Analysis of risk factors for weaning failure from mechanical ventilation in critically ill older patients with coronavirus disease 2019.

Objective: This study aimed to investigate the factors influencing weaning failure from invasive mechanical ventilation (IMV) in critically ill older patients with coronavirus disease 2019 (COVID-19). Methods: We enrolled critically ill older patients with COVID-19 who were admitted to the medical intensive care unit (ICU) and received IMV between December 2022 and June 2023. Results: We included 68 critically ill older patients with COVID-19 (52 male [76.5 %] and 16 female individuals [23.5 %]). The patients' median age (interquartile range) was 75.5 (70.3-82.8) years. The median length of ICU stay was 11.5 (7.0-17.8) days; 34 cases (50.0 %) were successfully weaned from IMV. The successfully weaned group had a higher proportion of underlying chronic obstructive pulmonary disease [6 (17.6 %) vs. 0, P = 0.033] and fewer cases of diabetes [7 (20.6 %) vs. 16 (47.1 %), P = 0.021] compared with the weaning failure group. Serum lactate levels [1.5 (1.2-2.3) vs. 2.6 (1.9-3.1) mmol/L, P < 0.001], blood urea nitrogen [8.2 (6.3-14.4) vs. 11.4 (8.0-21.3) mmol/L, P = 0.033], Acute Physiology and Chronic Health Evaluation (APACHE) II score [19.0 (12.0-23.3) vs. 22.5 (16.0-29.3), P = 0.014], and hospitalization days before endotracheal intubation [1.0 (0.0-5.0) vs. 3.0 (0.0-11.0), P = 0.023] were significantly decreased in the successfully weaned group, whereas PaO2/FiO2 [148.3 (94.6-200.3) vs. 101.1 (67.0-165.1), P = 0.038] and blood lymphocyte levels [0.6 (0.4-1.0) vs. 0.5 (0.2-0.6) 109/L, P = 0.048] were significantly increased, compared with the weaning failure group. Multivariate logistic regression analysis showed that diabetes (OR= 3.413, 95 %CI 1.029-11.326), P = 0.045), APACHE II Score (OR = 1.089, 95 % CI 1.008-1.175), P = 0.030), and hospitalization days before endotracheal intubation (OR = 1.137, 95 % CI 1.023-1.264), P = 0.017) were independent risk factors for weaning failure. Conclusion: In critically ill older patients with COVID-19 with diabetes, higher APACHE II Score, and longer hospitalization days before endotracheal intubation, weaning from IMV was more challenging. The study could help develop strategies for improving COVID-19 treatment.

Epicardial fat modifies the relationship between coronary calcium score and all-cause mortality: The St. Francis Heart Study.

Objective: Epicardial fat is associated with cardiovascular risk factors and adverse outcomes. However, it is not clear if epicardial fat remains to be a mortality risk when coronary calcium score (CAC) is taken into account. Methods: We studied the 1005 participants from the St. Francis Heart Study who were apparently healthy with CAC scores at 80th percentile or higher for age and gender, randomly assigned to placebo or statin therapy. At baseline, lipid profiles and non-contrast CT images were obtained where the epicardial fat volume was analyzed. Likelihood ratio testing was used to assess the additional prognostic value of epicardial fat to CAC for the risk of all-cause mortality. Results: Increased epicardial fat volume was associated with higher CAC. For each unit increase in lnCAC, the average epicardial fat volume increased by 3.34 mL/m2. After a mean follow-up period of 17 years, 179 (18%) participants died. Increased epicardial fat volume was associated with an adjusted hazard ratio of 1.11 (95% CI: 1.02 to 1.20) predicting all-cause mortality. In the stratified analysis testing strata of epicardial fat and CAC, those with increased epicardial fat and increased CAC had the highest risk of death. Compared with a model containing lnCAC and traditional risk factors, a model additionally containing epicardial fat volume yielded a better model fit (likelihood ratio test p < 0.001). Conclusion: Increased epicardial fat volume is associated with increased all-cause mortality risk. In addition, it portends incremental prognostic value to CAC score in mortality prediction.

A machine learning-derived risk score to predict left ventricular diastolic dysfunction from clinical cardiovascular magnetic resonance imaging.

Introduction: The evaluation of left ventricular diastolic dysfunction (LVDD) by clinical cardiac magnetic resonance (CMR) remains a challenge. We aimed to train and evaluate a machine-learning (ML) algorithm for the assessment of LVDD by clinical CMR variables and to investigate its prognostic value for predicting hospitalized heart failure and all-cause mortality. Methods: LVDD was characterized by echocardiography following the ASE guidelines. Eight demographic and nineteen common clinical CMR variables including delayed enhancement were used to train Random Forest models with a Bayesian optimizer. The model was evaluated using bootstrap and five-fold cross-validation. Area under the ROC curve (AUC) was utilized to evaluate the model performance. An ML risk score was used to stratify the risk of heart failure hospitalization and all-cause mortality. Results: A total of 606 consecutive patients underwent CMR and echocardiography within 7 days for cardiovascular disease evaluation. LVDD was present in 303 subjects by echocardiography. The performance of the ML algorithm was good using the CMR variables alone with an AUC of 0.868 (95% CI: 0.811-0.917), which was improved by combining with demographic data yielding an AUC 0.895 (95% CI: 0.845-0.939). The algorithm performed well in an independent validation cohort with AUC 0.810 (0.731-0.874). Subjects with higher ML scores (>0.4121) were associated with increased adjusted hazard ratio for a composite outcome than subjects with lower ML scores (1.72, 95% confidence interval 1.09-2.71). Discussion: An ML algorithm using variables derived from clinical CMR is effective in identifying patients with LVDD and providing prognostication for adverse clinical outcomes.

A robust web-based tool to predict viral shedding in patients with Omicron SARS-CoV-2 variants.

Background: Data on viral kinetics and variants affecting the duration of viral shedding were limited. Our objective was to determine viral shedding in distinct severe acute respiratory syndrome coronavirus 2 variants, including Omicron BA.4/5 and BF.7, and to identify the relevant influencing factors. Methods: We carried out a longitudinal cohort study at Beijing Xiaotangshan Fangcang shelter hospital from May to June 2022 (Omicron BA.4/5) and from November to December 2022 (Omicron BF.7). Nucleocapsid protein (N) and open reading frame (ORF) genes were considered as the target genes of the reverse transcription PCR. The daily results of cycle threshold (CT), including lowest ORF1ab-CT values for days 1-3 post-hospitalisation and lowest N-CT values for days 1-3 post-hospitalisation (CT3minN) and demographic and clinical characteristics were collected. Results: 1433 patients with coronavirus disease 2019 (COVID-19) were recruited from the Fangcang shelter hospital, in which 278 patients were diagnosed with Omicron BA.4/5 and 1155 patients with Omicron BF.7. Patients with BF.7 infection showed a longer duration of viral shedding. The duration of viral shedding was associated with the variants age, alcohol use, the severity of COVID-19 and CT3minN. Moreover, the nomogram had excellent accuracy in predicting viral shedding. Conclusions: Our results indicated that patients with Omicron BF.7 had a longer period of contagiousness than those with BA.4/5. The duration of viral shedding was affected by a variety of factors and the nomogram may become an applicable clinical instrument to predict viral shedding. Furthermore, we developed a new COVID-19 viral shedding predicting model that can accurately predict the duration of viral shedding for COVID-19, and created a user-friendly website to apply this prediction model (https://puh3.shinyapps.io/CVSP_Model/).

A challenging case of drug-related acute fibrinous and organizing pneumonia: A rare case report.

A 65-year-old man presented with intermittent fever and progressive shortness of breath. He responded poorly to antibiotics and corticosteroids (methylprednisolone 40 mg/d). Chest computed tomography scans showed diffuse consolidations and ground glass density patchy opacities in both lungs and these lesions progressed rapidly. The diagnosis of acute fibrinous and organizing pneumonia (AFOP) was confirmed through transbronchial cryobiopsy. This patient had prostate cancer with bone metastasis for 4 months and took the anti-prostate cancer medications including apalutamide and leuprorelin acetate. Considering his medication history, the patient was diagnosed with AFOP induced by anti-prostate cancer medications through panel discussion of multidisciplinary teams. Intravenous methylprednisolone of 500 mg/day was administered for 3 days and then slowly tapered. The patient's shortness of breath gradually subsided. In addition, the lesions in the lungs improved significantly on follow up imaging. AFOP induced by anti-prostate cancer medications is rare. To our knowledge, this is the first reported case and high-dose glucocorticoid treatment may be required in some of these cases.

[Meta analysis of the predictive efficacy of various derived indicators of sequential organ failure assessment in outcomes of patients with sepsis].

OBJECTIVE: To systematically review and evaluate the predictive efficacy of various derived indicators of sequential organ failure assessment (SOFA) in mortality rate of sepsis patients. METHODS: Literature on sepsis and SOFA scores were searched in PubMed, Embase and Cochrane Library. The retrieval time will be set to the time of database-building to February, 2023. The main outcome measures included 28-day mortality, 30-day mortality, in-hospital mortality, intensive care unit (ICU) mortality and long-term mortality. Literature screening, data extraction and quality evaluation were carried out independently by 2 researchers. Data were analyzed by Revman 5.3.5, Meta-disc and Stata software. Deek funnel plots were used to assess publication bias in the included studies. RESULTS: A total of 40 articles including 51 trials were included. Of these, 32 were in English and 8 in Chinese, 17 were in prospective trials and 34 were in retrospective trials, 38 were in initial SOFA-related trials and 9 were in the change of SOFA score (ΔSOFA)-related studies, a total of 59 962 patients were enrolled. (1) The area under the receiver operator characteristic curve (AUC) of initial SOFA and ΔSOFA for predicting outcome in sepsis was 0.773 and 0.787 (Z = 0.115, P > 0.05), respectively. There was no significant difference between the two indexes in predicting the outcome of patients with sepsis. (2) In subgroup analysis, due to limitations in the number of literature articles, the 28-day mortality rate and 30-day mortality rate were merged for discussion. The predictive power of ΔSOFA for 28-day or 30-day mortality was significantly higher than that of initial SOFA (AUC was 0.854, 0.787, Z = 2.603, P ≤ 0.01). (3) There were few studies on ΔSOFA in predicting in-hospital mortality, ICU mortality and long-term mortality of sepsis patients. The AUC of the initial SOFA for predicting the study endpoints described above was: ICU mortality (0.814) > 28-day or 30-day mortality (0.787) > in-hospital mortality (0.697) > long-term mortality (0.646). (4) Initial SOFA and ΔSOFA in patients with sepsis of non-Han original had good predictive performance and there was no significant difference between them (AUC was 0.766, 0.811, respectively). However, the pooled sensitivity of ΔSOFA was higher (92%). (5) In prospective studies, initial SOFA was better at predicting outcomes in patients with sepsis (AUC was 0.804, pooled sensitivity 64%). The sensitivity of ΔSOFA indicators in predicting the outcome of sepsis patients was significantly higher than the initial SOFA (78% vs. 64%). The funnel plot showed that there was no significant publication bias in the included literature. CONCLUSIONS: ΔSOFA has a relatively high diagnostic efficacy in predicting short-term (28-day or 30-day) mortality in patients with sepsis.

Association between Changes in Plasma Metabolism and Clinical Outcomes of Sepsis.

Current prognostic biomarkers for sepsis have limited sensitivity and specificity. This study aimed to investigate dynamic lipid metabolomics and their association with septic immune response and clinical outcomes of sepsis. This prospective cohort study included patients with sepsis who met the Sepsis 3.0 criteria. On hospitalization days 1 (D1) and 7 (D7), plasma samples were collected, and patients underwent liquid chromatography with tandem mass spectrometry. A total of 40 patients were enrolled in the study, 24 (60%) of whom were men. The median age of the enrolled patients was 81 (68-84) years. Thirty-one (77.5%) patients had a primary infection site of the lung. Participants were allocated to the survivor (25 cases) and nonsurvivor (15 cases) groups based on their 28-day survival status. Ultimately, a total of 113 lipids were detected in plasma samples on D 1 and D 7, of which 42 lipids were most abundant in plasma samples. The nonsurvival group had significantly lower lipid expression levels in lysophosphatidylcholine (LysoPC) (16 : 0, 17 : 0,18 : 0) and 18 : 1 SM than those in the survival group (p < 0.05) on D7-D1. The correlation analysis showed that D7-D1 16 : 0 LysoPC (r = 0.367, p = 0.036),17 : 0 LysoPC (r = 0.389, p = 0.025) and 18 : 0 LysoPC(r = 0.472, p = 0.006) levels were positively correlated with the percentage of CD3+ T cell in the D7-D1. Plasma LysoPC and SM changes may serve as prognostic biomarkers for sepsis, and lipid metabolism may play a role in septic immune disturbances.

Rare case of pulmonary fat embolism and acute respiratory distress syndrome after liposuction and fat grafting: a case report.

Background: Pulmonary fat embolism usually occurs after fracture, yet rarely observed after liposuction and fat grafting. Case presentation: We describe a 19-year-old female patient who presented with acute respiratory failure and diffuse pulmonary opacities on chest radiographic image shortly after liposuction and fat grafting. Bronchoalveolar lavage was performed and lipid content in alveolar cells contribute to the diagnosis of the fat embolism syndrome. The patient was successfully treated with noninvasive mechanical ventilation and a short course of glucocorticoids. Conclusions: Early recognition and appropriate treatment are very important to improve the outcome of pulmonary fat embolism. Considering that liposuction and fat grafting are increasingly common cosmetic surgeries, our aim is to raise awareness for this rare adverse event.

High-Flow Nasal Cannula versus Noninvasive Ventilation in AECOPD Patients with Respiratory Acidosis: A Retrospective Propensity Score-Matched Study.

Background: Limited data are available about the clinical outcomes of AECOPD patients with respiratory acidosis treated with HFNC versus NIV. Methods: We conducted a retrospective study to compare the efficacy of HFNC with NIV as initial ventilation support strategy in AECOPD patients with respiratory acidosis. Propensity score matching (PSM) was implemented to increase between-group comparability. Kaplan-Meier analysis was utilized to evaluate differences between the HFNC success, HFNC failure, and NIV groups. Univariate analysis was performed to identify the features that differed significantly between the HFNC success and HFNC failure groups. Results: After screening 2219 hospitalization records, 44 patients from the HFNC group and 44 from the NIV group were successfully matched after PSM. The 30-day mortality (4.5% versus 6.8%, p = 0.645) and 90-day mortality (4.5% versus 11.4%, p = 0.237) did not differ between the HFNC and NIV groups. Length of ICU stay (median: 11 versus 18 days, p = 0.001), length of hospital stay (median: 14 versus 20 days, p = 0.001), and hospital cost (median: 4392 versus 8403 $USD, p = 0.001) were significantly lower in the HFNC group compared with NIV group. The treatment failure rate was much higher in the HFNC group than in the NIV group (38.6% versus 11.4%, p = 0.003). However, patients who experienced HFNC failure and switched to NIV showed similar clinical outcomes to those who first received NIV. Univariate analysis showed that log NT-proBNP was an important factor for HFNC failure (p = 0.007). Conclusions: Compared with NIV, HFNC followed by NIV as rescue therapy may be a viable initial ventilation support strategy for AECOPD patients with respiratory acidosis. NT-proBNP may be an important factor for HFNC failure in these patients. Further well-designed randomized controlled trials are needed for more accurate and reliable results.

[Incidence of maternal sepsis in ICUs of hospitals in Beijing: a multicenter cohort study].

OBJECTIVE: To investigate the epidemiological data of maternal sepsis in intensive care unit (ICU), analyze the common causes, outcomes of maternal sepsis, and the risk factors of multi-drug resistant (MDR) bacteria. METHODS: A retrospective cohort study. Maternal sepsis cases admitted to ICUs of Peking University Third Hospital, Beijing Chao-Yang Hospital Affiliated to Capital Medical University, and Beijing Friendship Hospital Affiliated to Capital Medical University from January 2008 to September 2022 were enrolled. The following data were recorded: demographic characteristics, sequential organ failure assessment (SOFA) during infection, infection time, infection sites, invasive intervention measures before infection, microbial culture results, blood routine test during infection, body temperature, and clinical outcomes caused by infection. According to the time of sepsis occurrence, the patients were divided into pre-ICU sepsis group and ICU sepsis group, and the causes of sepsis in the two groups were analyzed. According to whether MDR occurred, the patients were divided into MDR group and non-MDR group, and clinical outcomes were analyzed. Multivariate Logistic regression was used to analyze the risk factors of MDR bacteria infection in obstetrics with sepsis. RESULTS: 160 patients were enrolled, among which 104 cases of sepsis happened before ICU and 56 cases of sepsis happened during ICU, 53 cases were with MDR bacteria and 107 cases were without MDR bacteria. The median age of the patients was 30.5 (28.0, 34.0) years old, the median temperature was 38.8 (38.2, 39.5) centigrade, and the median white blood cell count (WBC) was 17.2 (13.2, 21.3)×109/L, the median SOFA score was 5.0 (3.0, 8.0), and 130 cases (81.2%) were referred from other hospitals. The main infection sites were uterine cavity in 64 cases (40.0%), lung in 48 cases (30.0%), abdominal and pelvic cavity in 30 cases (18.8%), urinary system in 27 cases (16.9%). Sepsis led to hysterectomy in 6 cases (3.8%), stillbirth in 8 cases (5.0%), and neonatal death in 2 cases (1.3%). The main surgical intervention measures were cesarean section (44 cases, accounting for 27.5%), followed by exploratory laparotomy (19 cases, 11.9%). The median length of ICU stay was 5.0 (3.0, 10.0) days, and the median hospital length was 14.0 (10.0, 20.8) days. Intrauterine infection was the primary cause of sepsis happened during ICU, accounting for 50.0% (28/56), of which postpartum hemorrhage accounted for 85.7% (24/28). The proportion of diabetes [28.3% (15/53) vs. 14.0% (15/107)], intrauterine operation [41.5% (22/53) vs. 23.4% (25/107)], intrauterine infection [50.9% (27/53) vs. 34.6% (37/107)] and bacteremia [18.9% (10/53) vs. 2.8% (3/107)] in the MDR group were significantly higher than those in the non-MDR group (all P < 0.05). Multivariate Logistic regression analysis showed that diabetes [odds ratio (OR) = 2.348, 95% confidence interval (95%CI) was 1.006-5.480, P = 0.048] and intrauterine operation (OR = 2.541, 95%CI was 1.137-5.678, P = 0.023) were independent risk factors for MDR bacterial infection in obstetrics with sepsis. CONCLUSIONS: Intrauterine infection is the common cause of maternal sepsis in ICU, and postpartum hemorrhage is the common cause of secondary intrauterine infection in ICU. MDR bacteria can lead to serious clinical outcomes. Diabetes and intrauterine operation are independent risk factors for MDR bacteria' infection.

Baseline red blood cell distribution width and perforin, dynamic levels of interleukin 6 and lactate are predictors of mortality in patients with sepsis.

BACKGROUND: Sepsis is a critical illness often encountered in the intensive care unit. However, prognostic biomarkers for sepsis have limited sensitivity. This study aimed to identify more sensitive predictors of mortality through repeated monitoring of laboratory parameters. METHODS: Patients with sepsis (Sepsis 3.0 criteria met) were recruited and divided into the survivor and nonsurvivor groups after 28 days. Data on blood biochemistry, lymphocyte subsets, and cytokines were obtained on the first and seventh hospitalization days. Univariate and multivariate Cox regression analyses were performed to explore the correlation between these variables and patient mortality. RESULTS: Forty patients with sepsis were included. The mortality rate was 37.5%. Red blood cell distribution width-standard deviation (RDWSD) (hazard ratio [HR] = 1.107 [95% CI: 1.005-1.219], p = 0.040) and perforin level (HR = 1.001 [95% CI: 1-1.003], p = 0.035) on the first day, as well as lactate (HR = 112.064 [95% CI: 2.192-5729.629], p = 0.019) and interleukin 6 (IL-6) (HR = 1.005 [95% CI: 1.001-1.008], p = 0.014) levels on the seventh day, were independent risk factors of mortality. If the patients were divided into two groups based on RDWSD (normal: n = 31; increased: n = 9), the Kaplan-Meier curves showed that the group with increased RDWSD had a lower survival (p = 0.025). CONCLUSION: Baseline RDWSD and perforin, along with dynamic IL-6 and lactate levels, were independent predictors of mortality in patients with sepsis.

Etiology of Emergency Visit and In-Hospital Outcomes of Patients with COPD.

Backgrounds: Patients with COPD often visit the emergency department (ED) due to exacerbation of respiratory symptoms (dyspnea, cough, and sputum production). Because manifestations of acute exacerbation of COPD (AECOPD) are nonspecific, differential diagnosis is critical in this acute setting. The causes for emergency visiting and the in-hospital outcomes are varied in patients with COPD. This study aimed to investigate the distributions of etiologies and the in-hospital outcomes of patients with COPD who presented to the ED because of exacerbation of respiratory symptoms. Methods: This was a retrospective study on COPD patients who had visited the ED and been hospitalized in a tertiary hospital because of worsening respiratory symptoms including cough, sputum production, and dyspnea from January 2017 to April 2020. Demographics, clinical manifestations, and laboratory studies in the ED were collected as the baseline data. The primary diagnosis at discharge or death was recorded. The hospitalization settings (general wards and ICU), the in-hospital outcomes, and associated factors were analyzed. Results: During the study period, 392 patients with COPD (male 302 (77.0%)), with a median age of 78 years, visited the ED and hospitalized in this hospital. The first 3 causes for emergency visit were AECOPD (n = 314, 80.1%), acute coronary artery syndrome with or without congestive heart failure (n = 24, 6.1%), and pulmonary embolism (n = 13, 3.3%). For patients with AECOPD (n = 314), 51.6% (n = 162) was admitted to ICU, and 6.4% (n = 20) died. Multivariate logistic analysis showed that age, atrial fibrillation, NT-pro BNP ≥300 pg/ml, and blood pH <7.3 were independent risk factors for ICU admission. Age, comorbid malignancy, NT-pro BNP ≥1800 pg/ml, and pneumonia on CT scan were independent risk factors for hospital mortality in patients with AECOPD. Conclusion: In COPD patients visiting the ED because of worsening respiratory symptoms, nearly 20% were due to non-AECOPD causes. For those with AECOPD, age, atrial fibrillation, NT-pro BNP ≥300 pg/ml, and blood pH <7.3 were independent risk factors for ICU admission, while advanced age, underlying malignancy, elevated NT-pro BNP, and pneumonia on CT scan were risk factors for hospital mortality.

Sphingolipid profiles and their relationship with inflammatory factors in asthmatic patients of different sexes.

BACKGROUND: Asthma is a heterogeneous disease with distinct prevalence and manifestation between sexes. This study was to identify sex-specific features of asthma via metabolomic analysis of sphingolipids. METHODS: Forty-two asthma patients (27 women and 15 men) admitted to the Peking University Third Hospital from January 2015 to December 2015 were enrolled. Peripheral venous blood was collected for metabolomic analysis by targeted liquid chromatography-mass spectrometry. Sex hormones(estradiol, progesterone, testosterone, and androstenedione) and multiple inflammatory factors (periostin, leptin, IgE, IL-4, IL-5, IL-10, IL-13, IL-17A, and IFN-γ) were also assessed. The eosinophil percentage in induced sputum was also detected. All these data were applied to comparative analysis between sexes. RESULTS: Testosterone was negatively related to periostin (ρ = -0.420, P = 0.009) and IL-5 (ρ = -0.540, P = 0.012), while estradiol was positively related to the blood eosinophil percentage (ρ = 0.384, P = 0.025). Among the eighteen species of sphingolipids detected in the 42 patients, five ceramide (Cer) species (Cer16:0, Cer:20:0, Cer22:0, Cer24:0, and Cer26:0) and one sphingomyelin (SM) species (SM38:0) were significantly higher in male than in female patients. Further investigation found that the correlation between Cer20:0 and IL-5 was positive in males (ρ = 0.943, P = 0.005) but negative in females (ρ = -0.561, P = 0.030). CONCLUSIONS: Testosterone was negatively correlated with eosinophil inflammatory factors, but estradiol was positively correlated. Male asthma patients had higher ceramide and sphingomyelin levels than female patients. Different sexes had opposite correlations with ceramide and IL-5, respectively, suggesting that therapeutic strategies targeting ceramide should be different between sexes.

False-positive colloidal gold-based immunochromatographic strip assay reactions for antibodies to SARS-CoV-2 in patients with autoimmune diseases.

BACKGROUND: The outbreak of the novel 2019 coronavirus disease (COVID-19) was declared a global pandemic by the World Health Organization (WHO) on March 11, 2020. The diagnosis of COVID-19 is frequently based on a positive serological test. We noted the occurrence of false-positive results for COVID-19 in the colloidal gold-based immunochromatographic strip (ICS) assay in sera from patients with autoimmune diseases (ADs). This study aimed to evaluate the possible reasons for the false-positive results in two ICS assays (Wondfo ICS and Innovita ICS) and to investigate the effect of urea dissociation in reducing false-positive results. METHODS: The sera of 135 patients with ADs, 13 confirmed COVID-19 patients, 95 disease controls, and 120 healthy controls were tested for immunoglobin M (IgM) and IgG against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) using Wondfo and Innovita ICS kits. The distributions of auto-antibodies in antibody-positive and antibody-negative groups were also compared, and bivariable logistic regression was used to assess auto-antibodies associated with false-positive results. A urea dissociation test of ICS was performed for the SARS-CoV-2 antibody-positive samples. RESULTS: Specificity of Wondfo ICS for the 95 disease controls was 94.74% compared to 98.95% and 96.84% for Innovita SARS-CoV-2 IgM and IgG, respectively. Specificity of Wondfo ICS for the 120 healthy controls was 97.5% compared to 100% and 99.17% for Innovita SARS-CoV-2 IgM and IgG, respectively. Specificity of Wondfo ICS for AD patients was 73.33% compared to 97.78% and 96.30% for Innovita SARS-CoV-2 IgM and IgG, respectively. Sensitivity was 74.07% for Wondfo compared to 70.37% for Innovita IgM and 66.67% for Innovita IgG. Using the Wondfo ICS, the percentage of elevated rheumatoid factor (RF) level (>20 IU/mL) was higher in the SARS-CoV-2 antibody-positive group compared with the antibody-negative group [27/36 (75.0%) vs. 34/99 (34.34%), P=0.001]. The elevated RF was associated with antibody positivity, with an odds ratio of 4.671 [95% confidence interval (CI), 1.88-11.69]. The specificity of the Wondfo ICS assay for the AD patients was increased from 73.33% to 94.07% after the urea dissociation assay. CONCLUSIONS: An elevated serum RF level could lead to false-positive results when detecting SARS-CoV-2 antibodies using the Wondfo ICS kit, and the urea dissociation assay would be helpful in reducing the incidence of false-positive results.

Serum Glycerophospholipid Profile in Acute Exacerbation of Chronic Obstructive Pulmonary Disease.

Studies have shown that glycerophospholipids are involved in the pathogenesis of chronic obstructive pulmonary disease (COPD). This study adopted targeted metabolomic analysis to investigate the changes in serum glycerophospholipids in acute exacerbation of chronic obstructive pulmonary disease (AECOPD) and their differential expression in patients with different inflammatory subtypes. Patients with AECOPD admitted between January 2015 and December 2017 were enrolled, and their clinical data were collected. The patients' gender, age, body mass index, and lung function were recorded. Routine blood and induced sputum tests were performed. Liquid chromatography-mass spectrometry was used to detect the serum glycerophospholipid metabolic profiles and to analyze the metabolic profile changes between the acute exacerbation and recovery stages as well as the differences between different inflammatory subtypes. A total of 58 patients were hospitalized for AECOPD, including 49 male patients with a mean age of 74.8 ± 10.0 years. In the metabolic profiles, the expression of lysophosphatidylcholine (LPC) 18:3, lysophosphatidylethanolamine (LPE) 16:1, and phosphatidylinositol (PI) 32:1 was significantly reduced in the acute exacerbation stage compared to the recovery stage (P < 0.05). The three glycerophospholipids were used to plot the receiver operating characteristic curves to predict the acute exacerbation/recovery stage, and the areas under the curves were all above 70%. There were no differential metabolites between the two groups of patients with blood eosinophil percentage (EOS%) ≥2% and <2% at exacerbation. The expression of LPC 18:3, LPE 16:1, and PI 32:1 was significantly reduced in the acute exacerbation stage compared to the recovery stage in the inflammatory subtype with blood EOS <2% (P < 0.05). Abnormalities in the metabolism of glycerophospholipids may be involved in the onset of AECOPD, especially in the non-eosinophilic subtype.

An individualized administration model of vancomycin in elderly patients with sepsis and factors influencing augmented renal clearance.

WHAT IS KNOWN AND OBJECTIVE: Vancomycin efficacy is dependent on appropriate dosing, which should aim to achieve a target serum trough level. The purpose of this study was to determine the variables that predicted vancomycin serum trough concentrations in elderly patients with sepsis. METHODS: This retrospective cohort study, which was conducted in the medical ICU of a university-affiliated teaching hospital in China, included 87 medical patients with sepsis who were enrolled from January 2014 to December 2017. RESULTS AND DISCUSSION: All the patients were at least 60 years old (mean age = 74.8 ± 8.2 years), and 51.7% (n = 45) of them were male. The most common primary site of infection was the lungs (67.8%), followed by the abdomen (12.6%). Patients with septic shock accounted for 21.8% (n = 19) of the cases. The proportion of patients with vancomycin serum trough concentrations reaching target concentrations (≥15 mg/L) was 47.1% (41 cases). Multivariate linear regression showed that the creatinine clearance rate (CCR) and the daily dosage of vancomycin were independent predictors of vancomycin serum trough concentrations (both p's < 0.05), and the model for predicting vancomycin trough concentrations should be: serum trough concentration (mg/L) = 15.942 - 0.101 × CCR (mL/min) + 0.347 × vancomycin daily doses (mg/kg/d). Augmented renal clearance (ARC) was present in 13 patients (14.9%), and logistic regression revealed body mass index (OR = 1.420, p = .002) and serum creatinine level (OR = 0.883, p = .002) were independent predictors of ARC. WHAT IS NEW AND CONCLUSION: The CCR and daily dosage of vancomycin were significantly correlated with vancomycin serum trough concentrations in elderly patients with sepsis, and the individualized administration model should be verified through further clinical trials. BMI and serum creatinine level were identified to be independent predictors of ARC in elderly patients.

Pharmacokinetic-pharmacodynamic analysis of ciprofloxacin in elderly Chinese patients with lower respiratory tract infections caused by Gram-negative bacteria.

BACKGROUND: Ciprofloxacin is usually used in the treatment of lower respiratory tract infections (LRTIs). Recent studies abroad have shown ciprofloxacin is inadequately dosed and might lead to worse outcomes. The aim of this study was to perform pharmacokinetic and pharmacodynamic analyses of ciprofloxacin in elderly Chinese patients with severe LRTIs caused by Gram-negative bacteria. METHODS: From September 2012 to June 2014, as many as 33 patients were empirically administered beta-lactam and ciprofloxacin combination therapy. Patients were infused with 200 or 400 mg of ciprofloxacin every 12 h, which was determined empirically by the attending physician based on the severity of the LRTI and the patient's renal condition. Ciprofloxacin serum concentrations were determined by high-performance liquid chromatography. Bacterial culture was performed from sputum samples and/or endotracheal aspirates, and the minimum inhibitory concentrations (MICs) of ciprofloxacin were determined. The ratios of the area under the serum concentration-time curve to the MIC (AUC/MIC) and of the maximum serum concentration of the drug to the MIC (Cmax/MIC) were calculated. The baseline data and pharmacokinetic parameters were compared between clinical success group and clinical failure group, bacteriologic success group and bacteriologic failure group. RESULTS: Among the 33 patients enrolled in the study, 17 were infected with Pseudomonas aeruginosa, 14 were infected with Acinetobacter baumannii, and two were infected with Klebsiella pneumoniae. The mean age of the patients was 76.9 ± 6.7 years. Thirty-one patients (93.4%) did not reach the target AUC/MIC value of >125, and 29 patients (87.9%) did not reach the target Cmax/MIC value of >8. The AUC/MIC and Cmax/MIC ratios in the clinical success group were significantly higher than those in the clinical failure group (61.1 [31.7-214.9] vs. 10.4 [3.8-66.1], Z = -4.157; 9.6 [4.2-17.8] vs. 1.3 [0.4-4.7], Z = -4.018; both P < 0.001). The AUC/MIC and Cmax/MIC ratios in the patients for whom the pathogens were eradicated were significantly higher than those in the patients without the pathogens eradicated (75.3 [31.7-214.9] vs. 10.5 [3.8-66.1], Z = -3.938; 11.4 [4.2-17.8] vs. 1.4 [0.4-5.4], Z = -3.793; P < 0.001 for both). Receiver operating characteristic curve analysis showed that the AUC/MIC and Cmax/MIC values were closely associated with clinical and bacteriologic efficacies (P < 0.001 in both). CONCLUSIONS: Ciprofloxacin is inadequately dosed against Gram-negative bacteria, especially for those with relatively high MIC values. Consequently, the target values, AUC/MIC > 125 and Cmax/MIC > 8, cannot be reached.

Examining Interactions Between and Among Predictors of Net Ecosystem Exchange: A Machine Learning Approach in a Semi-arid Landscape.

Net ecosystem exchange (NEE) is an essential climate indicator of the direction and magnitude of carbon dioxide (CO2) transfer between land surfaces and the atmosphere. Improved estimates of NEE can serve to better constrain spatiotemporal characteristics of terrestrial carbon fluxes, improve verification of land models, and advance monitoring of Earth's terrestrial ecosystems. Spatiotemporal NEE information developed by combining ground-based flux tower observations and spatiotemporal remote sensing datasets are of potential value in benchmarking land models. We apply a machine learning approach (Random Forest (RF)) to develop spatiotemporally varying NEE estimates using observations from a flux tower and several variables that can potentially be retrieved from satellite data and are related to ecosystem dynamics. Specific variables in model development include a mixture of remotely sensed (fraction of photosynthetically active radiation (fPAR), Leaf Area Index (LAI)) and ground-based data (soil moisture, downward solar radiation, precipitation and mean air temperature) in a complex landscape of the Reynolds Creek Experimental Watershed (RCEW) in southwest Idaho, USA. Predicted results show good agreement with the observed data for the NEE (r2 = 0.87). We then validate the temporal pattern of the NEE generated by the RF model for two independent years at the two sites not used in the development of the model. The model development process revealed that the most important predictors include LAI, downward solar radiation, and soil moisture. This work provides a demonstration of the potential power of machine learning methods for combining a variety of observational datasets to create spatiotemporally extensive datasets for land model verification and benchmarking.