Abnormalities in the coordination of respiration and swallow in preterm infants with bronchopulmonary dysplasia

Abstract

Individual rhythms of suck, swallow, and respiration are disrupted in preterm infants with bronchopulmonary dysplasia (BPD). Integration of respiration into suck–swallow efforts is critical for establishing coordinated suckle feeding. This study quantitatively assessed the coordination of respiration and swallow in infants with and without BPD. Thirty-four preterm infants of 26 to 33 weeks' gestational age were included: 14 participants with BPD (eight males, six females)and 20 comparison participants without BDP (10 males, 10 females). Participants were studied at postmenstrual age 32 to 40 weeks and postnatal age 2 to 12 weeks using digital recordings of pharyngeal pressure, nasal thermistor flow, and thoraco-abdominal plethysmography. The coefficients of variation (COV; standard deviation/mean) of the swallow–breath (SW–BR) and breath–breath (BR–BR) intervals during swallow runs, the percentage of ‘apneic swallows’ (runs of [ges ]3 swallows without interposed breaths), and phase relationships of respiration and swallow were used to quantify rhythmic coordination and integration of respiration into feeding episodes. Apneic swallows were significantly increased after 35 weeks in infants with BPD (mean 13.4% [SE 2.4]) compared with non-BDP infants (6.7% [SE 1.8]; p<0.05), as were SW–BR phase relationships involving apnea. The BPD cohort also had significantly higher SW–BR COV and BR–BR COV than non-BPD infants, indicating less rhythmic coordination of swallowing and respiration during feeding. Results emphasize the need for frequent rests and closer monitoring when feeding infants with respiratory compromise. Quantitative assessment of the underlying rhythms involved in feeding may be predictive of longer-term feeding and neurological problems.