Two new interesting articles to address this important question.
Corvaglia, L., et al. (2014). “Cardiorespiratory Events with Bolus versus Continuous Enteral Feeding in Healthy Preterm Infants.” J Pediatr.
The authors evaluated the effects of bolus vs continuous tube feeding in 33 preterm babies on cardiorespiratory events, detected by polysomnographic monitoring. The infants received a bolus feed, followed by an infusion feed over 3 hours. Continuous tube feeding resulted in a significant increase of apneas and apneas-related hypoxic episodes compared with bolus feeding.
Nurses in my NICU often prolong the duration of feed infusion when they think the baby is not tolerating bolus feeds. Babies may end up with feeds over 2 hours out of 3, although they will not extend to continuous feeding without a medical order. many are convinced that longer feeding duration improves their baby’s tolerance, including having fewer apneas, I have never been sure, but for most babies, unless they are close to starting oral feeds, it is probably unimportant. This study by Corvaglia suggest the opposite, that prolonged feeds actually increase apneas.
In the next RCT, infants were randomized to either have gastric residuals measured routinely or not. In my career I have worked in NICUs where residuals were religiously measured and responded to, NICUs where they were measured but interpreted according to the day of the week, and one NICU where we had not measured a residual in 15 years. My impression was that the only difference in outcomes was that babies in NICU #3 achieved full feeds earlier, and had no increase in adverse outcomes. It is always nice to be proven right!
Torrazza, R. M., et al. (2014). “The value of routine evaluation of gastric residuals in very low birth weight infants.” J Perinatol. Perhaps ‘proven’ is a bit strong, this is a small RCT, just 30 very preterm babies per group, with a limited power as a result, but there is no evidence of adverse results in the group who had no measurement of residuals, and they got to full feeds sooner and stopped TPN and central venous access earlier than the controls.
I think that any NICU that wants to continue to use routine gastric residuals is now required to perform a bigger, adequately powered trial to prove that they are useful. Otherwise, everyone should stop.