This is a research study to determine if a particular method of providing nutrition improves the clinical outcomes of patients in the intensive care unit (ICU) who have undergone abdominal surgery and would require nutrition delivered via the bloodstream (called total parenteral nutrition or TPN). The nutrition method we are testing is a structured nutrition delivery plan that involves tube feeding, oral nutrition supplements, and the use of a device (called an indirect calorimeter or IC) to measure calorie needs. This study will also use two devices to measure fat and muscle mass to examine changes during hospitalization. Subjects will be followed throughout hospitalization where nutrition status and fat and muscle mass will be closely monitored.

Study activities will begin within 72 hours of a patient's abdominal surgery. TPN (total parenteral nutrition, a method of feeding that bypasses the usual process of eating and digestion) will be started, a non-invasive method of assessing calorie needs (indirect calorimetry (IC)) will be started, a urine sample will be collected to help assist in protein needs, and fat/muscle mass will be measured using bioelectrical impedance analysis (BIA), and an ultrasound. This is a minimal risk study and all products/devices used are non-invasive and FDA-approved. Indirect calorimetry and urine sample collection will be conducted every 3 days during the stay in the Intensive Care Unit - ICU, then every 5 days until hospital discharge. BIA and muscle ultrasound will be conducted every 7 days during ICU stay, then every 14 days until hospital discharge.

The purpose of this prospective trial is to study the impact of the utilization of structured nutrition delivery pathway on 300 adult abdominal trauma and surgery patients admitted to a Duke University Medical Center (DUMC) intensive care unit (ICU) through a structured nutrition delivery pathway from surgical intervention to hospital discharge. Objectives include evaluating the impact of a structured nutrition delivery pathway on 1) nosocomial infectious complications as defined by CDC guidelines after 7 days of ICU admission and 2) protein-calorie malnutrition, ventilator use, hospital disposition, hospital and ICU length of stay, ED/hospital utilization, total parenteral nutrition (TPN)-related complications, 1-year mortality, and hospital charges. Patient outcomes will be compared to a retrospective cohort of 300 historical matched control subjects.

The study intervention, a structured nutrition delivery pathway called the Nutrition Ecosystem pathway consists of the following collaborative parts to optimize nutrition intake and delivery within this patient population: 1) parenteral nutrition initiated within 72 hours of operative intervention 2) metabolic cart assessments to determine resting energy expenditure (REE) and guide registered dietitians (RDs) 3) expedited delivery of oral nutrition supplements and 4) a team-based approach on proper documentation of nutrition delivery and intake. The population group will consist of 300 surgical patients admitted to a DUMC ICU following emergent/urgent major abdominal surgery secondary to abdominal trauma, intra-abdominal sepsis, ischemic bowel/vascular emergencies, or penetrating trauma and are not expected to receive enteral or oral nutrition for at least 72 hours. 300 historical matched control subjects not having received TPN in the first 7 hospital days will be enrolled from Duke Electronic Health Record between January 2018 and June 2020.

This study poses minimal risks to patients as the study activities match the current standard of care medical treatment such as nutrition delivery via TPN. Patients will benefit from metabolic and physiologic assessments, closer monitoring, and interdisciplinary support for nutrition optimization from nurses, dietitians, and providers throughout their hospitalization. Given patients' energy expenditure will be routinely measured by indirect calorimetry via a metabolic cart, a greater accuracy in caloric requirements will help achieve precision and goal nutrition for all participants.

Inclusion Criteria:

1. Age >= 18 years
2. ICU admission with major abdominal trauma, intra-abdominal sepsis, ischemic bowel/vascular emergencies, or penetrating trauma
3. Not expected to receive oral or enteral nutrition for > 72 hours
4. Primary team approval of PN

4. < 72 hours post-operative intervention

Exclusion Criteria:

1. Expected death or withdrawal of life-sustaining treatment within the first 72 hours of ICU admission

2. Patients admitted with

   • Diabetic ketoacidosis or non-ketotic hyperosmolar coma
   • MELD > 20 or acute fulminant hepatic failure

3. Patients allergic to any component of parenteral nutrition or lipid solution

4. Pregnant or breastfeeding patients

5. Incarcerated or prisoner prior to admission