496 - Title: Preterm Infants with Feeding-Associated Cardiorespiratory Events Have Transient Dysmotility During Postnatal Development

Poster Number: 496
Publication Number: 496.424

Christopher F. Sawyer, University of Texas Southwestern Medical School, Dallas, TX, United States; Larry S. Brown, Parkland Health & Hospital System, Dallas, TX, United States; Lindsay Roblyer, University of Texas Southwestern Medical School, Dallas, TX, United States; Rinarani M. Sanghavi, University of Texas Southwestern Medical School, Dallas, TX, United States; Eric B. Ortigoza, UT Southwestern Medical Center, Dallas, TX, United States

Background: Preterm infants have immature respiratory control that can result in cardiorespiratory events. These events are common and occasionally occur during enteral feeding. It is unclear if these events are related to enteral feeding, or merely temporally associated. Gastric electrical activity, known as slow waves, functions as the pacemaker of the stomach, with a baseline of 3-4 cycles per minute. Tachygastria, defined as 4-9 cycles per minute, is associated with gastric hypomotility and gastrointestinal disorders. Preterm infants with frequent feeding-associated cardiorespiratory events may spend more time in tachygastria.

Objective: To determine if preterm infants who have many apneic or bradycardic events during feeding spend a greater percentage of time in gastric tachygastria (and thus, have more gastric dysmotility) compared to infants who have no events.

Design/Methods: We conducted a retrospective cohort study of preterm infants born < 34 weeks’ gestation who were previously enrolled in a longitudinal study of gastrointestinal development, including electrogastrography (EGG), a non-invasive method of measuring gastric slow waves. Infants underwent weekly EGG recordings until 40 weeks postmenstrual age or discharge, if earlier. All apneas (>10 seconds) and bradycardias ( < 100 beats per minute) that occurred during an enteral feed were counted for the 24-hour period that coincided with the EGG recording. Infants were stratified in to 3 groups: (A) apnea (number of events >2 standard deviations from the mean), (B) bradycardia (number of events >2SD from the mean), and (C) controls (no events) in any 24-hr period surrounding an EGG recording. A repeated measures ANOVA was performed to compare between groups (A vs. C, B vs. C, A and B vs. C, A or B vs. C).

Results: 60 infants were included in this study (see Table 1). The mean EGG frequencies per week are summarized in Figure 1. Repeated measures ANOVA did not reveal any differences between the groups. However, individual week analyses revealed that at week 5 of life infants with >2 apneas (group A) or >2 bradycardias (group B) spent 43.5% time in tachygastria and controls (group C) spent 40.1% time in tachygastria, which was statistically significant (p=0.03).Conclusion(s): Infants with many apnea or bradycardia events (>2 SD from the mean) occurring during enteral feeding have greater dysmotility at postnatal week 5 than infants who have no events. One possible hypothesis is that this may be secondary to gastrointestinal immaturity; however, the clinical significance of week 5 on gastric motility and cardiorespiratory events needs to be explored further.
CV - Sawyer, Christopher.pdf
Figure 1