Objective. To determine whether transition from tube to all oral feeding can be accelerated by the early introduction of oral feeding in preterm infants. It is hypothesized that this shortened transition time will lead to earlier attainment of all oral feeding.
Design. Twenty-nine infants (<30 weeks’ gestation) were randomized to an intervention or control group. The intervention group (n = 13) was initiated to oral feeding 48 hours after achieving full tube feeding (120 kcal/kg/d), and the feeding progression followed a structured protocol. The oral feeding management of the control infants (n = 16) was left to the discretion of their attending physicians. Oral feeding progress was monitored for achievement of selected feeding milestones: achievement of first and all successful oral feedings. Feeding performance was assessed by overall transfer (percent volume transferred during a feeding/total volume offered) and rate of milk transfer (mL/min), which were measured from introduction of oral feeding to first successful oral feeding.
Results. Infants in the experimental group, when compared with their control counterparts, were introduced to oral feeding significantly earlier (31.1 ± 1.3 vs 33.7 ± 0.9 weeks’ postmenstrual age, respectively) and attained all oral feeding significantly earlier as well (34.5 ± 1.6 vs 36.0 ± 1.5 weeks’ postmenstrual age, respectively). The transition time from full tube feeding to all oral feeding was 26.8 ± 12.3 days for the experimental group and 38.4 ± 14.0 days for the control group. Both groups of infants demonstrated similar increase in overall transfer and rate of milk transfer from introduction of oral feeding until achievement of first successful oral feeding.
Conclusions. Early introduction of oral feeding accelerates the transition time from tube to all oral feeding. This not only allows earlier attainment of all oral feeding, but it also provides practice opportunities that enhance the oral motor skills necessary for safe and successful feeding.
1. It is correct that some of the infants continued to receive Nasal CPAP therapy when introduced to oral feeding at 31 weeks postmenstrual age. We mentioned in the Methods section that from 0 to 4 oral feeding/day, the same investigator (CS) fed all the infants. This ensured that the infants were handled in a consistent manner and followed our feeding protocol (Fig. 1). We reported that episodes of oxygen desaturation and bradycardia were similar between groups during feeding; this included infants receiving NCPAP therapy. Importantly, our study was not conducted to determine the efficacy/safety of oral feeding and CPAP. However, we acknowledge that infants are precluded in their advancement to oral feeding because of CPAP therapy. We hope that this preliminary study will stimulate others to study a protocol of oral feeding and CPAP therapy.
2. The aim of the study was not to monitor breastfeeding success. However, because our hospital is a strong proponent of breastfeeding, bottle feeding only was offered when mothers could not be present. In addition, there is no evidence to support that early introduction of bottles in this population interferes with breastfeeding.
3. We would like to stress that this study was conducted to determine whether oral feeding skills at 31 wks postmenstrual age allowed successful and safe oral feeding. We are not advocating that oral feeding be started at that time. Rather, we are emphasizing that the delay in the initiation of oral feeding affects success.
We hope these responses answer your questions and prompt you to pursue a study on the initiation of oral feeding during NCPAP therapy!
Two issues which may affect clinicians' decisions on the timing of introduction of oral feeds in preterm infants deserve discussion and were not commented on by the authors. The first is the advisability of oral feeds in infants still on positive airway pressure. According to Table 1, the infants in the experimental group (early oral feeding) were on mechanical ventilation for an average of 6.1 days and nasal CPAP for 24.6 days for a total of 30.7 days of "respriatory support." According to Table 2, the average postnatal age of initiation of oral feeds in this same group was 22.9 days. This would mean that several infants were orally fed before weaning from nasal CPAP. This is not common practice and it would be of interest to know how this subgroup's tolerance and success with oral feeds compared to those not still on CPAP. A second issue is the potential adverse effect bottle feeds may have on successful nursing. Since most of these infants were also being breastfed, was there any difference in breastfeeding success- (e.g.milk transfer, successful or exclusive breastfeeding at discharge) in the early feeding group compared to the control group?