Algorithm for Calculating the Protein Intake in Enteral and Parenteral Nutrition in Premature Infants.

Introduction: Calculating the exact nutritional balance especially for the premature infant has always been a challenge for the daily practice of the clinician.

Purpose: we intend to establish a simplified formula and mathematical algorithms to calculate the necessary amino acids and proteins for the nutrition of the premature newborn, covering most of the international recommendations and also to give to the neonatal intensive care physician the opportunity of their rapid customization for each case.

Methods: following an extensive literature revision we have established the protein intake recommendations, indications and contraindications for enteral and parenteral nutrition in premature infants, by age of gestation, birth weight and postnatal age. Then, these recommendations were translated into simplified mathematical equations and we have proceeded to develop logical algorithms to enable the rapid choice of the best equation that fits each individual case with all its peculiarities, at a defined time.

Results: for all three premature categories, we have identified intervals for enteral and parenteral nutrition, which were translated into mathematical formulas and management regulations and then transposed into logic algorithms.

Conclusions: although mathematically one can use a simplified calculation, for a rapid appreciation, the clinician is still required to go through these algorithms daily and sometimes several times a day. Moreover, to optimize protein intake, we have to calculate the protein / energy ratio and the non-protein calories / gram of protein ratio. This involves extending the calculation for the carbohydrates, fats and calories-practically the entire nutrition.