Management of diuretic treatment: a challenge in the obese patient.

The obesity epidemic is a major health concern. The diagnosis of acute illness and fluid imbalance in the obese patient is complicated by a wide range of comorbidities such as cardiovascular disease, obesity hypoventilation syndrome, non-alcoholic steatohepatitis and lymphoedema. Thus, obesity warrants particularly careful clinical and biochemical assessment owing to its resemblance to fluid retention. Dosing of diuretics is difficult in these patients. The blood urea:creatinine ratio should be widely used to detect emerging cardiovascular and renal complications. This report presents an obese patient with congestive heart failure due to a myocardial infarction, who subsequently was overdosed with diuretics. His prerenal acute renal failure resolved when diuretics were stopped and the high urea:creatinine ratio was diagnostic.