Purpose This study aimed to evaluate the clinical outcomes of high-flow nasal cannula (HFNC) compared with conventional oxygen therapy (COT) in patients with hypercapnic chronic obstructive pulmonary disease (COPD), including arterial partial pressure of carbon dioxide (PaCO 2 ), arterial partial pressure of oxygen (PaO 2 ), respiratory rate (RR), treatment failure, exacerbation rates, adverse events and comfort evaluation. Patients and Methods PubMed, EMBASE and the Cochrane Library were retrieved from inception to September 30, 2022. Eligible trials were randomized controlled trials and crossover studies comparing HFNC and COT in hypercapnic COPD patients. Continuous variables were reported as mean and standard derivation and calculated by weighted mean differences (MD), while dichotomous variables were shown as frequency and proportion and calculated by odds ratio (OR), with the 95% confidence intervals (Cl). Statistical analysis was performed using RevMan 5.4 software. Results Eight studies were included, five with acute hypercapnia and three with chronic hypercapnia. In acute hypercapnic COPD, short-term HFNC reduced PaCO 2 (MD −1.55, 95% CI: −2.85 to −0.25, I² = 0%, p <0.05) and treatment failure (OR 0.54, 95% CI: 0.33 to 0.88, I² = 0%, p<0.05), but there were no significant differences in PaO 2 (MD −0.36, 95% CI: −2.23 to 1.52, I² = 45%, p=0.71) and RR (MD −1.07, 95% CI: −2.44 to 0.29, I² = 72%, p=0.12). In chronic hypercapnic COPD, HFNC may reduce COPD exacerbation rates, but there was no advantage in improving PaCO 2 (MD −1.21, 95% CI: −3.81 to 1.39, I² = 0%, p=0.36) and PaO 2 (MD 2.81, 95% CI: −1.39 to 7.02, I² = 0%, p=0.19). Conclusion Compared with COT, short-term HFNC reduced PaCO 2 and the need for escalating respiratory support in acute hypercapnic COPD, whereas long-term HFNC reduced COPD exacerbations rates in chronic hypercapnia. HFNC has great potential for treating hypercapnic COPD.

Background: Genome-wide association studies of lung cancer have shown a common variation at 15q24-25.1 as a determinant of risk, but the role of specific genes has not been proven. This study aims to explore the expression of mutations and the prognostic significance of 15q25 (CHRNA5 and PSMA4) mRNA in lung adenocarcinoma (LAC) based on immunohistochemistry, TCGA and bioinformatics. Methods: The expression of mutations on chromosome 15q25 of 576 primary LAC patients was selected and survival and gene expression data were extracted from TCGA. The relationship between expression of genes on 15q25 and clinical and prognostic Significance of LAC. An experiment with Beas-2b, A549 and H1299 cell lines was performed to further prove the difference in CHRNA5 and PSMA4 expression between lung cancer and normal cells. Immunohistochemistry data of CHRNA5 and PSMA4 were detected in LAC and normal tissues from 122 patients. Finally, Gene enrichment analysis (GSEA) was conducted to predict the regulatory genes of CHRNA5 and PSMA4. Results: CHRNA5 and PSMA4 are frequently mutated in TCGA (CHRNA5, 1.7%; PSMA4, 1.3%). Besides, the expression of CHRNA5 and PSMA4 was obviously higher in A549 and H1299 cells. And the immunohistochemical staining revealed that the levels of CHRNA5 and PSMA4 were considerably higher in the LAC group than in the normal group. Meanwhile, there was a significant association between high CHRNA5 expression and smoking history (P=0.011), smoking history pack year value (P=0.010). Furthermore, there was a significant correlation between CHRNA5 and PSMA4 expression levels and prognosis (P=0.003; P=0.008), and between higher expression and worse prognosis. GSEA results suggested that between samples with high CHRNA5 and PSMA4 expression were respectively enriched to cell cycle, base excision repair, oxidative phosphorylation, protein export, and aminoacyl tRNA biosynthesis, among others. Conclusions: CHRNA5 and PSMA4 mRNA expression has a significant impact on the clinical and survival of LAC, and they may be a potential target for treating patients with lung adenocarcinoma.

Background To explore the mutations expression and prognostic significance of 15q25 (CHRNA5 and PSMA4) mRNA in lung adenocarcinoma (LAC) based on immunohistochemistry, TCGA and bioinformatics.Methods Mutations expression on chromosome 15q25 of 576 primary LAC patients was selected. And their survival and gene expression data were extracted from TCGA. The cell experiment about Beas-2b, A549 and H1299 cell lines were done to further prove the CHRNA5 and PSMA4 expression difference between lung cancer and normal cells. Immunohistochemistry data of CHRNA5 and PSMA4 were detected in LAC and normal tissues from 122 patients.Finally, Gene enrichment analysis (GSEA) was used to predict the regulatory genes of CHRNA5 and PSMA4.Results CHRNA5 and PSMA4 are frequently mutated in the TCGA (CHRNA5, 1.7%; PSMA4, 1.3%).The expression of CHRNA5 and PSMA4 were obviously higher in A549 and H1299 cells. Immunohistochemical staining revealed that the level of CHRNA5 and PSMA4 was considerably higher in LAC group than in normal group. There was a significant association between high expression of CHRNA5 and Smoking History (P = 0.011), Smoking History Pack Year Value(P = 0.010). Besides, there was a significant correlation between CHRNA5 and PSMA4 expression level and prognosis (P = 0.003; P = 0.008),and the higher expression, the worse prognosis. GSEA results suggested that CHRNA5 and PSMA4 high expression samples were respectively enriched to cell cycle, base excision repair, oxidative phosphorylation, protein export, aminoacyl tRNA biosynthesis etc.Conclusions The expression of CHRNA5 and PSMA4 mRNA has a significant impact on survival of LAC, they may be a potential target for treating patients with lung adenocarcinoma.