17 - Eating Disorders Flashcards
What is anorexia nervosa and the epidemiology of this?
Eating disorder characterised by restriction of energy intake resulting in low body weight and an intense fear of weight gain
More common in females
0.1-0.3% prevalence at any time
What are some risk factors for developing anorexia nervosa?
- Female
- Age (young)
- FHx of eating disorders, depression, or substance abuse
- Previous criticism of eating habits and weight
- Increased pressures to be slim (e.g. ballet dancers, models, athletes)
- History of sexual abuse
- Low self-esteem
- Obsessive personality
- Emotionally unstable personality disorder
What are some clinical features of anorexia nervosa?
- Restriction of energy intake
- Low body weight
- Features of body dysmorphia
- Intense fear of weight gain
- Rapid weight loss
- Aggressive weight-loss techniques (laxatives, diuretics, vomiting)
- Often a lack of insight or denial
- Withdrawal from social settings
- Loss of libido
What are some signs you might see of someone with anorexia nervosa?
- Amenorrhea
- Lanugo
- Hypothyroidism
- Hypotension
- Hypokalaemia
- Hypothermia
What are some cardiac complications with anorexia nervosa?
- Arrhythmia
- Cardiac atrophy
- Sudden cardiac death
What is a screening questionnaire you can use for anorexia?
Used in primary care to help refer on, score of 2 or more could mean anorexia or bulimia
SCOFF
- S – Do you make yourself Sick because you feel uncomfortably full?
- C – Do you worry you have lost Control over how much you eat?
- O – Have you recently lost more than One stone (6.35 kg) in a three-month period?
- F – Do you believe yourself to be Fat when others say you are too thin?
- F – Would you say Food dominates your life?
What is the ICD-10 diagnostic criteria for anorexia nervosa?
- Weight <85% expected or BMI<17.5
- Avoidance of fattening foods or compensatory behaviours
- Disordered body image
- Wide spread endocrine disorder e.g amenorrhea
What are some compensatory behaviours in anorexia nervosa?
- Calorie limits
- Avoiding food groups
- Food rules e.g timing, only when others eat
What management plan is used for eating disorders?
MARSIPAN
What examinations should you do if you suspect someone to have anorexia nervosa?
- Hydration status
- Height, weight and BMI. Centile chart if <18
- Vital signs: bradycardia, hypothermia and postural blood pressure drop
- Sit-up, Squat–stand test: tests the patient’s ability to sit up from lying and to squat down and stand back up
What investigations should you do for someone with anorexia?
- ECG: bradycardia, prolonged QT interval or arrhythmias
- Blood sugar: hypoglycaemia
- Blood tests: FBC, LFTs, U+Es, TFT, bone profile, magnesium
- Additional: pregnancy test and hormonal panels
How is anorexia nervosa managed in general terms?
- Talking therapies
- Supervised weight gain: weight gain of 0.5–1kg/week being wary of refeeding syndrome
- Inpatient: if bradycardia, ECG changes, electrolyte abnormalities, very low BMI, rapid weight loss, dehydration, organ failure, suicide risk)
What talking therapies are used in anorexia nervosa?
CBT-ED, MANTRA, SSCM
- CBT
- Interpersonal
- Supportive
- Family therapy - First line for children (FT-AN)
What is the prognosis with anorexia nervosa?
1⁄3 recover completely, 1⁄3 improve, and 1⁄3 develop a chronic eating disorder
Highest mortality of any mental health illness (5x general population)
Causes of death: cardiovascular complications, infections and suicide
Mortality is higher if: aged 20–29 at presentation, delayed access to treatment, bingeing, and vomiting
What is refeeding syndrome and the pathophysiology of this?
If nutritional intake is resumed too rapidly after a period of relatively low caloric intake
Rapidly increasing insulin levels lead to shifts of potassium, magnesium and phosphate from extracellular to intracellular spaces. Also utilisation of thiamine
This is potentially fatal
What are some risk factors for refeeding syndrome?
What are the features of refeeding syndrome?
- Oedema
- Confusion (Wernicke’s as thiamine stores only last 7 days)
- Tachycardia
- Hypotension
- Seizures
How is refeeding syndrome diagnosed?
HYPOPHOSPHATAEMIA
‘Refeeding’ bloods
- Urea & electrolytes (gives a potassium)
- Bone profile (gives a phosphate)
- Magnesium
- Blood glucose monitoring
- ECG monitoring
What actions are taken to prevent refeeding syndrome?
Before initiation of feeding:
- Electrolyte derangements should be corrected
- Patients started on thiamine or Pabrinex
- ECG to look for QTc and any arrhythmias
Feeding:
- No more than 50% of energy requirements if > 5 days with minimal intake
- Alternatively, aim for 10-20 kcal/kg/day in high-risk patients and increase over 5-7 days as possible with electrolyte correction
- Daily monitoring of refeeding bloods
- ECG monitoring
What is Bulimia Nervosa and the epidemiology of this?
Eating disorder characterised by episodes of binging followed by purging (usually by induced vomiting but laxative abuse is also common)
Often have a normal BMI
0.5-1% prevalence
What is the ICD10 criteria for bulimia?
A. Recurrent episodes of overeating (binges)
B. Persistent preoccupation with eating and a strong desire to eat (craving).
C. The patient attempts to counteract the fattening effects of food by compensatory behaviours
What is a binge and a purge?
- Binge eating: Loss of control, eating enormous amounts with thousands of calories, often in sense of urgency and compulsion
- Purging: binges causes feelings of shame and guilt leading to attempts to ‘undo damage’ vomiting, laxatives, diuretics, can also be exercise
What are some features you may spot in an OSCE or GP with someone with bulimia?
- BMI >17.5
- Dental erosion
- Parotid gland swelling
- Russell’s sign (calluses on knuckles)
- Complaints of reflux or abdo pain
What are some biochemical changes you may see on the bloods of a person with bulimia?
- Hypokalaemia
- Alkalosis on blood gas due to vomiting HCL
How is bulimia managed?
- CBT
- Fluoxetine
What is binge eating disorder?
Type of atypical eating disorder
Episodes where the person excessively overeats, often as an expression of underlying psychological distress
Not a restrictive condition and patients are likely to be overweight
Why may hypothyroidism develop in an eating disorder?
The body adjusts its free T4 to reduce its metabolic requirements
The GP suspects Josie has an ED, what is important to enquire about in the history?
The GP decides to arrange some initial investigations before making a referral to the Eating Disorders team. What should they request?
What aetiological/epidemiological factors can contribute to developing an eating disorder?
- Genetic
- Personality traits – perfectionism, cluster C traits
- Societal – social media, advertising, pursuit of size 0 culture.
- Family environment – Familiar pressure to succeed, conflict in family home, overprotectiveness
- Social class – higher rates in middle to high income families
Why is there amenorrhea in anorexia nervosa?
Decreased leptin as less adipose tissue so less stimulation of GnRH secretion, less FSH/LH, less oestrogen
Why are TCAs dangerous in anorexia?
QTc prolongation
