Étude de la dynamique laryngée au cours de la ventilation nasale non-conventionnelle par Neuro-asservissement de la ventilation assistée (NAVA) et par oscillations à haute fréquence (VOHF) chez l’agneau nouveau-né sans sédation

INTRODUCTION : We have previously shown that nasal pressure support ventilation (nPSV) can lead to an active laryngeal closure in non-sedated newborn lambs. This, in turn, can limit lung ventilation and divert air into the digestive system, with potentially deleterious consequences. Nasal neurally adjusted ventilator assist (nNAVA) and nasal high frequency oscillatory ventilation (nHFOV) are new attractive non-invasive ventilation modalities in newborns. Neurally adjusted ventilator assist (NAVA) seems to be a more physiological ventilator mode than PSV: it is more synchronized with neural control. However, HFOV is associated with less lung injury and does not require synchronization. Thus, the aim of the present study was to assess the effects of nNAVA and nHFOV on laryngeal dynamics in non-sedated newborn lambs, testing the hypothesis that active laryngeal closure does not develop during both nHFOV and nNAVA. METHODS : Polysomnographic recordings were performed in two groups of non-sedated chronically instrumented lambs (nHFOV, 7 lambs) and (nNAVA, 8 lambs), which were ventilated with progressively increased levels of nPSV and nHFOV or nNAVA, in random order. States of alertness, diaphragm and glottal muscle electrical activity, mask and tracheal pressure, tracheal end tidal CO[subscript 2] (P[subscript ET]CO[subscript 2]) and blood gases were continuously recorded in each group. RESULTS: While active laryngeal closure appeared with increasing levels of nPSV, it was never observed at any nHFOV power or nNAVA levels in any lamb. In addition, a decrease in PaCO[subscript 2] was neither necessary nor sufficient for the development of active laryngeal closure. nHFOV at 4Hz dramatically inhibited central respiratory drive. However, no active laryngeal closure was observed at 4 Hz. CONCLUSION: nHFOV and nNAVA does not induce active laryngeal closure in inspiration in non-sedated newborn lambs, in contrast to nPSV. nNAVA and nHFOV could be an alternatives in the treatment of neonatal respiratory disorders.

Name thesis:degree_name

Ph. D.

Level thesis:degree_level

Doctorat

Discipline thesis:degree_discipline

Physiologie

Grantor dc:publisher

Université de Sherbrooke

Year dc:date.issued

2014

Author dc:creator

• Hadj Ahmed, Mohamed Amine

Advisor dc:contributor.advisor

• Praud, Jean-Paul

• NAVAn
• VOHFn
• Aln et dynamique laryngée
• nNAVA
• nHFOV
• nPSV and laryngeal dynamics

Language dc:language.iso

fr

Handle dc:identifier.uri

https://hdl.handle.net/11143/121

OAI identifier oai:identifier

oai:usherbrooke.scholaris.ca:11143/121