Background

Current practice regarding timing of feed initiation and feed tolerance largely relies on anecdotal practice and protocols. This study aims to provide an objective measure to guide clinical practice by analyzing changes in splanchnic regional oxygen saturation and Doppler patterns with feeds.

Methods

A systematic review was performed. Inclusion criteria were: 1) patients under 1 year of age; 2) splanchnic regional oxygen saturation with near infrared spectroscopy before and after feeds or mesenteric Doppler findings before and after feeds; and 3) clinical parameters must have been presented as either mean and standard deviation or median and range. Endpoints of interest included splanchnic regional oxygen saturation, splanchnic systolic velocity, and splanchnic diastolic velocity. Meta-analyses were conducted using an inverse-variance model. The pooled effects are reported as mean difference and 95% confidence interval. Meta-regression was conducted for each endpoint with the following independent variables entered into the model: study year, gestational age, birth weight, time to measurement, and age at time of study.

Results

This study included 8 studies with a total of 240 patients. Splanchnic regional oxygen saturation did not significantly differ after feeds (mean difference +1.0, 95% CI -2.9 to 4.9, p-value 0.62). Sensitivity analyses demonstrated that gestational age under 28 weeks was associated with a significant decrease in splanchnic regional oxygen saturation and GA over 30 weeks was not. Splanchnic artery systolic velocity was significantly higher after feeds (mean difference +34.0 cm/s, 95% CI 11.1 to 57.0 cm/s, p-value < 0.01). Sensitivity analyses for gestational age and birth weight did not find any significant difference in pooled effect.

Conclusion

Splanchnic regional oxygen saturation was significantly decreased after feeds in those patients under 28 weeks of gestation compared to those over 30 weeks. Systolic and diastolic Doppler velocities were significantly higher after feeds without differences in gestational age.