Eating Disorders Flashcards
State three eating disorders to be aware of as classified in ICD-10
- Anorexia nervosa
- Bulimia nervosa
- Other eating disorders/atypical eating disorders (includes binge eating disorder)
Define anorexia nervosa
Eating disorder characterised by deliberate weight loss, an intense fear of fatness, distorted body image and endocrine disturbances
Describe two subtypes of anorexia nervosa
- Restrictive type: restrict food
- Binge eating/purging type: compensatory behaviours (e.g. vomitting, laxative abuse, excessive exericse) and may also binge. *NOTE: don’t have to binge to purge.
State some prediposing risk factors for anorexia nervosa- consider biological, psychological & social factors
State some precipitating risk factors for anorexia nervosa- consider biological, psychological & social factors
State some perpetuating risk factors for anorexia nervosa- consider biological, psychological & social factors
Discuss for anorexia nervosa:
- Male:female ratio
- Age of onset
- Females more affected (male:female is 1:10)
- Mid-adolescence
- 10-30 per 100,000
Discuss the ICD-10 criteria for anorexia nervosa
HINT: mneumonic FEEDD
- Fear of weight gain
- Endocrine disturbances (resulting in amenorrhoea in females & loss of sexual interest and potency in males. May also delay or arrest puberty)
- Emaciated: body weight at least 15% below expected weight (either lost weight or never achieved) or BMI <17.5kgm2
- Deliberate weight loss by avoidance of fatty foods (may also increase exercise, use appetite supressants)
- Distorted body image
NOTE: ICD puts fear of weight gain & distorted body image together as one point and puts delayed or arrested puberty as seperate to endocrine disturbances
Alongside the ICD-10 criteria for anorexia nervosa, what other symptoms/features may someone with anorexia nervosa present wtih?
*HINT: P, P, S, S
Physical
- Fatigue
- Hypothermia
- Bradycardia
- Arrhythmias
- Peripheral oedema (hypoalbuminaemia)
- Headaches
- Lanugo hair
Preoccupation with food:
- Dieting
- Preparing elaborate meals for others
Social
- Socially isolated
- Sexuality feared
Other symptoms
- E.g. of depression, obesessions
NOTE: consultant said that she thinks diagnostic criteria for AN may change in ICD-11; BMI and amenorrhoea will be removed because average size of population has increased hence you may have AN pts who don’t have BMI <17.5 but did have, for example, BMI of 45 and now BMI of 22
Remind yourself of the BMI ranges for:
- Underweight
- Healthy weight
- Overweight
- Obese
- Morbidly obese
Discuss the psychology behind how restriction of food can result in AN
*Talked about in lecture
- Restriction leads to preoccupation with food
- Preoccupation with food in pts with AN leads to fear of loss of control if they eat
- Hence they restrict
- Others without AN would respond to preoccupation with food with eating
Example questions for anorexia nervosa history
Discuss a potential MSE for pt with anorexia nervosa
What other examinations are vital in anorexia nervosa pt?
Full systems examintsions should be carried out to assess degree of emacation, exlude differential diagnoses and look for possible complications
What investigations are required for someone with anorexia nervosa?
Structure answer as bedside, bloods, imaging/other and for each STATE WHY you would do it
Bedside
- ECG: look for arhythmias e.g. sinus bradycardia, prolonged QT
- Plasma glucose
- VBG: look for metabolic acidosis (laxatives) or metabolic alkalosis (vomiting)
- Questionaires: e.g. EAT (eating attitudes test)
Bloods
- FBC: anaemia, thrombocytopenia, leukopenia
- U&ES: low potassium, phosphate, magnesium & chloride. R**aised urea & creatinin if dehydrated
- LFTs: low albumin
- Lipids: raised cholesterol
- Cortisol: raised
- Sex hormones: low LH, FSH, oestrogens & progesterones
- Amylase: pancreatitis can be a complication
- B12, folate, Fe: low
Imaging/other
- DEXA scan: if osteoporosis suspected
State some potential differential diangoses for anorexia nervosa
- Bulimia nervosa
- Eating disorder not otherwise specified (EDNOS)/ atypical eating disorder- similar to anorexia nervosa, bulimia nervosa and/or binge eating but doesn’t met diagnostic criteria
- OCD
- Depression
- Alcohol or substance misuse
- Schizophrenia with delusions about food
- Organic cause e.g. diabetes, hyperthyroidism, malignancy
Discuss how the body adapts to low body weight
Sick euthymic syndrome occurs: a state of adaptation or dysregulation of thyrotropic feedback control wherein the levels of T3 and/or T4 are abnormal, but the thyroid gland does not appear to be dysfunctional. Adjusts thyroid hormone levles to reduce metabolic requirements leading to:
- Reduced resting metabolic rate
- Reduced body temp
- Bradycardia
Body can continue like this for some time but eventually will decompensate and it’s hard to predict when. This is why pts with AN can look well as they haven’t decompensated yet.
State some potential complications of anorexia nervosa
To help, think about different body systems:
- Endocrine
- Cardiovascular
- GI
- Renal
- Neurological
- Haematological
- Metabolic
- MSK
Also risk of refeeding syndrome when reintroduce food
Discuss the management of anorexia nervosa using the biopsychosocial model
- Structured eating plan with oral nutrition
- Monitoring of weight
- Psychoeducation regarding nutrition
- Psychotherapy:
- CBT for AN (indiviudal)- abou 40 weeks
- MANTRA (maudsley anorexia nervosa treatment for adults. Like CBT but with bit extra)
- Interpersonal therapy
- Family therapy in children (about 20 sessions)
- Treatment of medical complications e.g. electrolyte disturbnaces
- Treatment of any co-morbid conditions
- Support groups e.g. Beat eating disorders
- Admission if required
Alongside biopsychosocial management mentioned in previous flashcard, state some other aspects of the management of anorexia nervosa
- Risk assessment (self harm, sucide, medical complications)
- Whether hospitalisation is required (severe anorexia BMI <14 or severe electrolyte abnormalities)
- Do you need MHA or children’s act for life-saving treatment e.g. NG feeding
Treatment for anorexia nervosa is usually as an outpatient, when woudl you need hospitalisation?
- Severe anorexia with BMI <14
- Physical/medical complications that require treatment
- Significan trisk e.g. suicide
What is the weight gain targets in anorexia nervosa for:
- Inpatients
- Outpatients
- Inpatients: 0.5-1kg/week
- Outpatients: 0.5kg/week
What guidelines can you use to help treat pts with anorexia nervosa?
MARSIPAN: Management of really sick patietnts with anorexia nervosa
NOTE from lecture: common myth is that if you binge and vomit you must have bulimia but in fact you could have binge purge AN. It’s about BMI and other endocrine disturbances (based on current ICD-10 criteria)
Summary of medical complications of AN from lecture
Refeeding syndrome is a potential complication of anorexia nervosa, discuss:
- What it is
- Whether route of nutrition affects risk
- Biochemical features- highlighting hallmark electrolyte distrubance
- Potentially life-threatening condition defined by severe electrolyte and fluid shifts as a result of a rapid reintroduction of nutrition after a period of inadequate nutritional intake.
- Route of nutrition does not affect risk
- Biochemical features:
- Hypophosphataemia
- Hypomagnesaemia
- Hypokalaemmia
- Fluid shifts/abnormalities in fluid balance
*High carboydrate feeding is most risky!
Explain the pathophysiology of refeeding syndrome
- In starvation, secretion of insulin is decreased because there is reduced intake of carbohydrates
- In starvation, body uses fat & protein stores to produce energy
- During prolonged starvation several intracellular minerals become depleted however plasma concentrations often remain normal (as most of minerals intracellular).
- When re-introduce food, glycaemia causes insulin surge and you get a sudden shift from fat catabolism to carbohydrate catabolism
- Insulin stimulates glycogen, fat & protein synthesis; all of which requier minerals such as phosphate, magnesium & co-factors such as thiamine
- Phosphate, magnesium & potassium are taken up by cells and water follows by osmosis
- Decreases plasma concentration of phosphate, magnesium & potassium
- Furthemore, the change in carbohydrate metabolism causes an increase in Na+ and water retention so if you hydrate pt with aim of achieving normal fluid output they will become quickly fluid overloaded
Another summary of refeeding syndrome focusing on phosphate
State some clinical features of refeeding syndrome
- Fatigue
- Weakness
- Confusion
- Arrhythmias
- Difficulty breathing
- Hypertension
- Oedema
- Heart failure
Hypophosphataemia is hallmark of refeeding syndrome; what can hypophosphataemia lead to (in the heart)?
Phosphate depletion causes reduction in cardiac muscle activity which can lead to cardiac failure
Dsicuss how you can prevent refeeding syndrome
- Identify risk (use MUST screening tool)
- Measure serum electrolytes prior to feeding (phosphate, magnesium, potassium, calcium)
- If low, replace orally or IV. Consider replacement of thiamine and other vitamins. *NOTE: latest guidance says you can correct fluids, electrolytes and vitamins as you start feeding- don’t have to correct before as this prolongs malnourishment
- Slow initial feed rate/low calorie intake and gradually increase every 5 days
- Monitor bloods
- Monitor for clinical features of refeeding syndrome e.g. hypertension, oedema, tachycardia
How do you treat refeeding syndrome?
- Slow done rate of feeding/decrease calories
- Replenish electrolytes & vitamins
State some potential complications of refeeding syndrome
- Cardiac failure
- Seizures
- Respiratory failure
- Renal failure
- Death
Discuss prognosis of anorexia nervosa
- Recovery
- Soruces vary from 25% to 46% (NICE) making full recovery
- 34% partial recovery
- 20% chronic anorexia nervosa
- Relapse is common (30%) and is most likely in first year
- Mortality rates are >5x higher for people with anorexia nervosa
Why is anorexia nervosa so difficult to treat?
Ego-systonic (it feels right so people don’t want to stop)
Other factors include:
- AN helps them manage their emotions
- Helps them control relationships (e.g. might fear partner will leave if get better but won’t leave an ill person)
- Helps them communicate (if they get better people will think they are okay but they aren’t)
- Self-esteem (being really good at losing weight increases their self-esteem)
Define bulimia nervosa
Eating disorder characterised by repeated episodesof uncontrolled binge eating followed by compensatory weight loss behaviours and overvalued ideas regarding ideal body shape/weight.
Discuss the epidemiology of bulimia nervosa, include:
- Age os onset
- Male:female ratio
- Socioeconomic class distribution
- Adolescence- young adult (age of presentation of BN is slightly later than AN)
- More common in females (male:female, 1:10)
- Equal socioeconomic class distribution unlike AN which is more common in higher classes
- BN could develop as sequel to persistent AN pts (e.g. start to recover but then become BN) and vice versa
State some predisposing risk factors for bulimia nervosa- include biological, psychological & social
*NOTE: role of genetics in BN is unclear but in AN there is clear genetic link
State some precipitating risk factors for bulimia nervosa- include biological, psychological & social
State some perpetuating risk factors for bulimia nervosa- include biological, psychological & social
Describe the vicious cycle of bulimia nervosa
- Get strong cravings
- Binge eat
- Then feel guilty about binge eating
- Then do compensatory behaviours e.g. self-induced vomitting, exercising excessively, laxative abuse or alternate binge eating with prolonged periods of starvation
Discuss the psychology behind bulimia nervosa
There are two subtypes of bulimia nervosa (however ICD-10 does not differentiate between the two); state and describe the two subtypes of bulimia nervosa
- Purging type: pt uses self-induced vomiting and other ways of expelling food from body (e.g. laxatives, enemas, diuretics)
- Non-purging type: pt used excessive exercise or fasting after a binge. Purging types may also exercise and fast but this is not the main form of weight control for them
- *PURGING type is most common*
Discuss the ICD-10 criteria for bulimia nervosa
*HINT: Bulimia Patients Fear Obesity
- Behaviours to prevent weight gain to compensate for binge eating
- Preoccupation with eating (a sense of compulsion/craving to eat which leads to bingeing. Bingeing typically followed by regret or shame)
- Fear of fatness (pt sets themselves sharply defined weight threshold, well below the premorbid weight that constitutes the optimum or healthy weight in the opinion of the physician)
- Overeating (rule of thumb should be at least 2 episodes per week over a period of 3 months but ICD-10 does not specify this)
Alongside features listed in ICD-10 criteria, state some other features of bulimia nervosa
- Normal weight: usually potential for weight gain from bingeing is counteracted by weight loss behaviours
- Depression and low self-esteem
- Irregular periods
- Signs of dehydration (decreased BP, dry mucous membranes, increased cap refill time, decreased skin turgor, sunken eye
- Often a history of AN (AN may not have been fully expressed/just seen as minor episode)
State some examples of compensatory weight loss behaviours seen in BN
- Self-induced vomiting
- Alternating periods of starvation
- Drugs
- Laxatives
- Apetite supressants
- Thyroxine
- Amphetamines
- Diuretics
- Excessive exercise
- Omit or reduce insulin if diabetic (diabulimia)
State some common co-morbid conditions in bulimia nervosa pts
- Depression
- Anxiety
- DSH
- Substance misuse
- EUPD
Hypokalaemia is a potentially life-threatening complication of excessive vomiting, discuss:
- Threshold for hypokalaemia
- Clinical features
- ECG features for hypokalaemia
- Management (of mild and of severe)
- <3.5mmol/L
- See image for clinical features
- ECG:
- Flattened/inverted T
- Prominent U wave
- Increase P wave amplitude
- Prolonged PR
- Management:
- Mild (3-3.4): oral replacement e.g. K+ rich foods and/or oral supplements (Sando-K)
- Severe (<2.5): IV K+ replacement
Some example questions for bulimia nervosa history
Discuss potential MSE for bulimia nervosa pt
What investigations would you do for a pt with bulimia nervosa?
Structure your answer bedside, bloods & imaging/other
Bedside
- ECG: check for arrhythmias as consequence of hypolakaemia
- VBG: check electrolytes quickly, may show metabolic akalosis from vomiting
- Plasma glucose
Bloods
- FBC: may be anaemic
- U&Es: check for hypokalaemia, urea may be raised if dehydration
- LFTs: drug overdose or excessive exercise may elevate
- CK: drug overdose or excessive exercise may elevate
- Magnesium: may be low
- Phosphate: may be low
- Calcium: may be low
Imaging/other
- ?dexa scan
State some differential diagnoses for bulimia nervosa
- Anorexia nervosa with bulimic symptoms
- EDNOS
- Depression
- OCD
- Organic causes of vomiting e.g. gastric outlet obstruction
State some potential complications of bulimia nervosa
- Dehydration
- Pancreatitis
- Hypokalaemia
- Oesophageal rupture
- Tooth erosion
- Irregular periods
State some potential complications of repeated vomiting in bulimia nervosa
Images of signs seen from excessive vomiting
Discuss the management of bulimia nervosa
Structure as first line, second line etc… think about biopsychosocial model
First line:
- CBT- BN (CBT specifically designed for BN)
- or family therapy (children)
- Nutrition counselling by trained dietician
- Meal support (therapist can give techniques to avoid binge eating e.g. eating in comppany, distractions, manageing triggers)
- Support groups
Other options if above doesn’t work:
- SSRIs (fluoxetine 60mg) BUT less effective than CBT
- Other psychotherapies e.g. interpersonal therapy
Alongside biopschosocial managment of BN, state some other aspects of management
- Risk assessment
- Monitoring of electrolytes
Discuss the prognosis of bulimia nervosa
- Better recovery rates & lower mortality than anorexia nervosa
- 30-60% make full recovery
- Nature of illness is often relapsing & remitting
Compare anorexia nervosa & bulimia nervosa in terms of:
- Weight
- Endocrine disturbances
- Carvings & bingeing
- Compensatory weight loss behaviours
What is binge eating disorder?
Recurrent episodes of binge eating withouth compensatory behaviours
What proportion of pts referred to ED clinics have atypical/other eating disorders?
1/3, could be:
- Atypical AN
- Atypical BN
- Binge eating disorders
- Others which defy classification
*Idea that can think of as on a spectrum and may not completely fit into one diagnosis
Slide from lecture of risk factors for ED’s
When would you consider inpatient admission for EDs?
- Wants to change but not progressing with outpatient treatment
- Immediate danger
- No adequete treatment locally
What predicts a good outcome in EDs?
- Pt has motivation to change
- Short duration of illness
- Level of severity/mild
- Onset in adolescence
- Good family function
- Lack of comorbid conditions
