Impact of neonatal noninvasive resuscitation strategies on lung mechanics, tracheal pressure, and tidal volume in preterm lambs.
Am J Physiol Lung Cell Mol Physiol
; 327(2): L203-L217, 2024 Aug 01.
Article
en En
| MEDLINE
| ID: mdl-38771135
ABSTRACT
This study investigated the relationship between three respiratory support approaches on lung volume recruitment during the first 2 h of postnatal life in preterm lambs. We estimated changes in lung aeration, measuring respiratory resistance and reactance by oscillometry at 5 Hz. We also measured intratracheal pressure in subsets of lambs. The first main finding is that sustained inflation (SI) applied noninvasively (Mask SI; n = 7) or invasively [endotracheal tube (ETT) SI; n = 6] led to similar rapid lung volume recruitment (â¼6 min). In contrast, Mask continuous positive airway pressure (CPAP) without SI (n = 6) resuscitation took longer (â¼30-45 min) to reach similar lung volume recruitment. The second main finding is that, in the first 15 min of postnatal life, the Mask CPAP without SI group closed their larynx during custom ventilator-driven expiration, leading to intratracheal positive end-expiratory pressure of â¼17 cmH2O (instead of 8 cmH2O provided by the ventilator). In contrast, the Mask SI group used the larynx to limit inspiratory pressure to â¼26 cmH2O (instead of 30 cmH2O provided by the ventilator). These different responses affected tidal volume, being larger in the Mask CPAP without SI group [8.4 mL/kg; 6.7-9.3 interquartile range (IQR)] compared to the Mask SI (5.0 mL/kg; 4.4-5.2 IQR) and ETT SI groups (3.3 mL/kg; 2.6-3.7 IQR). Distinct physiological responses suggest that spontaneous respiratory activity of the larynx of preterm lambs at birth can uncouple pressure applied by the ventilator to that applied to the lung, leading to unpredictable lung pressure and tidal volume delivery independently from the ventilator settings.NEW & NOTEWORTHY We compared invasive and noninvasive resuscitation on lambs at birth, including or not sustained inflation (SI). Lung volume recruitment was faster in those receiving SI. During noninvasive resuscitation, larynx modulation reduced tracheal pressure from that applied to the mask in lambs receiving SI, while it led to increased auto-positive end-expiratory pressure and very large tidal volumes in lambs not receiving SI. Our results highlight the need for individualizing pressures and monitoring tidal volumes during resuscitation at birth.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Asunto principal:
Tráquea
/
Volumen de Ventilación Pulmonar
/
Pulmón
/
Animales Recién Nacidos
Límite:
Animals
Idioma:
En
Revista:
Am J Physiol Lung Cell Mol Physiol
Asunto de la revista:
BIOLOGIA MOLECULAR
/
FISIOLOGIA
Año:
2024
Tipo del documento:
Article
País de afiliación:
Italia