Conclusions: Nutritional support is essential, particularly in those patients with a significant level of hyponutrition before surgical intervention, low weighed patients, or in those submitted to gastrointestinal surgery. In our study, baseline PN prescriptions were adjusted to recent recommendations in more than half of the patients; however, in patients with low weight or low BMI we observed higher caloric-protein excess in the prescribed PN since the intake has not been reduced by individualizing it to the body weight. Standardization of PN formulations is a tool of quality and safety, although in these patients it should be individually assessed. More studies are needed to validate the clinical benefits of individualized nutritional intake in post-surgical critically ill patients.