Bin Fang

Mesenchymal stromal cell (MSC) therapy is a potential therapy for treating acute lung injury (ALI) or acute respiratory distress syndrome (ARDS), which was widely studied in the last decade. The purpose of our meta-analysis was to investigate the efficacy of MSCs for simulated infection-induced ALI/ARDS in animal trials. PubMed and EMBASE were searched to screen relevant preclinical trials with a prespecified search strategy. 57 studies met the inclusion criteria and were included in our study. Our meta-analysis showed that MSCs can reduce the lung injury score of ALI caused by lipopolysaccharide or bacteria (standardized mean difference (SMD) = −2.97, 95% CI [−3.64 to −2.30], P < 0.00001) and improve the animals’ survival (odds ratio = 3.64, 95% CI [2.55 to 5.19], P < 0.00001). Our study discovered that MSCs can reduce the wet weight to dry weight ratio of the lung (SMD = −2.58, 95% CI [−3.24 to −1.91], P < 0.00001). The proportion of the alveolar sac in the MSC group was higher than that in the control group (SMD = 1.68, 95% CI [1.22 to 2.13], P < 0.00001). Moreover, our study detected that MSCs can downregulate the levels of proinflammatory factors such as interleukin (IL)-1β, IL-6, and tumor necrosis factor-α in the lung and it can upregulate the level of anti-inflammatory factor IL-10. MSCs were also found to reduce the level of neutrophils and total protein in bronchoalveolar lavage fluid, decrease myeloperoxidase (MPO) activity in the lung, and improve lung compliance. MSC therapy may be a promising treatment for ALI/ARDS since it may mitigate the severity of lung injury, modulate the immune balance, and ameliorate the permeability of lung vessels in ALI/ARDS, thus facilitating lung regeneration and repair.

Double lumen intubation and one-lung ventilation should be applied without delay in cases of traumatic main bronchial rupture. In most cases, when the patients’ vital signs have been stabilized, the repair can be performed. However, when one-lung ventilation is complicated by traumatic wet lung, the mortality rate is likely to be much higher. In this case, the patient experienced a left main bronchial rupture, bilateral traumatic wet lung, and acute respiratory distress syndrome (ARDS) because of severe thoracic trauma. Though the patient was treated with intubation and mechanical ventilation (MV), his oxygenation was still not stable. Thus, veno-venous extracorporeal membrane oxygenation (V-V ECMO) was initiated; upon improvement of oxygenation, the patient received an exploratory thoracotomy. Unfortunately, the rupture proved to be irreparable, resulting in a total left pneumonectomy. As there was severe ARDS caused by trauma, ECMO and ultra-low tidal volume (VT) MV strategy (3 ml/kg) were utilized for lung protection post-op. ECMO was sustained up to the 10th day, and MV until the 20th day, post-operation. With the support of MV, ECMO and other comprehensive measures, the patient made a recovery. V-V ECMO and ultra-low VT MV helped this thoracic trauma patient survive the lung edema period and prevented ventilator associated pneumonia (VAP). In extreme situations, with the support of ECMO, the tidal volume may be lowered to 3 ml/kg.