Respiratory muscle responses to changes in chemoreceptor drive in infants

Academic Article

Abstract

  • Upper airway muscles and the diaphragm may have different quantitative responses to chemoreceptor stimulation. To compare the respiratory muscle responses to changes in CO , 10 ventilator-dependent preterm infants (gestational age 28 ± 1 wk, postnatal age 40 ± 6 days, weight 1.4 ± 0.1 kg) were passively hyperventilated to apnea and subsequently hypoventilated. Electromyograms from the genioglossus, alae nasi, posterior cricoarytenoid, and diaphragm were recorded from surface electrodes. Apneic CO thresholds of all upper airway muscles (genioglossus 46.8 ± 4.3 Torr, alae nasi 42.4 ± 3.6 Torr, posterior cricoarytenoid 41.6 ± 3.2 Torr) were higher than those of the diaphragm (38.8 ± 2.6 Torr, all P < 0.05). Above their CO threshold levels, responses of all upper airway muscles appeared proportional to those of the diaphragm. We conclude that nonproportional responses of the respiratory muscles to hypercapnia may be the result of differences in their CO threshold. These differences in CO threshold may cause imbalance in respiratory muscle activation with changes in chemical drive, leading to upper airway instability and obstructive apnea. 2 2 2 2 2
  • Authors

    Digital Object Identifier (doi)

    Author List

  • Carlo WA; DiFiore JM
  • Start Page

  • 1041
  • End Page

  • 1047
  • Volume

  • 68
  • Issue

  • 3