Biphasic positive airway pressure spontaneous breathing attenuates lung injury in an animal model of severe acute respiratory distress syndrome

Abstract

Objective To compare the effects of unassisted spontaneous breathing (SB) and complete muscle paralysis (PC) on early severe acute respiratory distress syndrome (ARDS) in an animal model, and to explore the possibility of biphasic positive airway pressure (BIPAP) as lung protective ventilation support for patients in the early stage of severe ARDS. Methods Twelve healthy beagle dogs between the ages of 10 and 15 months were randomly divided into two groups: the SB group (BIPAPSB) and the PC group (BIPAPPC). Arterial blood samples were drawn before modelling. Arterial blood gas analysis and mechanical tests were conducted. The animal model of severe ARDS was established using a deep intravenous injection of oleic acid, and BIPAP ventilation was performed for 8 hours. Lung tissue and blood were taken to detect lung function, inflammatory reactions and degree of pathological damage. Results At the beginning of the experiment, there was no significant difference in the arterial blood gas analysis between the two groups (p > 0.05). After successful modelling, the oxygenation index and the end-expiratory lung volume in the SB group were significantly higher than those in the PC group 8 hours after MV. Pathologically, the wet-dry ratio and pathological score of the PC group were higher than those of the SB group; the lung injury in the gravity-dependent area in the SB group was less than that in the PC group (p< 0.05). Conclusions In the early stage of severe ARDS induced by oleic acid, compared with PC, retention of the BIPAP mode of SB can reduce the risk of lung injury and improve respiratory function.

PCV‐VG combined individualized PEEP determination in one‐lung ventilated patients with PEEP step change direction: A randomized controlled trial

“…Due to shunting on the non‐ventilated side of the lung, some blood is not oxygenated, and pulmonary atelectasis occurs on the ventilated side of the lung, resulting in disproportionate ventilation blood flow, which further impairs arterial oxygenation and promotes hypoxemia 19 . During anesthesia, when respiratory muscle groups relax and lose tone, the diaphragm moves cephalad, thoracic volume changes, and functional residual air volume and Cydn decrease, eventually causing disproportionate pulmonary ventilation blood flow on the ventilating side 20 . From the perspective of a pulmonary protective ventilation strategy, appropriate PEEP during OLV is particularly important to prevent mechanical lung injury caused by V T and pulmonary atelectasis 21 .…”

“… 19 During anesthesia, when respiratory muscle groups relax and lose tone, the diaphragm moves cephalad, thoracic volume changes, and functional residual air volume and Cydn decrease, eventually causing disproportionate pulmonary ventilation blood flow on the ventilating side. 20 From the perspective of a pulmonary protective ventilation strategy, appropriate PEEP during OLV is particularly important to prevent mechanical lung injury caused by V T and pulmonary atelectasis. 21 In addition, high FiO 2 was used in this study before OLV because of the high hypoxia, and high FiO 2 is more commonly used in OLV and TLV 22 , 23 despite the adverse consequences of high oxygen levels, as reported in previous studies.…”

Desarrollo y evaluación de mascarillas de oxigenación en 3D diseñadas para caninos en recuperación post quirúrgica

“…La fisiología de la respiración en perros involucra una serie de procesos que aseguran el intercambio eficiente de gases en los pulmones, durante la inhalación, los músculos inspiratorios como el diafragma y los músculos intercostales se contraen, lo que provoca la expansión de la cavidad torácica y el descenso del diafragma (Tagliabue et al, 2022), este aumento de volumen intratorácico genera una presión negativa en los pulmones, permitiendo que el aire ingrese a través de las vías respiratorias superiores hacia los alvéolos pulmonares (Zhou et al, 2022).…”