A nurse is caring for a client with bulimia nervosa who has been admitted to the medical unit for electrolyte imbalances. Which assessment finding would be the priority concern requiring immediate intervention?

Priority Assessment and the ABC Framework

In clients with bulimia nervosa, the purging behaviors (self-induced vomiting, laxative, or diuretic misuse) create a high-risk state for fluid and electrolyte disturbances. When applying the nursing process, the ABC (Airway, Breathing, Circulation) priority-setting framework dictates that physiological threats to circulation and cardiac function take precedence over structural changes or chronic weight trends. Among the options, a serum potassium level of 3.0 mEq/L (hypokalemia) accompanied by cardiac dysrhythmias represents an immediate threat to the client's circulatory status and life. This finding signals a disruption in myocardial cell membrane potential, which can rapidly deteriorate into lethal arrhythmias or cardiac arrest ^[1].

Pathophysiology of Hypokalemia in Purging Behaviors

The link between purging and hypokalemia is direct and dangerous. In the purging subtype of eating disorders, frequent vomiting leads to the loss of hydrochloric acid from the stomach. This volume depletion triggers a metabolic alkalosis and secondary hyperaldosteronism. In the kidneys, aldosterone promotes sodium reabsorption in exchange for potassium and hydrogen ion secretion, leading to excessive renal potassium wasting. Similarly, the misuse of laxatives and diuretics directly causes large intestinal and renal potassium losses, respectively ^[1]. The resulting hypokalemia destabilizes the resting membrane potential of cardiac cells, making them hyperexcitable and prone to generating ectopic impulses. This manifests on the cardiac monitor as dysrhythmias such as premature ventricular contractions (PVCs), ventricular tachycardia, or Torsades de Pointes, which can be fatal without immediate potassium replacement and cardiac monitoring.

Differentiating Priority from Expected Findings

The other options, while clinically significant, do not represent an immediate, life-threatening crisis requiring the nurse's first intervention.

• Option 1 (Dental erosion and enlarged parotid glands): These are chronic, structural complications of repeated vomiting due to gastric acid exposure and parotid hypertrophy. They are important for the client's overall health and body image but are not acutely life-threatening.


• Option 3 (Body weight 15% below ideal body weight): This finding is more characteristic of anorexia nervosa than bulimia nervosa, where weight is often normal or slightly above average. Even if present, weight restoration is a long-term goal, whereas a cardiac dysrhythmia demands immediate intervention ^[1].


• Option 4 (Reports of using laxatives and diuretics daily): This is a critical piece of the client's history that explains the etiology of the electrolyte imbalance. However, the report of the behavior itself is not the priority; the physiological consequence of that behavior—the hypokalemic dysrhythmia—is the immediate concern. The nurse must first stabilize the cardiac complication, then later address the purging behaviors through therapeutic communication and psychoeducation.

The case report underscores that in severe eating disorders with purging, the intricate relationship between the psychiatric drivers and physical health complications means that medical stabilization, particularly of cardiac and electrolyte status, must always be the first step in management before any psychiatric intervention can safely occur ^[1].