Nitrogen balance for estimating protein requirements in critically ill patients a literature review

In critically ill patients, marked protein catabolism is prevalent. Protein demanding for such patients has been based on commending nitrogen balance, in most cases. Due to the stress response, critically ill patients tend to fall into a negative nitrogen balance state. Metabolic changes, particularly in elderly critically ill patients, increase the risk of the worsening nitrogen balance. Some evidence suggested optimal nitrogen balance may not indeed equalize to the best clinical outcome. On the contrary, several studies reported the available nitrogen balance data in establishing new recommendations for the protein required by critically ill patients. There is a hypothesis that adequate protein supplementation utilizing nitrogen balance could be correlated with improved results for patients in intensive care unit (ICU). Therefore, this literature review aims to deliver a brief explanation of whether nitrogen balance can be useful in documenting the effectiveness of nutritional therapy in critical illness or not.