Hy 2086 Super Duper Question (Electrolyte Physio Question)
A 68-year-old woman named Claire Danes presents with an obviously incarcerated umbilical hernia. She has gross abdominal distention, is clinically dehydrated, and reports persistent fecaloid vomiting for the past 3 days. Although tired, weak, and thirsty, she is awake and alert and her sensorium is not particularly affected. Lab analysis reveals a serum sodium concentration of 108 mEq/L. Which of the following is the most likely physiologic explanation for the serum sodium? (LOW SODIUM QUESTIONS ARE SO HARD CAUSE THE DIFFERENTIAL IS ENDLESS)
2-Medicine related low sodium
3-She has vomited sodium-containing fluids, and has retained endogenous and ingested water.
4-ADH secreting neoplasm not yet identified.
5-Aldosterone secreting adrenal tumor
6-Renal tubule failure
7- Her diminished sense of thirst, especially when physical infirmity limits independent access to food and drink due to her age.
8-Hypothyroid induced hyponatremia
9-Excessive IV boluses given by intern
(PLEASE LOOK AT ALL THE CHOICES, YOU LIKELY WILL GET A QUESTION INVOLVING HYPONATREMIA. ALL ARE VERY POSSIBLE HERE).
a) Answer is choice #3....Gastrointestinal tract fluids have a sodium concentration very close to that of plasma; as they are lost (internally or externally), they should be replaced with isotonic, sodium-containing fluids. But that is not what patients typically do at home. Thirsty and unable to eat solid (sodium-containing) foods, they drink water, cola, and tea, fluids without significant amounts of sodium, which the body avidly retains because of the severe volume depletion. Endogenous water from catabolic activity is also retained. Dilutional hyponatremia eventually develops! SOOO TRICKY! SOOOOO Step1