Anorexia Nervosa & Bulimia Nervosa
The client with anorexia may look medically stable — until a potassium level crashes and a fatal dysrhythmia strikes. Knowing which eating disorder causes which metabolic disaster changes your nursing priorities.
Core Concept
Anorexia nervosa involves severe caloric restriction with intense fear of weight gain and distorted body image, often presenting with BMI below 17.5, lanugo, amenorrhea, bradycardia, and hypothermia. Bulimia nervosa involves recurrent binge-purge cycles; the client is typically at or near normal weight, making it harder to detect. Purging (vomiting, laxative abuse) causes hypokalemia, metabolic alkalosis, dental enamel erosion, parotid gland swelling, and Russell sign (calluses on knuckles). Both disorders carry cardiac risk — hypokalemia below 3.5 mEq/L predisposes to lethal dysrhythmias. Refeeding syndrome is the most dangerous complication when nutrition is restored too rapidly in anorexia: as cells take up glucose, phosphate shifts intracellularly, causing hypophosphatemia, heart failure, and seizures. Refeeding begins slowly with continuous cardiac monitoring. Nursing priorities include daily weights taken in a hospital gown after voiding (same time, same scale), observing the client for 1–2 hours after meals to prevent purging, monitoring electrolytes (especially potassium, phosphate, magnesium), and establishing a structured, nonjudgmental mealtime environment. Therapeutic communication avoids power struggles over food — the focus is on feelings, not calories.
Watch Out For
Don't confuse anorexia (restriction, underweight, bradycardia) with bulimia (binge-purge, near-normal weight, metabolic alkalosis from vomiting). Students mistake refeeding syndrome for simple overfeeding — it's a phosphate-driven crisis, not a caloric one. Russell sign and parotid swelling point to bulimia, not anorexia — these are purging markers.
Clinical Pearl
Refeeding kills through phosphate, not food. When you restart nutrition in a starved client, monitor phosphorus levels before you worry about the meal plan.
Test Your Knowledge
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