Standard continuous feeding versus intermittent feeding among mechanically ventilated patients in intensive care: A systematic review and meta-analysis of randomized controlled trials

Abstract

Background: Previous meta-analyses on the mode of enteral nutrition in intensive care unit (ICU) have not explored whether the standard practice of continuous enteral feeding is superior to intermittent or bolus feeding among mechanically ventilated patients. Large feed volumes maybe one of the barriers for the use of intermittent feeding. However, intermittent feeding when routinely paired with right lateral tilt positioning may be better tolerated. Aligning feeding-fasting periods with circadian patterns may also be beneficial during critical illness in relation to important patient-centered clinical outcomes.

Objectives: This systematic review and meta-analysis will summarize the current state of evidence from all randomized controlled trials (RCTs) comparing standard continuous gastric feeding and intermittent gastric feeding (with or without right lateral tilt positioning) among critically ill adult patients receiving mechanical ventilation in ICU.

Methods: A systematic search was conducted in MEDLINE, EMBASE and CENTRAL for relevant RCTs published in the English language until September 2024. The primary outcome was all cause hospital mortality, expressed as pooled risk ratio (RR) for the standard continuous feeding relative to intermittent feeding. Key secondary outcomes were ICU length of stay, gut intolerance (vomiting and diarrhoea) and pneumonia.

Results: Sixteen studies were identified for full text review out of a total of 678 records screened. Eight RCTs enrolling a total of 993 patients were included in this meta-analysis. There was a substantial heterogeneity in outcomes selection, definitions, and reporting among these RCTs. Aggregate effect size for the primary outcome was RR 0.97 (95 % confidence interval 0.72-1.32, I² = 9 %) for standard continuous feeding versus intermittent feeding. There were no between-group differences for any of the other secondary outcomes. Of all the included RCTs, the point estimate for all-cause mortality was least favourable (RR 1.55, 95 % CI 0.82 to 2.93) for the standard continuous feeding in the RCT that compared it against intermittent postural feeding.

Conclusions: Overall, our meta-analysis did not detect any clinically relevant differences in important clinical outcomes between the two groups. Future RCTs should prioritise clinically meaningful, patient-centred outcomes such as mortality or ventilator-free days as primary endpoints.

Prospero registration number: CRD42024591074.

Keywords: Continuous feeding; Critical illness; Enteral nutrition; Intensive care units; Intermittent feeding methods; Mechanical ventilation.