will make the blood over diluted or hydrated.

According to the severity of condition the treatment strategy is decided. The main treatment is to supplement sodium ions

• Sevre condition. 100 mL of 3% NaCl iv for three times over 10 minutes

• In moderate cases, 3% NaCl infusion.