Unit 3: Nutrition and Feeding Practice in Preterm Infants

Picture used with kind permission of Dr. Darius Gruszfeld

As already mentioned in Lesson 2.7 from Unit 1, preterm infants who develop BPD have a higher energy expenditure, O2 consumption and higher REE. Preterm infants with BPD often show growth faltering.

High BPD risk infants should receive a diet prescription during the first few days after birth with fluid restriction and an energy provision of at least 50 to 60 kcal/kg/day.

Fluid restriction is a measure widely used in BPD. However, the health care provider must be careful not to cause insufficient nutrient intake through an exaggerated fluid restriction and consequently jeopardize the preterm growth (Fusch & Jochum 2014). 

Diuretics are often prescribed to these patients to deal with the pulmonary edema. The use of the diuretics thiazide and furosemide has been assessed by systematic reviews in these patients. Thiazide with spironolactone was shown to significantly reduce the risk of death before discharge for patients with chronic lung disease (CLD), however they increased the risk of hypokalemia and hyponatremia (supplementation might be required) (Stewart et al. 2011). Preterm infants older than 3 weeks of age with CLD responded well to a long-term treatment with furosemide, with improved oxygenation and lung compliance. However, the use of furosemide is discouraged due to lack of data from randomized control trials in long-term outcomes (Stewart & Brion 2011).

In these patients, the enteral route is the ideal route of feeding. However, in the first days of life the parenteral route is often the only possibility. The parenteral administration should be done with a combination of glucose and amino acids, plus lipid emulsion. When administering high glucose infusions, hyperglycemia is a main concern. Particularly, high glucose rates over 10 to 12 mg/kg/min may cause problems for infants who have difficulties in CO2 elimination.

Protein intakes should follow the normal requirements for preterm infants. Lipid emulsions, preferably mixed oil based, are an important source of energy particularly for preterm infants. Lipid solutions containing LC-PUFA are preferable, mainly for their DHA content (Moya 2014).

Continuous feeding in infants with respiratory instability may be beneficial when compared to intermittent feedings. Intermittent feeding in this population has been shown to increase pulmonary resistance and decrease tidal volume, dynamic compliance and minute ventilation (Blondheim et al. 1993).

In patients with established BPD (a chest radiograph of an infant with BPD can be seen here), fluid restriction is typically continued. However, it is important to supply enough water needed for growth. Again, continuous feeding should be preferred, mainly in those most respiratory unstable infants. High fat diets in these patients have shown to decrease CO2 production while permitting adequate growth (Pereira et al. 1994).  In some BPD patients, higher energy intake beyond 120 -130 kcal/kg/day might be beneficial. However, there is still no consensus how it should be administrated. Increasing energy intake through easily digestible sources is preferable over feed concentration.

These interventions are often necessary for weeks or months after birth, since BPD patients are at higher risk for growth faltering even after the perinatal period (Moya 2014).