Case reports CASE 1

A 26 year old man was admitted to hospital with a history of two to three days of nausea and vomiting and increasingly frequent watery stools. He had also complained of a sore throat for two to three days, for which his family doctor had prescribed pivampicillin. He had not travelled overseas nor had he eaten any food outside his own home. He worked as a security officer near the Thames but never swam there. He had no previous history of weight loss, abdominal pain, or cardiovascular symptoms nor any important past medical history.

Initial examination showed him to be dehydrated with a temperature of 37.5°C, a pulse rate of 120 beats a minute, and blood pressure of 85/60 mm Hg (with no postural drop). No hyperpigmentation of skin creases or mucous membranes was noted. His tonsillar bed was inflamed. Examination of his abdomen was unremarkable. Haematological investigations gave normal results, in particular sodium 135 mmol/l (normal range 135-150 mmol/l), potassium 5.9 mmol/l (normal range 3.5-5.3 mmol/l), creatinine 233 µmol/l, urea 15.4 mmol/l, and glucose 3.9 mmol/l (normal range 3.0-8.0 mmol/l).

His electrocardiogram showed a sinus tachycardia with a normal axis, voltage, and T waves. A chest x ray picture revealed a normal heart with normal lung fields. Urine analysis and microscopy were …