Abstract: Two randomised controlled trials with a total of 141 preterm infants met the inclusion criteria for the comparison of routine monitoring versus no monitoring of gastric residual in preterm infants. Both trials were done in infants with birth weight < 1500 g. Routine monitoring of gastric residual may have little or no effect on the incidence of necrotising enterocolitis (risk ratio (RR) 3.07, 95% confidence interval (CI) 0.50 to 18.77; participants = 141; studies = 2; low-quality evidence). Routine monitoring may increase the risk of feed interruption episodes (RR 2.07, 95% CI 1.39 to 3.07; participants = 141; studies = 2; low-quality evidence); the number needed to treat for an additional harmful outcome (NNTH) was 3 (95% CI 2 to 6). Routine monitoring of gastric residual may increase time taken to establish full enteral feeds (mean difference (MD) 3.92, 95% CI 2.06 to 5.77 days; participants = 141; studies = 2; low-quality evidence), time taken to regain birth weight (MD 1.70, 95% CI 0.01 to 3.39 days; participants = 80; studies = 1; low-quality evidence), and number of total parenteral nutrition days (MD 3.29, 95% CI 1.66 to 4.92 days; participants = 141; studies = 2; low-quality evidence). We are uncertain as to the effect of routine monitoring of gastric residual on other outcomes such as incidence of surgical necrotising enterocolitis, extrauterine growth restriction at discharge, parenteral nutrition-associated liver disease, duration of central venous line (CVL) usage, incidence of invasive infection, mortality before discharge, and duration of hospital stay. We found no data for outcomes such as aspiration pneumonia, gastroesophageal reflux, growth measures following discharge, and neurodevelopmental outcome. Only one trial with 87 preterm infants met the inclusion criteria for the comparison of using two different criteria of gastric residual to interrupt feeds while monitoring gastric residual. The trial was done in infants with birth weight of 1500 to 2000 g. We are uncertain as to the effect of using two different criteria of gastric residual on outcomes such as incidence of necrotising enterocolitis or surgical necrotising enterocolitis, time to establish full enteral feeds, time to regain birth weight, number of total parenteral nutrition days, number of infants experiencing feed interruption episodes, extrauterine growth restriction at discharge, parenteral nutrition-associated liver disease, incidence of invasive infection, and mortality before discharge (very low quality evidence). We found no data on duration of CVL usage, aspiration pneumonia, gastroesophageal reflux, duration of hospital stay, growth measures following discharge, and neurodevelopmental outcome. Review authors found insufficient evidence as to whether routine monitoring of gastric residual reduces the incidence of necrotising enterocolitis because trial results are imprecise. Low-quality evidence suggests that routine monitoring of gastric residual increases the risk of feed interruption episodes, increases the time taken to reach full enteral feeds and to regain birth weight, and increases the number of total parenteral nutrition (TPN) days. Available data are insufficient to comment on other major outcomes such as incidence of invasive infection, parenteral nutrition-associated liver disease, mortality before discharge, extrauterine growth restriction at discharge, number of CVL days, and duration of hospital stay. Further randomised controlled trials are warranted to provide more precise estimates of the effects of routine monitoring of gastric residual on important outcomes, especially necrotising enterocolitis, in preterm infants.

Plain-language summary: The literature searches are up-to-date as of 19 February 2018. We found two small randomised controlled trials with a total of 141 preterm infant participants that compared routine monitoring versus no monitoring of stomach aspirates in preterm infants. We found one trial for the comparison of using two different criteria of aspirates to interrupt feeds while monitoring stomach aspirates in preterm infants. There is uncertainty as to whether routine monitoring of stomach aspirates reduces necrotising enterocolitis because trial results are imprecise. Preterm infants on routine monitoring of stomach aspirates may reach full feeds later, regain birth weight later, require longer duration of parenteral nutrition, and may be at increased risk of feed interruption episodes. There is uncertainty as to whether using two different criteria of gastric residual to interrupt feeds has effect on important outcomes in preterm infants. There is uncertainty as to whether routine monitoring of stomach aspirates has any benefits. Routine monitoring may increase the number of feed interruption episodes and the time taken to reach full feeds.