Gastric residual volume constitutes an important marker of good feeding tolerance in a VLBW neonate. There is dispute in the literature as to where the upper limit of normal residual in bolus feeding should be. No evidence exists whatsoever for continuous feeding.
Objective To examine the effects of bolus and continuous methods of feeding on gastric emptying and gastric residual volume (GRV) of VLBW neonates.
Study design In a randomized cross over design study including 22 newborns (BW<1200 grams and GA<30 weeks), we measured gastric emptying by performing serial (7) ultrasound measurements of the antral cross-sectional area (ACSA) and also assessed GRV by aspiration, on two occasions: after bolus and during continuous feeding. Every newborn was administered the same quantity and quality of milk on both occasions. 11 newborns were randomly assigned to have the first measurement taken during bolus feeding and the remaining 11 during continuous feeding.
Result A significant difference of the mean ACSA between bolus and continuously fed neonates was found in the last measurement (120„), (p = 0.000). There was also significant difference (p = 0.000) in the mean GRV between the two groups. Gastric residual was 4% in bolus feeding (median, range 0–25%) whereas in continuous feeding it was 44% (median, range 15–80%).
Conclusion During continuous and bolus feeding, the finding of a residual volume in the stomach up to 80% and 25% respectively can be well tolerated. Thus, different upper thresholds of GRV are required as indicators of feeding tolerance.