Peri-Operative Pulmonary Hypertension in Paediatric Patients: Current Strategies in Children with Congenital Heart Disease

Congenital heart disease (CHD) is responsible for pulmonary hypertension (PH) in children in about 50% of cases. This pre-operative dynamic pulmonary hypertension can be superimposed and aggravated by acute post-operative PH or persist as chronic PH, especially in children who are not operated on early enough. Inhaled iloprost, a stable prostacyclin analogue, is used for the post-operative management of PH in infants and children with CHD. In a prospective open-label proof-of-concept study, the efficacies of inhaled nitric oxide (iNO) and inhaled iloprost were directly compared. Primary endpoints were the occurrence of a major or minor pulmonary hypertensive crisis. No significant difference between the effects of iNO versus iloprost on peri-operative PH was observed. Neither substance on its own prevented pulmonary hypertensive crises in high-risk infants, so a combination of both substances should be tested in future trials. In China, there are more than 4 million untreated CHD patients. More than 50% of them are untreated adults. Acute pulmonary vasoreactivity tests were performed in CHD patients between 9 months and 43 years of age using inhaled iloprost, in order to find out whether a pre-operative response to inhaled iloprost is a good predictor for the post-operative performance of these patients. The results showed that patient selection criteria for surgery should include both a 20% reduction in pulmonary vascular resistance (PVR) index after iloprost inhalation and a resulting PVR index <11 Wood U/m(2). CHD children between 14 days and 11 years of age took part in a placebo-controlled pilot study that investigated the role of aerosolized iloprost in the treatment of PH after corrective surgery. They received either low- or high-dose iloprost or placebo. Inhaled iloprost significantly improved haemodynamics in a dose-dependent manner and prevented reactive PH and pulmonary hypertensive crises in most of these mechanically ventilated children after CHD repair.