Over the next 3 days, she continued to be managed with high-frequency ventilation, inhaled nitric oxide and inotropic infusions, in line with the presumed diagnosis of PPHN. Over this weekend, she remained clinically stable on this support but there was no opportunity to wean the inspired oxygen, which remained at 100 % on 20 ppm of iNO. Her arterial blood gases were satisfactory during this period. Therefore, little change was made with the hope that with supportive management the pulmonary hypertension would improve.

On Monday, day 4 of life, she was assessed by a different team who were starting their week on service. On review it became clear that, although her clinical parameters and blood gases were satisfactory on the support she was receiving, there was no evidence of improvement of her oxygenation. The presumptive diagnosis of PPHN was therefore challenged and it was noted that her oxygen saturations did not deteriorate when the oxygen was reduced. The question of possible cyanotic congenital heart disease was raised, given the lack of response to the management of PPHN and supplemental oxygen.

An echocardiogram was immediately repeated which showed evidence of a supra-cardiac total anomalous pulmonary venous connection (TAPVC) (Fig. 15.3). The findings were discussed with the paediatric cardiologist at the regional paediatric cardiac centre who agreed with the findings. Following this, the support was slowly weaned, and the baby came off all inotropes and iNO and was managed with ventilation alone. She was transferred to the paediatric intensive care unit at day 7 of life for the surgical management of her TAPVC.