Bone Marrow Mesenchymal Stem Cell Transplantation in Combination with Nasal Continuous Positive Airway Pressure Improves Acute Exacerbation of Chronic Obstructive Pulmonary Disease (AECOPD)

We aimed to explore the efficacy of bone marrow mesenchymal stem cell (BMSC) transplantation combined with nasal continuous positive airway pressure (nCPAP) for treating severe acute exacerbation of chronic obstructive pulmonary disease (AECOPD). SD rat AECOPD model was established by injecting endotoxin and Staphylococcus aureus and then treated with nCPAP, BMSCs, or nCPAP combined with BMSCs (n = 20) and their conditions were evaluated with BBB score at 1 d, 3 d, 7 d, 14 d, 28 d after treatment along with analysis of apoptosis and BrdU-positive cells as well as NF200 expression by TUNEL kit staining and levels of Th1, Th7 and Th12 before and after treatment. As revealed by BBB score and HE staining, all treatments significantly alleviated the symptom of severe APEOPD (p < 0.05), while compared with nCPAP, the combined treatment exhibited higher efficacy. Besides, upon treatment, apoptosis and level of Th1, Th7 and Th12 was reduced but N200 absorbance value was elevated, with significant difference in combination group (p < 0.05). In conclusion, BMSC transplantation in combination with nCPAP alleviates severe AECOPD by reducing cell apoptosis, repairing cell damage, and regulating T-cell subsets.

Positive Airway Pressure at Extubation Minimizes Subglottic Secretion Leak In Vitro

Accumulated secretion above the endotracheal tube cuff can be aspirated during extubation after deflation. The possible techniques for minimizing pulmonary aspiration from subglottic secretion during extubation have not been well explored. This study aimed to determine the effect of different extubation techniques on secretion leakage. An endotracheal tube was placed in a tube mimicking an airway. We measured the leak volume of water or artificial sputum of different viscosities with three extubation techniques—negative pressure with suctioning; positive pressure with a resuscitator; and continuous positive airway pressure set at 5, 10, and 20 cm H2O. Extubation with continuous positive airway pressure resulted in lower secretion leakage than that with negative pressure with suctioning and positive pressure with a resuscitator. Increasing the continuous positive airway pressure level decreased secretion leakage volume during extubation. We further determined a correlation of leak volume with sputum viscosity. Continuous positive airway pressure at 5 cm H2O produced lower volume secretion leakage than the other two techniques, even with higher secretion viscosity. Based on these results, using continuous positive airway pressure with a previous ventilator continuous positive airway pressure/positive end-expiratory pressure setting for extubation is recommended.

Safety of Bottle-Feeding Under Nasal Respiratory Support in Preterm Lambs With and Without Tachypnoea

Aim: Convalescing preterm infants often require non-invasive respiratory support, such as nasal continuous positive airway pressure or high-flow nasal cannulas. One challenging milestone for preterm infants is achieving full oral feeding. Some teams fear nasal respiratory support might disrupt sucking–swallowing–breathing coordination and induce severe cardiorespiratory events. The main objective of this study was to assess the safety of oral feeding of preterm lambs on nasal respiratory support, with or without tachypnoea.Methods: Sucking, swallowing and breathing functions, as well as electrocardiogram, oxygen haemoglobin saturation, arterial blood gases and videofluoroscopic swallowing study were recorded in 15 preterm lambs during bottle-feeding. Four randomly ordered conditions were studied: control, nasal continuous positive airway pressure (6 cmH2O), high-flow nasal cannulas (7 L•min–1), and high-flow nasal cannulas at 7 L•min–1 at a tracheal pressure of 6 cmH2O. The recordings were repeated on days 7–8 and 13–14 to assess the effect of maturation.Results: None of the respiratory support impaired the safety or efficiency of oral feeding, even with tachypnoea. No respiratory support systematically impacted sucking–swallowing–breathing coordination, with or without tachypnoea. No effect of maturation was found.Conclusion: This translational physiology study, uniquely conducted in a relevant animal model of preterm infant with respiratory impairment, shows that nasal respiratory support does not impact the safety or efficiency of bottle-feeding or sucking–swallowing–breathing coordination. These results suggest that clinical studies on bottle-feeding in preterm infants under nasal continuous positive airway pressure and/or high-flow nasal cannulas can be safely undertaken.