Eating disorders Flashcards
Describe three types of eating disorders
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Anorexia Nervosa
- Restricted food intake; persistent interfered weight gain
- Associated body image disturbance; fear of weight gain
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Bulimia Nervosa
- Recurrent uncontrolled eating of abnormal quantity
- Followed by compensatory behaviour eg. vomiting
-
Binge eating disorder
- Recurrent binge eating; marked by lack of control
- Absence of compensatory behaviours
- Atypical eating disorders: do not precisely meet above criteria
How is BMI calculated?
Weight (kg) / Height (m) 2
What tool can be used to screen for eating disorders?
SCOFF questionnaire
2+ postive answers is suggestive of AN/BN
Name four risk factors for eating disorders
- Adolescence and early adulthood
- Rare in women over 30
- Female (10:1)
- Overweight as a child
- FHx of eating disorder; mental illness; substance use
- Personality traits: obsessive compulsive, perfectionism
- Anxiety; depression; low self-esteem; body image issues
- Life events: bullying, stress etc.
- Societal pressure
When should emergency admission be considered for eating disorders?
- Severely compromised physical health, including:
- BMI/weight below safe range
- Cardiovascular instability eg. HR <40bpm; long QT
- Hypothermia
- Electrolyte imbalance; hypoglycaemia
- Risk of refeeding syndrome
- Acute mental health risk
- Risk of suicide attempt
- Serious self-harm
- Lack of support at home
Request five investigations for suspected eating disorders
- FBC; ESR (organic cause); U+E; LFTs; glucose
- Urinalysis
- ECG
- Ca2+; Mg3+; PO4-
- B12; folate; ferritin
- TFTs
- FSH; LH; PrL
Outline the diagnostic criteria for anorexia nervosa
DSM-5
- A: BMI <17.5 or 15% below expected weight (children)
-
B: Extreme fear of becoming fat; self-induced weight loss
- eg. Vomiting, exercise, laxatives
-
C: Body image distortion
- Overvalued ideas
- Imposed low weight threshold
- Lack of insight
Endocrine disorders: Amenorrhoea; reduced libido
Describe how anorexia nervosa differs between sexes
- Female (10:1)
- 0.3% of young women
- Mean age of onset:
- Female 16-17
- Male 12
What endocrine abnormalities are seen in Anorexia nervosa?
- High:
- Cortisol
- Growth hormone
- Low:
- FSH
- LH
- Oestrogen
- Testosterone
What are the effects of starvation?
How do these maintain anorectic behaviour?
- Delayed gastric emptying and slower GI motility
- Early satiety, not wanting to eat
- Reduced leptin, increased restlessness
- Urge to be active and exercise
- Preoccupation with food
- Fear of overeating, increased dietary control
- Increased thought rigidity and obsessions
- Rigid dietary rules, ritualised eating
What is sick euthyroid syndrome, and why does it appear in Anorexia nervosa?
Low T4, normal TSH
Biological adaptation to low body weight
Attempted reduction of metabolic rate and energy expenditure
What are medical complications of Anorexia nervosa a result of?
Medical complications of AN are the negative consequences of starvation that appear when body systems are unable to adapt to the low body weight.
Suggest five complications of anorexia nervosa
- Psychological: anxiety; social withdrawal; low mood; suicidal ideation
- Social: disrupted relationships; isolation; employment; financial
- Family/carer stress
- CV: arrhythmias; hypotension; peripheral oedema; sudden death
- MSK: muscle weakness; low BMD; fractures; growth restriction
- Endocrine: thyroid abnormalities; poor 2o sexual characteristics; amennorhoea; hypothermia
- GI: slow motility; constipation; mallory-weiss tears; abnormal LFTs
- Haem: low WCC; thrombocytopenia
- Metabolic: dehydration; electrolyte disturbance; refeeding syndrome
- Cognitive impairment
- Renal failure
- Dry skin; alopecia; lanugo hair
- Infertility; sexual dysfunction; miscarriage; IUGR; preterm birth
Why is anorexia nervosa difficult to treat?
Ego syntonic disorder ➔ behaviour is acceptable to the goals of the patient
Deliberate weight loss provides a sense of control and achievement
Giving up anorexia can be experiences as a failure/loss.
Outline the management of Anorexia nervosa
Eating disorder clinic with specialist psychological intervention
-
Biological
- Weight restoration; correction of electrolyte disturbances
- Dietary counselling; vitamin and mineral supplements
-
Psychotherapy, any of:
- ED-focused CBT (CBT-ED)
- Maudsley AN treatment for adults (MANTRA)
- Specialist supportive clinical management (SSCM)
- AN-focused family therapy (FT-AN): CAMHS
-
Social
- Adaptation to life without functional aspects of anorexia
What is the prognosis of Anorexia nervosa?
- Highest mortality rate of any psychiatric disorder (6%)
- Half due to suicide
- Half due to medical complications
- 20% recover completely
- 20-30% develop chronic presentation
Which patients are most at risk of serious medical conditions of Anorexia nervosa?
- BMI <14
- Rapid weight loss
- High levels of self-induced vomiting
Outline the DSM-5 diagnostic criteria for Bulimia nervosa
- Recurrent episodes of binge eating, requiring both:
- Eating an abnormal quantity in a discrete period of time
- Sense of lack of control over eating during the episode
- Recurrent inappropriate compensatory behaviour
- Both occur, on average, at least once a week for 3/12
- Self-evaluation is influenced by body shape and weight
- Disturbance does not occur exclusive during AN episodes
Name three medical complications associated with purging in Bulimia nervosa
- Gum disease and dental erosion
- Oesophagitis; oesophageal tears; Mallory-Weiss tears
- Aspiration pneumonitis
- Russell’s sign: knuckle calluses from induced vomiting
- Hypokalaemia
- Muscles cramps, tetany, cardiac dysarrhythmia
- Dehydration; obesity (30% of BN are/become obese)
Name three behavioural changes that occur in Bulimia nervosa
- Binge-purge cycling
- Eating in secrecy
- Loss of control when eating
- Frequent use of bathroom after eating
Describe the vicious cycle of Bulimia nervosa
- Trigger - damaged self esteem
- Strict dieting rules with goal of weight loss
- Hunger ➔ Binge-eating
- Guilt and compensatory behaviours
- Repeat from step 2
Outline the management of Bulimia nervosa
Most are distressed about bulimia nervosa & motivated to recover, unlike anorexia nervosa
- Psychotherapy
- BN-focused self-help
- CBT-ED
- Family therapy (FT-BN): CAMHS
Define refeeding syndrome
The potentially fatal shifts in fluids and electrolytes that can occur in malnourished patients receiving artificial refeeding
Metabolic disturbances: may result in organ failure
- Hypophosphataemia
- Hypokalaemia
- Hypomagnesaemia: risk of torsades de pointes
- Abnormal fluid balance
Name three patient groups at high risk of refeeding syndrome
- Anorexia nervosa
- Chronic alcoholism
- Cancer
- Elderly patients with comorbidites
- Uncontrolled diabetes mellitus
- Chronic malnutrition: marasmus
How can refeeding syndrome be prevented?
- Patients who have eaten little or nothing for >5 days
- Start at no more than 50% of energy requirements
- Increase rate if no refeeding problems detected
- K+, PO4-, Ca2+, Mg3+ supplements as needed
- Check electrolytes daily
- Vitamin supplementation
- Treat hypoglycaemia with IV glucose and/or oral sucrose
