An infant with respiratory distress and failure to thrive.

A 4-month-old male was referred to the Dept of Paediatric Surgery at the authors9 institution, for the investigation of respiratory distress, failure to thrive and complete situs viscerum inversus since birth. A chest radiograph obtained a few hours after birth showed situs viscerum inversus, left apical atelectasis, hyperinflation and hyperlucency of the remaining left lung, and a mild shift of the mediastinum toward the right. The right lung was normal. The infant was born at term, after an uneventful pregnancy, by elective caesarean section. The parents were consanguineous and the baby had a positive maternal family history for situs viscerum inversus and chronic respiratory diseases. On admission, the infant9s general condition was poor, his body weight was 5.490 kg (5th percentile) and he was 62.5 cm in height (10th percentile). Clinical examination disclosed tachypnoea (70 breaths?min), chest retractions and barrel chest. The arterial oxygen saturation in room air was 90% when the child was awake, reaching 97% with 2 L?min of oxygen. The cardiac frequency was 150 beats?min. On examination of the chest, auscultation revealed diffuse bilateral expiratory wheezing and right posterobasal crackles. The remainder of the examination was compatible with situs viscerum inversus and negative. Cardiac evaluation (electrocardiogram and echocardiogram) was compatible with dextrocardia. Arterial blood gas analysis at room air showed an arterial oxygen tension of 6.8 kPa (51 mmHg) and an arterial carbon dioxide tension of 5.7 kPa (43 mmHg). Red blood cells were found at a level of 5.05610?L, haemoglobin at 14 g?dL, white blood cells at 12.66 10 L (neutrophils 37%, eosinophils 3%, basophils 2%, lymphocytes 51%, and monocytes 7%), and the erythrocyte sedimentation rate at the first hour was 13. C-reactive protein, immune profile, blood chemistry, and sweat test were normal. Microbiological studies for common bacteria, Mycoplasma pneumoniae, Chlamidia trachomatis, respiratory viruses, cytomegalovirus, and Epstein Barr virus, were negative. A chest radiograph was repeated (fig. 1). Flexible bronchoscopy showed a slightly right-shifted trachea and a normal inverted bronchial tree, without signs of inflammation or mucus plugs. The child also underwent perfusion (fig. 2) and ventilation lung scintigraphy, with measurement of the ventilation/perfusion ratio (V9/Q9 ratio), and virtual computed tomography (CT) scan (fig. 3). The V9/Q9 ratio calculated from the lung scan showed a moderate mismatch involving the right upper lung (V9/Q9 ratio: 2.2–2.3), with a normal right lower lobe (V9/Q9 ratio: 0.86–1.08) and left lung (V9/Q9 ratio: 0.85–1.04).