Randomized, double-blind, controlled clinical trial to evaluate the effect of parenteral nutrition (PN) supplemented with lipid emulsions containing 0.1-0.2 g omega 3 polyunsaturated fatty acids (n-3 PUFA)/kg body weight/day for 7 days on malondialdehyde (MDA) levels, a marker of lipoperoxidation of reactive species, compared with a control group (without n-3 PUFA) in patients with intestinal failure (IF).

IF is the loss of intestinal function that affects the decrease in the absorption of macronutrients, water, and electrolytes, so it requires intravenous supplementation such as PN and/or intravenous fluids to maintain health and/or growth. IF type II is associated with complex infectious and metabolic complications and patients require PN for weeks or months. Long-term PN use, however, includes the risk of complications, among which a serious one is the intestinal failure-associated liver disease (1). It has been proposed that metabolic endotoxemia (2-3), inflammation (4) and oxidative stress (5) are involved in the development of this intestinal failure-associated liver disease.

Although some studies have reported beneficial effects of n-3 PUFA to prevent and reverse the liver disease associated with IF (6-7), due to its antioxidant (8-10) and anti-inflammatory activity (11-12) and in the modulation of the intestinal microbiota (13), the literature on the use of n-3 PUFA in non-critical patients with IF and PN is limited and the results have not been conclusive.

Therefore, a randomized, double-blind, controlled clinical trial to evaluate the effect of PN supplemented with lipid emulsions containing n-3 PUFA/kg body weight/day for 7 days on oxidative stress (concentrations of MDA), compared with a control group (without n-3 PUFA) will be performed.

Inclusion Criteria:

• Patients admitted in the non-critical areas of the Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán (INCMNSZ) with a nutritional risk between January 2019 and July 2020 will be considered eligible.
• Patients with recent diagnosis of IF type II (an evolution >28 days) originate from various gastrointestinal or systemic diseases (short bowel, intestinal fistula, intestinal dysmotility, mechanical obstruction, and extensive small bowel mucosal disease).

Exclusion Criteria:

• Patients with contraindications for PN
• Patients with known allergies to the components of the PN formula
• Severe liver or renal insufficiency
• Uncontrolled diabetes mellitus
• Certain acute and life-threatening conditions
• Immunological diseases (such as autoimmune diseases, human immunodeficiency virus infection, cancer, etc.)
• Those that take immunosuppressant medications
• Severe hemorrhagic disorders
• Pregnant or lactating

A team researcher will use Stata 12, to perform randomization with a 1:1 allocation using random block sizes of 4. Once the treatment group is determined, the PN will be prescribed accordingly and the preparation will be carried out in the pharmacy and it will have the same appearance in both arms. Patients and researchers who will evaluate the outcomes and perform the statistical analysis will be blinded to the assigned group.