Congenital Heart Defect (CHD) – Cyanotic

Anesthesia Implications

Anesthesia Implications

Thorough assessment – The primary implication of these defects is cyanosis. Get as many details as you can (typically from the parents) about the condition itself and what worsens and improves symptoms.

Debubble – most of these conditions involve cross-circulation at the heart. If lines are not free of bubbles, the bubble could migrate to arterial circulation and result in a paradoxical embolism.

Cyanotic CHD implications – “cyanotic” implies that the body is not receiving the oxygen required for normal function and/or development. Supply sufficient O2, lower demand (stress/effort), and reduce right-to-left shunts, if applicable

Pathophysiology

Cyanotic CHDs are the most complex type of cardiac birth defect. They occur in utero and arise from abnormal formation of the heart and/or its major blood vessels. Most are idiopathic. However, some have been linked to maternal environmental exposures.

Cyanotic CHDs include tetralogy of fallot (TOF), transposition of great arteries (TGA), Eisenmenger syndrome, tricuspid atresia, truncus arteriosus, partial anomalous pulmonary venous return, total anomalous pulmonary venous return, and hypoplastic left heart syndrome. TOF is the most common.

Correction required – most patients born with a cyanotic heart defect require surgical correction. Otherwise there is a low likelihood of survival into adulthood

Possible Right-to-left cardiac shunt – blood bypasses the lungs without picking up oxygen. This blood is pumped directly into the systemic circulation which leads to cyanosis. Infants will often appear blue and have O2 sats less than 75%.

Cyanosis can occur due to an interchange of the pulmonary artery and aorta, single ventricular lesions, pulmonary outflow obstruction, and poorly developed cardiac valves.

Cyanotic CHDs include tetralogy of fallot (TOF), transposition of great arteries (TGA), Eisenmenger syndrome, tricuspid atresia, truncus arteriosus, partial anomalous pulmonary venous return, total anomalous pulmonary venous return, and hypoplastic left heart syndrome. TOF is the most common.

If the patient has had chronic hypoxemia, the body compensates by overproduction of red blood cells (erythrocytosis) and hyperviscosity syndrome. Hyperviscosity syndrome can result in thromboembolism, lightheadedness, and headaches.

Chronic cyanosis can also result in reduced lung compliance, pulmonary hypertension, renal insufficiency, heart failure, and arrhythmias

Unknown Incidence – multiple and varying degrees of CHD make it difficult to establish specific incidence. However, 8 in 1000 live births will have some form of CHD. The most prevalent of these is tetralogy of fallot and transposition of great arteries.

References

Hines. Stoelting’s anesthesia and co-existing disease. 7th edition. 2018.
UpToDate. Retrieved from www.uptodate.com. 2019.