Respiratory effort in mechanical ventilation weaning Prediction: An observational, case-control study.

BACKGROUND: The diaphragm is crucial for ventilator weaning, but its specific impact on weaning indicators needs further clarification. This study investigated the variability in weaning outcomes across different diaphragm function populations and the value of respiratory drive and inspiratory effort in weaning. METHODS: This observational case-control study enrolled patients on mechanical ventilation for more than 48 h and completed a 30-minute spontaneous breathing trial (SBT) with pressure-support ventilation for the first time. After the SBT, airway pressure at 100 ms during occlusion (P0.1), inspiratory effort, and diaphragmatic ultrasound were evaluated to predict weaning outcomes. Weaning failure was defined as re-intubation within 48 h of weaning, the need for therapeutic non-invasive ventilation, or death. RESULTS: 68 patients with a mean age of 63.21 ± 15.15 years were included. In patients with diaphragm thickness (DT) ≥ 2 mm, P0.1 (P=0.002), pressure-muscle index (PMI) (P=0.012), and occluded expiratory airway pressure swing (ΔPocc) (P=0.030) were significantly higher in those who failed weaning. Conversely, for patients with DT<2 mm, PMI (P=0.003) and ΔPocc (P=0.002) were lower in the weaning failure group. Additionally, within the DT≥2 mm group, P0.1 demonstrated a higher area under the curve (AUC) for weaning prediction (0.889 vs. 0.739) compared to those with DT<2 mm. CONCLUSIONS: PMI and ΔPocc are predictive of weaning outcomes in patients with diaphragm thickness ≥ 2 mm, where the assessment value of P0.1 is notably higher. Diaphragm function significantly influences the accuracy of weaning predictions based on respiratory drive and inspiratory effort. IMPLICATIONS FOR CLINICAL PRACTICE: Our findings indicate that the effectiveness of respiratory drive and inspiratory effort in predicting successful weaning from mechanical ventilation may vary across different patient populations. Diaphragm function plays a crucial role in weaning assessments, particularly when using P0.1, the pressure-muscle index (PMI), and occluded expiratory airway pressure swing (ΔPocc).

MASS cohort: Multicenter, longitudinal, and prospective study of the role of microbiome in severe pneumonia and host susceptibility.

The MASS cohort comprises 2000 ICU patients with severe pneumonia, covering community-acquired pneumonia, hospital-acquired pneumonia, and ventilator-associated pneumonia, sourced from 19 hospitals across 10 cities in three provinces. A wide array of samples including bronchoalveolar lavage fluid, sputum, feces, and whole blood are longitudinally collected throughout patients' ICU stays. The cohort study seeks to uncover the dynamics of lung and gut microbiomes and their associations with severe pneumonia and host susceptibility, integrating deep metagenomics and transcriptomics with detailed clinical data.

Clinical Characteristics and Prognosis of Patients With Severe Pneumonia With Pneumocystis jirovecii Colonization: A Multicenter, Retrospective Study.

BACKGROUND: For decades, the incidence and clinical characteristics of Pneumocystis jirovecii colonization in patients with severe pneumonia was unclear. RESEARCH QUESTION: What are the clinical features and outcomes associated with P jirovecii colonization in individuals diagnosed with severe pneumonia? STUDY DESIGN AND METHODS: In this multicenter, retrospective, matched study, patients with severe pneumonia who underwent bronchoalveolar lavage clinical metagenomics from 2019 to 2023 in the ICUs of 17 medical centers were enrolled. Patients were diagnosed based on clinical metagenomics, pulmonary CT scans, and clinical presentations. Clinical data were collected retrospectively, and according to propensity score matching and Cox multivariate regression analysis, the prognosis of patients with P jirovecii colonization was compared with that of patients who were P jirovecii-negative. RESULTS: A total of 40% of P jirovecii-positive patients are considered to have P jirovecii colonization. The P jirovecii colonization group had a higher proportion of patients with immunosuppression and a lower lymphocyte count than the P jirovecii-negative group. More frequent detection of cytomegalovirus, Epstein-Barr virus, human herpesvirus-6B, human herpesvirus-7, and torque teno virus in the lungs was associated with P jirovecii colonization than with P jirovecii negativity. By constructing two cohorts through propensity score matching, we incorporated codetected microorganisms and clinical features into a Cox proportional hazards model and revealed that P jirovecii colonization was an independent risk factor for mortality in patients with severe pneumonia. According to sensitivity analyses, which included or excluded codetected microorganisms, and patients not receiving trimethoprim-sulfamethoxazole treatment, similar conclusions were reached. INTERPRETATION: Immunosuppression and a reduced lymphocyte count were identified as risk factors for P jirovecii colonization in patients with non-Pneumocystis pneumonia. More frequent detection of various viruses was observed in patients colonized with P jirovecii, and P jirovecii colonization was associated with an increased 28-day mortality in patients with severe pneumonia.

Electrocatalytic Cascade Selenylation/Cyclization/Deamination of 2-Hydroxyaryl Enaminones: Synthesis of 3-Selenylated Chromones under Mild Conditions.

Herein, we disclosed a highly efficient pathway toward 3-selenylated chromone derivatives via electrocatalytic cascade selenylation/cyclization/deamination of 2-hydroxyaryl enaminones with diselenides. This method showed mild conditions, easy operation, wide substrate scope, and good functional group tolerance. Furthermore, this electrosynthesis strategy was amendable to scale-up the reaction. Additionally, the preliminary experiments revealed that this reaction probably proceeded via a cation pathway instead of a radical pathway.

Effect of heparin for the prevention of venous thromboembolism in patients with spontaneous intracranial cerebral hemorrhage: a meta-analysis.

Background: Venous thromboembolism (VTE) has a serious impact on the prognosis of patients with spontaneous intracranial hemorrhage (sICH). However, the use of prophylactic heparin remains controversial. Objectives: This study investigated the safety and timing of prophylactic heparin for VTE in patients with sICH. Design: This study followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) reporting guidelines. Methods: Two authors systematically searched Web of Science, Cochrane Library, Embase, and PubMed to find all published research before June 2023. The incidence of deep venous thrombosis (DVT) and mortality were set as primary endpoints. Results: This meta-analysis included seven randomized controlled trials (RCTs) and five observational studies involving a total of 4419 sICH patients in the heparin (n = 2808) and control (n = 1183) groups. Among these patients, 205 received early heparin administration, while 223 received late heparin administration. The results suggested that, compared to the control group, patients in the heparin group had a lower incidence of VTE [odds ratio (OR), 0.47; 95% CI, 0.31-0.71; p < 0.001], DVT (OR, 0.53; 95% CI, 0.33-0.85; p = 0.009), pulmonary embolism (OR, 0.31 95% CI, 0.15-0.65; p = 0.002), and mortality (OR, 0.70; 95% CI, 0.54-0.90; p = 0.006), but there were no statistical differences in hematoma enlargement, extracranial hematoma, and major disability (p > 0.05). There was no statistically significant difference in DVT, mortality, hematoma enlargement, and extracranial hemorrhage between the early heparin group (<24-48 h) and the late heparin group (p > 0.05). Conclusion: In patients with sICH, prophylactic use of heparin may be beneficial because it reduces the incidence of VTE and mortality without increasing the risk of additional bleeding. In addition, early prophylactic use of heparin appears to be safe. However, large-scale RCTs are lacking to support this evidence.

Prophylactic use of heparin reduces the incidence of venous thromboembolism and reduces overall mortality in patients with spontaneous bleeding in the brain Why was the study done? Venous thromboembolism has a serious impact on the prognosis of patients with spontaneous bleeding in the brain. However, the use of prophylactic heparin remains controversial. This study investigates the safety and timing of prophylactic heparin for venous thromboembolism in patients with spontaneous bleeding in the brain. What did the researchers find? Our results showed that patients in the heparin group had lower rates of blood clot in a deep vein, death, and pulmonary embolism compared with the control group, and there were no significant differences in hematoma enlargement, extracranial hematoma, and severe disability. There were no significant differences in blood clot in a deep vein, mortality, hematoma enlargement, and extracranial hemorrhage between the early and late heparin groups. What do the findings mean? This study suggests that prophylactic use of heparin may be beneficial in patients with spontaneous bleeding in the brain, and that early prophylactic use of heparin appears to be safe.

Systemic immune-inflammation index upon admission correlates to post-stroke cognitive impairment in patients with acute ischemic stroke.

BACKGROUND: The purpose of this prospective study was to evaluate the association of systemic immune-inflammation index (SII) and systemic inflammation response index (SIRI), with PSCI in patients with acute ischemic stroke (AIS). METHODS: First-onset AIS patients were consecutively included from January 1, 2022 to March 1, 2023. The baseline information was collected at admission. Fasting blood was drawn the next morning. Cognitive function was assessed by the Montreal Cognitive Assessment (MoCA) 3 months after onset. Logistic regression analysis was performed to explore the correlation between SII, SIRI, and PSCI. Receiver operating characteristic (ROC) was conducted to evaluate the predictive ability of SII. RESULTS: 332 participants were recruited, and 193 developed PSCI. Compared with patients without PSCI, the patients with PSCI had higher SII (587.75 (337.42, 988.95) vs. 345.66 (248.44, 572.89), P<0.001) and SIRI (1.59 (0.95, 2.84) vs. 1.02 (0.63, 1.55), P=0.007). SII and SIRI negatively correlated with MoCA scores (both P<0.05). The multivariable logistic regression analysis indicated that SII was independently associated with PSCI (P<0.001), while SIRI was not. The optimal cutoff for SII to predict PSCI was 676.83×109/L. CONCLUSIONS: A higher level of SII upon admission was independently correlated to PSCI three months later in AIS patients.

High triglyceride-glucose index at admission is a predictor of post-stroke cognitive impairment in patients with acute ischemic stroke.

BACKGROUND: Post-stroke cognitive impairment (PSCI) is a very common complication of ischemic stroke (IS). Triglyceride-glucose (TyG) index was an effective alternative marker of insulin resistance (IR). This prospective study was designed to explore the correlation between TyG index and PSCI. METHODS: Between January 1 2021 to June 30 2022, consecutive patients with first onset IS were enrolled prospectively. Baseline information was collected at admission and fasting blood was drawn the next morning. Montreal Cognitive Assessment (MoCA) was used to evaluate cognitive function at three months after stroke. Multiple regression analysis was used to explore the correlation between PSCI and TyG. Receiver operating characteristic (ROC) was performed to evaluate the predictive ability. RESULTS: Ultimately, 313 patients were enrolled in this study. The TyG index was higher in patients with PSCI than those without PSCI (8.99 (8.55, 9.54) vs. 8.61(8.25, 8.87), P<0.001). The spearman correlation analysis indicated that TyG index was negatively correlated with MoCA score (r=-0.272, P<0.001). The multivariate logistic regression analysis demonstrated that TyG index was correlated with PSCI independently (P<0.001) regardless of whether the patients had diabetes or not. The area under curve (AUC) of the ROC was 0.684 (95%CI=0.635-0.768, P<0.001). The optimal cutoff value of TyG index for predicting PSCI was 8.81, with a sensitivity of 61.7% and a specificity of 73.6%. CONCLUSION: A higher TyG index level at admission was independently correlated with increased risk of PSCI three months later and could be used as a predictor.

Edaravone dexborneol ameliorates cognitive impairment by regulating the NF-κB pathway through AHR and promoting microglial polarization towards the M2 phenotype in mice with bilateral carotid artery stenosis (BCAS).

Cerebral small vessel disease (CSVD) is one of the most important causes of stroke and vascular dementia, so exploring effective treatment modalities for CSVD is warranted. This study aimed to explore the anti-inflammatory effects of Edaravone dexborneol (C.EDA) in a CSVD model. Mice with CSVD showed distinct cognitive decline, as assessed by the Morris water maze (MWM). Pathological staining verified leakage across the blood‒brain barrier (BBB), microglial proliferation, neuronal loss and demyelination. Western blot analysis demonstrated that M1 microglia dominated prophase and released proinflammatory molecules; the aryl hydrocarbon receptor (AHR) was found to participate in modulating nuclear factor-kappa B (NF-κB) signalling activation through tumour necrosis factor receptor-associated factor-6 (TRAF6). C.EDA treatment resulted in the polarization of microglia from the M1 to the M2 phenotype. Mice sequentially treated with C.EDA exhibited a significant improvement in cognitive function; expression of the anti-inflammatory cytokines and modulatory proteins AHR and TRAF6 was upregulated, while the levels of pNF-κBp65 and pIΚBα were downregulated. C.EDA promoted microglial activation towards the M2 phenotype by upregulating AHR expression, which prevented TRAF6 ubiquitination, promoted NF-κB RelA/p65 protein degradation and inhibited subsequent NF-κB phosphorylation. Mechanistically, the anti-inflammatory effect of C.EDA alleviated neuronal loss and myelin damage, while at the functional level, C.EDA improved cognitive function and thus showed good application prospects.

Reducing single-use cutlery with green nudges: Evidence from China's food-delivery industry.

Rising consumer demand for online food delivery has increased the consumption of disposable cutlery, leading to plastic pollution worldwide. In this work, we investigate the impact of green nudges on single-use cutlery consumption in China. In collaboration with Alibaba's food-delivery platform, Eleme (which is similar to Uber Eats and DoorDash), we analyzed detailed customer-level data and found that the green nudges-changing the default to "no cutlery" and rewarding consumers with "green points"-increased the share of no-cutlery orders by 648%. The environmental benefits are sizable: If green nudges were applied to all of China, more than 21.75 billion sets of single-use cutlery could be saved annually, equivalent to preventing the generation of 3.26 million metric tons of plastic waste and saving 5.44 million trees.

iEarth: an interdisciplinary framework in the era of big data and AI for sustainable development.

The Intelligent Earth (iEarth) framework, composed of four major themes: iEarth data, science, analytics, and decision, is proposed to define and build an interdisciplinary and synergistic framework for research, practice, and education that simultaneously safeguards the sustainable development of our living planet.

The combined use of parasternal intercostal muscle thickening fraction and P0.1 for prediction of weaning outcomes.

BACKGROUND: A variety of parameters and diaphragmatic ultrasound in ventilator weaning has been studied extensively, and the findings yield inconsistent conclusions. The parasternal intercostal muscle holds important substantial respiratory reserve capacity when the central drive is enhanced, the predictive value of combining parasternal intercostal muscle ultrasound parameters with P0.1(airway occlusion pressure at 100 msec) in assessing ventilator weaning outcomes is still unknown. OBJECTIVES: Our study aimed to evaluate the predictive efficacy of parasternal intercostal muscle ultrasound in conjunction with P0.1 in determining weaning failure. METHODS: We recruited patients who had been admitted to ICU and had been receiving mechanical ventilation for over two days. All patients underwent a half-hour spontaneous breathing trial (SBT) with low-level pressure support ventilation (PSV). They were positioned semi-upright for parasternal intercostal muscle ultrasound evaluations, including parasternal intercostal muscle thickness (PIMT), and parasternal intercostal muscle thickening fraction (PIMTF); P0.1 was obtained from the ventilator. Weaning failure was defined as the need for non-invasive positive pressure ventilation or re-intubation within 48 h post-weaning. RESULTS: Of the 56 enrolled patients with a mean age of 63.04 ± 15.80 years, 13 (23.2%) experienced weaning failure. There were differences in P0.1 (P = .001) and PIMTF (P = .017) between the two groups, but also in patients with a diaphragm thickness ≥ 2 mm. The predictive threshold values were PIMTF ≥ 13.15% and P0.1 ≥ 3.9 cmH2O for weaning failure. The AUROC for predicting weaning failure was 0.721 for PIMTF, 0.792 for P0.1, and 0.869 for the combination of PIMTF and P0.1. CONCLUSIONS: The parasternal intercostal muscle thickening fraction and P0.1 are independently linked to weaning failure, especially in patients with normal diaphragm thickness. The combination of parasternal intercostal muscle thickening fraction and P0.1 can serve as a valuable tool for the precise clinical prediction of weaning outcomes. TRIAL REGISTRATION: Chinese Clinical Trial Registry website (ChiCTR2200065422).

Incidence and clinical features of HHV-7 detection in lower respiratory tract in patients with severe pneumonia: a multicenter, retrospective study.

PURPOSE: The significance of detecting human herpesvirus 7 (HHV-7) in the lower respiratory tract of patients with severe pneumonia is unclear. This study aims to evaluate the clinical characteristics and prognosis of detecting HHV-7 in the lower respiratory tract of patients with severe pneumonia. METHODS: Patients with severe pneumonia requiring invasive mechanical ventilation and underwent commercial metagenomic next-generation sequencing (mNGS) testing of bronchoalveolar lavage fluid from January 2019 to March 2023 were enrolled in 12 medical centers. Clinical data of patients were collected retrospectively, and propensity score matching was used for subgroup analysis and mortality assessment. RESULTS: In a total number of 721 patients, 45 cases (6.24%) were identified with HHV-7 positive in lower respiratory tract. HHV-7 positive patients were younger (59.2 vs 64.4, p = 0.032) and had a higher rate of co-detection with Cytomegalovirus (42.2% vs 20.7%, p = 0.001) and Epstein-Barr virus (35.6% vs 18.2%, p = 0.008). After propensity score matching for gender, age, SOFA score at ICU admission, and days from ICU admission to mNGS assay, there was no statistically significant difference in the 28-day mortality rate between HHV-7 positive and negative patients (46.2% vs 36.0%, p = 0.395). Multivariate Cox regression analysis adjusting for gender, age, and SOFA score showed that HHV-7 positive was not an independent risk factor for 28-day mortality (HR 1.783, 95%CI 0.936-3.400, p = 0.079). CONCLUSION: HHV-7 was detected in the lungs of 6.24% of patients with severe pneumonia. The presence of HHV-7 in patients with severe pneumonia requiring invasive mechanical ventilation is associated with a younger age and co-detected of Cytomegalovirus and Epstein-Barr virus. While HHV-7 positivity was not found to be an independent risk factor for mortality in this cohort, this result may have been influenced by the relatively small sample size of the study.

Evaluating bronchial anastomotic stenosis dynamically by electrical impedance tomography in a lung transplant recipient: a case report.

Background: Lung transplantation has become the first-choice treatment method for end-stage pulmonary disease patients. However, various postoperative airway complications hinder the progress of lung transplantation, with the most frequently reported complication being bronchial stenosis. Pendelluft is an intrapulmonary air redistribution in areas with different time constants and this phenomenon is largely unobservable. Meanwhile, pendelluft is the movement of gas in the lung without a change in tidal volume and can contribute to injury by introducing regional overdistension and tidal recruitment. Electrical impedance tomography (EIT) is a radiation-free and noninvasive imaging tool that can be used to evaluate pulmonary ventilation and perfusion. EIT is also a novel imaging technique that allows real-time detection of pendelluft. Case Description: A single lung transplant recipient had bronchial anastomotic stenosis caused by necrosis. The patient was admitted to the intensive care unit for the second time due to worsening oxygenation. We evaluated the patient's pulmonary ventilation and perfusion and pendelluft effect dynamically by EIT. The saline bolus injection method was used to evaluate pulmonary perfusion distribution. We removed the bronchial anastomosis necrosis using bronchoscopy biopsy forceps. The ventilation/perfusion (V/Q) matching in the transplanted lung improved compared to that before necrosis removal. After necrosis removal, the global pendelluft in the lung transplant recipient improved. Conclusions: EIT can be used to quantitatively evaluate the pendelluft and V/Q matching due to bronchial stenosis in lung transplantation. This case also demonstrated the potential of EIT as a dynamic pulmonary functional imaging tool for lung transplantation.

Distribution pattern of iron deposition in the basal ganglia of different motor subtypes of Parkinson's disease.

OBJECTIVE: The quantitative susceptibility mapping (QSM) technique was used to analyze the distribution pattern of iron deposition in the basal ganglia region of patients with motor subtypes of Parkinson's disease (PD) and to explore the difference in iron content in the basal ganglia region of PD motor subtypes on the major motor symptomatic side. METHODS: The study included 76 patients with PD and 37 healthy controls (HC). Patients with PD were divided into two groups: postural instability/gait disorder (PIGD)(n = 48), and tremor dominance (TD)(n = 28). We classified patients with PD according to the side of the major motor symptoms as left PIGD (n = 23), left TD (n = 14), right PIGD (n = 25), and right TD (n = 14). All subjects underwent brain magnetic resonance scanning to obtain QSM and susceptibility values in the corresponding regions of interest (ROI). RESULTS: (1) Compared with the HC, the bilateral SN in the PD-PIGD and TD group showed greater susceptibility values. The susceptibility values in the left CN, bilateral PUT were also greater in the PD-PIGD group than the HC. (2) Compared with the TD, the left PUT susceptibility values were greater in the PIGD group, especially in patients whose major symptomatic side were on the right limb. (3) Correlation analysis showed that in the PD group, bilateral SN was positively correlated with the unified Parkinson's disease rating scale III part scores of the Movement Disorder Society (MDS-UPDRS III) and the Hoehn-Yahr stage. Bilateral dentate nucleus (DN) susceptibility values were significantly positively correlated with TD scores, and left PUT susceptibility values were positively correlated with PIGD scores. The left SN within the PIGD group was positively correlated with the PIGD score. CONCLUSION: There were different iron deposition patterns in the basal ganglia between the PD-PIGD and TD groups. There also seems to be a difference in iron deposition in PD motor subtypes on different major motor symptom sides.

10.3% Efficient Green Cd-Free Cu2 ZnSnS4 Solar Cells Enabled by Liquid-Phase Promoted Grain Growth.

Small grain size and near-horizontal grain boundaries are known to be detrimental to the carrier collection efficiency and device performance of pure-sulfide Cu2 ZnSnS4 (CZTS) solar cells. However, forming large grains spanning the absorber layer while maintaining high electronic quality is challenging particularly for pure sulfide CZTS. Herein, a liquid-phase-assisted grain growth (LGG) model that enables the formation of large grains spanning across the CZTS absorber without compromising the electronic quality is demonstrated. By introducing a Ge-alloyed CZTS nanoparticle layer at the bottom of the sputtered precursor, a Cu-rich and Sn-rich liquid phase forms at the high temperature sulfurization stage, which can effectively remove the detrimental near-horizontal grain boundaries and promote grain growth, thus greatly improving the carrier collection efficiency and reducing nonradiative recombination. The remaining liquid phase layer at the rear interface shows a high work function, acting as an effective hole transport layer. The modified morphology greatly increases the short-circuit current density and fill factor, enabling 10.3% efficient green Cd-free CZTS devices. This work unlocks a grain growth mechanism, advancing the morphology control of sulfide-based kesterite solar cells.

Short- and medium-term impacts of strict anti-contagion policies on non-COVID-19 mortality in China.

The effects of coronavirus disease-19 (COVID-19) public health policies on non-COVID-19-related mortality are unclear. Here, using death registries based on 300 million Chinese people and a difference-in-differences design, we find that China's strict anti-contagion policies during the COVID-19 pandemic significantly reduced non-COVID-19 mortality outside Wuhan (by 4.6%). The health benefits persisted and became even greater after the measures were loosened: mortality was reduced by 12.5% in the medium term. Significant changes in people's behaviours (for example, wearing masks and practising social distancing) and reductions in air pollution and traffic accidents could have driven these results. We estimate that 54,000 lives could have been saved from non-COVID-19 causes during the 50 days of strict policies and 293,000 in the subsequent 115 days. The results suggest that virus countermeasures not only effectively controlled COVID-19 in China but also brought about unintended and substantial public health benefits.

Critically ill patients with COVID-19 with ECMO and artificial liver plasma exchange: A retrospective study.

COVID-19 is an emerging infectious disease capable of causing severe pneumonia. We aimed to characterize a group of critically ill patients in a single-center study.This was a retrospective case series of 23 patients with confirmed COVID-19-related critical illness in the intensive care unit (ICU) of a hospital in Hangzhou Zhejiang Province between January 22 and March 20, 2020.Of the 23 critically ill patients, the median age was 66 years (interquartile range [IQR] 59-80 years). The median time from disease onset to ICU admission was 10 days (IQR 6-11 days), to mechanical ventilation (MV) was 11 days (IQR 7.75-13 days), to artificial liver plasma exchange was 12 days (IQR 9.75-14.75 days), and to extracorporeal membrane oxygenation (ECMO) was 22 days (IQR 17.5-30 days). Nine patients required high flow oxygen. Fourteen patients received MV. Six required ECMO. Nine received artificial liver plasma exchange. Mortality was 0 at day 28.Mortality was 0 at day 28 in our single-center study. Extracorporeal membrane oxygenation reduced the requirements for ventilator support. Artificial liver plasma exchange significantly reduced inflammatory cytokine levels. These supportive therapies helped to extend the patients' survival times and increase the chance of follow-up treatments.

[Clinical experience of high-flow nasal cannula oxygen therapy in severe COVID-19 patients].

Acute respiratory failure due to acute hypoxemia is the major manifestation in severe coronavirus disease 2019 (COVID-19). Rational and effective respiratory support is crucial in the management of COVID-19 patients. High-flow nasal cannula (HFNC) has been utilized widely due to its superiority over other non-invasive respiratory support techniques. To avoid HFNC failure and intubation delay, the key issues are proper patients, timely application and improving compliance. It should be noted that elder patients are vulnerable for failed HFNC. We applied HFNC for oxygen therapy in severe and critical ill COVID-19 patients and summarized the following experiences. Firstly, to select the proper size of nasal catheter, to locate it at suitable place, and to confirm the nose and the upper respiratory airway unobstructed. Secondly, an initial ow of 60 L/min and 37℃ should be given immediately for patients with obvious respiratory distress or weak cough ability; otherwise, low-level support should be given first and the level gradually increased. Thirdly, to avoid hypoxia or hypoxemia, the treatment goal of HFNC should be maintained the oxygen saturation (SpO2) above 95% for patients without chronic pulmonary disease. Finally, patients should wear a surgical mask during HFNC treatment to reduce the risk of virus transmission through droplets or aerosols.

Mitigating the air pollution effect? The remarkable decline in the pollution-mortality relationship in Hong Kong.

Using transboundary pollution from mainland China as an instrument, we show that air pollution leads to higher cardio-respiratory mortality in Hong Kong. However, the air pollution effect has dramatically decreased over the past two decades: before 2003, a 10-unit increase in the Air Pollution Index could lead to a 3.1% increase in monthly cardio-respiratory mortality, but this effect has declined to 0.5% using recent data and is no longer statistically significant. Exploratory analyses suggest that a well-functioning medical system and immediate access to emergency services can help mitigate the contemporaneous effects of pollution on mortality.