Major Eating Disorders
Anorexia Nervosa
- Anorexia Nervosa: Characterized by significantly low body weight, intense fear of gaining weight, and distorted body image. Patients restrict energy intake relative to requirements, leading to significantly low body weight in the context of age, sex, developmental trajectory, and physical health.
- Two subtypes exist: Restricting type (primarily restricting food intake) and Binge-eating/purging type (restricting with episodes of binge eating and/or purging behaviors).
Clinical Scenario
A 16-year-old female presents with BMI of 16.2, amenorrhea for 4 months, lanugo on arms and back, bradycardia (HR 45), and hypotension. She reports feeling "fat" despite her emaciated appearance and admits to restricting to 500 calories daily while exercising 2 hours each day. These findings are consistent with Anorexia Nervosa, restricting type, with medical complications requiring immediate intervention.
Key Points
- Medical complications include electrolyte imbalances, cardiac abnormalities (bradycardia, prolonged QT interval), osteopenia/osteoporosis, and endocrine disturbances.
- Nursing assessment should include vital signs, weight (measured with patient wearing only a gown, after voiding), electrolyte levels, and cardiac monitoring.
Bulimia Nervosa
- Bulimia Nervosa: Characterized by recurrent episodes of binge eating followed by compensatory behaviors to prevent weight gain. Diagnostic criteria include binge eating and compensatory behaviors occurring at least once weekly for 3 months.
- Compensatory behaviors include self-induced vomiting, misuse of laxatives/diuretics, fasting, or excessive exercise. Unlike anorexia, individuals with bulimia typically maintain weight within or above normal range.
Patients with bulimia may have normal weight but can develop serious electrolyte disturbances, especially hypokalemia, which can lead to cardiac arrhythmias and sudden death.
Key Points
- Physical signs include dental erosion, parotid gland enlargement, Russell's sign (calluses on knuckles), and esophageal tears.
- Assessment should include electrolyte monitoring, dental examination, and cardiac evaluation.
Binge Eating Disorder
- Binge Eating Disorder: Characterized by recurrent episodes of eating large quantities of food with a sense of lack of control, marked distress, and absence of compensatory behaviors. Binge episodes are associated with eating rapidly, until uncomfortably full, when not physically hungry, alone due to embarrassment, and feeling disgusted or depressed afterward.
- Most common eating disorder, affecting 2-5% of the population, with more equal gender distribution than other eating disorders.
Key Points
- Often associated with obesity and related health complications (type 2 diabetes, hypertension, dyslipidemia).
- Psychological assessment should include evaluation for depression, anxiety, and low self-esteem.
Other Specified Feeding or Eating Disorders (OSFED)
- OSFED includes presentations where symptoms characteristic of feeding and eating disorders cause clinically significant distress but do not meet full criteria for any specific disorder.
- Examples include atypical anorexia nervosa (all criteria met except underweight), bulimia or binge eating disorder of low frequency/limited duration, purging disorder, and night eating syndrome.
Key Points
- OSFED is not a "less serious" diagnosis and can have severe medical and psychological consequences.
- Requires comprehensive assessment and individualized treatment planning.
Commonly Confused Eating Disorders
| Feature |
Anorexia Nervosa |
Bulimia Nervosa |
Binge Eating Disorder |
| Body Weight |
Significantly low (BMI <18.5) |
Normal or slightly above |
Often overweight/obese |
| Eating Pattern |
Severe restriction |
Binge/purge cycles |
Binge episodes without purging |
| Compensatory Behaviors |
Restriction, excessive exercise (purging in binge/purge subtype) |
Purging, laxatives, diuretics, excessive exercise |
None |
| Body Image |
Severely distorted |
Distorted |
Negative body image, but less distortion |
| Key Physical Findings |
Emaciation, lanugo, bradycardia, hypotension, amenorrhea |
Dental erosion, parotid enlargement, Russell's sign |
Often obesity-related complications |
Nursing Management
Medical Stabilization
- Initial nursing priorities focus on medical stabilization, including correction of electrolyte imbalances, rehydration, and cardiac monitoring. For severely malnourished patients with anorexia nervosa, refeeding syndrome is a serious concern requiring careful monitoring.
- Refeeding syndrome involves potentially fatal shifts in fluids and electrolytes (particularly phosphate, potassium, and magnesium) that may occur when reintroducing nutrition to malnourished patients.
During refeeding, monitor for signs of refeeding syndrome including hypophosphatemia, hypokalemia, hypomagnesemia, fluid retention, and cardiac arrhythmias. Start refeeding at low caloric levels (typically 1,000-1,200 kcal/day) and increase gradually by 200-300 kcal every 2-3 days.
Key Points
- Monitor vital signs, electrolytes, and cardiac status closely during initial refeeding.
- Hospitalization criteria include severe malnutrition (BMI <16), rapid weight loss, severe electrolyte disturbances, cardiac abnormalities, and suicidal ideation.
Nutritional Rehabilitation
- Nutritional rehabilitation aims to restore weight, normalize eating patterns, and correct nutritional deficiencies. This process requires a multidisciplinary approach involving registered dietitians, nurses, and medical providers.
- For anorexia nervosa, weight restoration goals typically include 0.5-1 kg per week for inpatients and 0.2-0.5 kg per week for outpatients.
Supervised Meal Protocol
- Prepare the environment: quiet, supportive setting with minimal distractions.
- Set clear expectations: explain meal plan, required portions, and time limits (typically 30 minutes for meals, 15 minutes for snacks).
- Provide supportive presence: sit with patient, model normal eating, use distraction techniques for anxiety.
- Monitor for food hiding, excessive fluid intake, or other compensatory behaviors.
- Provide post-meal support for 30-60 minutes to prevent purging behaviors.
- Document intake, behaviors, and interventions.
Key Points
- Nutritional rehabilitation should be gradual to prevent medical complications.
- Meals should be structured, supervised, and supported by knowledgeable staff.
Psychosocial Interventions
- Therapeutic approaches include Cognitive Behavioral Therapy (CBT), Dialectical Behavior Therapy (DBT), Family-Based Treatment (FBT, especially for adolescents), and Interpersonal Psychotherapy (IPT).
- Nurses provide psychoeducation, motivational interviewing, cognitive challenging, and support for behavioral change. Establishing a therapeutic alliance based on trust and empathy is essential.
Key Points
- Approach patients with non-judgmental attitude and avoid power struggles about food and weight.
- Address underlying issues of control, perfectionism, body image, and emotional regulation.
Pharmacological Management
- Medication is typically adjunctive to psychological and nutritional interventions. For anorexia nervosa, no medications have been consistently shown to improve weight restoration or core symptoms.
- For bulimia nervosa and binge eating disorder, SSRIs (particularly fluoxetine at 60mg/day for bulimia) have demonstrated efficacy. Topiramate and lisdexamfetamine dimesylate (Vyvanse) may be beneficial for binge eating disorder.
Key Points
- Medications primarily target comorbid conditions (depression, anxiety) rather than core eating disorder symptoms in anorexia nervosa.
- Monitor for medication side effects, particularly cardiac effects in malnourished patients.
Discharge Planning and Continuity of Care
- Eating disorders typically require long-term treatment across multiple levels of care. Discharge planning should begin early and include arrangements for appropriate level of care (residential, partial hospitalization, intensive outpatient, outpatient).
- Relapse prevention planning includes identifying triggers, developing coping strategies, and establishing clear criteria for stepped-up care if needed.
Key Points
- Recovery is often a lengthy process with periods of improvement and relapse.
- Family education and involvement improve outcomes, particularly for adolescents.
Study Tips and Common Pitfalls
NCLEX Approach to Eating Disorder Questions
- NCLEX questions on eating disorders often focus on prioritization of care, safety concerns, therapeutic communication, and recognition of complications.
- Apply the nursing process (assessment, diagnosis, planning, implementation, evaluation) and Maslow's hierarchy of needs when answering questions.
Eating Disorder Complications Memory Aid: "ABCDEF"
A - Arrhythmias and cardiac complications
B - Bone density loss (osteopenia/osteoporosis)
C - Cognition issues (poor concentration, obsessive thoughts)
D - Dental erosion and damage
E - Electrolyte imbalances
F - Fertility issues and endocrine disruption
Key Points
- Physiological needs and safety are typically prioritized over psychological interventions in acute situations.
- Therapeutic communication techniques emphasize empathy, avoiding judgment, and focusing on feelings rather than food behaviors.
Common Pitfalls
- Focusing solely on weight restoration without addressing psychological aspects of the disorder.
- Misinterpreting manipulative behaviors as personal attacks rather than symptoms of the illness.
- Failing to recognize medical emergencies such as refeeding syndrome, severe electrolyte imbalances, or cardiac complications.
Never assume a patient with normal weight cannot have a serious eating disorder. Bulimia nervosa and atypical anorexia can present with normal BMI but severe medical complications.
Key Points
- Avoid power struggles and confrontational approaches; use motivational interviewing techniques instead.
- Recognize that eating disorders are serious mental illnesses, not choices or lifestyle preferences.
Self-Assessment Checklist
- Use this checklist to ensure you understand key concepts related to eating disorders.
Quick Check
1. A patient with anorexia nervosa who has been restricting food intake is started on nutritional rehabilitation. Which electrolyte should be monitored most closely during initial refeeding?
Answer: Phosphate (hypophosphatemia is a hallmark of refeeding syndrome)
2. Which eating disorder is most likely to present with Russell's sign (calluses on knuckles)?
Answer: Bulimia nervosa (from self-induced vomiting)
3. A 15-year-old with anorexia nervosa is refusing to eat dinner. What is the most appropriate initial nursing response?
Answer: "I understand eating can feel scary right now. Let's sit together for a while and talk about what's making this meal difficult."