What to do With the Dreaded Gastric Residual?

I think I have seen practically every different color in the gastric residuals presented to me by my bedside nurses over the years. From fluorescent green to deep forest green, neon yellow to periwinkle purple, etc. About half of all feeding intolerance is due to gastric residuals.

Dealing with feeding intolerance is a daily chore for neonatal healthcare professionals. We collectively manage each and every feeding of our infants at least 8 times per day 7 days a week for sometimes 4-5 months in our smallest infants. That amounts to over a thousand feedings for some of these infants! The bulk of feeding intolerance is based on a combination of signs including gastric residuals, abdominal distension, vomiting, blood in upper or lower gut, diarrhea, gas, etc. About 70% of our very low birth weight infants have some kind of feeding intolerance.

These statistics should infer then that we are really, really good at managing such a frequent problem. It is ironic and sad, then, that dealing with the gastric residual does not have good science behind it. In fact, most of the medical evidence would support actually not caring about the specific volumes, color or shape. Volumes up to 3 mL have been found in an unfed stomach with up to 3 mL to be of no clinical consequence and color has not been helpful.^{1, 2}

So what does the gastric residual really represent? I really like Dr. Jadcherla, from Columbus, OH who described it as follows: “Pregavage residuals and bilious residuals reflect poor gastric emptying, duodeno-gastric reflux, and gastroduodenal hypomotility.”³ In short, gastric residuals represents poor gastric emptying. That’s it, nothing more, nothing less. It neither has specificity for something bad and sensitivity to be present as a warning sign. Do we see it just before an abdominal disaster such as perforation or septic ileus is about to happen? Sure. But we also see it happening before many, many benign scenarios, even when bowel sounds are present and the infant is happily stooling. This means the gastric residual is a very non-specific sign. It is my belief then that the presence of significant (we may need to agree on how to define significant) gastric residual in isolation, without any abdominal signs is not significant. Is there really a color of the residual that is important? The only really worrisome color that requires some response are those that represent blood (any hue of red, or coffee ground color). The other color that I have found to be relevant is a very dark almost collard green since this seems to only happen when there is a serious ileus or obstructions; any other shade of green I have been seen plenty in infants who have not amounted to much.

What are the possible solutions to this? How can we move on beyond the gastric residual? The answer seems simple for some-just stop looking. Interestingly I have come across several units in the country that have done just that. No more looky see. The primary concern I have about this approach is not of something being missed but that we are removing a practical, albeit not completely accurate, approach of verify that the tip of the enteral feeding tube is in the stomach. Having seen some infants accidentally get fed into their lungs and get very sick, this localization technique is part of good clinical practice. Clearly if a unit does choose to move away from checking for residuals, they will need an alternate highly accurate method of detecting the placement of the tube. This is an area that needs more work for the future.

Another practice that is nonsensical is that of discarding the residual because of how ugly it looked. I get that reaction from nurses and doctors, but why does it make sense to discard valuable gastric juices (including electrolytes) and digestive enzymes just to “clear the way” for the next feeding? Frequent discards could act like frequent emesis in losing important electrolytes and stressing acid-base balance. Although there is no evidence for either practice (discard or no discard), I am a huge fan of returning what was there in the first place.

There are several gastric residual studies underway that I am aware of based on ClinicalTrials.gov. In a few years, I hope we will find out about the benefits of not looking and also what the value of returning the residual to the patient is.

Conclusions

So, the gastric residual continues to haunt us on a daily basis but I believe like all other areas of high variability a standardized approach to the management of feeding intolerance is the first step to reducing unwanted effects and also discovering what works best with one’s practice. Now whatever you do, don’t get me started on the meaning of abdominal girth…

References:

1. Malhotra AK, Deorari AK, Paul VK, Bagga A, Singh M. Gastric residuals in preterm babies. J Trop Pediatr. 1992;38(5):262-4.

2. Mihatsch WA, von Schoenaich P, Fahnenstich H, Dehne N, Ebbecke H, Plath C, et al. The significance of gastric residuals in the early enteral feeding advancement of extremely low birth weight infants. Pediatrics. 2002;109(3):457-9.

3. Jadcherla SR, Kliegman RM. Studies of feeding intolerance in very low birth weight infants: definition and significance. Pediatrics. 2002;109(3):516-7.