Baylor

We have observed in an earlier study conducted on 'healthy' preterm infants born less than 30 weeks gestation (Lau et al ,J Pediatr 1997; 130: 561-9) that the postmenstrual age at which these infants attain independent oral feeding, i.e., no tube feeding, was correlated with their performance at the time they attempted their first oral feeding. Performance was assessed in function of their overall efficiency (ml/min) during the entire feeding session and proficiency (% volume taken/total volume prescribed during the first 5 min of the feeding). When overall efficiency (y- axis) was plotted against proficiency (x-axis), 4 'quadrants' delineated by an overall efficiency of 1.5 ml/min and a proficiency of 35% were identified. The postmenstrual age at which the infants attained independent oral feeding differed depending upon which quadrant they fell into at their first oral feeding attempt. The Introduction and advancement of daily oral feedings were left to the discretion of the attending physicians. Infants in quadrant 3, (efficiency greater than 1.5 ml/min and proficiency greater than 35%) were introduced to oral feeding at a significantly earlier postmenstrual age (p< 0.004) than those in quadrants 1 (efficiency less than 1.5 ml/min; proficiency less than 35%) and quadrant 2 (efficiency greater than 1.5 ml/min; proficiency less than 35%) and attained independent oral feeding at an earlier postmenstrual age (p < 0.04). However, the number of days from introduction to full PO was similar amongst infants within all 3 quadrants. It was speculated at the time of this study, that overall efficiency and proficiency may be useful markers for readiness to oral feeding. However, in this study, milk was offered to the infants using an reservoir open to atmospheric pressure. In a subsequent study (Lau & Schanler, Acta Paediatr 2000; 89:453-9), we observed that this 'open' system enhanced the oral feeding performance of these preterm infants when compared to the use of a 'closed' system, i.e., the regular bottles used in nurseries. This discrepancy resulted from the vacuum build-up naturally occurring as an infant was withdrawing millk from a bottle while maintaining a seal around the nipple. The increasing negative pressure inside the bottle counteracted the sucking pressure to withdraw milk exerted by the infant, thereby leading to a poorer performance when a bottle was offered.

The purpose of this protocol is to reassess whether the same observations made in our earlier study mentioned above, i.e., potential markers of readiness to oral feeding, can be replicated when infants are fed with a regular bottle; more specifically, to identify the cut-off for overall efficiency and proficiency that will help identify the infants who will attain independent oral feeding sooner than others.

Other

The risks are minimal insofar as we are only collecting measures from the charts and 2 additional ones that caretakers can provide us when they are feeding their patients for the first time.

We expect that the data collected from this study will help us identify specific markers of readiness to and advancement of oral feeding which do not exist at this time. This would be of great assistance to clinicians.