Abstract
Congenital heart defects (CHD) are classified as acyanotic and cyanotic. In cyanotic CHD, a mixing of deoxygenated in oxygenated blood reduces arterial oxygenation and the child may be cyanotic, i.e., bluish. Many children with CHD need cardiac surgery. Congenital cardiac surgery often aims to restore normal circulation and correct the defect as seen in vast majority of pulmonary atresia with ventricular septal defect (PA+VSD), but palliative surgery may also be needed or may be the only possible treatment strategy. After congenital cardiac surgery excessive extravascular lung water (EVLW) may appear and impair optimal gas exchange. Effective clearance of EVLW and lung edema rests on active airway epithelial Na+ transport. Postoperative lung edema after congenital cardiac surgery has principally been assessed by chest radiography (CXR), which may be inaccurate and causes irradiation. Excessive EVLW promotes appearance of artifacts called B-lines in lung ultrasound (US), whereas lung compliance associates negatively with increased EVLW. In this thesis the effect of chronic hypoxemia on lung liquid transport was studied in children with CHD. Second, feasibility of lung US and lung compliance in assessment of EVLW and in predicting short-term clinical outcome was tested after congenital cardiac surgery. Third, the long-term survival of a cyanotic CHD was retrospectively evaluated in patients with PA+VSD. According to our findings, the airway epithelial Na+ transport was impaired in profoundly hypoxemic children with cyanotic CHD. After congenital cardiac surgery, lung US B-line score and static lung compliance correlated with CXR lung edema assessment. However, ventilator-derived dynamic lung compliance may not reflect the state of lung parenchyma similar to static compliance. Furthermore, both early postoperative lung US B-line and CXR lung edema scorings predicted short-term outcome interpreted as length of postoperative mechanical ventilation and intensive care. Among factors affecting the long-term survival of PA+VSD the primary anatomy of pulmonary circulation and achievement of repair were most important. In summary, our results emphasize the effect of postoperative pulmonary complications on short-term outcome after congenital cardiac surgery. Our data suggests that hypoxemia may attenuate the constitutional mechanism of the lung to prevent excessive lung liquid accumulation. To detect this, lung US can be used to complement CXR when assessing EVLW in children undergoing cardiac surgery. This may be particularly useful in profoundly hypoxemic children with cyanotic CHD and may promote early recognition of postoperative pulmonary complications. Although primary anatomical factors affect long-term outcome of PA+VSD, an important form of cyanotic heart disease, the treatment should aim for corrective surgery in all PA+VSD patients.
Original language | English |
---|---|
Place of Publication | Helsinki |
Publisher | |
Print ISBNs | 978-951-51-2981-9 |
Electronic ISBNs | 978-951-51-2982-6 |
Publication status | Published - 2017 |
MoE publication type | G5 Doctoral dissertation (article) |
Fields of Science
- 3123 Gynaecology and paediatrics
- 3126 Surgery, anesthesiology, intensive care, radiology