Psychiatry - Anorexia Nervosa Flashcards
Defintion
Eating disorder where Px partake in behaviour which interferes with weight gain due to a complex overlay of biopsychosocial factors.
Epidemiology
- Female gender
- Adolescence : two peaks at 14 years old and 18 years old
- Obsessive and perfectionist traits
- Family history
- Low self-esteem
- History of adverse life events
Pathophysiology
There is a strong genetic component with a 12-fold increased risk in those with a positive family history. The role of impaired neurotransmitter signalling has been implicated, with reward pathways involving serotonin and dopamine affected, as well as satiety-related hormones such as adiponectin and ghrelin
Signs
- Low BMI
- Dry skin and hair loss
- Hypothermia
- Bradycardia
- Postural hypotension
- Enlarged salivary glands
Symptoms
- Calorie restriction
- Prevention of weight gain e..g purging or laxatives
- Fear of gaining weight
- Body image disturbances
- Fatigue and poor concentration
- Amenorrhoea
Diagnosis
FBC -
- normocytic anaemia
- mild leukopenia
- thrombocytopenia
- elevated growth hormone, glucose, cortisol, cholesterol, carotinaemia
Serum biochemistry -
- all electrolytes typically low
- metabolic alkalosis from vominting
- hypoglycaemia
LFTs -
- mild transaminitis due to malnutrition
TFTs -
- Low T3 common but T4 and TSH often normal
Hormones
- Low LH, FSH, oestrogens, and testosterone
ECG -
- Prolonged QTc
- Bradycardia
Urinalysis
- Ketonuria due to starvation
Screening tools
The SCOFF questionnaire: ≥2 positive answers suggest anorexia or bulimia nervosa, but this alone cannot be used to make a diagnosis:
- Sick = Do you ever make yourself sick because you feel uncomfortably full?
- Control = Do you worry that you have lost control over how much you eat?
- One stone = Have you recently lost more than one stone in a 3-month period
- Fat = Do you believe yourself to be fat when others say you are too thin?
- Food = Would you say that food dominates your life
Diagnostic criteria
DSM-5:
- Restriction of energy intake = 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 = Despite being significantly underweight
- Disturbance in body image = Undue influence of body weight or shape on self-evaluation, or persistent lack of recognition of the seriousness of the current low body weight
Mild: BMI ≥ 17 kg/m²
Moderate: BMI 16-17 kg/m²
Severe: BMI 15-16 kg/m²
Extreme: BMI < 15 kg/m²
Treatment
- Patients must be urgently referred to a community-based eating disorder service.
- Management following referral includes psychotherapy and a structured eating plan .
- If the patient is deemed high risk they can be admitted to an inpatient unit.
- Psychotherapy for children:
FIRST LINE: anorexia-focused family-focused therapy
Second-line : individual eating-disorder-focused cognitive behaviour therapy (CBT)
Psychotherapy for adults: One of:
- Individual eating-disorder-focused CBT
- Maudsley Anorexia Nervosa Treatment for Adults (MANTRA) or
- Specialist Supportive Clinical Management (SSCM)
Complications
Metabolic:
- Poor nutrition leads to low electrolytes
- Rapid refeeding can lead to potentially life-threatening electrolyte imbalances, known as refeeding syndrome
Endocrine : anorexia causes disruption of the hypothalamic-pituitary axis, e.g. primary amenorrhoea
Cardiac: conduction defects e.g. long QTc , hypotension
Musculoskeletal: osteopenia or osteoporosis, which may not be corrected even with restoration of nutrition
