Gastric Residuals: 3 Reasons for Standardization

 

The practice of checking gastric residuals has been a part of neonatal nursing care for as long as I can remember. Even as a graduate nurse in 1997, I can recall gently pulling back on the syringe prior to each feed to verify the stomach contents of my patient.

At the time, the practice was based on what I had been taught by my preceptor. I then dutifully reported my findings to the physician to make decisions based on what was found. My understanding of the rationale for this protocol was threefold:

1. To check tube placement
2. Evaluate gastric emptying
3. To determine stomach contents volume and color to help with evaluation for other medical conditions such as NEC or obstruction

More recently, however, this routine practice has come under scrutiny for a variety of reasons:

Is the information accurate?

What does it actually mean?

Are we doing the right thing when making medical decisions based on this information?

Tube Placement Accuracy

Accurate placement of an orogastric or nasogastric tube is critical to reduce potential complications to the neonate such as tracheal aspiration or esophageal perforation. Ideally, verification of the tube placement would be done via x-ray.¹ However, due to radiation exposure, cost, and the impracticality of this test, it is estimated that 83% of nurses routinely use the gastric residual check to determine placement, even though the literature states that it may be an unreliable indicator of feeding tube placement and does not protect against placement in the infant’s trachea.2, 3

In fact 38% of gastric residual checks fail to obtain any aspirate at all, primarily because of the multitude of variables that can affect the accuracy of this measurement such as body position, feeding tube size, technique, feeding temperature, and viscosity of feed. 4, 5

Gastric Emptying

So if the data is potentially flawed based on the multitude of influencing factors that confound the results, is it a true reflection of gastric emptying? If 38% of checks do not yield any residuals in our syringe, how do we know that the infant’s motility is “ok,” and how does that impact our decision-making in terms of advancing feeds? These questions shed some light on the insightful conversations that need to be had by clinicians, as well as an evaluation of the current literature.

Additionally, if the measurement is flawed, why are we basing medical decision on flawed data? Most likely it is because, at the moment, there is no method that is as easy, cost-effective, and convenient as checking a GR at the bedside. But is that enough of a reason to continue the practice?

Certain practice implications need to be analyzed. Is withholding feeds and delaying attainment to full feeds based on gastric results now putting that child at risk of neurodevelopmental impairment and higher risk of sepsis related to delay in central line removal? Are we harming rather than helping? It is in this area that the literature shows a definite gap.

Evaluation of Gastric Contents

Another confusing component of gastric residuals is exactly how to define them. Much variation exists across the nation. Is it greater than 30% or 50% of the prior feeding? If there is color variation, how do we medically manage it? Do we re-feed and hold future feeds, or discard and feed fresh milk? Traditionally, the green residual raised a red flag for obstruction or possible precursor to NEC. Now in many NICUs if the clinical exam is normal it can be viewed as a part of the premature gut and poor motility related to prematurity. But the consensus varies, and because it is based on poor data the picture becomes that much more difficult to interpret.

One thing is for certain when it comes to the gastric residual check: creating a standardized policy within your unit will only benefit further evaluation of the practice. Additionally, more research is needed to clarify what we are doing with this practice, whether it is of benefit or not, and investigate potential practice options to gain the information we seek without putting our patients at risk.

References:

1. Gastric Residual Evaluation in Preterm Neonates: A Useful Monitoring Technique or a Hindrance, Li, Yue-Feng et al. Pediatrics & Neonatology , Volume 55 , Issue 5, 335 – 340
2. Parker LA, Withers J, Talaga E. Survey of NICU nurses: Methods of NG/OG insertion and verification. 2014
3. Geraldo V, Pyati S, Joseph T, Pildes RS. Gastric Residual (GR): Reliability of the Measurement. Pediatric research. 1997; 41:150.
4. Bartlett Ellis RJ, Fuehne J. Examination of Accuracy in the Assessment of Gastric Residual Volume: A Simulated, Controlled Study. JPEN. Journal of parenteral and enteral nutrition. 2014 Feb 21.
5. Metheny NA, Stewart J, Nuetzel G, Oliver D, Clouse RE. Effect of feeding-tube properties on residual volume measurements in tube-fed patients. JPEN. Journal of parenteral and enteral nutrition. 2005 May-Jun;29(3):192–197. [PubMed: 15837779]