Anorexia Nervosa

Define anorexia nervosa?

A diagnosis of anorexia requires four diagnostic criteria as defined in the DSM-IV:

  • Refusal to maintain weight within a normal range for height and age (more than 15 percent below ideal body weight)
  • Intense fear of weight gain, even though underweight
  • Severe body image disturbance in which body image is the predominant measure of self-worth with denial of the seriousness of the illness
  • In post menarche females, absence of the menstrual cycle, or amenorrhea (greater than three cycles).

There are two distinctive subtypes of anorexia: restricting; and binge eating/purging.
Who gets it?

90% of affected persons are female; most develop the disease after puberty but before age 25 years.

How can it be diagnosed?

The SCOFF questionnaire is a simple screening tool. The original study describing SCOFF reported that a “yes” to two or more questions was associated with a sensitivity and specificity of 100 and 87.5 percent for the diagnosis of an eating disorder.

  • Do you make yourself Sick because you feel uncomfortably full?
  • Do you worry you have lost Control over how much you eat?
  • Have you recently lost more than one stone (14 pounds or 6.35 kg) in a three month period?
  • Do you believe yourself to be Fat when others say you are too thin?

Would you say that Food dominates your life?

When do these patients need hospital admission?

The APA (American Psychiatric Association) criteria for hospitalization:

  • Medical instability [significant bradycardia <40, hypotension <90/60, metabolic abnormality: glucose or electrolytes (K <3), dehydration, or evidence of organ compromise]
  • Suicidal with high lethality plan or attempt.
  • Weight <85 percent normal body weight or rapid decline with food refusal despite outpatient or partial hospitalization treatment
  • Co-morbid psychiatric conditions
  • Poorly motivated patient needing assistance to eat or cooperative only in a highly structured environment.

What are the Royal college of Psychiatrist guidelines for referral for primary care?

  • Mild anorexia- BMI >17 and no additional co-morbidity. Monitor for 8 weeks and consider referral, if failure to respond
  • Moderate anorexia- BMI 15-17 and no evidence of system failure- routine referral to eating disorders unit
  • Severe anorexia- BMI <15, rapid weight loss, evidence of system failure- urgent referral to eating disorders unit (Archived copy at WebCite)

Discuss the investigations for anorexia nervosa?

FBC, U&E, Ca, Mg, PO4, TSH, ESR, TTG, LFTs
Raised amylase of salivary source is common in anorexia.

Discuss the treatment?

  • The most difficult part of management is engaging the patient with their treatment. A characteristic of people with anorexia nervosa is that they don’t accept that anything is wrong.
  • It’s useful to involve the family in treatment plans, particularly with younger patients. Helping relatives to understand that anorexia is an illness may avoid confrontation.
  • Inpatient nutritional treatment-
    • Correct fluid and electrolyte imbalance
    • Monitor for refeeding syndrome.
    • A weight gain of 0.5–1.0 kg per week is generally recommended for inpatients.
    • The use of oral thiamin supplements is recommended for in-patients and outpatients undergoing rapid weight gain. Parenteral B and C vitamins should be given before starting enteral feeding for at least the first 3 days of refeeding.
  • Patients with anorexia nervosa are at risk for osteopenia. Treatment includes daily supplementation with 1200 to 1500 mg of elemental calcium plus vitamin D.  Estrogen/progestin replacement may be appropriate in selected women. Bisphosphonates such are not recommended for use in patients with anorexia in the APA guidelines
  • Avoid drugs that prolong the QTc interval on the ECG; for example, antipsychotics, tricyclic antidepressants, macrolide antibiotics, and some antihistamines. In patients with anorexia nervosa at risk of cardiac complications, these drugs may compromise cardiac functioning.

Can compulsory treatment be used?
Compulsory treatment should be a last resort. The Mental Health Act can be used. The clinicians should still negotiate treatment options with patients who are receiving compulsory treatment.

What’s the long term prognosis?

One review found that approximately 50 percent of patients have good outcomes as defined by return of menses and weight gain, 25 percent have intermediate outcomes with some weight regain and some relapse, and 25 percent have a poor outcome.
Most deaths result from suicide or direct medical complications.

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