Baseline immune status and the effectiveness of response to enteral nutrition among ICU patients with COVID-19: An observational, retrospective study

Objectives: This study aimed to compare how immunocompromised and immunocompetent patients responded differently to enteral nutrition (EN) support in intensive care units (ICUs) during the COVID-19 pandemic, including serum nutritional biomarkers, inflammatory biomarkers, gastrointestinal (GI) intolerance symptoms, and clinical outcomes.

Methods: An observational, retrospective study was conducted in the ICUs of a teaching hospital in southwest China. We recruited a convenience sample of 154 patients between December 2022 and February 2023. We defined immunocompromise as primary immunodeficiency diseases, active malignancy, receiving cancer chemotherapy, HIV infection, solid organ transplantation, hematopoietic stem cell transplantation, receiving corticosteroid therapy with a target dose, receiving biological immune modulators, or receiving disease-modifying antirheumatic drugs or other immunosuppressive drugs. We conducted a Mann-Whitney U test, χ² test, or generalized estimation equation model to explore the differences between immunocompromised and immunocompetent patients.

Results: Among the 154 study participants, 41 (27%) were defined as immunocompromised. The immunocompromised patients were younger than the immunocompetent patients. There were no statistically significant differences between the two groups with respect to serum nutritional biomarkers, inflammatory biomarkers, incidence of GI intolerance symptoms, and in-hospital mortality. However, the immunocompromised patients exhibited a longer hospitalization duration than the immunocompetent patients.

Conclusion: We found that the immunocompromised patients spent more time in the hospital. These findings may help us to standardize the participants before EN interventional studies better and better individualize EN supports based on patients' immunity status.