[The TPN of newborn infants: the rationalization of the calculations and of the prescription]. / NPT de neonatos: racionalización de los cálculos y de la presecripción.

We try to simplify the calculus of TPN necessities in newborns adjusting the most common bibliography tabulated values to mathematical equations. Values are transformed into factors: Fn (g of N/Kg of weight), Fk (no protein Kcal/g of N), Fg (glucose Kcal/total Kcal) and Fv (volume/total Kcal) that can be correlated with the analytical state of patient, weight and nutrition day. Once the functions were established we automated calculations using a spreadsheet program that simplifies and make easier the TPN elaboration.