Eating Disorders Flashcards
Anorexia nervosa diagnostic criteria
- Restriction of energy intake relative to requirements leading to a significantly low body weight in the context of age, sex, developmental trajectory, and physical health.
- 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.
Epidemiology of anorexia nervosa
90% of patients are female
predominately affects teenage and young-adult females
What do NICE reccomend one of in the treatment of anorexia nervosa
- individual eating-disorder-focused cognitive behavioural therapy (CBT-ED)
- Maudsley Anorexia Nervosa Treatment for Adults (MANTRA)
- specialist supportive clinical management (SSCM).
Treatment of anorexia nervosa in young people
In children and young people, NICE recommend ‘anorexia focused family therapy’ as the first-line treatment. The second-line treatment is cognitive behavioural therapy.
Anorexia nervosa: characteristic clinical signs and physiological abnormalities
Features
reduced body mass index
bradycardia
hypotension
enlarged salivary glands
lanugo hair (fine hair covering the body)
Low BMI
Amennorhea
Physiological abnormalities
**hypokalaemia
**low FSH, LH, oestrogens and testosterone - sex hormones
raised cortisol and growth hormone
impaired glucose tolerance
hypercholesterolaemia
hypercarotinaemia
low T3
Weight loss in anorexia nervosa
Deliberate - induced and sustained by the patient. Disregard of impact on physical health
Importance of ECG in anorexia nervosa
Because of the resulting malnutrition, those with Anorexia Nervosa are predisposed to cardiac
arrhythmias.
An ECG should always be performed in those admitted to hospital with Anorexia Nervosa,
in outpatient treatment or in those with symptoms such as dizziness, fainting or light-headedness.
In the body’s attempts to reduce energy expenditure with minimal calorie intake, bradycardia and
hypotension are commonly seen, as well as a prolonged QT interval. A prolonged QT interval increases the risk of a fatal arrhythmia such as Ventricular Fibrillation.
What is refeeding syndrome and what are the metabolic consequences
Refeeding syndrome describes the metabolic abnormalities which occur on feeding a person following a period of starvation. It occurs when an extended period of catabolism ends abruptly with switching to carbohydrate metabolism.
The metabolic consequences include:
hypophosphataemia
hypokalaemia
hypomagnesaemia: may predispose to torsades de pointes
abnormal fluid balance
These abnormalities can lead to organ failure.
Which patients are at risk of refeeding syndrome
Patients are considered high-risk if one or more of the following:
BMI < 16 kg/m2
unintentional weight loss >15% over 3-6 months
little nutritional intake > 10 days
hypokalaemia, hypophosphataemia or hypomagnesaemia prior to feeding (unless high)
If two or more of the following:
BMI < 18.5 kg/m2
unintentional weight loss > 10% over 3-6 months
little nutritional intake > 5 days
history of: alcohol abuse, drug therapy including insulin, chemotherapy, diuretics and antacids
NICE recommend that if a patient hasn’t eaten for > 5 days, aim to re-feed at no more than 50% of requirements for the first 2 days.
Why might refeeding syndrome occur?
If nutritional intake is resumed too rapidly after a period of relatively low caloric intake, the patient is at high risk of refeeding syndrome.
Rapidly increasing glucose levels leads to rapidly increasing insulin levels.
This leads to shifts of potassium, magnesium and phosphate from extracellular to intracellular spaces.
This is potentially fatal if refeeding is too rapid.
Symptoms of refeeding syndrome may include edema, confusion and tachycardia. Blood tests initially show hypophosphataemia and it is treated with phosphate supplementation.
Refeeding syndrome symptoms and treatment
Symptoms of refeeding syndrome may include edema, confusion and tachycardia. Blood tests initially show hypophosphataemia and it is treated with
phosphate supplementation.
Slowly reintroducing food with restricted calories
Magnesium, potassium, phosphate and glucose monitoring along with other routine bloods
Fluid balance monitoring
ECG monitoring may be required in severe cases
Supplementation with electrolytes and vitamins, particularly B vitamins and thiamine
Cardiac complications of anorexia nervosa
Prolonged QT
Cardiac complications include arrhythmia, cardiac atrophy and sudden cardiac death.
What happens on the cellular level in refeeding syndrome
Metabolism in the cells and organs dramatically slows during prolonged periods of malnutrition. As the starved cells start to process glucose, protein and fats again they use up magnesium, potassium and phosphorus. This leads to:
Hypomagnesaemia
Hypokalaemia
Hypophosphataemia
These patients are also at risk of cardiac arrhythmias, heart failure and fluid overload.
General management of eating disorders
Patient and carer education is key to the condition. Management is centred around changing behaviour and addressing environmental factors:
Self help resources
Counselling
Cognitive behavioural therapy (CBT)
Addressing other areas of life, such as relationships and past experiences
Severe cases may require admission for observed refeeding and monitoring for refeeding syndrome.
SSRI medication may be used ( in children, by a specialist in child and adolescent mental health)
How do patients with anorexia nervosa restrict calories
Minimal food intake
Often the person exercises excessively and may use diet pills or laxatives to restrict absorption of food.
What is bulimia nervosa and what are the features
Unlike with anorexia, people with bulimia often have a normal body weight. Their body weight tends to fluctuate. The condition involves binge eating, followed by “purging” by inducing vomiting or taking laxatives to prevent the calories being absorbed.
Features of bulimia nervosa:
BMI >17.5
Body image disotoriton
Purging and binge eating
Alkalosis, due to vomiting hydrochloric acid from the stomach
Hypokalaemia
Erosion of teeth
Swollen salivary glands
Mouth ulcers
Gastro-oesophageal reflux and irritation
Calluses on the knuckles where they have been scraped across the teeth. This is called Russell’s sign.
Parotid gland swelling
Unique presenting features of bulimia nervosa
Normal body weight that presents with swelling to the face or under the jaw (salivary glands), calluses on the knuckles and alkalosis on a blood gas. The presenting complaint may be abdominal pain or reflux.
DSM 5 diagnostic criteria for a diagnosis of bulimia nervosa:
recurrent episodes of binge eating (eating an amount of food that is definitely larger than most people would eat during a similar period of time and circumstances)
a sense of lack of control over eating during the episode
recurrent inappropriate compensatory behaviour in order to prevent weight gain, such as self-induced vomiting, misuse of laxatives, diuretics, or other medications, fasting, or excessive exercise.
recurrent vomiting may lead to erosion of teeth and Russell’s sign - calluses on the knuckles or back of the hand due to repeated self-induced vomiting
the binge eating and compensatory behaviours both occur, on average, at least once a week for three months.
self-evaluation is unduly influenced by body shape and weight.
the disturbance does not occur exclusively during episodes of anorexia nervosa.
Management of bulimia nervosa
referral for specialist care is appropriate in all cases
NICE recommend bulimia-nervosa-focused guided self-help for adults
If bulimia-nervosa-focused guided self-help is unacceptable, contraindicated, or ineffective after 4 weeks of treatment, NICE recommend that we consider individual eating-disorder-focused cognitive behavioural therapy (CBT-ED)
children should be offered bulimia-nervosa-focused family therapy (FT-BN)
pharmacological treatments have a limited role - a trial of high-dose fluoxetine is currently licensed for bulimia but long-term data is lacking
What is Russles sign and when is it seen?
Calluses on the knuckles where they have been scraped across the teeth.
Bulimia nervosa
Binge eating disorder
Binge eating disorder is characterised by episodes where the person excessively overeats, often as an expression of underlying psychological distress. This is not a restrictive condition like anorexia or bulimia, and patients are likely to be overweight.
Binges may involve:
A planned binge involving “binge foods”
Eating very quickly
Unrelated to whether they are hungry or not
Becoming uncomfortably full
Eating in a “dazed state”
Risk factors for bulimia
Genetic risk factors for bulimia include:
Family history of eating disorders
Family history of mental illness
Family history of impulse control disorders
Psychosocial risk factors for bulimia include:
Prior mental health diagnosis
Poor self-esteem
History of abuse or trauma
Having a career or hobby dependent on appearance
History of engaging in restricting and bingeing cycles
Typical symptoms of bulimia
Engaging in binge eating behaviours
Distress over body image
Frequent bathroom trips following meals
Uncomfortable eating food in the presence of others
Mood disturbance: irritability, depression, suicidal ideation and self-harm behaviours
Differential diagnosis to consider in ?bulimia nervosa
Anorexia nervosa: patients with anorexia often present with a severely low BMI, unlike in bulimia where the BMI is usually normal or raised. In anorexia, there is a restriction of energy intake, whereas in bulimia recurrent episodes of binge eating with compensatory mechanisms are evident.
Body dysmorphic disorder
Depression
Obsessive-compulsive disorder
Relevant investigations in ?bulimia nervosa
Bedside:
Height and weight: to calculate BMI
Basic observations: including blood pressure and heart rate
Urinalysis: may show ketones if the patient has co-morbid diabetes mellitus. Some patients may skip insulin to control their weight. This is often referred to as ‘diabulimia’.
ECG: important to perform if there is a severe deficiency in potassium or magnesium. Features of hypokalaemia include increased P wave amplitude, prolonged PR interval, ST depression and T wave flattening/inversion and prominent U waves.
Relevant laboratory investigations include:
Urea & electrolytes: these may show hypokalaemia and/or increased creatinine. Elevated bicarbonate usually indicates alkalosis due to loss of gastric acid.
Magnesium: may be low
Full blood count: may show anaemia
Liver function tests: may be abnormal as excess exercise can elevate aminotransferases
ICD 11 criteria for bulimia
Preoccupation with controlling body weight
Repeated bouts of overeating
Compensatory behaviours after overeating, including self-induced vomiting, using laxatives and excessive exercise
These binge eating and compensatory behaviours usually occur at least once weekly for three months
Pharmacological management of bulimia
Selective serotonin-reuptake inhibitors (SSRIs) are used for the pharmacological management of bulimia. Fluoxetine is typically used first-line, followed by sertraline if this is poorly tolerated.
These may be used when cognitive behaviour therapy (CBT) isn’t available or when it has been tried and the patient hasn’t seen any improvement.
The medications should be given at a time of day when they are unlikely to be purged.2
SSRIs are also useful in the case of comorbid disorders (e.g. depression and anxiety).
Potential complications of bulimia nervosa
Irregular menstrual cycles and fertility issues
Mental health conditions such as depression and anxiety
Gastric ulcers
Osteoporosis
Heart issues including arrhythmias, heart attacks or failure and cardiomyopathy
What is an eating disorder? What are the most common types?
Eating disorders are mental health conditions in which the person uses the control of food to cope with feelings and/or other situations. This usually involves eating too little or too much, purging behaviours or worrying excessively about body weight or shape.
The three most common eating disorders are:
Anorexia nervosa: an eating disorder characterised by weight loss, inability to maintain appropriate body weight for age/height and often associated with distorted body image. It generally involves the restricting of calories and sometimes also involves excessive (and compulsive) exercise and purging.
Bulimia: often involves bingeing and then purging. People with bulimia often make themselves sick or take medications such as laxatives or diuretics to help them get rid of calories.
Binge eating disorder: involves eating excessive amounts of food in a short period and then having feelings of guilt and upset.
What should be explored in an eating disorder history
Weight history
Eating behaviour
Adaptive behaviours
Physical symptoms including red flags
Psychological symptoms
How to structure weight history
SLIM
S: stages - weight during childhood/adult/teenage years, any time of drastic change
L: loss - any periods of excessive or rapid weight-loss, triggers for any weight loss/gain
I: ideal - what do they think is a health weight, how do they feel currently about their weight
M: Maximum and minimum - heaviest and lightest weights
Questions to establish eating behaviours
Establish what would be a normal day for them and what their beliefs around eating are. It is also helpful to understand if they believe they have a problem:
“What would a typical day’s food intake look like for you?”
“Do you think that your eating habits are similar to your friends and families?”
“Has anyone expressed they are concerned about the amount you are eating?”
Examples of adaptive behaviours in eating disorders
Exercise - how much, what type
Purging - vommiting or medication including insulin
Binge eating - what triggers this?
What physical symptoms of eating disorder are considered red flag features
Rapid weight loss
Heart rate <40
Significant orthostatic changes in systolic BP (>20 mmHg)
History of recurrent syncope
ECG abnormalities (prolonged QTc, arrhythmias, signs of electrolyte abnormalities)
Fluid refusal or signs of severe dehydration (reduced urine output, tachypnoea, tachycardia, reduced skin turgor, sunken eyes)
Low temperature (hypothermia)
Signs of electrolyte disturbance
Unable to stand up from squatting or sit up from laying (SUSS test)
What might you ask a patient with an eating disorder when exploring psychological symptoms
Current mood
Periods of high or low moods
symtpoms of anxiety or panic attack
Obsessive or compulsive thoughts
Thoughts of self harm/plans/obstructive factors
Systems enquired in eating disorder
Neurological: memory, concentration, numbness or weakness in limbs, dizziness on sitting to standing
Respiratory: shortness of breath particularly on exercise
Cardiovascular: palpitations or chest pain
Gastrointestinal: changes to bowel habits, abdominal pain, reflux, bloating
Genitourinary: changes to urinary frequency, changes to or absence of menstruation
Miscellaneous: hair loss or growth, dry skin, lethargy
Eating disorders: family history
Ask the patient if there is any family history of psychiatric disease in first-degree relatives:
Ask about a family history of gastrointestinal disease (e.g. inflammatory bowel disease, coeliac disease) when considering other causes of weight loss.
It may be useful to draw a genogram displaying this information.
Questions which can help establish a patients general social context
“Are you feeling particularly stressed at the moment in any area of your life?” (school, work, home)
“How are your eating habits impacting your family/relationship/friends?”
“Has anyone else commented on your mood or behaviours recently?”
“Have you spoken about your concerns to any friends/family/partner?”
What is the cause of amenorrhoea in anorexia nervosa?
Anorexia nervosa is complicated by hypothalamic-pituitary dysregulation, including hypothalamic amenorrhea
What characterises a ‘binge’
Eating a larger than usual amount of food in a discrete period of time
Usually highly calorific (“bad foods”)
Lack of control during the episode
Eat rapidly and until uncomfortably full
Eating when not hungry
Usually very secretive
Physical appearance features of AN
Cachexia, signs of dehydration, lanugo hair, salviary gland enlargement
