Analysis of Current Use of Early Parenteral Nutrition and Clinical Significance of Non-protein Calorie: Nitrogen in Surgical Critically Ill Patients

Heo, Eunjeong; Park, Kayoung; Jeon, Sujeong; Namgung, Hyungwook; Lee, Eunsook; Song, Inae

Abstract

PUROPOSE: Surgical critically ill patients require adequate nutrition support and the American Society for Parenteral and Enteral Nutrition (A.S.P.E.N.) guidelines recommend low non-protein calorie:nitrogen ratio (NPC:N ratio, 70~100) for critically ill pateints. In this study, we assess the current use of early parenteral nutrition of surgical critically ill patients and analyze the clinical significance of NPC:N.
METHODS
This is a retrospective study of critically ill adult patients who remained in the intensive care unit (ICU) for over 3 days and could not receive enteral nutrition for the first 7 days. Data on parenteral intake of patients were collected from electronic medical records. Association of NPC:N scores with clinical outcome (length of ICU stay, length; of hospital stay, duration of ventilation, and mortality) were analyzed using Pearson correlation and multiple regression.
RESULTS
The study included 72 cases, average parenteral calorie intake was 14.6 kcal/kg/day and protein intake was 0.5 g/kg/day. We assessed the NPC:N scores to determine the patients' NPC:N for the first 7 days in ICU close to the A.S.P.E.N guidelines. NPC:N scores showed weak negative correlation with length of hospital stay and duration of mechanical ventilation (r=-0.259, P=0.028; r=-0.495, P=0.001). Multiple regression adjusted with APACHE (Acute Physiology and Chronic Health Evaluation) II score, age, and body mass index showed correlation of higher NPC:N score with decreased length of hospital stay and shorter duration of ventilation (P=0.0001, P=0.035, respectively). However, length of ICU stay and mortality within 60 days showed no significant correlation with NPC:N scores.
CONCLUSION
Parenteral calories and protein intakes of critically ill patients in ICU were lower in comparison to A.S.P.E.N. recommendation in this study. Low NPC:N scores might be related to shorter length of hospital stay, duration of mechanical ventilation. Consultation of a nutritional support team could have a positive effect in providing appropriate nutrition support.