MALNUTRITION AND FEEDING PROBLEMS IN THE CHILD WITH CONGENITAL HEART DISEASE
Globally, congenital heart disease (CHD) represents one-third of all major congenital anomalies, affecting between 0.3% and 1.5% of all pregnancies (around 40,000 children are born with CHD per year in the United States).1 Growth faltering is commonly seen in children with CHD, particularly those with cyanotic disease and univentricular physiology. Children with CHD exhibit early and progressive falls in their growth trajectory in comparison to healthy children, with reductions in weight-for-age Z-score, head circumference, and length-for-age Z-score. The process of surgery and bypass, in addition to the effects of cardiac failure and chronic disease, involve a significant degree of metabolic and nutritional stress, such that postoperative malnutrition presents a further burden on restoring growth toward normal parameters. Early nutrition support is crucial, particularly in those undergoing surgery in the neonatal and infant period, where there is little reserve during what is a critical time for brain development.
A number of factors contribute to malnutrition in children undergoing surgery for congenital heart disease, as the following sections explain.
Single-ventricle and complex cardiac lesions are associated with a greater risk of malnutrition. These children may also have had restricted feeds preoperatively in the setting of heart failure and fluid restriction. While there is no evidence that enteral feeding increases the risk of necrotizing enterocolitis (NEC), some clinicians withhold feeds if there are concerns about splanchnic perfusion (single-ventricle lesions, severe left ventricular outflow tract, and aortic arch anomalies).
Children with cyanotic lesions usually have symmetrical growth restriction and are shorter and lighter, whereas those with acyanotic lesions tend to have asymmetrical growth retardation with a low weight-for-age and normal height. In addition, children with left-to-right shunts tend to weigh less than cyanotic children do, which may be due to pulmonary hypertension. Where there is pulmonary stenosis and/or coarctation of the aorta, linear growth is usually more affected than weight. The presence of hypoxia and breathlessness is common, and while the duration of the hypoxia may affect growth, the severity does not appear to affect tissue metabolism profoundly.2
Inadequate Caloric Intake
Children with CHD often have comorbidities that may affect the ability to swallow or absorb feeds effectively. In addition, prolonged intubation and hospitalization are likely to add to swallowing problems and oral aversion. Gastroesophageal reflux is relatively common in neonates with CHD, and may reduce the success of oral feeds at the volumes needed to restore growth. Other factors that contribute to an inadequate calorie intake include:3
Fatigue on feeding leading to low intake
Increased metabolic expenditure
Frequent use of antibiotics affecting gut flora
Postoperative fluid restriction will inevitably restrict the volume available to provide feeds. Children with heart failure ...