History
A 21-year-old woman presents in the emergency department with acute abdominal pain and vomiting and diarrhoea. The pain is cramping in nature. The diarrhoea and vomiting have been present for 2 days without any abatement. Prior to this her eating has been very variable. Sometimes she goes for the whole day without eating as she does not like eating in public. Occasionally she gets ravenous and eats large quantities of junk food (for example, whole packets of biscuits and cakes). She then tends to feel guilty and says that the guilt makes her feel sick. She does not like how she looks as she feels she is much bigger than her peers and she cannot wear current fashions as well as they can. She has not been on holiday and has not been unwell, although is gradually feeling weaker. She denies being on any prescribed medication but says she had been taking a herbal remedy to clear her bowels as part of a detoxification programme. Recently she says she is not depressed, can enjoy herself and has no thoughts of self-harm. She has not used any illicit drugs, does not smoke and only occasionally consumes alcohol. There is no other previous history of note.
Physical examination
The woman looks dehydrated. She has no fever. Her pulse is 84/min and her blood pressure is 130/70 mmHg. Her body mass index (BMI) is 24.9 (height 152 cm, weight 58 kg). She has calluses on her knuckles (which she states she got having hit her hand on a wall). Her teeth are discoloured and in poor condition.
Her abdomen is not tender and rectal examination shows that she is constipated.
Normal Haemoglobin 12.8 g/dL 11.7–15.7 g/dL White cell count 8.8 × 109/L 3.5–11.0 × 109/L
Platelets 280 × 109/L 150–440 × 109/L
Sodium 139 mmol/L 135–145 mmol/L
Potassium 3.1 mmol/L 3.5–5.0 mmol/l
Urea 4.4 mmol/L 2.5–6.7 mmol/L
Glucose 5.3 mmol/L 4.0–6.0 mmol/L
Creatinine 75 μmol/L 70–120 μmol/L Alkaline phosphatase 88 IU/L 30–300 IU/L Alanine aminotransferase 12 IU/L 5–35 IU/L
ANSWER 39
When considering the gastrointestinal presentation, many things are ruled out by history, examination and investigations. These include gastrointestinal problems (especially upper GI tract) such as infection or repeated vomiting as a result of physical disorders (for example, right ventricular failure). Prolonged starvation does not fit with the body mass index. Anxiety or depression should be monitored but given her history bulimia is the most likely diagnosis. The hypokalaemia and signs on the knuckles and teeth are likely caused by repeated self-induced vomiting. The purging type is the most likely as she has been making herself sick and she may also have been using diuretics to control her weight. Hypokalaemia can be caused by the sudden uptake of potassium ions from the bloodstream by muscle or other organs or by an overall depletion of the body’s potassium. The most common cause of hypokalaemia is diuretics. Other common causes of hypokalaemia are excessive diarrhoea, enema abuse or vomiting. It can also occur in medical conditions such as diabetes (ketoacidosis), adrenal tumours, hyperaldosteronism and renal artery stenosis, although these can be ruled out by history and investigation. Up to 20% of people complaining of chronic diarrhoea practise laxative abuse. Laxative abuse is often part of eating disorders, such as anorexia nervosa or bulimia nervosa. Hypokalaemia in eating disorders may be life-threatening with symptoms ranging from lethargy and cloudy thinking to cardiac arrhythmias and death.
The acute management will be to medically stabilize this woman. She will need to be carefully monitored while she is assessed and treated. Treatment of the hypokalaemia involves addressing the cause, in this case psychoeducation about the risk this woman is putting herself at. High-potassium food such as oranges and bananas can be used for mild hypokalaemia (not below 3 mmol/L) with oral potassium supplementation if necessary. If her potassium levels were below 2.5 mmol/L, intravenous potassium should be given. The speed of administration should be slow to avoid rapid changes in potassium levels, which can trigger adverse events such as arrhythmias. Regardless she will need referral for the support and management of her bulimia nervosa.
In bulimia there is often a lack of control over eating, sometimes to the point of physical discomfort. Eating patterns are often not healthy and may be covert. There may be signs of purging such as going to the bathroom after meals to vomit and overt or covert use of laxatives or diuretics. These all need to be addressed.
• Weight gain
• Abdominal pain, bloating
• Chronic sore throat, hoarseness
• Tooth decay and mouth sores
• Broken blood vessels in the eyes
• Swollen cheeks and salivary glands
• Acid reflux or ulcers
• Weakness and dizziness
• Amenorrhoea
Medical complications and adverse effects of bulimia
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The most usual treatment is cognitive behaviour therapy with counselling and support, but there are several other bulimia treatments that are effective. Interpersonal psychotherapy helps people with bulimia solve relationship issues and interpersonal problems that are contributing to their eating disorder. Interpersonal psychotherapy may also help depression and low self-esteem which are common with bulimia. Group therapy is also helpful in bulimia treatment involving education about the eating disorder and strategies for overcoming it. Self-help and support groups are also of benefit. If there is co-morbid depression, consider using selective serotonin reuptake inhibitor medication (SSRIs).
• Bulimia is often well-hidden and may present through medical complications.
• There is often co-morbidity especially with depression, substance misuse and emotionally unstable personality disorder.