Eating Disorders: GP Tips

Eating Disorders: GP Tips

With thanks to Prof Chris Fairburn (Professor of Psychiatry at the University of Oxford, and author of CBT and Eating Disorders and Overcoming Binge Eating) and Dr Debbie Waller (GP, co-editor Oxford Book of Women’s Health and part of the NICE Eating Disorders Guidelines Development Group).

How common are eating disorders, and how are they defined?

Anorexia Nervosa (1 or 2 patients per 2,000 people)

• Extreme concern about shape and weight (with denial of thinness)
• Marked under eating and maintenance of an unduly low body weight (BMI<17.5)

Bulimia nervosa (18 per 2,000)

• Extreme concern about shape and weight (marked fear of fatness)
• Strict dieting punctuated by frequent episodes of loss of control (binges)
• Extreme behaviour to try to avoid weight gain e.g. self-induced vomiting, strict dieting, mis-use of laxatives etc

 ENDOS ‘eating disorder not otherwise specified’ (>20 per 2,000)

• Resembles AN or BN but do not meet their diagnostic criteria

How should I pick them up?

By thinking and asking! Often hidden due to denial (AN) or shame about binge eating (BN), and often somatic or psychiatric presentations before diagnosis. Keep antennae alert, and consider if

• Low weight in a young woman
• Inappropriate requests for help with dieting
• Fatigue, dizziness, syncope, GI symptoms
• Oligomenorrhea
• Depression (or Anxiety)

And ask the questions:

• Do you think you have an eating problem? 
• Do you have a problem controlling your eating?
• Do you worry unduly about your weight?  Do other people think you do?

Safety first: how should I assess patients’ level of risk?

Measure and record:

• BMI, BP and pulse
• Muscle strength (’the squat test’)
• Co-existent psychopathology
• Depression, anxiety, self-harm and suicide risk
• Lab tests
• Routine blood tests sufficient (FBC, electrolytes, glucose)
• Monitor electrolytes if repeated vomiting/laxative abuse
• Check ECG if BMI<15.5
• Check bone density scanning if amenorrhoeic

What are the broad principles of management?

• Recognition by the patient that they have a problem is the critical first step
• This process may take many weeks and requires a good therapeutic relationship, sensitive handling and family involvement
• Reliable education from reliable sources are key
• Teenagers: either family therapy or CBT.
• Adults: outpatient CBT is key, especially for BN and associated eating disorders. CBT is now also the leading treatment for AN, if the patient can be managed on an outpatient basis. Treatment of severe AN may require a more intensive, approach
• Regular monitoring of physical health by GP if needed.
• Weight only needs regular monitoring if BMI is very low, or dropping
• Osteoporosis may develop quickly in AN, and is partially reversible. Restoration of weight and normal menstruation is key. There is no evidence to support drug treatment (e.g. COCP or HRT) although supplementation with calcium and vitamin D is generally recommended.
• Encourage dental review in patients with frequent vomiting
• Comorbid depression responds to antidepressant medication (fluoxetine well tolerated) but higher than usual doses are often required.

When should I refer to specialist services?

• Refer early to specialist services all cases of AN
• Urgent referral if BMI <13.5, accelerated/rapid weight loss (>1kg per week) and/or significant medical/psychiatric complications
• BN
• GP-guided self-help is first step.  
• Recommend ‘Overcoming Binge Eating’, and offer to see every 2-4 weeks for support/encouragement
• Fluoxetine 60mg mane is not routinely recommended, as the therapeutic effect is so transitory in reducing binges. However, have low threshold for treating co-morbid depression.
• If fail to respond, refer for individualized CBT

What about University students and fitness to study?

Oxford University Guidelines for intermission from college:

• Significantly compromised physical (e.g. BMI<15  women <16 for men, electrolyte disturbance) or mental state
• Rapid weight loss e.g. >0.5 kg per week
• Fit to return when stable physical and mental state and BMI >16

Useful reading

·        Fairburn, CG.  Overcoming Binge Eating. Guilford Press, New York.

·        Treasure, J.  Anorexia nervosa: a survival guide for families, friends and sufferers. Psychology Press, Hove.

·        Abraham, S and LLewellyn-Jones, D. Eating Disorders: the Facts. OUP.

Recommended website: Eating Disorders Association: http://www.edauk.com/

Simon

With many thanks to Prof Chris Fairburn for his expert advice

http://www.psychiatry.ox.ac.uk/research/researchunits/credo/professor-christopher-fairburn