[Clinical thinking and decision-making in practice. A new-born with dyspnea].

A 2-day-old girl, born at term after an uneventful pregnancy and delivery, was admitted to the paediatric intensive care unit with dyspnoea and tachypnoea. Misleading interpretations of the radiological investigations suggested a congenital diaphragmatic hernia. The patient underwent laparotomy but a diaphragmatic hernia was not found. Meanwhile the patient developed unexplained pulmonary hypertension and a progressive forward failure of the heart. The differential diagnosis did not take the pulmonary hypertension into account. Finally further investigations led to the diagnosis of a very rare congenital pulmonary vascular anomaly: an absent left pulmonary artery and systemic to pulmonary collateral arteries. The condition was considered inoperable and the patient, whose condition meanwhile had deteriorated markedly, died. This case illustrates (a) that the differential diagnosis must be based on all of the abnormal clinical findings, which should preferably be grouped together under one final diagnosis, and (b) that one must not jump to conclusions--which in this case led to unnecessary diagnostic and therapeutic interventions--, but as long as a diagnosis cannot be established, the diagnostic investigations should not be considered completed.