Early enteral nutrition for mechanically ventilated COVID-19 patients: a systematic review and meta-analysis

Background: This study aims to systematically review the efficacy of early enteral nutrition for mechanically ventilated coronavirus disease 2019 (COVID-19) patients. Methods: Relevant clinical studies published from December 2019 to May 2023 were retrieved from the electronic databases. The primary outcome was overall mortality. The secondary outcomes included length of hospitalization, intensive care unit length of stay, and duration of mechanical ventilation. The quality of enrolled studies was evaluated using the ROBINS-I tool. The meta-analysis was performed using RevMan 5.4 software. Results: A total of 1229 potentially relevant titles and abstracts were screened. After reviewing, five studies enrolling 2054 patients were eventually included. All five articles were retrospective cohort studies. There was no significant difference in overall mortality (relative risk = 0.92, 95% confidence interval [0.74,1.15], P = 0.48) between the early enteral nutrition group and the late enteral nutrition group. The patients who received early enteral nutrition tend to stay in the hospital for less time but the difference is not significant (mean difference = −4.82, 95% confidence interval [−11.47, 1.83], P = 0.16). The mechanical ventilation days of patients who received early enteral nutrition were shortened (mean difference = −0.70, 95% confidence interval [−0.99, −0.40], P < 0.00001). Conclusion: Early enteral nutrition helps to wean patients from the ventilator, may reduce intensive care unit hospitalization, and help reach the feeding target of ventilated patients with COVID-19. Owing to the small number of included studies and the relatively low quality of study design, more rigorous, and large-scale clinical trials are urgently needed to verify above findings.