Chapter 1 Anorexia Nervosa
PATHOPHYSIOLOGY
Anorexia nervosa is an eating disorder that typically begins in adolescence and is characterized by the refusal to maintain a body weight within the minimal range of normal for height, weight, and body frame. The patient denies the seriousness of weight loss and has a distorted body image. Despite being dangerously thin, the individual feels fat. In addition, there may be a focus on the shape and size of particular body parts (Box 1-1).
Box 1-1 Diagnostic Criteria for Anorexia Nervosa
• Refusal to maintain body weight at or above a minimally normal weight for age and height (e.g., weight loss leading to maintenance of body weight less than 85% of that expected; or failure to make expected weight gain during period of growth, leading to body weight less than 85% of that expected).
• Intense fear of gaining weight or becoming fat, even though underweight.
• Disturbance in the way in which one’s body weight or shape is experienced, undue influence of body weight or shape on self-evaluation, or denial of the seriousness of the current low body weight.
• Amenorrhea in postmenarchal females, i.e., the absence of at least three consecutive menstrual cycles. (A woman is considered to have amenorrhea if her periods occur only following hormone, e.g., estrogen, administration.)
From American Psychiatric Association: Diagnostic and statistical manual of mental disorders, ed 4, text revision (DSM-IV-TR), Washington, DC, 2000, The Association.
There are two general subtypes of anorexia nervosa. The restricting type involves severe restriction of food intake and compulsive exercising. The binge eating and purging type involves restricted dietary intake coupled with intermittent episodes of binge eating, followed by purging. Self-induced vomiting and use of ipecac, laxatives, diuretics, or enemas are common means of purging. Excessive use of appetite suppressants or diet pills is seen in both types.
Purging and semistarvation may induce electrolyte imbalance and cardiac problems, which may ultimately lead to death. Starvation creates a range of medical symptoms. Changes in growth hormone levels, diminished secretion of sex hormones, defective development of bone marrow tissue, structural abnormalities of the brain, cardiac dysfunction, and gastrointestinal difficulties are common. A notable problem associated with anorexia in adolescents is the potential for growth retardation, delay of menarche, and peak bone mass reduction. When normal eating is reestablished and laxative use is stopped, the youth may be at risk for developing medical complications.
A variety of psychologic factors are associated with anorexia nervosa. Personality traits of perfectionism and compulsiveness are common. Low self-esteem also plays a role. In many cases, weight loss is experienced as an achievement, and self-esteem becomes dependent on body size and weight. At the same time the adolescent may experience peer, familial, and cultural pressures to be thin. There is a high incidence of co-occurring mood disorders in anorexic patients. In some cases, major depression may result from nutritional deprivation. Individuals with anorexia nervosa may lack spontaneity in social situations and may be emotionally restrained. Family dynamics may play a role in development of symptoms. Eating behaviors ostensibly emerge in an unconscious attempt to gain control in cases where parents are perceived to be controlling and overprotective. For some adolescents, diminished weight and loss of secondary sexual characteristics are related to difficulty accepting maturation into adulthood. A reflection of the sociocultural ideal of thinness, disordered eating that is not severe enough to meet criteria for anorexia nervosa is common among adolescent girls in the United States and is on the rise in males.
INCIDENCE
1. More than 90% of individuals with anorexia are females.
2. Rate of incidence among those aged 15 through 24 years is 14.6% for females and 1.8% for males.
3. Mortality rates range between 6% and 15%; half the deaths result from suicide.
4. Prevalence continues to be higher in Western industrialized nations with predominantly white populations and among middle- and upper-class females. Increasing diversity in the ethnic and socioeconomic groups of those affected is being reported. For immigrants, degree of acculturation may play a role.
5. Cardiac complications occur in 87% of affected youth.
6. Renal complications occur in approximately 70% of affected youth.
CLINICAL MANIFESTATIONS
1. Sudden, unexplained weight loss
2. Emaciated appearance, loss of subcutaneous fat
3. Changes in eating habits, unusual eating times
4. Excessive exercise and physical activity
7. Lanugo on extremities, back, and face
8. Yellowish discoloration of skin
10. Chronic constipation or diarrhea, abdominal pain, bloating
11. Esophageal erosion (from frequent vomiting)
13. Excessive focus on high achievement (individual becomes distressed when performance is not above average)
14. Excessive focus on food, eating, and body appearance
15. Erosion of tooth enamel and dentin on lingual surfaces (late effects from frequent vomiting)
COMPLICATIONS
1. Cardiac: bradycardia, tachycardia, arrhythmias, hypotension, cardiac failure
2. Gastrointestinal: esophagitis, peptic ulcer disease, hepatomegaly
3. Renal: serum urea and electrolyte abnormalities (hypokalemia, hyponatremia, hypochloremia, hypochloremic metabolic alkalosis), pitting edema
4. Hematologic: mild anemia and leukopenia (common) and thrombocytopenia (rare)
5. Skeletal: osteoporosis, pathologic fractures
6. Endocrine: reduced fertility, elevated cortisol and growth hormone levels, elevated gluconeogenesis
7. Metabolic: decreased basal metabolic rate, impaired temperature regulation, sleep disturbances
8. Death caused by complications, including cardiac arrest and electrolyte imbalance, and suicide
LABORATORY AND DIAGNOSTIC TESTS
1. Electrocardiogram—bradycardia is common
2. Erect and supine blood pressure—to assess for hypotension
3. Serum urea, electrolyte, creatinine levels (in severe cases, monitor every 3 months)—may show low blood urea nitrogen level due to dehydration and inadequate protein intake; metabolic alkalosis and hypokalemia due to vomiting
4. Urinalysis, urine creatinine clearance (in severe cases, monitor annually)—pH may be elevated; ketones may be present
5. Complete blood count, platelet count (in severe cases, monitor every 3 months)—usually normal; normochromic, normocytic anemia may be present
6. Fasting blood glucose level (in severe cases, monitor every 3 months) decreased levels may be due to malnutrition
7. Liver function tests (in severe cases, perform every 3 months)—abnormal results indicate possible starvation
8. Thyroid-stimulating hormone, cortisol levels (in severe cases, monitor semiannually)
9. Bone density (in severe cases, monitor annually)—demonstrates osteopenia
10. Body composition (in severe cases, monitor annually using calipers or water immersion)—to determine loss of significant body mass
11. Presence of hypercarotenemia (causes yellowing of skin, also known as pseudojaundice)—due to vegetarian diet or decreased metabolism
MEDICAL MANAGEMENT
Treatment is provided on an outpatient basis unless severe medical problems develop. An interdisciplinary approach is needed to ensure optimal outcome. Outpatient treatment includes medical monitoring, dietary planning to restore nutritional state, and psychotherapy. Therapeutic approaches include individual, family, and group psychotherapy. Family involvement is crucial. Use of psychotropic medication should be considered only after weight gain has been established. Medication may be used to treat depression, anxiety, and obsessive-compulsive behaviors. Hospitalization is indicated if the adolescent weighs less than 20% of ideal body weight or is unable to adhere to the treatment program on an outpatient basis, or if neurologic deficits, hypokalemia, or cardiac arrhythmias are present. Hospitalization is limited to brief stays focusing on acute weight restoration and refeeding.
Psychiatric hospitalization is indicated rather than admission to a general pediatric unit, since these clients require care from nurses with experience in refeeding protocols and psychiatric illnesses. Refeeding begins with 1200 to 1500 kcal per day and is increased by 500 kcal every 4 days, until about 3500 kcal for females and 4000 kcal for males per day is reached. To some degree, refeeding reduces apathy, lethargy, and food-related obsessions. Close monitoring is required during refeeding. Vital signs should be taken regularly and attention paid to electrolyte concentrations, peripheral edema, and cardiopulmonary functioning. Refeeding syndrome occurs in about 6% of hospitalized adolescents. Symptoms range from the more minor transient pedal edema to, more seriously, prolonged QT intervals and weakness, confusion, and neuromuscular dysfunction resulting from hypophosphatemia. Refeeding syndrome is most likely to occur in clients whose weight is less than 70% of their ideal body weight or in those who are receiving parenteral or enteral nutrition, or when oral refeeding is too vigorous.
NURSING ASSESSMENT
1. Assess psychologic status with psychologic inventories. The Eating Disorder Examination is designed for structured interviews. Clinical self-reports include the Eating Disorder Inventory (for ages 14 years and older). The Eating Attitudes Test and the Kids Eating Disorder Survey may be used for school-aged children. The Children’s Depression Inventory may be used to assess level of depression in 7- to 17-year-olds.
2. Assess height and weight using growth charts and body mass index (weight measurements are taken after the individual has undressed and voided).
3. Assess pattern of elimination.
NURSING INTERVENTIONS
1. Participate in interdisciplinary team that uses multiple modalities such as individual and group psychotherapy, assertiveness training, music and/or art therapy, and nutritional education.
2. Support involvement of family members who are vital to recovery.
3. Provide information about adequate nutritional intake and effect of inadequate intake on energy level and psychologic well-being.
4. Organize eating of meals with others, record amount of food eaten, and monitor activity for 2 hours after eating.
5. Initiate specific plan of exercise to reinforce positive behavioral outcomes.
6. Establish trusting relationship that promotes disclosure of feelings and emotions.
7. Promote adolescent’s sense of responsibility and involvement in recovery and treatment.
American Psychiatric Association. Diagnostic and statistical manual of mental disorders, ed 4. Washington, DC: The Association, 2000. text revision (DSM-IV-TR)
American Psychiatric Association Work Group on Eating Disorders. Practice guideline for the treatment of patients with eating disorders (revision). Am J Psychiatry. 2000;157(Suppl 1):1.
Carpenito L. Handbook of nursing diagnosis, ed 8. Philadelphia: JB Lippincott, 2005.
Ebeling H, et al. A practice guideline for treatment of eating disorders in children and adolescents. Ann Med. 2003;35(7):488.
Sparks S, Taylor C. Nursing diagnostic reference manual, ed 6. Philadelphia: Lippincott, Williams & Wilkins, 2005.
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