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

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 calorienitrogen ratio (NPCN 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 NPCN. 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 NPCN 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 NPCN scores to determine the patients' NPCN for the first 7 days in ICU close to the A.S.P.E.N guidelines. NPCN 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 NPCN 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 NPCN 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 NPCN 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.