Relationship between very early enteral nutrition and persistent inflammation, immunosuppression, and catabolism syndrome in cardiovascular surgery patients: a propensity score-matched study

Background: Early enteral nutrition (EN) is recommended for patients with critical illness to maintain intestinal immunity. However, the optimal timing of the commencement of EN remains unclear, particularly after cardiovascular surgery. Objectives: We herein focused on Persistent Inflammation, Immunosuppression, and Catabolism Syndrome (PICS) as a predisposing immunodeficiency and investigated its association with very early EN (VEEN) (<24 h) in patients who underwent cardiovascular surgery. Methods: In this retrospective study, we used an administrative claims database with laboratory examinations between 2008 and 2021 to identify adult patients admitted to the intensive care unit after cardiovascular surgery. Patients who received EN the day after surgery were assigned to the EN <24 h group, whereas those who received EN on day 2 or day 3 were assigned to the control group. The primary outcome was a composite of the incidence of PICS and mortality on day 14 after surgery. We defined PICS as patients who were hospitalized for >14 day and meeting >= 2 of the following conditions: a lymphocyte count <800/mu L, albumin <3.0 g/dL, and C-reactive protein >2.0 mg/dL. We compared the 2 groups using propensity score analysis. Results: A propensity score matching generated 2082 pairs. The primary outcome was significantly lower in the EN <24 h group than in the control group on days 14 {risk difference [95% confidence interval (CI)]: -3.1% [-5.9%, -0.3%]} and 28 (risk difference [95% CI]: -2.1% [-3.7%, -0.4%]). Mortality did not significantly differ between the 2 groups. The length of hospital stay was significantly shorter in the EN <24 h group: the difference (95% CI) was -2.2 (-3.7, -0.7) d. Conclusions: Among patients who underwent cardiovascular surgery, VEEN provided on the day after surgery was associated with a lower incidence of PICS and a shorter length of hospital stay than EN provided 2 day or 3 day after surgery.