Effects of continuous versus intermittent enteral feeding on feeding tolerance in critically ill adults: a systematic review and meta-analysis.

Objectives: This study aims to comprehensively evaluate the impact of continuous versus intermittent enteral feeding regimens on feeding tolerance in critically ill patients during clinical practice. Method: A systematic search was conducted in the databases of PubMed, Web of Science, Embase, and the Cochrane Library for studies published up to June 30, 2025, to identify clinical studies evaluating the effects of continuous versus intermittent enteral feeding strategies in critically ill patients. The primary outcomes were defined as the incidence of gastrointestinal intolerance events, including diarrhea, constipation, vomiting, gastric residual volume, and abdominal distension, as well as feeding-related complications such as aspiration and pneumonia. Secondary outcomes included ICU mortality, length of ICU stay, and achieved energy intake. Results: A total of 3,517 studies were initially identified, with 17 randomized controlled trials meeting the eligibility criteria and included in the meta-analysis. The results demonstrated that continuous enteral feeding was associated with an elevated risk of constipation (RR = 1.40, 95% CI = 1.01-1.95). No statistically significant differences were observed between the two feeding regimens for the outcomes of diarrhea, vomiting, gastric residual volume, abdominal distension, aspiration, ICU mortality, and length of ICU stay. Subgroup analyses based on intervention duration (<7 days versus ≥7 days) indicated a higher risk of constipation with continuous feeding in the subgroup with an intervention duration <7 days (RR = 2.55, 95% CI = 1.15-5.69), whereas no significant difference was found in the subgroup with an intervention duration ≥7 days (RR = 1.25, 95% CI = 0.89-1.75). The included studies carried some risk of bias. According to the GRADE approach, the overall certainty of the evidence for all outcome measures was low or very low. Conclusion: In critically ill patients, continuous enteral feeding is associated with an elevated risk of constipation, and this risk is particularly elevated during short-term interventions (<7 days). No significant differences were observed between the two feeding regimens for other clinical outcomes. Given the generally low quality of evidence and the small sample sizes of the included studies, these conclusions should be interpreted with caution. Future large-scale, high-quality studies with long-term follow-up are necessary to further validate the efficacy of intermittent enteral feeding in alleviating gastrointestinal intolerance. Systematic review registration: https://www.crd.york.ac.uk/PROSPERO/view/CRD420251145362, identifier CRD420251145362.