High-frequency oscillatory ventilation combined with partial liquid ventilation in experimental lung injury: effects on lung cell apoptosis

Conventional vs High-Frequency Ventilation for Weaning from Total Liquid Ventilation in Lambs

OBJECTIVE

To compare conventional gas ventilation (GV) and high-frequency oscillatory ventilation (HFOV) for weaning from total liquid ventilation (TLV).

METHODS

Sixteen lambs were anesthetized. After 1 h of TLV with perflubron (PFOB), they were assigned to either GV or HFOV for 2 h. Oxygen requirements, electrical impedance tomography and videofluoroscopic sequences, and respiratory system compliance were recorded.

RESULTS

The lambs under GV needed less oxygen at 20 min following TLV (40 [25, 45] and 83 [63, 98]%, p = 0.001 under GV and HFOV, respectively). During weaning, tidal volume distribution was increased in the nondependent regions in the GV group compared to baseline (p = 0.046). Furthermore, residual PFOB was observed in the most dependent region. No air was detected by fluoroscopy in that region at the end of expiration in the GV group.

CONCLUSION

GV offers a transient advantage over HFOV with regards to oxygenation for TLV weaning.

miRNA-23a has effects to improve lung injury induced by sepsis in vitro and vivo study

AIM

The aim of this study is to explain the effects and mechanism of miRNA-23a in lung injury which were induced by sepsis in vitro and vivo.

METHODS

In the vitro study, The BEAS-2B cells were divided into 4 groups: NC, MC, miRNA and miRNA + PTEN agonist groups. The cell proliferation and apoptosis of difference groups were measured by MTT and flow cytometry, the relative proteins expression of difference groups were measured by WB assay. In the vivo study, the rats were also divided into 4 groups: NC, MC, miRNA and miRNA + PTEN agonist groups. The miRNA-23a expression of difference groups were evaluated by ISH in lung tissues of rats. The cell apoptosis of difference groups were evaluated by TUNEL assay in lung tissues; the relative proteins expression of difference groups were evaluated by IHC assay.

RESULTS

Compared with NC group, the cell apoptosis rate of MC groups were significantly increased in vitro and vivo studies (P ＜ 0.05, respectively). The relative proteins (PTEN, PI3K, AKT and P53) expressions of MC group were significantly differences (P ＜ 0.05, respectively) compared with those of NC groups in vitro and vivo studies. However, with miRNA-23a infection, the cell apoptosis of miRNA group were significantly suppressed compared with MC groups, and the relative proteins (PTEN, PI3K, AKT and P53) of miRNA group were also significantly differences compared with MC groups in vitro and vivo studies (P ＜ 0.05, respectively).

CONCLUSION

The miRNA-23a has improved lung injury induced by sepsis via PTEN/PI3K/AKT/P53 pathway in vitro and vivo studies.

High-frequency oscillatory ventilation: still a role?

PURPOSE OF REVIEW

In light of emerging data from clinical trials, the place of high-frequency oscillatory ventilation (HFOV) in the management of acute respiratory distress syndrome (ARDS) is uncertain. This review provides an overview of these new clinical data and also explores new areas of investigation for HFOV in adults.

RECENT FINDINGS

While prior meta-analyses suggested benefit for HFOV, updated systematic reviews published this year, which include two large recent clinical trials, now show no statistically significant impact of HFOV on mortality in adults with ARDS. It is possible that HFOV would be safer and more effective with a more individualized approach to setting mean airway pressure (mPaw). Possible techniques to achieve this include titrating mPaw in response to oxygenation or hemodynamic changes after HFOV initiation, by measuring respiratory system impedance, or by following echocardiographic changes.

SUMMARY

Although not first-line, HFOV remains a tool in the armamentarium of the intensivist managing the patient with severe ARDS and refractory hypoxemia. A refinement in the approach to delivering HFOV is warranted, with more attention paid to its adverse hemodynamic consequences.

Digital gene expression analysis in mice lung with coinfection of influenza and streptococcus pneumoniae

Influenza A virus (IAV) and Streptococcus pneumoniae (SP) are two major upper respiratory tract pathogens that can also cause infection in polarized bronchial epithelial cells to exacerbate disease in coinfected individuals which may result in significant morbidity. However, the underlying molecular mechanism is poorly understood. Here, we employed BALB/c ByJ mice inflected with SP, IAV, IAV followed by SP (IAV+SP) and PBS (Control) as models to survey the global gene expression using digital gene expression (DGE) profiling. We attempt to gain insights into the underlying genetic basis of this synergy at the expression level. Gene expression profiles were obtain using the Illimina/Hisseq sequencing technique, and further analyzed by enrichment analysis of Gene Ontology (GO) and Pathway function. The hematoxylin-eosin (HE) staining revealed different tissue changes in groups during which IAV+SP group showed the most severe cell apoptosis. Compared with Control, a total of 2731, 3221 and 3946 differentially expressed genes (DEGs) were detected in SP, IAV and IAV+SP respectively. Besides, sixty-two GO terms were identified by Gene Ontology functional enrichment analysis, such as cell killing, biological regulation, response to stimulus, signaling, biological adhesion, enzyme regulator activity, receptor regulator activity and translation regulator activity. Pathway significant enrichment analysis indicated the dysregulation of multiple pathways, including apoptosis pathway. Among these, five selected genes were further verified by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). This study shows that infection with SP, IAV or IAV+SP induces apoptosis with different degrees which might provide insights into the molecular mechanisms to facilitate further research.

[A Meta analysis of the efficacy of high-frequency oscillatory ventilation versus conventional mechanical ventilation for treating pediatric acute respiratory distress syndrome]

OBJECTIVE

To systematically assess the clinical efficacy of high-frequency oscillatory ventilation (HFOV) and conventional mechanical ventilation (CMV) for treating pediatric acute respiratory distress syndrome (ARDS).

METHODS

Data from randomized controlled trials comparing HFOV and CMV in the treatment of pediatric ARDS published before July 2016 were collected from the Cochrane Library, PubMed, Medline, CNKI, and Wanfang Data. Literature screening, data extraction, and quality assessment were performed by two independent reviewers according to the inclusion and exclusion criteria. The selected studies were then subjected to a Meta analysis using the RevMan 5.3 software.

RESULTS

A total of 6 studies involving 246 patients were included. The results of the Meta analysis showed that there were no significant differences between the HFOV and CMV groups in the in-hospital or 30-day mortality rate, incidence of barotrauma, mean ventilation time, and oxygenation index (P>0.05). However, compared with CMV, HFOV increased the PaO2/FiO2 ratio by 17%, 24%, and 31% at 24, 48, and 72 hours after treatment respectively, and improved oxygenation in patients.

CONCLUSIONS

Although the mortality rate is not reduced by HFOV in children with ARDS, this treatment can result in significant improvement in oxygenation compared with CMV. Further large-sample, multicenter, randomized clinical trials will be required to draw a definitive conclusion.

[A Meta analysis of the efficacy of high-frequency oscillatory ventilation versus conventional mechanical ventilation for treating pediatric acute respiratory distress syndrome]

OBJECTIVE

To systematically assess the clinical efficacy of high-frequency oscillatory ventilation (HFOV) and conventional mechanical ventilation (CMV) for treating pediatric acute respiratory distress syndrome (ARDS).

METHODS

Data from randomized controlled trials comparing HFOV and CMV in the treatment of pediatric ARDS published before July 2016 were collected from the Cochrane Library, PubMed, Medline, CNKI, and Wanfang Data. Literature screening, data extraction, and quality assessment were performed by two independent reviewers according to the inclusion and exclusion criteria. The selected studies were then subjected to a Meta analysis using the RevMan 5.3 software.

RESULTS

A total of 6 studies involving 246 patients were included. The results of the Meta analysis showed that there were no significant differences between the HFOV and CMV groups in the in-hospital or 30-day mortality rate, incidence of barotrauma, mean ventilation time, and oxygenation index (P>0.05). However, compared with CMV, HFOV increased the PaO₂/FiO₂ ratio by 17%, 24%, and 31% at 24, 48, and 72 hours after treatment respectively, and improved oxygenation in patients.

CONCLUSIONS

Although the mortality rate is not reduced by HFOV in children with ARDS, this treatment can result in significant improvement in oxygenation compared with CMV. Further large-sample, multicenter, randomized clinical trials will be required to draw a definitive conclusion.