Effects of nasal continuous positive-airway pressure on nutritive swallowing in lambs

Abstract

Praud JP. Effects of nasal continuous positive-airway pressure on nutritive swallowing in lambs. J Appl Physiol 112: 1984 -1991, 2012. First published April 12, 2012 doi:10.1152/japplphysiol.01559.2011.-Current knowledge suggests that, to be successful, oral feeding in preterm infants should be initiated as soon as possible, often at an age where immature respiration still requires ventilatory support in the form of nasal continuous positive airway pressure (nCPAP). While some neonatologist teams claim great success with initiation of oral feeding in immature infants with nCPAP, others strictly wait for this ventilatory support to be no longer necessary before any attempt at oral feeding, fearing laryngeal penetration and tracheal aspiration. Therefore, the aim of the present study was to provide a first assessment of the effect of various levels of nCPAP on bottle-feeding in a neonatal ovine model, including feeding safety, feeding efficiency, and nutritive swallowing-breathing coordination. Eight lambs born at term were surgically instrumented 48 h after birth to collect recordings of electrical activity of laryngeal constrictor muscle, electrocardiography, and arterial blood gases. Two days after surgery, lambs were bottle-fed under five randomized nCPAP conditions, including without any nCPAP or nasal mask and nCPAP of 0, 4, 7, and 10 cmH2O. Results revealed that application of nCPAP in the full-term lamb had no deleterious effect on feeding safety and efficiency or on nutritive swallowing-breathing coordination. The present study provides a first and unique insight on the effect of nCPAP on oral feeding, demonstrating its safety in newborn lambs born at term. These results open the way for further research in preterm lambs to better mimic the problems encountered in neonatology.

Effects of Moderate Hyperbilirubinemia on Nutritive Swallowing and Swallowing-Breathing Coordination in Preterm Lambs

“…In a previous study, we reported that term lambs have less than one apnea during bottle-feeding [19]. This is in sharp contrast to our present observations of prolonged apneas/hypopneas during NS bursts in control preterm lambs.…”

“…The attenuation of NS burst-related respiratory inhibition in HB preterm lambs is intriguing and raises the possibility of an increased maturation of NS-breathing coordination by HB. However, mature NS-breathing coordination in term lambs implies regular occurrence of swallows and respirations without apneas [19] whereas, in contrast, NS and respiratory rhythms were chaotic in HB preterm lambs. We therefore propose that prolonged apneas accompanying NS bursts in control preterm lambs, although reflecting an immature NS-breathing coordination, represent an ‘alternative' coordination to prevent aspirations within the context of prematurity.…”

Nasal Continuous Positive Airway Pressure Inhibits Gastroesophageal Reflux in Newborn Lambs

“…In the past few years, we have used our newborn ovine model to show the absence of effects of nCPAP on nutritive swallowing [6] and, more specifically, on esophagodeglutition [7]. In addition, we have established the newborn lamb as a unique model to study neonatal GER [8].…”

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

“…However, our previous results showing a decreased number of NNS elicited during laryngeal chemoreflexes suggest that NNS alterations by early postnatal ETS exposure might predispose to lung aspiration during acute challenges such as pharyngolaryngeal reflux. In this respect, it would be of interest to study the effects of postnatal ETS exposure on nutritive swallowing, which constitutes another challenge for swallowing function (Bernier et al, 2012).…”