title: Alae nasi activation in preterm infants during oral feeding.
abstract: Preterm infants may demonstrate impaired ventilation during oral feeding with resultant hypoxemia and hypercarbia. This study was designed to determine whether infants activate a representative upper airway muscle, the ala nasi, in response to these ventilatory changes. Ten preterm infants (postconceptional age at study 35 +/- 4 wk, weight 2.2 +/- 0.1 kg) were studied during a control period, continuous feeding, subsequent intermittent feeding, and a period of nonnutritive sucking. Nasal airflow was measured with a pneumotachometer to quantify minute ventilation. The alae nasi electromyogram (EMGAN) was recorded with surface electrodes, and sucking pressure was detected by a catheter in the feeding nipple. End-tidal CO2 and O2 saturation were also recorded during each period. The percentage of breaths associated with EMGAN activity increased from 41 +/- 13% during the control period to 95 +/- 5% and 93 +/- 7% during continuous and intermittent sucking, respectively (p < 0.05). Eighty-seven +/- 5% of EMGAN activity occurred during inspiration. During continuous and intermittent sucking, the amplitude of EMGAN activity also increased (6.8 +/- 5.2 and 6.7 +/- 4.0 arbitrary units/breath, respectively) compared with the control period (2.4 +/- 2.8 units/breath, p < 0.05). In association with the increase in EMGAN activity, O2 saturation fell from 98 +/- 1% in the control period to 95 +/- 1% during both continuous and intermittent feeding (p < 0.05), and minute ventilation fell from 274 +/- 80 mL/min/kg during the control period to 190 +/- 81 and 208 +/- 57 mL/min/kg during continuous and intermittent feeding, respectively (p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Rainbow Babies' and Children's Hospital, Case Western Reserve University, Cleveland, Ohio 44106.
authors.forename: B J
authors.initials: BJ
authors.lastname: Timms
authors.forename: J M
authors.initials: JM
authors.lastname: DiFiore
authors.forename: R J
authors.initials: RJ
authors.lastname: Martin
authors.forename: W A
authors.initials: WA
authors.lastname: Carlo
authors.forename: M J
authors.initials: MJ
authors.lastname: Miller
mesh_terms: D002245:Carbon Dioxide / Q000097:blood; D003679:Deglutition / Q000502:physiology; D004435:Eating / Q000502:physiology*; D004576:Electromyography; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature / Q000502:physiology*; D009296:Nasal Cavity / Q000502:physiology; D015656:Respiratory Mechanics / Q000502:physiology; D012132:Respiratory Muscles / Q000502:physiology*; D013391:Sucking Behavior / Q000502:physiology
chemical_list: D002245:Carbon Dioxide