NT-proBNP change is useful for predicting weaning failure from invasive mechanical ventilation among postsurgical patients: a retrospective, observational cohort study.

BACKGROUND: To evaluate the predictive value of N-terminal prohormone B-type natriuretic peptide (NTproBNP) for weaning failure among patients undergoing major surgeries during spontaneous breathing trial (SBT), compared to traditional weaning parameters. METHODS: The observational cohort study retrospectively included postsurgical patients who received IMV and underwent a 2 h SBT. According to weaning outcome, NTproBNP level at initiation (NTproBNP1) and at end of 2 h SBT(NTproBNP2), the ΔNTproBNP%, RSBI and MV were compared between weaning failure and weaning success group. Multiple logistical regression and ROC curve were used to evaluate the capability of NTproBNP to predict weaning failure. RESULTS: Out of the 323 included postsurgical patients, 45 (13.9%) patients had failed weaning. The ΔNTproBNP% was a better predictor for weaning failure (AUC 0.744;95%CI,0.693-0.791) than NTproBNP1(AUC 0.639; 95%CI,0.580-0.694)), NTproBNP2(AUC 0.742, 95%CI,0.688-0.792) and other traditional weaning index such as RSBI (AUC 0.651; 95%CI, 0.597-0.703) and MV (AUC 0.552; 95%CI,0.496-0.607). The cutoff value of ΔNTproBNP% for predicting weaning failure was 23.3% with the sensitivity75.76% and specificity73.38%. The multiple logistic regression analysis found that ΔNTproBNP%>23.3% was an independent predictor of weaning failure. CONCLUSION: ΔNTproBNP% may be a useful marker for predict weaning failure for postsurgical patients, and it's better to be more careful to withdraw from invasive mechanical ventilation for those postsurgical patients with ΔNTproBNP% >23.3%. The corresponding interventions to optimize cardiac function should be actively given to these patients.

Sputum deposition classification for mechanically ventilated patients using LSTM method based on airflow signals.

A novel sputum deposition classification method for mechanically ventilated patients based on the long-short-term memory network (LSTM) method was proposed in this study. A wireless ventilation airflow signals collection system was designed and used in this study. The ventilation airflow signals were collected wirelessly and used for sputum deposition classification. Two hundred sixty data groups from 15 patients in the intensive care unit were compiled and analyzed. A two-layer LSTM framework and 11 features extracted from the airflow signals were used for the model training. The cross-validations were adopted to test the classification performance. The sensitivity, specificity, precision, accuracy, F1 score, and G score were calculated. The proposed method has an accuracy of 84.7 ± 4.1% for sputum and non-sputum deposition classification. Moreover, compared with other classifiers (logistic regression, random forest, naive Bayes, support vector machine, and K-nearest neighbor), the proposed LSTM method is superior. In addition, the other advantages of using ventilation airflow signals for classification are its convenience and low complexity. Intelligent devices such as phones, laptops, or ventilators can be used for data processing and reminding medical staff to perform sputum suction. The proposed method could significantly reduce the workload of medical staff and increase the automation and efficiency of medical care, especially during the COVID-19 pandemic.

Application of deep learning-based diagnostic systems in screening asymptomatic COVID-19 patients among oversea returnees.

INTRODUCTION: Our study aimed to investigate the performance of deep learning (DL)-based diagnostic systems in alerting against COVID-19, especially among asymptomatic individuals coming from overseas, and to analyze the features of identified asymptomatic patients in detail. METHODOLOGY: DL diagnostic systems were deployed to assist in the screening of COVID-19, including the pneumonia system and pulmonary nodules system. 1,917 overseas returnees who underwent CT examination and rRT-PCR tests were enrolled. DL pneumonia system promptly alerted clinicians to suspected COVID-19 after CT examinations while the performance was evaluated with rRT-PCR results as the reference. The radiological features of asymptomatic COVID-19 cases were described according to the Nomenclature of the Fleischner Society. RESULTS: Fifty-three cases were confirmed as COVID-19 patients by rRT-PCR tests, including 5 asymptomatic cases. DL pneumonia system correctly alerted 50 cases as suspected COVID-19 with a sensitivity of 0.9434 and specificity of 0.9592 (within 2 minutes per case); while the pulmonary nodules system alerted 2 of the 3 missed asymptomatic cases. Additionally, five asymptomatic patients presented different characteristics such as elevated creatine kinase level and prolonged prothrombin time, as well as atypical radiological features. CONCLUSIONS: DL diagnostic systems are promising complementary approaches for prompt screening of imported COVID-19 patients, even the imported asymptomatic cases. Unique clinical and radiological characteristics of asymptomatic cases might be of great value in screening as well. ADVANCES IN KNOWLEDGE: DL-based systems are practical, efficient, and reliable to assist radiologists in screening COVID-19 patients. Differential features of asymptomatic patients might be useful to clinicians in the frontline to differentiate asymptomatic cases.

Mean platelet volume as a predictive biomarker for in-hospital mortality in patients receiving invasive mechanical ventilation.

BACKGROUND: Although mean platelet volume (MPV) has been reported to be associated with poor prognosis of various critical illness, the relationship between MPV and in-hospital mortality among patients undergoing invasive mechanical ventilation (IMV) is unclear. METHODS: A retrospective observational study including patients receiving IMV was conducted from January, 2014 to January, 2019. The patients were divided into two groups by MPV cutoff value. The receiver operating characteristics curve was used to evaluate the predictive ability of MPV for in-hospital mortality. Univariate and multivariate Cox regression analysis were conducted to analyze the value of MPV for predicting in-hospital mortality. Kaplan-Meier cumulative incidence curve was employed to observe the incidence of in-hospital mortality. RESULTS: A total of 274 patients were enrolled in the study, and 42 patients (15.3%) died in hospital. MPV > 11.4 fl was a valuable predictor for in-hospital mortality (AUC0.848; 95%CI, 0.800-0.889) with sensitivity 66.7%, and specificity = 86.21%. MPV > 11.4 fl was an independent risk factor for in-hospital mortality (adjusted HR 2.640, 95%CI, 1.208-5.767, P = 0.015). Compared to the group of MPV ≤ 11.4 fl, patients with MPV > 11.4 fl had increased mortality (log-rank test = 40.35, HR = 8.723, P < 0.0001). The relationship between MPV and in-hospital mortality was stronger in female patients than in male patients. CONCLUSION: MPV > 11.4 fl is a more useful marker for predicting in-hospital mortality among critically ill patients receiving IMV, especially in female patients. Attention to the MPV marker is simple and profitable with immediate applicability in daily clinical practice.

Fibrinogen, a Promising Marker to Evaluate Severity and Prognosis of Acute Exacerbation of Chronic Obstructive Pulmonary Disease: A Retrospective Observational Study.

Background: Fibrinogen is increasingly being studied as an inflammatory biomarker in chronic obstructive pulmonary disease (COPD), but there are limited data on the role of fibrinogen in assessing the severity of acute exacerbation of COPD (AECOPD). This study aimed to explore whether circulating fibrinogen could be used as a surrogate to measure the severity and predict the prognosis of AECOPD. Methods: A total of 535 AECOPD patients diagnosed at our center from January 2016 to June 2021 were retrospectively enrolled in this study. The electronic medical record of each patient was retrieved to collect data on baseline characteristics and laboratory parameters, as well as the use of noninvasive positive-pressure ventilation (NPPV) and prognosis. Multiple linear regression analysis was used to identify independent factors associated with circulating fibrinogen values. Receiver-operating characteristic curve and multivariate logistic regression analysis were applied to further verify the use of fibrinogen to predict NPPV failure. Results: Compared to patients with fibrinogen <4 g/L, patients with increased fibrinogen levels (>4 g/L) tended to have elevated inflammatory response and higher incidence of DVT/PTE, emphysema, pneumonia, and atherosclerosis. In addition, fibrinogen levels in NPPV-failure patients were significantly higher than non-NPPV patients and NPPV-success ones. The presence of emphysema, pneumonia, and history of long-term oxygen therapy and higher CRP levels and leukocyte counts were independent risk factors associated with increased fibrinogen levels in AECOPD. Furthermore, our data indicated that fibrinogen could be considered as a reliable biomarker to predict NPPV failure (AUC, 0.899, 95% CI 0.846-0.952), with an OR of 7.702 (95% CI 2.984-19.875; P<0.001). Conclusion: The level of circulating fibrinogen can be used to measure severity of AECOPD, and among AECOPD patients managed with NPPV, fibrinogen >3.55 g/L can independently predict NPPV failure.

A combination of the APACHE II score, neutrophil/lymphocyte ratio, and expired tidal volume could predict non-invasive ventilation failure in pneumonia-induced mild to moderate acute respiratory distress syndrome patients.

Background: Noninvasive ventilation (NIV) failure rate is relatively high in patients with acute respiratory distress syndrome (ARDS). Currently the data regarding prediction of NIV failure of pneumonia-induced mild to ARDS patients were scarce. Methods: A total of 364 patients (from January 2016 to December 2020) diagnosed with hypoxemic respiratory failure and managed with NIV were initially included and finally 131 pneumonia-induced mild to moderate ARDS patients were enrolled in this study. Electronic medical records were reviewed to determine whether NIV succeeded or failed for each patient. The relationship between the Acute Physiology And Chronic Health Evaluation II (APACHE II) score , neutrophil/lymphocyte ratio (NLR), expired tidal volume (Vte) and NIV failure were specifically analyzed. Multivariate logistic regression analyses were conducted to identify the independent factors of NIV failure. Receiver-operating characteristic curves were used to assess the efficacy of the variables in predicting NIV failure. Kaplan-Meier curves for 28-day survival were used to compare the mortality rates of different groups. Results: Of the patients, 64 (48.9%) experienced NIV failure, APACHE II score [odds ratio (OR) =0.77; P=0.002], NLR (OR =0.838; P=0.046), and Vte (OR =0.343; P=0.009) were independent factors for predicting NIV failure. A combined value comprising the APACHE II score, NLR, and Vte had better efficacy at predicting NIV failure [area under the curve (AUC) =0.9; 95% confidence interval (CI): 0.845-0.955] than the APACHE II score (AUC =0.818; 95% CI: 0.745-0.891), NLR (AUC =0.839; 95% CI: 0.765-0.913), or Vte (AUC =0.805; 95% CI: 0.729-0.881) alone. The cumulative survival probability within 28 days was lower in patients with a combined value >59.17 (P<0.001 by the log-rank test), an APACHE II score >16.5 (P<0.001 by the log-rank test), an NLR >7.22 (P<0.001 by the log-rank test), and a Vte >8.96 mL/kg (P<0.001 by log-rank test). Conclusions: A combined value comprising an APACHE II score >16.5, a NLR >7.22, and a Vte >8.96 mL/kg may be a useful surrogate for predicting NIV failure among pneumonia-induced ARDS patients, and patients with a combined value >59.17 should be cautiously monitored during NIV. A further study with a larger sample size is warranted.

Mean platelet volume is useful for predicting weaning failure: a retrospective, observational study.

BACKGROUND: To evaluate the usefulness of mean platelet volume (MPV), a marker of inflammation and stress, for predicting weaning failure in patients undergoing invasive mechanical ventilation (IMV) compared to traditional inflammation markers. METHODS: The retrospective observational study including patients who received IMV and underwent spontaneous breathing trial (SBT) was conducted in ICU at Beijing Chao-Yang hospital in China from January, 2013 to December, 2019. According to the weaning outcome, MPV, leukocyte count and C-reaction protein(CRP) were compared between weaning failure and weaning success group. Receiver-operating characteristics (ROC) curves and multivariate logistical regression analysis were constructed to analyze the value of these inflammatory markers for predicting weaning failure. RESULTS: A total of 261 patients were enrolled in the study and 54 patients (20.7%) experienced weaning failure (45 SBT failure and 9 extubation failure after successful SBT). MPV was a better predictor for weaning failure (AUC 0.777;95%CI, 0.722-0.826) than leukocyte count (AUC 0.6;95%CI,0.538-0.66) and CRP (0.627;95%CI,0.565-0.685). The cutoff value of MPV for predicting weaning failure was 11.3 fl with sensitivity 55.56%, specificity 87.92%, and diagnostic accuracy 81.22%. According to multivariate logistic regression analyses, MPV > 11.3 fl was an independent risk factor for predicting weaning failure. CONCLUSIONS: MPV could be a more valuable marker for predicting weaning failure. and the patients with MPV > 11.3 fl should be attentively evaluated before weaning since they are at high risk of weaning failure, and it would be auspicable for those patients to undergo a noninvasive ventilation or high-flow nasal cannula oxygen therapy after extubation or even an early tracheostomy.

Physiological effects of high-intensity versus low-intensity noninvasive positive pressure ventilation in patients with acute exacerbation of chronic obstructive pulmonary disease: a randomised controlled trial.

BACKGROUND: High-intensity noninvasive positive pressure ventilation (NPPV) is a novel ventilatory approach to maximally decreasing elevated arterial carbon dioxide tension (PaCO2) toward normocapnia with stepwise up-titration of pressure support. We tested whether high-intensity NPPV is more effective than low-intensity NPPV at decreasing PaCO2, reducing inspiratory effort, alleviating dyspnoea, improving consciousness, and improving NPPV tolerance in patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD). METHODS: In this physiological, randomised controlled trial, we assigned 24 AECOPD patients to undergo either high-intensity NPPV (n = 12) or low-intensity NPPV (n = 12). The primary outcome was PaCO2 24 h after randomisation. Secondary outcomes included gas exchange other than PaCO2 24 h after randomisation, inspiratory effort, dyspnoea, consciousness, NPPV tolerance, patient-ventilator asynchrony, cardiac function, ventilator-induced lung injury (VILI), and NPPV-related adverse events. RESULTS: Inspiratory positive airway pressure 24 h after randomisation was significantly higher (28.0 [26.0-28.0] vs. 15.5 [15.0-17.5] cmH2O; p = 0.000) and NPPV duration within the first 24 h was significantly longer (21.8 ± 2.1 vs. 15.3 ± 4.7 h; p = 0.001) in the high-intensity NPPV group. PaCO2 24 h after randomisation decreased to 54.0 ± 11.6 mmHg in the high-intensity NPPV group but only decreased to 67.4 ± 10.6 mmHg in the low-intensity NPPV group (p = 0.008). Inspiratory oesophageal pressure swing, oesophageal pressure-time product (PTPes)/breath, PTPes/min, and PTPes/L were significantly lower in the high-intensity group. Accessory muscle use and dyspnoea score 24 h after randomisation were also significantly lower in that group. No significant between-groups differences were observed in consciousness, NPPV tolerance, patient-ventilator asynchrony, cardiac function, VILI, or NPPV-related adverse events. CONCLUSIONS: High-intensity NPPV is more effective than low-intensity NPPV at decreasing elevated PaCO2, reducing inspiratory effort, and alleviating dyspnoea in AECOPD patients. TRIAL REGISTRATION: ClinicalTrials.gov (NCT04044625; registered 5 August 2019).

Baseline Level and Reduction in PaCO2 are Associated with the Treatment Effect of Long-Term Home Noninvasive Positive Pressure Ventilation in Stable Hypercapnic Patients with COPD: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

Purpose: The evidence of long-term home noninvasive positive pressure ventilation (LTHNIPPV) in patients with stable hypercapnic chronic obstructive pulmonary disease (COPD) is controversial. In this meta-analysis study, we sought to establish whether a baseline level and reduction in partial pressure of arterial carbon dioxide (PaCO2) were associated with the treatment effect of LTHNIPPV in these patients. Patients and Methods: Six electronic databases were comprehensively searched from January 1980 until June 2020. Randomized clinical trials (RCTs) comparing LTHNIPPV with control treatment were included. Two authors independently extracted data, assessed the study quality, and used the GRADE approach to evaluate evidence quality. The main outcome was mortality. Results: Nineteen studies involving 1482 patients (LTHNIPPV, n = 730; control, n = 752) were included. LTHNIPPV significantly reduced mortality (relative risk [RR] = 0.76; 95% confidence interval [CI]: 0.61-0.95; p = 0.02; I2 = 14%), the frequency of hospital admissions, PaCO2, and improved partial pressure of oxygen (PaO2) compared to control treatment. LTHNIPPV also relieved dyspnea and improved exercise capacity and health-related quality of life (HRQL) but showed no significant benefit for improving the forced expiratory volume in one second in predicted (FEV1% pred). Subgroup analysis revealed that the baseline level and reduction in PaCO2 were associated with decreased mortality (baseline PaCO2 ≥ 55 mmHg RR = 0.69, P = 0.02; vs baseline PaCO2 < 55 mmHg RR = 0.87, P = 0.32; and higher dPaCO2 RR = 0.42, P < 0.0001; vs lower dPaCO2 RR = 0.91, P = 0.38). Conclusion: LTHNIPPV significantly reduced mortality. The baseline level and reduction in PaCO2 were associated with the treatment effect of LTHNIPPV in patients with stable hypercapnic COPD. Large-scale, multicenter RCTs are needed to confirm our results.

Dynamics of Detection of Anti-SARS-CoV-2 IgG/IgM and SARS-CoV-2 RNA in Respiratory Tract Specimens in 48 COVID-19 Patients.

BACKGROUND: The rapid spread of pneumonia caused by SARS-CoV-2 has seriously threatened people. In this study, we detected the expression of anti-SARS-CoV-2 IgG/IgM and respiratory tract SARS-CoV-2 RNA in patients with COVID-19 and explored the correlation and clinical significance between SARS-CoV-2 antibody and respiratory SARS-CoV-2 RNA. METHODS: From March 5, 2020 to April 28, 2020, 48 cases with COVID-19 diagnosed in Beijing Xiaotangshan Hospital were enrolled. SARS-CoV-2 RNAs were detected by real-time fluorescence RT-PCR method. Serum SARS-CoV-2 IgG/IgM antibodies were determined by colloidal gold immunochromatography. The statistical analysis was performed using chi-squared test. RESULTS: In all the patients, SARS-CoV-2 RNA among 270 upper respiratory tract (nasal or throat swabs) samples, 71 lower respiratory tract (sputum) samples, and anti-SARS-CoV-2 IgM/IgG antibodies in 123 serum samples were detected during the hospitalization period. The positive rate of anti-SARS-CoV-2 IgG was significantly higher than that of anti-SARS-CoV-2 IgM within the first week after symptom onset (p < 0.05). The positive rate of anti-SARS-CoV-2 IgG was also significantly higher than that of anti-SARS-CoV-2 IgM during day 8 - 30 after symptom onset (p < 0.01). The positive rate of SARS-CoV-2 RNA in the lower respiratory tract specimens (64.8%, 46/71) was significantly higher than that in the upper respiratory tract (46.7%, 126/270) (p < 0.05). The positive rate (100%, 4/4) of SARS-CoV-2 RNA detection in the lower respiratory tract specimens before IgG seroconversion was significantly higher than that of the positive rate (59.3%, 32/54) after IgG seroconversion (p < 0.01). The positive rate (72.2%, 57/79) of SARS-CoV-2 RNA detection in the upper respiratory tract specimens before IgG seroconversion was significantly higher than that of the positive rate (30.7%, 39/127) after IgG seroconversion (p < 0.01). CONCLUSIONS: Anti-SARS-CoV-2 IgG might be detected within the first week after symptom onset. The application of SARS-CoV-2 antibody (IgG/IgM) detection is important for the suspected cases of SARS-CoV-2 infection with negative SARS-CoV-2 RNA results. The positive rate of SARS-CoV-2 RNA detection in the lower respiratory tract specimens was significantly higher than that in the upper respiratory tract. Sputum detection is recommended for the detection of SARS-CoV-2 RNA. Using lower respiratory tract specimens may reduce the false negative PCR tests. The detection of SARS-CoV-2 RNA can be improved by investigating follow-up specimens over time.

The Neutrophil/Lymphocyte Ratio Could Predict Noninvasive Mechanical Ventilation Failure in Patients with Acute Exacerbation of Chronic Obstructive Pulmonary Disease: A Retrospective Observational Study.

Purpose: To determine the effectiveness of neutrophil/lymphocyte ratio (NLR), compared to traditional inflammatory markers, for predicting noninvasive mechanical ventilation (NIMV) failure in acute exacerbation of chronic obstructive pulmonary disease (AECOPD) patients. Patients and Methods: We conducted this retrospective observational study including 212 AECOPD patients who required NIMV during hospitalization from January 2015 to December 2020 in the department of respiratory and critical care medicine of Beijing Chao-Yang Hospital (west campus). We reviewed the medical record to determine if NIMV succeeded or failed for each patient, and compared NLR with traditional markers (leukocyte, C-reactive protein [CRP] and procalcitonin [PCT]) between NIMV failure and NIMV success group. Receiver-operating characteristic (ROC) curve and multivariate logistic regression analysis were used to assess the accuracy of these markers for predicting NIMV failure. Results: A total of 38 (17.9%) patients experienced NIMV failure. NLR was a more sensitive biomarker to predict NIMV failure (AUC, 0.858; 95% CI 0.785-0.931) than leukocyte counts (AUC, 0.723; 95% CI 0.623-0.823), CRP (AUC, 0.670; 95% CI 0.567-0.773) and PCT (AUC, 0.719; 95% CI 0.615-0.823). There was statistically positive correlation between NLR and leukocytes count (r=0.35, p<0.001), between NLR and CRP (r=0.258, p<0.001), between NLR and PCT (r=0.306, p<0.001). The cutoff value of NLR to predict NIMV failure was 8.9 with sensitivity 0.688, specificity 0.886 and diagnostic accuracy 0.868. NLR>8.9 (odds ratio, 10.783; 95% CI, 2.069-56.194; P=0.05) was an independent predictor of NIMV failure in the multivariate logistic regression model. Conclusion: NLR may be an effective marker for predicting NIMV failure in AECOPD patients, and the patients with NLR>8.9 should be handled with caution since they are at higher risk of NIMV failure and require intubation. Further study with a larger sample size and with more data is necessary to confirm our study.

Prevention of SARS-CoV-2 transmission from international arrivals: Xiaotangshan Designated Hospital, China.

A surge in the number of international arrivals awaiting coronavirus disease 2019 (COVID-19) screening overwhelmed health-care workers and depleted medical resources in designated hospitals in Beijing, China in March 2020. The People's Government of Beijing Municipality therefore issued a policy which required the mandatory transfer of all asymptomatic passengers arriving from a foreign country to designated quarantine hotels, and the transfer of passengers with fever or respiratory symptoms to designated hospitals. Xiaotangshan Designated Hospital, a severe acute respiratory syndrome hospital in 2003, was rapidly renovated and put into operation with the main tasks of screening and isolating symptomatic international arrivals at Beijing Capital International Airport, providing basic medical care for mild to moderate COVID-19-positive cases, and rapidly referring severe to critical COVID-19-positive cases to higher-level hospitals. During the month-long period of its operation, 2171 passengers were screened and 53 were confirmed as having COVID-19 (six severe to critical). We describe how the use of Xiaotangshan Designated Hospital in this way enabled the efficient grouping and assessment of passengers arriving from a foreign country, the provision of optimal patient care without compromising public safety and the prioritization of critically ill patients requiring life-saving treatment. The designated hospital is a successful example of the World Health Organization's recommendation to renovate existing medical infrastructures to improve the COVID-19 response capacity. The flexible design of Xiaotangshan Designated Hospital means that it can be repurposed and reopened at any time to respond to the changing pandemic conditions.

En mars 2020, la brusque hausse du nombre d'arrivées internationales en attente de dépistage de la maladie à coronavirus 2019 (COVID-19) a submergé les professionnels de la santé et épuisé les ressources médicales dans les hôpitaux de référence à Beijing, en Chine. Le gouvernement populaire de la municipalité de Beijing a réagi en ordonnant que tous les passagers asymptomatiques en provenance d'un pays étranger soient transférés vers des hôtels reconvertis en centres de quarantaine, et que ceux manifestant de la fièvre ou des symptômes respiratoires soient envoyés dans des hôpitaux de référence. L'hôpital de référence Xiaotangshan, construit en 2003 pour lutter contre le syndrome respiratoire aigu sévère, a rapidement été rénové et mis en service. Ses tâches principales: dépister et isoler les passagers internationaux symptomatiques débarquant au Beijing Capital International Airport, prodiguer les soins médicaux de base aux cas positifs de COVID-19 souffrant d'une forme légère à modérée, et adresser dès que possible les cas positifs de COVID-19 dans un état grave ou critique aux hôpitaux spécialisés. En l'espace d'un mois, 2171 passagers ont été testés et 53 se sont révélés positifs à la COVID-19 (6 étant dans un état grave ou critique). Nous décrivons la façon dont l'hôpital de référence Xiaotangshan a ainsi permis de regrouper et d'évaluer efficacement les arrivées en provenance de l'étranger, d'offrir une prise en charge optimale des patients sans compromettre la sécurité publique, et d'établir des priorités afin que les malades gravement atteints puissent bénéficier d'un traitement dans les plus brefs délais. Cet hôpital de référence est un exemple réussi de la mise en œuvre de la recommandation formulée par l'Organisation mondiale de la Santé: rénover les infrastructures médicales existantes afin d'améliorer les capacités de lutte contre la COVID-19. Grâce à sa conception flexible, l'hôpital Xiaotangshan peut être réutilisé et rouvert à n'importe quel moment pour réagir à un contexte pandémique en perpétuelle évolution.

Un aumento del número de llegadas de vuelos internacionales en espera de la detección del coronavirus 2019 (COVID-19) sobrecargó al personal sanitario y agotó los recursos médicos en los hospitales designados de Pekín (China) en marzo de 2020. Por lo tanto, la policía del Gobierno Popular del municipio de Pekín se tuvo que hacer cargo del traslado obligatorio de todos los pasajeros asintomáticos que llegaran de un país extranjero a los hoteles de cuarentena designados, y el traslado de los pasajeros con fiebre o síntomas respiratorios a los hospitales designados. El hospital designado de Xiaotangshan, un hospital especializado en el síndrome respiratorio agudo severo en 2003, se rehabilitó rápidamente y se puso en funcionamiento con las tareas principales de examinar y aislar a los sintomáticos que llegaban al Aeropuerto Internacional de Pekín, proporcionando atención médica básica a los casos positivos de COVID-19 de leves a moderados, y derivando rápidamente los casos positivos de COVID-19 de graves a críticos a hospitales de nivel superior. Durante el mes que duró su funcionamiento, se examinó a 2.171 pasajeros y se confirmó que 53 tenían la COVID-19 (6 de ellos con intensidad de grave a crítica). Describimos cómo el uso del hospital designado de Xiaotangshan permitió agrupar y evaluar eficazmente a los pasajeros que llegaban de un país extranjero, prestar una atención óptima a los pacientes sin comprometer la seguridad pública y priorizar a los pacientes en estado crítico que requerían tratamiento para salvar su vida. El hospital designado es un ejemplo de éxito de la recomendación de la Organización Mundial de la Salud de renovar las infraestructuras médicas existentes para mejorar la capacidad de respuesta ante la COVID-19. El diseño flexible del hospital designado de Xiaotangshan significa que puede utilizarse y volver a habilitarse en cualquier momento para responder a las condiciones cambiantes de la pandemia.

Novel assisted cough system based on simulating cough airflow dynamics.

ABSTRACT: Cough is a defensive behavior that protects the respiratory system from infection and clears airway secretions. Cough airflow dynamics have been analyzed by a variety of mathematical and experimental tools. In this paper, the cough airflow dynamics of 42 subjects were obtained and analyzed. An identification model based on piecewise Gauss function for cough airflow dynamics is proposed through the dimensionless method, which could achieve over 90% identification accuracy. Meanwhile, an assisted cough system based on pneumatic flow servo system is presented. The vacuum situation and feedback control are used to increase the simulated peak cough flow rate, which are important for airway secretion clearance and to avoid airway collapse, respectively. The simulated cough peak flow could reach 5 L/s without the external assistance such as manual pressing, patient cooperation and other means. Finally, the backstepping control is developed to generate a simulated cough airflow that closely mimics the natural cough airflow of humans. The assisted cough system opens up wide opportunities of practical application in airway secretion clearance for critically ill patients with COVID 2019 and other pulmonary diseases.

Moderate vs. mild cases of overseas-imported COVID-19 in Beijing: a retrospective cohort study.

This study compared the differences in the clinical manifestations, treatment courses and clinical turnover between mild and moderate coronavirus disease 2019 (COVID-19). Clinical data of the patients with imported COVID-19 admitted to Beijing Xiaotangshan Designated Hospital between March 15 and April 30, 2020, were retrospectively analysed. A total of 53 COVID-19 patients were included, with 21 mild and 32 moderate cases. Compared with the mild group, the moderate group showed significant differences in breathing frequency, lymphocyte count, neutrophil percentage, neutrophil/lymphocyte ratio, procalcitonin, C-reactive protein, and dynamic erythrocyte sedimentation rate. In the moderate group, 87.5% exhibited ground-glass opacities, 14% exhibited consolidative opacities, 53.1% exhibited local lesions and 68.8% exhibited unilateral lesions. The proportion of patients who received antiviral or antibiotic treatment in the moderate group was higher than that in the mild group, and the number of cases that progressed to severe disease in the moderate group was also significantly higher (18.7% vs. 0%, p = 0.035). Compared with patients with mild COVID-19, those with moderate COVID-19 exhibited more noticeable inflammatory reactions, more severe pulmonary imaging manifestations and earlier expression of protective antibodies. The overall turnover of the moderate cases was poorer than that of the mild cases.

Mechanical ventilation strategy for pulmonary rehabilitation based on patient-ventilator interaction.

Mechanical ventilation is an effective medical means in the treatment of patients with critically ill, COVID-19 and other pulmonary diseases. During the mechanical ventilation and the weaning process, the conduct of pulmonary rehabilitation is essential for the patients to improve the spontaneous breathing ability and to avoid the weakness of respiratory muscles and other pulmonary functional trauma. However, inappropriate mechanical ventilation strategies for pulmonary rehabilitation often result in weaning difficulties and other ventilator complications. In this article, the mechanical ventilation strategies for pulmonary rehabilitation are studied based on the analysis of patient-ventilator interaction. A pneumatic model of the mechanical ventilation system is established to determine the mathematical relationship among the pressure, the volumetric flow, and the tidal volume. Each ventilation cycle is divided into four phases according to the different respiratory characteristics of patients, namely, the triggering phase, the inhalation phase, the switching phase, and the exhalation phase. The control parameters of the ventilator are adjusted by analyzing the interaction between the patient and the ventilator at different phases. A novel fuzzy control method of the ventilator support pressure is proposed in the pressure support ventilation mode. According to the fuzzy rules in this research, the plateau pressure can be obtained by the trigger sensitivity and the patient's inspiratory effort. An experiment prototype of the ventilator is established to verify the accuracy of the pneumatic model and the validity of the mechanical ventilation strategies proposed in this article. In addition, through the discussion of the patient-ventilator asynchrony, the strategies for mechanical ventilation can be adjusted accordingly. The results of this research are meaningful for the clinical operation of mechanical ventilation. Besides, these results provide a theoretical basis for the future research on the intelligent control of ventilator and the automation of weaning process.

Different value of HDL-C in predicting outcome of ARDS secondary to bacterial and viral pneumonia: A retrospective observational study.

BACKGROUND: High density lipoprotein-cholesterol (HDL-C) concentration decreases in septic patients and the low level of HDL-C is associated with poor prognosis. However, no study has yet analyzed its prognostic implication specifically in pneumonia-ARDS cohort. OBJECTIVES: To evaluate the prognostic value of HDL-C levels in ARDS patients secondary to bacterial and viral pneumonia. METHODS: This was a retrospective observational study on 108 pneumonia-ARDS patients in RICU from 2017 to 2019. These patients were stratified into bacterial ARDS group (56) and viral ARDS group (52). The primary outcome was the association between HDL-C levels and 28-day mortality. RESULTS: HDL-C levels were statistically lower in bacterial ARDS patients than those in viral ARDS patients (p<0.001). There were statistic negative correlations between HDL-C and APACHE II/SOFA score in bacterial ARDS patients (r=-0.284, p = 0.034 and r=-0.369, p = 0.005), but not in viral ARDS patients (r=-0.103, p = 0.469 and r=-0.225, p = 0.108). ROC analysis demonstrated that HDL-C had superior prediction value for 28-day mortality and identified HDL-C < 0.42 mmol/L was significantly associated with adverse outcomes in bacterial ARDS patients. The low HDL-C was an independent risk factor for death of bacterial ARDS patients (OR 0.027, 95% CI [0.001-0.905], P = 0.044). CONCLUSIONS: HDL-C might be a valuable marker to assess the 28-d mortality for bacterial ARDS patients rather than viral ARDS patients.