Effects of reflux laryngitis on non-nutritive swallowing in newborn lambs

Abstract

Reflux laryngitis in infants may be involved not only in laryngeal disorders, but also in disorders of cardiorespiratory control through its impact on laryngeal function. Our objective was to study the effect of reflux laryngitis on non-nutritive swallowing (NNS) and NNS-breathing coordination. Two groups of six newborn lambs, randomized into laryngitis and control groups, were surgically instrumented for recording states of alertness, swallowing and cardiorespiratory variables without sedation. A mild to moderate reflux laryngitis was induced in lambs from the experimental group. A significant decrease in the number of NNS bursts and apneas was observed in the laryngitis group in active sleep (p = 0.03).In addition, lower heart and respiratory rates, as well as prolonged apnea duration (p < 0.0001) were observed. No physiologically significant alterations in NNS-breathing coordination were observed in the laryngitis group. We conclude that a mild to moderate reflux laryngitis alters NNS burst frequency and autonomous control of cardiac activity and respiration in lambs. ABSTRACTReflux laryngitis in infants may be involved not only in laryngeal disorders, but also in disorders of cardiorespiratory control through its impact on laryngeal function. Our objective was to study the effect of reflux laryngitis on non-nutritive swallowing (NNS) and NNS-breathing coordination. Two groups of six newborn lambs, randomized into laryngitis and control groups, were surgically instrumented for recording states of alertness, swallowing and cardiorespiratory variables without sedation. A mild to moderate reflux laryngitis was induced in lambs from the experimental group. A significant decrease in the number of NNS bursts and apneas was observed in the laryngitis group in active sleep (p = 0.03).In addition, lower heart and respiratory rates, as well as prolonged apnea duration (p < 0.0001) were observed. No physiologically significant alterations in NNS-breathing coordination were observed in the laryngitis group. We conclude that a mild to moderate reflux laryngitis alters NNS burst frequency and autonomous control of cardiac activity and respiration in lambs.

Effects of postnatal environmental tobacco smoke on non-nutritive swallowing-breathing coordination in newborn lambs

“…We have previously shown that NNS beginning in inspiration are predominant over NNS beginning in expiration in lambs (Reix et al, 2003). In addition, we have reported that NNS-breathing coordination in lambs is unaltered by various neonatal conditions such as nasal application of continuous or intermittent positive airway pressure (Samson et al, 2005), hypoxia (Duvareille et al, 2007), preterm birth (Reix et al, 2004) and reflux laryngitis (Brisebois et al, 2010), suggesting that NNSbreathing coordination is established well before birth, in keeping with its importance for preventing both lung aspiration and respiratory inhibition. Until now, hypercapnia in newborn lambs (Duvareille et al, 2007) and volition in adult humans (Kelly et al, 2007) were the only conditions known to alter NNS-breathing coordination.…”