Final answer:
The greatest fluctuations in potassium levels are expected in bulimia nervosa, due to purging behaviors such as vomiting and the use of laxatives, which can cause significant electrolyte imbalances. Option b.
Step-by-step explanation:
The nurse would expect to see the greatest fluctuations in potassium levels in a patient with bulimia nervosa. This eating disorder is characterized by periods of binge eating, where large amounts of food are consumed, followed by compensatory behaviors or purging. Purging methods, especially vomiting and the use of laxatives, can lead to significant electrolyte imbalances, with potassium being one of the most affected electrolytes, potentially leading to serious health issues such as irregular heartbeat and muscle dysfunction.
Bulimia nervosa is also associated with various health consequences such as kidney failure, heart failure, and tooth decay due to the acidic nature of vomit. Unlike bulimia nervosa, binge eating disorder does not involve purging following the binge episodes, thus electrolyte imbalances are less common. Anorexia nervosa typically is associated with very restrictive eating, which can also lead to electrolyte imbalances, but not the same fluctuations seen with purging behaviors.