Routine Versus no Assessment of Gastric Residual Volumes in Preterm Infants

The term "gastric residuals" in neonates refers to aspiration of gastric contents before each feeding in an infant receiving enteral feeding using an intermittent feeding tube. The presence of significant gastric residual volume (GRV) (Greater than 50% of the feeding volume) is a manifestation of delayed gastrointestinal maturation in a preterm neonate. The presence of GRV and its characteristics usually delays advancement of enteral feedings in premature infants because a large volume of undigested milk usually prompts the clinicians to hold the feeding.

Advancement of early enteral nutrition is delayed or discontinued for >24 hours in nearly 75% of all extremely preterm infants. This is despite clinical evidence showing that early establishment of enteral nutrition is associated with reductions in the severity of critical illness, and long-lasting benefits on linear growth and neurodevelopmental outcomes.

The magnitude and characteristics of GRV combined with specific findings based on abdominal examinations are usually considered by clinicians in decisions to continue with the scheduled enteral feeding plan. There are no studies to establish the normal volume of gastric residuals, its characteristics and whether routinely checking for them prior to each feed prevents necrotizing enterocolitis. A recent cohort study using retrospective controls showed that not monitoring GRV is associated with earlier attainment of full feeding in very low birth weight infants. Two small randomized studies conducted outside the United States and one study conducted in the United States showed no difference in outcomes when GRV are not checked routinely in preterm infants. These studies have several drawbacks and the practice of checking GRV continues.

Study Objectives

Primary Objective/Aim/Goal/Hypothesis

The primary objective of this study is to demonstrate that not monitoring GRV in infants with birth weights < 1,250 g, and who are being fed intermittently by gastric tube, will result in earlier attainment of full feeding.

Hypothesis:

In preterm infants, changing the clinical practice from routine gastric residuals evaluation to no aspiration for gastric residuals will decrease the number of days to reach full enteral feeds.

Secondary Objective/Aim/Goal/Hypothesis

A secondary objective is to show that there will be no difference in the incidence of NEC (necrotizing enterocolitis) in the experimental vs the control group.

Sample Size Determination

Our NICU database shows that for infants <1,250 g the days to full feeding was 16.4 ±7.3 days. To detect a relative decrease of 20% in the experimental group will require 73 infants in each group with an alpha of 0.05 and a power of 0.8.

Statistical Analysis Plan

Primary Objective Analysis

The primary outcome analysis is the number of days to reach full feeding volume, defined as volume > 120 ml/kg/d. This time will be compared between the two groups using analysis of variance.

Secondary Objective Analysis

Secondary analysis will be focused the frequency of feeding interruptions, incidences of NEC between the two groups using analysis of variance.

Inclusion criteria

• Birth weight ≤1250g
• Gestational age of < 33 weeks
• Expected to receive feeds via gastric tubes

Exclusion criteria

• Death expected within 72 hours of birth
• Major chromosomal or congenital anomaly
• Major GI anomaly such as gastroschisis, spontaneous perforation etc.