Assignment task: Below is a patient scenario with a question following. The answer to the question is #2 in bold. Could you explain why that's the correct response/choice?
J.M. is an 83-year-old great-grandmother of five who is admitted to your clinical unit with a diagnosis of hyponatremia and fluid volume deficit. J.M. lives alone since her husband died 3 years ago. Her daughter lives nearby but is very busy working and taking care of her own grandchildren. The daughter found her mother lying on the living room couch very confused and disoriented. There were several empty bottles of water lying on the coffee table. J.M. is unable to state how long she has not been feeling well, but her daughter states that her mother has been complaining of nausea, vomiting, and diarrhea for 1 week.
Question: Based on the sketchy history available for J.M., which assumption best identifies the pathophysiologic basis of her fluid and electrolyte imbalance?
1. J.M. probably suffered a stroke and was unable to regulate her fluid intake appropriately as a result of disorientation and confusion
2. J.M. lost sodium-rich fluid with vomiting and diarrhea. The water that J.M. drank further diluted the sodium concentration
3. J.M. lost isotonic fluid with vomiting and diarrhea, but caused a dilutional hyponatremia by drinking too much water afterwards
4. J.M.'s nausea, vomiting, and diarrhea activated the renin-angiotensin-aldosterone system, cousin the release of aldosterone that further exacerbated J.M.'s fluid deficit