A young mother, strapped for cash, has been diluting her baby’s formula with water...

A young mother, strapped for cash, has been diluting her baby’s formula with water to make it last longer.  Suddenly, after feeding the baby the diluted formula for a few weeks, the baby stops breathing and begins to have a seizure.  At the hospital she is told by the doctor that the baby has water intoxication brought on by diluting the formula with too much water.  She is also told that it is much easier for young infants to develop this condition, and that she should stop diluting the baby’s formula.

1.  How does water intoxication affect blood osmolarity?  Which electrolyte is most affected & why?

2.  Explain how the water intoxication leads to a seizure and cessation of breathing?

3.  If someone is over-hydrated, how can the body respond to correct the fluid/electrolyte imbalance?  Include which hormones would be secreted/or inhibited to correct the imbalance, and describe exactly how this fixes the imbalance.   

4.  This mom wants to know how diluting the formula can cause this and why babies are more susceptible. What do you tell her?