Introduction: Currently, there is a lack of evidence on the utilization of high-flow nasal cannula (HFNC) in patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD) accompanied by hypercapnic respiratory failure. We aimed to explore the efficacy and safety of HFNC compared with conventional oxygen therapy (COT) in such patients. Methods: This was a prospective, randomized, controlled trial. Patients with AECOPD with a baseline arterial blood gas pH ≥7.35, PaO 2 <60 mmHg, and PaCO 2 >45 mmHg were enrolled. The primary endpoint was treatment failure, which needs mechanical ventilation. Results: A total of 320 patients were randomized to either the HFNC group (n = 160) or the COT group (n = 160). Sixteen (10.0%) patients in the HFNC group had treatment failure during hospitalization, which was significantly lower than the COT group figure of 31 (19.4%) patients (p = 0.026). Twenty-four hours after recruitment, the PaCO 2 of the HFNC group was lower than that of the COT group (54.1 ± 9.79 mmHg vs 56.9 ± 10.1 mmHg, p = 0.030). PaCO 2 higher than 59 mmHg after HFNC for 24 h was identified as an independent risk factor for treatment failure [OR 1.078, 95% CI 1.006-1.154, p = 0.032]. Conclusion: In AECOPD patients with acute compensated hypercapnic respiratory failure, HFNC improved the prognosis compared with COT. Therefore, HFNC might be considered for first-line oxygen therapy in select patients. Trial Registration Number: ClinicalTrials.Gov: NCT02439333.

Purpose: We hypothesized that increased level of serum β2-microglobulin (β2M) is an independent factor associated with higher mortality in hospitalized patients with exacerbated chronic obstructive pulmonary disease (COPD). Patients and Methods: We retrospectively analyzed 488 hospitalized patients with exacerbated COPD as the first diagnosis at Beijing Chao-Yang hospital, P. R. China between December 31st, 2012 and December 28th, 2017. Concentrations of serum β2M and other clinical indexes were measured or collected on admission, and all patients were followed up to 90 days. The relationship between β2M and 30-and 90-day all-cause mortality was explored by Cox regression analysis adjusted for age, C-reactive protein values, N-terminal pro-brain natriuretic peptide/100, respiratory failure [RF, defined as partial arterial oxygen pressure (PaO 2) <60 mmHg on room air or PaO 2 over the fraction of inspired oxygen (PaO 2 /FiO 2) < 300], eosinopenia, consolidation, and acidaemia. Results: Median concentrations of β2M were significantly higher in non-survivals compared to survivals within 30 days (4.11 mg/L (IQR 3.10-6.60) vs 2.79mg/L (IQR 2.13-3.76), P < 0.001) and 90 days (3.79 mg/L (IQR 2.61-6.69) vs 2.79 mg/L (IQR 2.13-3.73), P < 0.001). Serum levels of β2M were correlated with 30-day and 90-day mortality in overall exacerbated COPD patients, with hazard ratios (HRs) of 1.09 (95% CI 1.04-1.14, P = 0.001) and 1.09 (95% CI 1.05-1.14, P < 0.001). In exacerbated COPD patients without RF and with RF, the HRs were 1.06 (95% CI 0.995-1.137, P = 0.069) and 1.14 (95% CI 1.02-1.27, P = 0.021) for 30-day mortality, 1.09 (95% CI 1.02-1.15, P = 0.010) and 1.14 (95% CI 1.03-1.26, P = 0.014) for 90-day mortality, respectively. Conclusion: Our data showed that concentrations of serum β2M were associated with an increased risk of mortality, suggesting that β2M might be a valuable predictor of poor prognosis for hospitalized patients with exacerbated COPD.

Background Acute respiratory distress syndrome (ARDS) is a clinical syndrome characterized by acute hypoxaemia, and few studies have reported the incidence of deep vein thrombosis (DVT) in direct ARDS caused by bacterial pneumonia. We performed a study to evaluate the prevalence, risk factors, prognosis and potential thromboprophylaxis strategies of DVT in these patients. Methods Ninety patients were included. Demographic, and clinical data, laboratory data and outcome variables were obtained, and comparisons were made between the DVT and non-DVT groups. Results Of the 90 patients, 40 (44.4%) developed lower extremity DVT. Compared with non-DVT patients, DVT patients had higher systemic inflammatory response syndrome (SIRS) scores, lower serum creatinine levels, higher D-dimer levels, and higher rates of sedative therapy and invasive mechanical ventilation (IMV). Multivariate analysis showed an association between the SIRS score (OR 3.803, P = 0.027), level of serum creatinine (OR 0.988, P = 0.001), IMV (OR 5.822, P = 0.002) and DVT. The combination of SIRS score, serum creatinine level and IMV has a sensitivity of 80.0% and a specificity of 74.0% for screening for DVT. The survival rate within 28 days after ARDS in the DVT group was significantly lower than that in the non-DVT group (P = 0.003). There was no difference in the prevalence of DVT between the 41 patients who received thromboprophylaxis and the 49 patients who did not receive thromboprophylaxis (41.5% vs 46.9%; P = 0.603). Conclusions The prevalence of DVT is high in hospitalized patients with direct ARDS caused by bacterial pneumonia and may be associated with adverse outcomes. The current thromboprophylaxis strategies may need to be further optimized.