Pathophysiology Clinical Scenario Question

Question

1. A 16-year-old girl is seen by her primary care doctor because her parents are concerned about her binge eating and their recent discovery that she engages in self-induced vomiting. Initial laboratory tests reveal a serum K+ of 3.0mEq/L and Cl- of 93.  
2. Explain the mechanism behind her low K+ and Cl- .  
3. What type of acid-base abnormality would you expect her to have?

Does anyone know the answer to this? Thanks in advance. :)

Answer 1

The description of her symptoms leads to a diagnosis of bulimia. In bulimia, patients tend to binge on large amounts of food, and purge to get rid of it. The purging can be from self induced vomiting and/or laxative use. The frequent purging can result in dehydration, which can lead to altered electrolyte levels (including low K+ and Cl-). While each patient is different and without more information a definitive acid base imbalance cannot be diagnosed, the one you might most expect to see would be metabolic alkalosis. This is primarily due to a fluid contraction throughout the body due to purging.