[Clinical thinking and decision making in practice. A child with tachypnea and dyspnea].

A 6-year-old girl had been ill for a number of weeks, had fever for 5 days and complained of pain below the left costal arch and in the left shoulder, linked to the breathing. An unexplained tachypnoea was also present. The leukocyte differentiation showed 90% blasts; a bone marrow puncture then led to the diagnosis of acute non-lymphatic leukaemia, and hyperhydration and alkalinization were started. The patient died unexpectedly after a few days from massive leukostasis in pulmonary arteries. If vital functions are impaired, it should always be attempted to find an explanation, for which an underlying disease may serve as a guideline.