What is gastric residual volume and when should it be checked?

• A. Amount of feed left in the stomach during feedings; check for NG tubes only; feedings should not be stopped for volumes less than 500 ml unless signs of intolerance; check primarily in the first 48-72 hours.
• B. Volume of feed delivered in the last hour.
• C. Volume of water flushed.
• D. Total daily formula volume.

Answer: (A)

Gastric residual volume reflects how much gastric contents remain in the stomach after a feeding, used to assess gastric emptying and tolerance to enteral feeding. It is measured by aspirating contents through a gastric tube (such as an NG tube), so checks are done when a tube is in place. The correct statement defines GRV as the amount of feed left in the stomach during feedings and notes that you check it via the NG tube; if residuals are below a threshold (here, 500 mL) and there are no signs of intolerance, feeds can continue. Checking is emphasized in the first 48–72 hours because tolerance and gastric motility are most variable early on. Other options describe volumes that are not residual (volume delivered, water flushed, total daily volume), so they don’t represent GRV.