Eating Disorders Flashcards
What is the difference between anorexia nervosa (AN) and bulimia nervosa (BN)?
AN: Involves weight loss methods and results in extreme emaciation
BN: binge eating followed by vomiting, BMI can be normal or high
Outline the aetiology of AN and BN using a bio-psycho-social model
Biological:
- Genes: heritability of AN is 58%, less prominent for BN
- Gender and age: AN more common in females aged 16-22, BN usually starts mid-adolescence
- FH: depression, substance misuse, obesity (BN)
Psychological
- Perfectionism and low self-esteem
- Weight loss enhances the sense of achievement and autonomy
- Parental expectation
Social
- Social pressure to be thin (media, promotion of dieting)
- Childhood experience: bullying, abuse, neglect, trauma
- High risk occupations (emphasis on weight and body image): models, athletes, dancers etc.
Define anorexia nervosa (ICD-10/DSM-5)
ICD-10
Anorexia nervosa is a disorder characterized by deliberate weight loss, induced and/or sustained by the patient
DSM-5:
Persistent restriction of energy intake leading to significantly low body weight
Fear of gaining weight, persistent behaviour that interferes with weight gain
Persistent lack of recognition of the seriousness of the current low body weight
What are the 4 main diagnostic points clinically present in AN?
BMI <17.5 or weight 15% less than expected
Deliberate weight loss:
E.g: restricted calorie intake, excessive exercise, laxatives, diuretics, vomiting, thyroxine, stimulants (cocaine), diabetics skipping insulin doses
Distorted Body Image:
Overvalued ideas that they are fat, despite being very thin.
Endocrine Dysfunction:
Amenorrhoea in women and impotence in man.
Libido is lost in both sexes.
AN beginning before puberty: delayed menarche and breast development
Give some physical signs of AN in the following systems: general, CV, GI, musculoskeletal, maetabolic, neurological
General • Emaciation • Dry skin, brittle hair/nails, lanugo hair (fine) • Blue/cold extremities • Anaemia • Low SaO2 • Hypothermia • From vomiting: Russell’s sign (calluses or cuts on knuckles from self-induced vomiting)
CV • Bradycardia • Low BP/postural drop • Peripheral oedema • From vomiting: arrhythmias
GI
• Tender abdomen
• From vomiting: tender abdomen, erosions of dental enamel, ulcers, oesophageal tears
Musculoskeletal
• Muscle wasting (general and proximalmyopathy)
Metabolic
• Hypercholesterolaemia
• Hypercarotenaemia (yellow skin tinge,
especially soles and palms)
Neurological
• Peripheral neuropathy
Outline the appropriate investigations for AN with the key findings
o Height, weight and BMI
o Squat test
Ask the patient to squat down and rise without using their arms (tests proximal myopathy)
o Essential blood tests
• ESR, TFTs (excludes more organic causes e.g. hyperthyroidism, chronic inflammatory disease)
• FBC, U&E, phosphate, albumin, LFT, creatine kinase, glucose
- Most things low
- G’s and C’s raised: growth hormone, glucose, cortisol, cholesterol, carotineamia
o ECG
Bradycardia, arrhythmias and prolonged QT interval
o Other tests as indicated
DEXA (low bond density)
Give some differentials for AN
Medical causes of weight loss
• Hyperthyroidism, malignancy, GI disease, Addison’s disease, chronic infection, inflammatory conditions, AIDS
Depression
• Severe depression (weight loss would NOT be denied unlike in AN)
Bulimia Nervosa
• Bingeing and vomiting can occur in AN
• BN should be diagnosed if bingeing and vomiting is the predominant behaviour and the patient is NOT underweight
Eating Disorders Not Otherwise Specified (EDNOS)
• Term used for atypical presentations
Body Dysmorphic Disorder (BDD)
• Characterised by body image distortion (e.g. nose is misshapen)
• Deliberate weight loss is unusual in BDD
Psychosis
• Self-starvation may occur if food is believed to be poisoned
What are the domains of management of AN?
o Engagement
o Psycho-education
o Treat co-morbid psychiatric illness
o Nutritional management and weight restoration
• Realistic weekly weight gain target (usually 0.5-1 kg/week)
o Psychotherapies
• Motivational Interviewing, Family Therapy, Interpersonal Therapy, CBT
o Medical Treatment
• Particularly important if there are physical complications, rapid weight loss or BMI < 13.5
o Inpatient Treatment
• May be necessary if:
• BMI < 13 or extremely rapid weight loss
• Serious physical complications
• High suicide risk
• Mental Health Act may be needed to enable compulsory feeding
RISK ASSESSMENT
Describe the following psychotherapy management techniques for AN: CBT-ED, SSCM, MANTRA
CBT-ED
o Addresses control, low self-esteem and perfectionism
o Usually up to 40 sessions over 40 weeks
Specialist Supportive Clinical Management (SSCM)
o Offer 20 or more weekly sessions
o Explore the main problems that cause anorexia
o Educate about nutrition and how eating habits cause symptoms
o Also explore other aspects of management (e.g. improving relationships, getting back to work)
Maudsley Anorexia Nervosa Treatment for Adults (MANTRA)
o Offer 20 sessions with a practitioner
o Helps the patient understand the cause of their anorexia (focuses on what is important to the patient)
What is 1st line treatment for children with AN?
Family Therapy
o Some sessions should be for the whole family and others should be separate
o Usually 18-20 sessions over 1 year
o Review 4 weeks after treatment, then every 3 months
Outline the possible complications of AN
General
a. Lethargy and cold intolerance
b. Pancytopenia in severe anorexia
c. Infections due to decreased immunity
Cardiovascular
a. Problems include bradycardia, hypotension (postural drop), arrhythmias (usually secondary tohypokalaemia), mitral valve dysfunction and cardiac failure
- Gastrointestinal
a. Range of constipation and abdominal pain to ulcers, oesophageal tears and gastric rupture due to vomiting.
b. Delayed gastric emptying makes patients feel bloated after eating even small amounts.
c. Nutritional hepatitis occurs in 1/3 of patients, detected by a low serum protein, with raised bilirubin, lactate
dehydrogenase and alkaline phosphatase.
Reproductive
a. In women, amenorrhoea is a diagnostic criterion and infertility (due to atrophy of ovaries or testes) may also
occur in both women and men.
b. Loss of libido
Musculoskeletal
a. Osteoporosis leads to fractures and proximal myopathy is often severe.
Neurological
a. Peripheral neuropathy
b. Delirium
c. Convulsions and coma
AND IMPORTANTLY: REFEEDING SYNDROME
What is refeeding syndrome?
Caused by an intracellular shift of ions due to switching to carbohydrate metabolism
Outline the biochemical and clinical features of refeeding syndrome
Biochemical Features: low phosphate, low magnesium, low potassium, low thiamine, salt and water retention
Clinical Features: fatigue, weakness, confusion, high blood pressure, seizures, arrhythmia, heart failure
Outline the management for refeeding syndrome
- Assess risk
- Prescribe thiamine
- Feed and hydrate gradually
- Monitor electrolytes
What are the 4 main diagnostic points clinically present in BN?
- Binge eating:
o Repeated bouts of overeating characterizes BN.
o Irresistible cravings for food and loss of control
o Binges frequently triggered by distress - Purging:
o Binges cause feelings of shame and guilt, and result in desperate measures to undo the damage e.g. vomiting,
use of laxatives or diuretics. - Body image distortion
o Patients feel fat, are pre-occupied with their shape and weight, and often hate their body - BMI >17.5
o In contrast with AN, patients with BN are normal or slightly increased weight and periods are usually present.
