Is discard better than return gastric residual aspirates: a systematic review and meta-analysis

The assessment of residual gastric volume is common practice in critical care units. However, the effects and safety of discarding or returning gastric aspirates remain uncertain. Therefore, we aimed to evaluate the role of discarding or returning gastric aspirates on the gastric residual volumes in critically ill patients.

A comprehensive, systematic meta-analysis of randomized controlled trials (RCTs) on the efficacy and safety of discarding or returning gastric aspirates in critical ill patients was performed. Studies were identified by searching Pubmed and other databases (from inception to 31 Sept 2018). Summary odd ratios (ORs) or mean differences (MDs) with 95% confidence intervals were calculated using fixed- or random-effects model for outcome assessment.

Four RCTs, with a total number of 314 adult patients, were included in the analysis. No significant differences were found in the 48th hour residual volume (MD = 8.89, 95% CI: 11.97 to 29.74), the average potassium level (MD = 0.00, 95% CI: - 0.16 to 0.16), the episodes of gastric emptying delay (OR = 0.98, 95% CI: 0.35 to 2.80), the incidence of aspiration pneumonia (OR = 0.93, 95% CI: 0.14 to 6.17), the episodes of nausea or vomiting (OR = 0.53, 95% CI: 0.07 to 4.13) and diarrhea (OR = 0.99, 95% CI: 0.58 to 1.70).

No evidence confirms that returning residual gastric aspirates provides more benefits than discarding them without increasing potential complications. Rigorously designed, multi-center, large-sample randomized controlled trials must be further conducted to validate the role of discarding or returning residual gastric aspirates.