Eating disorders

Clinical features

History

• Obsession with weight/food, body dysmorphia
• Participation in activities with close monitoring of weight is a risk factor
• High rates of co-incident depression, anxiety, obsessive-compulsive and substance abuse
• Lifetime risk of major depression with anorexia is 80%
• 30% prevalence of OCD
• Substance abuse in 15% of anorexia and 50% of bulimia
• Risk factors for attempted and completed suicide
• Suicide attempts in 1/3 of bulimic patients but completed not at increased rates
• Anorexia carries a 50-fold increased risk of completed suicide

Clinical types

• Restrictive
  • Cachexia
  • Starvation ketosis
  • Growth retardation
  • Osteopaenia
  • Primary or secondary amenorrhoea
  • Cardiac: Bradycardia, orthostatic hypotension arrhythmia, prolonged QT, conduction abnormalities
  • Bone marrow suppression
  • Impaired cellular immunity
  • Peripheral neuropathy
  • Wernicke encephalopathy
  • Euthyroid sick syndrome
  • Dry brittle hair, lanugo
  • Electrolyte disturbances

• Purging
  • Dental caries
  • Salivary gland hypertrophy
  • Palatal abrasions
  • Knuckle calluses
  • Facial petechiae
  • Pharyngitis/oesophagitis
  • Mallory-Weiss tears
  • Pancreatitis
  • Dehydration
  • Electrolyte disturbances – Vomiting, laxatives, diuretics
  • Acid-base disturbances – Vomiting, laxatives, diuretics
  • Compulsive exercise complications e.g. stress fractures, rhabdo, overuse syndromes

Diagnosis

• Anorexia
  • Refusal to maintain weight in normal range(>15% below ideal body weight)
  • Fear of weight gain
  • Severe body image disturbance with denial of seriousness of disease
  • Secondary amenorrhoea for >3 cycles or primary amenorrhoea in females
• Bulimia
  • Episodes of binge eating with loss of control
  • Followed by compensatory purging or non-purging (exercise, fasting, strict diet)
  • 2 times per week for 3 months at minimum
  • Dissatisfaction with body shape/size
  • Does not occur during episodes of anorexia nervosa
• ED-Not otherwise specified
  • All criteria for anorexia but still menstruating
  • All criteria for anorexia but normal weight
  • All criteria for bulimia but lower frequency or duration
  • Regular use of compensatory measures after small amounts of food
  • Chewing/spitting out, but not swallowing, large amounts of food
  • Binge eating disorder

Investigations

• FBC
• hCG
• Glucose
• ECG
• UEC
• Urinalysis for ketones
• LFT
• TFT
• VBG

Treatment

• Goals of inpatient treatment
  • Medical stabilisation
  • Prevention and treatment of refeeding syndrome
  • Engagement of carers/family/community
  • Reversal of cognitive effects of starvation to allow psychotherapy to provide benefit
  • Ensure patient is able consume adequate nutrition and contain compensatory behaviours both on and off the ward prior to discharge
  • Arrange appropriate outpatient follow-up
• Bulimia – CBT + SSRI
  • Better outcomes than anorexia
  • 30% still meet diagnostic criteria at 10 years though
• Anorexia – Multidisciplinary group therapy
  • Pharmacottherapy of limited utility
    • May be useful for comorbid psychological illness
  • 50% of patients have good outcome
  • 25% achieve some weight gain but suffer relapses
  • 25% poor outcomes
  • Mortality rate at 10 years of 6.6%

Bold in above refers to adolescent parameters.

• Postural HR and BP should be measured after a 2 minute break between lying and standing
• Postural tachycardia is common in young females, especially if deconditioned. This alone is not a criterion for readmission and a historical diagnosis of postural orthostatic tachycardia syndrome (POTS) should be sought.

Medical Treatment

• Address dehydration and electrolyte disturbances
• Maximum refeeding rate 40cal/kg/day
• IV/IM thiamine supplementation prior to prompt nutrition provision (liquid supplements or food)
• If meeting medical criteria
  • IV/IM thiamine 300mg prior to feeding and daily for three days
  • Supplement K, Mg and PO4 as required
  • Multivitamin 1 tab oral daily
  • Insert NG
  • Commence Nutrision Energy 40mL/hr
• If meeting psychiatric criteria
  • Refer to inpatient psychiatry team with plan for oral meal plan
• If NOT meeting any criteria for admission
  • Consider psychiatric review to determine if admission beneficial to address failure of outpatient treatment
• Before discharge from ED
  • Arrange follow-up with community services including letter to GP requiring weekly monitoring and ongoing psychiatric support in community

If refuses treatment

• Assess capacity and consider treatment under the Guardianship Act or Mental Health Act (Queensland)
• Eating Disorders are Mental Health Disorders and as such can be managed under the Mental Health Act
  • If the patients impaired capacity is putting them at risk of harm and there is no less restrictive way of ensuring they receive treatment

ARFID – Avoidant Restrictive Food Intake Disorder

This is a relatively new diagnosis (added to DSM-V in 2013) defined by limited volume or variety of food intake motivated by one or more of:

• Sensory sensitivity (e.g. to taste, texture, appearance, smell)
• Fear of aversive consequences (e.g. choking, vomiting, GI pain)
• Lack of interest in food secondary to low appetite

Specifically, patients with ARFID are not restricting to avoid weight gain.

It has a very high rate of comorbid medical and psychological issues e.g. OCD, generalised anxiety, autism and learning difficulties.

Patients are at risk of inadequate caloric intake and micronutrient deficiencies. The goals of inpatient care are similar to other eating disorders with additional consideration of:

• Micronutrient deficiency assessment and management
• Excluding possible medical causes of limited oral intake e.g. gastroenterology review, swallow assessment
• Emphasis on adequate nutrition vs. normalised
• Continued vitamin and mineral supplementation until meal plan can be designed to meet these requirements

Last Updated on June 13, 2022 by Andrew Crofton