This study used a retrospective cohort study based on Multi-time longitudinal monitoring data were used to analyze the correlation mechanism between the dynamic evolution characteristics of nutrition-related biochemical indicators and individualized nutritional intervention in patients with mechanical ventilation. The inflammation-nutrition interaction model was constructed to correct the interference effect of inflammatory microenvironment on nutritional status assessment, so as to provide a basis for further achieving precision nutritional support.

Inclusion Criteria:

• age ≥18 years old;
• ICU admission ≥72 hours with invasive mechanical ventilation ≥24 hours;
• start nutrition therapy within 72 hours after ICU admission and receive enteral or parenteral nutrition support for ≥3 days;
• Relatively complete nutritional intervention records and nutrition-related biomarkers test results on the 1st, 3rd, and 7th (±1) days of ICU admission;

Exclusion Criteria:

• women of childbearing age who have a positive pregnancy test, are pregnant or lactating;

• chronic diseases with serious organ function damage or serious complications;

  1. Kidney: chronic kidney disease stage 4 or 5;
  2. Liver: previous history of liver failure, hepatic encephalopathy, or hepatic coma, gastrointestinal bleeding due to portal hypertension or Child-Pugh score ≥10 in recent years;

• advanced malignant tumor, or chemotherapy or immunotherapy received within one month before admission;

• severe immunodeficiency or current use of potent immunosuppressive agents, agranulocytosis (N<0.5×10^9/L), active hematologic malignancies or HIV stage III infection; Patients who were treated with immune-inducing drugs, such as antithymocyte globulin (ATG), antilymphocyte globulin (ALG), interleukin-2 receptor a chain antibody (IL-2RA), interleukin-6 receptor A antibody (IL-6RA); glucocorticoid therapy was continued for nearly 2 weeks, with a daily dose exceeding the hydrocortisone equivalent of 200mg;

• critical illness, death in ICU within 1 week or palliative care only because death outcome was inevitable;

• combined with severe or more severe burns: more than 30% of total body surface area burned or more than 10% of third-degree burn area; Or the total area is less than 30%, but the whole body condition is severe, or there are shock, combined injury, and respiratory tract burn.

Patients admitted to the ICU