Axillary vein as an alternative venous access site for VV-ECMO cannulation: a case report.

BACKGROUND: Ultrasound-guided percutaneous axillary vein cannulation can reduce cannulation failure and mechanical complications, is as safe and effective as internal jugular vein cannulation, and is superior to subclavian vein cannulation using landmark technique. As far, reports of venovenous extracorporeal membrane oxygenation (VV-ECMO) with percutaneous axillary vein cannulation are rare. CASE PRESENTATION: A 64-year-old man presenting with dyspnea and chest tightness after aspirating sewage was admitted to the emergency department. Computed tomography (CT) showed diffuse exudation of both lungs and arterial blood gas analysis showed an oxygenation index of 86. He was diagnosed with aspiration pneumonia-induced acute respiratory distress syndrome (ARDS) and intubated for deteriorated oxygenation. Despite the combination therapy of protective mechanical ventilation and prone position, the patient's oxygenation deteriorated further, accompanied with multiple organ dysfunction syndrome, which indicated the requirement of support with VV-ECMO. However, vascular ultrasound detected multiple thrombus within bilateral internal jugular veins. As an alternative, right axillary vein was chosen as the access site of return cannula. Subsequently, femoral-axillary VV-ECMO was successfully implemented under the ultrasound guidance, and the patient's oxygenation was significantly improved. Unfortunately, the patient died of hyperkalemia-induced ventricular fibrillation after 36 h of VV-ECMO running. Despite the poor prognosis, the blood flow during ECMO run was stable, and we observed no bleeding complication, vascular injury, or venous return disorder. CONCLUSIONS: Axillary vein is a feasible alternative access site of return cannula for VV-ECMO if internal jugular vein access were unavailable.

Dynamic arterial elastance as a predictor of arterial pressure response to norepinephrine weaning in mechanically ventilated patients with vasoplegic syndrome-a systematic review and meta-analysis.

Introduction: During the de-escalation phase of circulatory shock, norepinephrine weaning may induce diverse arterial pressure responses in patients with different vasomotor tones. Dynamic arterial elastance (Eadyn) has been extensively studied to predict the arterial pressure response to interventions. We conducted this meta-analysis to systematically assess the predictive performance of Eadyn for the mean arterial pressure (MAP) response to norepinephrine weaning in mechanically ventilated patients with vasoplegic syndrome. Materials and methods: A systematic literature search was conducted on May 29, 2023 (updated on January 21, 2024), to identify relevant studies from electronic databases. The area under the hierarchical summary receiver operating characteristic curve (AUHSROC) was estimated as the primary measure of diagnostic accuracy because of the varied thresholds reported. Additionally, we observed the distribution of the cutoff values of Eadyn, while computing the optimal value and its corresponding 95% confidential interval (CI). Results: A total of 5 prospective studies met eligibility, comprising 183 participants, of whom 67 (37%) were MAP responders. Eadyn possessed an excellent ability to predict the MAP response to norepinephrine weaning in patients with vasoplegic syndrome, with an AUHSROC of 0.93 (95% CI: 0.91-0.95), a pooled sensitivity of 0.94 (95% CI: 0.85-0.98), a pooled specificity of 0.73 (95% CI: 0.65-0.81), and a pooled diagnostic odds ratio of 32.4 (95% CI: 11.7-89.9). The cutoff values of Eadyn presented a nearly conically symmetrical distribution; the mean and median cutoff values were 0.89 (95% CI: 0.80-0.98) and 0.90 (95% CI: not estimable), respectively. Conclusions: This meta-analysis with limited evidences demonstrates that Eadyn may be a reliable predictor of the MAP response to norepinephrine weaning in mechanically ventilated patients with vasoplegic syndrome. Systematic Review Registration: PROSPERO CRD42023430362.

Mortality and Cumulative Kidney Score are Associated with Transient and Persistent Acute Kidney Injury in Septic Patients: A Retrospective Study Based on MIMIC-IV.

BACKGROUND: Acute kidney injury (AKI) is frequently caused by sepsis. Recently, the Acute Disease Quality Initiative (ADQI) workgroup further classified AKI as transient or persistent. Oliguria and increased serum creatinine represent two different kinds of renal impairment. The aim of the study was to assess mortality and cumulative AKI score associated with transient and persistent AKI in septic patients. METHODS: Septic patients were stratified according to the presence and AKI development (considered persistent when remaining >48 h) were included. An adjusted logistic regression model was used to determine hospital mortality. In addition, we calculated an AKI score by combining both Kidney Disease: Improving Global Outcomes (KDIGO) criteria of urine output and creatinine AKI stages. The relationship between the cumulative AKI score and persistent AKI was further examined using the logistic regression model and receiver operating characteristic (ROC) curve analysis. RESULTS: 12928 septic patients were enrolled in the study. AKI occurred in 73.7% of septic patients, in 39.5% was transient and in 60.5% was persistent. Patients with persistent AKI had higher severity scores and more severe renal dysfunction upon admission. Persistent AKI, but not transient AKI, was associated with increased intensive care units (ICUs) and hospital mortality. Then we found that the cumulative AKI score was associated with an increased risk of persistent AKI. This association was consistent across three original KDIGO severity stages and subgroup analyses. CONCLUSIONS: It was found that persistent AKI was independently associated with mortality in septic patients. Furthermore, serum creatinine and urine output criteria had cumulative effects on KDIGO AKI staging and provided more information about the relationship between AKI and outcomes.

Prophylactic noninvasive respiratory support in the immediate postoperative period after cardiac surgery - a systematic review and network meta-analysis.

BACKGROUND: Noninvasive respiratory support has been increasingly applied in the immediate postoperative period to prevent postoperative pulmonary complications (PPCs). However, the optimal approach remains uncertain. We sought to evaluate the comparative effectiveness of various noninvasive respiratory strategies used in the immediate postoperative period after cardiac surgery. METHODS: We conducted a frequentist random-effect network meta-analysis (NMA) of randomized controlled trials (RCTs) comparing the prophylactic use of noninvasive ventilation (NIV), continuous positive airway pressure (CPAP), high flow nasal cannula (HFNC), or postoperative usual care (PUC) in the immediate postoperative period after cardiac surgery. Databases were systematically searched through September 28, 2022. Study selection, data extraction, and quality assessment were performed in duplicate. The primary outcome was the incidence of PPCs. RESULTS: Sixteen RCTs enrolling 3011 patients were included. Compared with PUC, NIV significantly reduced the incidence of PPCs [relative risk (RR) 0.67, 95% confidence interval (CI): 0.49 to 0.93; absolute risk reduction (ARR) 7.6%, 95% CI: 1.6-11.8%; low certainty] and the incidence of atelectasis (RR 0.65, 95% CI: 0.45 to 0.93; ARR 19.3%, 95% CI: 3.9-30.4%; moderate certainty); however, prophylactic NIV was not associated with a decreased reintubation rate (RR 0.82, 95% CI: 0.29 to 2.34; low certainty) or reduced short-term mortality (RR 0.64, 95% CI: 0.16 to 2.52; very low certainty). As compared to PUC, the preventive use of CPAP (RR 0.85, 95% CI: 0.60 to 1.20; very low certainty) or HFNC (RR 0.74, 95% CI: 0.46 to 1.20; low certainty) had no significant beneficial effect on the incidence of PPCs, despite exhibiting a downward trend. Based on the surface under the cumulative ranking curve, the highest-ranked treatment for reducing the incidence of PPCs was NIV (83.0%), followed by HFNC (62.5%), CPAP (44.3%), and PUC (10.2%). CONCLUSIONS: Current evidence suggest that the prophylactic use of NIV in the immediate postoperative period is probably the most effective noninvasive respiratory approach to prevent PPCs in patients undergoing cardiac surgery. Given the overall low certainty of the evidence, further high-quality research is warranted to better understand the relative benefits of each noninvasive ventilatory support. CLINICAL TRIAL REGISTRATION: PROSPERO, https://www.crd.york.ac.uk/prospero/ , registry number: CRD42022303904.

Mortality and Cumulative Kidney Score are Associated with Transient and Persistent Acute Kidney Injury in Septic Patients: A Retrospective Study Based on MIMIC-IV

Background: Acute kidney injury (AKI) is frequently caused by sepsis. Recently, the Acute Disease Quality Initiative (ADQI) workgroup further classified AKI as transient or persistent. Oliguria and increased serum creatinine represent two different kinds of renal impairment. The aim of the study was to assess mortality and cumulative AKI score associated with transient and persistent AKI in septic patients. Methods: Septic patients were stratified according to the presence and AKI development (considered persistent when remaining >48 h) were included. An adjusted logistic regression model was used to determine hospital mortality. In addition, we calculated an AKI score by combining both Kidney Disease: Improving Global Outcomes (KDIGO) criteria of urine output and creatinine AKI stages. The relationship between the cumulative AKI score and persistent AKI was further examined using the logistic regression model and receiver operating characteristic (ROC) curve analysis. Results: 12928 septic patients were enrolled in the study. AKI occurred in 73.7% of septic patients, in 39.5% was transient and in 60.5% was persistent. Patients with persistent AKI had higher severity scores and more severe renal dysfunction upon admission. Persistent AKI, but not transient AKI, was associated with increased intensive care units (ICUs) and hospital mortality. Then we found that the cumulative AKI score was associated with an increased risk of persistent AKI. This association was consistent across three original KDIGO severity stages and subgroup analyses. Conclusions: It was found that persistent AKI was independently associated with mortality in septic patients. Furthermore, serum creatinine and urine output criteria had cumulative effects on KDIGO AKI staging and provided more information about the relationship between AKI and outcomes (AU)

Effective biodegradation of chlorophenols, sulfonamides, and their mixtures by bacterial laccase immobilized on chitin.

Coexisting multi-pollutants like sulfonamides (SAs) and chlorophenols (CPs) in the ecological environment pose a potential risk to living organisms. The development of a strategy for the effective removal of multiple pollutants has become an urgent need. Herein, we systematically investigated the potential of immobilized bacterial laccase to remove chlorophenols (CPs), sulfonamides (SAs), and their mixtures. Laccase from Bacillus pumilus ZB1 was efficiently immobilized on chitin and its thermal stability, pH stability, and affinity to substrates were improved. Reusability assessment showed the immobilized laccase retained 75.5% of its initial activity after five cycles. The removal efficiency of CPs and SAs by immobilized laccase was significantly improved compared with that of free laccase. In particular, the removal of 2,4-dichlorophenol and 2,4,6-trichlorophenol reached 96.9% and 89.3% respectively within 8 h. The immobilized laccase could remove 63.70% of 2,4-dichlorophenol after four cycles. The degradation pathways of 2,4-dichlorophenol and sulfamethazine were proposed via LC/MS analysis. When the co-pollutants containing 2,4,6-trichlorophenol and sulfamethoxazole, immobilized laccase showed 100% removal of 2,4,6-trichlorophenol and 38.71% removal of sulfamethoxazole simultaneously. Cytotoxicity and phytotoxicity tests indicated that immobilized laccase can alleviate the toxicity of co-pollutants. The results demonstrate that chitin-based laccase immobilization can be an effective strategy for the removal of SAs, CPs, and their co-pollutants.

Deciphering the alkaline stable mechanism of bacterial laccase from Bacillus pumilus by molecular dynamics simulation can improve the decolorization of textile dyes.

Laccases are considered promising tools for removing synthetic dyes from textile and tannery effluents. However, the alkaline pH in the effluents causes laccase instability, inactivation, and difficulty in its bioremediation. Based on a Bacillus pumilus ZB1 (BpLac) derived alkaline stable laccase, this study aimed to elucidate its alkaline stable mechanism at molecular level using molecular dynamics simulation. The effects of metal ions, organic solvents, and inhibitors on BpLac activity were assessed. BpLac formed more salt bridges and negatively charged surface in alkaline environment. Thereafter, pH-induced conformation changes were analyzed using GROMACS at pH 5.0 and 10.0. Among the identified residues with high fluctuation, the distance between Pro359 and Thr414 was stable at pH 10.0 but highly variable at pH 5.0. DSSP analysis suggested that BpLac formed more ß-sheet and less coil at pH 10.0. Principal component analysis and free energy landscape indicated that irregular coils formed at pH 5.0 benefit for activity, while rigid α-helix and ß-sheet structures formed at pH 10.0 contributed to alkaline stability. Breaking the α-helix near T1 copper center would not reduce alkaline stability but could improve dye decolorization by BpLac. Overall, these findings would advance the potential application of bacterial laccase in alkaline effluent treatment.

Successful management of hemodynamic instability secondary to saddle pulmonary embolism-induced cardiac arrest using VA-ECMO in advanced malignancy with brain metastases.

BACKGROUND: Saddle pulmonary embolism (SPE) represents a rare type of venous thromboembolism that frequently causes circulation collapse and sudden death. While venoarterial extracorporeal membrane oxygenation (VA-ECMO) has been well established as a salvage treatment for SPE-induced circulatory shock, it is infrequently administered in patients with advanced malignancy, especially those with brain metastases, given the potential bleeding complications and an uncertain prognosis. As far, there are rare case reports regarding the successful management of hemodynamic instability secondary to SPE-induced cardiac arrest using VA-ECMO in advanced malignancy patients with brain metastases. CASE PRESENTATION: A 65-year-old woman presenting with cough and waist discomfort who had a history of lung cancer with brain metastases was admitted to the hospital to receive chemoradiotherapy. She suffered sudden cardiac arrest during hospitalization and returned to spontaneous circulation after receiving a 10-min high-quality cardiopulmonary resuscitation. Pulmonary embolism was suspected due to the collapsed hemodynamics and a distended right ventricle identified by echocardiography. Subsequent computed tomographic pulmonary angiography revealed a massive saddle thrombus straddling the bifurcation of the pulmonary trunk. VA-ECMO with adjusted-dose systemic heparinization was initiated to rescue the unstable hemodynamics despite receiving thrombolytic therapy with alteplase. Immediately afterward, the hemodynamic status of the patient stabilized rapidly. VA-ECMO was successfully discontinued within 72 h of initiation without any clotting or bleeding complications. She was weaned off invasive mechanical ventilation on the 6th day of intensive care unit (ICU) admission and discharged from the ICU 3 days later with good neurological function. CONCLUSION: VA-ECMO may be a 'bridging' therapy to circulation recovery during reperfusion therapy for SPE-induced hemodynamic collapse in malignancy patients with brain metastases.

Effects of low-FODMAP diet on irritable bowel symptoms in patients with quiescent inflammatory bowel disease: A protocol for a systematic review and meta-analysis.

BACKGROUND: Inflammatory bowel disease (IBD) is a chronic disease whose etiology is not yet fully understood, and their course is characterized by periods of exacerbation and remission. In quite a few cases, actual disease remission may also accompany with inflammatory bowel disease (IBS)-like symptoms such as abdominal pain, bloating, flatulence, and diarrhea, may greatly impact quality of life. An army of strong evidence to support the FODMAPs diet (LFD) compounds as an effective dietary approach to IBS treatment. However, there is no significant evidence showing the effectiveness of LFD in treating quiescent IBD and its side effects; this lack of evidence is also an important factor hindering its promotion in the treatment of IBD and its complications. Therefore, this systematic review and meta-analysis will evaluate the efficacy and safety of LFD in the treatment of quiescent IBD patients with IBS-like symptoms. METHOD: We searched the following databases from their establishment until December 2021: PubMed, Web of Science, Embase, Cochrane Library, CNKI, VIP, and Wanfang databases. No restrictions regarding publication date or language were applied. Keywords such as "Crohn's disease," "ulcerative colitis," "inflammatory bowel disease," and "FODMAPs" have been combined for search. Ongoing and unpublished research in the Clinical Trials Registry Research will also be included. At the same time, we will manually search all reference lists from relevant systematic reviews for other eligible studies. The selected studies were randomized controlled clinical trials. We will meta-analyze the selected literature by Review Manager software (REVMAN v5.4 Cochrane Collaboration). Two researchers will independently review the research selection, data extraction, and research quality assessments. Finally, we will observe the outcome measures. RESULTS: This study will provide evidence-based data for TFD treatment of IBD and provide new treatment options for future clinical applications. ETHICS AND DISSEMINATION: The protocol of the systematic review does not require ethical approval because it does not involve humans. This article will be published in peer-reviewed journals and presented at relevant conferences. REGISTRATION NUMBER: INPLASY202220060.

Optimizing left ventricular-arterial coupling during the initial resuscitation in septic shock - a pilot prospective randomized study.

BACKGROUND: Left ventricular-arterial coupling (VAC), defined as the ratio of effective arterial elastance (Ea) to left ventricular end-systolic elastance (Ees), has been extensively described as a key determinant of cardiovascular work efficacy. Previous studies indicated that left ventricular-arterial uncoupling was associated with worse tissue perfusion and increased mortality in shock patients. Therefore, this study aims to investigate whether a resuscitation algorithm based on optimizing left VAC during the initial resuscitation can improve prognosis in patients with septic shock. METHODS: This pilot study was conducted in an intensive care unit (ICU) of a tertiary teaching hospital in China. A total of 83 septic shock patients with left ventricular-arterial uncoupling (i.e., the Ea/Ees ratio ≥ 1.36) were randomly assigned to receive usual care (usual care group, n = 42) or an algorithm-based resuscitation that attempt to reduce the Ea/Ees ratio to 1 within the first 6 h after randomization (VAC-optimized group, n = 41). The left VAC was evaluated by transthoracic echocardiography every 2 h during the study period. The primary endpoint was 28-days mortality. The secondary endpoints included lactate clearance rate, length of ICU stay, and duration of invasive mechanical ventilation (IMV). RESULTS: Eighty-two patients (98.8%) completed the study and were included in the final analysis. The Ea/Ees ratio was reduced in both groups, and the decrease in Ea/Ees ratio in the VAC-optimized group was significantly greater than that in the usual care group [median (interquartile range), 0.39 (0.26, 0.45) vs. 0.1 (0.06, 0.22); P < 0.001]. Compared with the usual care group, the VAC-optimized group likely exhibited the potential to reduce the 28-days mortality (33% vs. 50%; log-rank hazard ratio = 0.526, 95% confidence interval: 0.268 to 1.033). Moreover, the VAC-optimized group had a higher lactate clearance rate than the usual care group [27.7 (11.9, 45.7) % vs. 18.3 (- 5.7, 32.1) %; P = 0.038]. No significant difference was observed in terms of the length of ICU stay or duration of IMV. CONCLUSIONS: During the initial resuscitation of septic shock, optimizing left ventricular-arterial coupling was associated with improved lactate clearance, while likely having a beneficial effect on prognosis. TRIAL REGISTRATION: Chinese Clinical Trial Registry, ChiCTR1900024031 . Registered 23 June 2019 - Retrospectively registered.

Predictive performance of dynamic arterial elastance for arterial pressure response to fluid expansion in mechanically ventilated hypotensive adults: a systematic review and meta-analysis of observational studies.

BACKGROUND: Dynamic arterial elastance (Eadyn) has been extensively considered as a functional parameter of arterial load. However, conflicting evidence has been obtained on the ability of Eadyn to predict mean arterial pressure (MAP) changes after fluid expansion. This meta-analysis sought to assess the predictive performance of Eadyn for the MAP response to fluid expansion in mechanically ventilated hypotensive patients. METHODS: We systematically searched electronic databases through November 28, 2020, to retrieve studies that evaluated the association between Eadyn and fluid expansion-induced MAP increases in mechanically ventilated hypotensive adults. Given the diverse threshold value of Eadyn among the studies, we only reported the area under the hierarchical summary receiver operating characteristic curve (AUHSROC) as the primary measure of diagnostic accuracy. RESULTS: Eight observational studies that included 323 patients with 361 fluid expansions met the eligibility criteria. The results showed that Eadyn was a good predictor of MAP increases in response to fluid expansion, with an AUHSROC of 0.92 [95% confidence interval (CI) 0.89 to 0.94]. Six studies reported the cut-off value of Eadyn, which ranged from 0.65 to 0.89. The cut-off value of Eadyn was nearly conically symmetrical, most data were centred between 0.7 and 0.8, and the mean and median values were 0.77 and 0.75, respectively. The subgroup analyses indicated that the AUHSROC was slightly higher in the intensive care unit (ICU) patients (0.96; 95% CI 0.94 to 0.98) but lower in the surgical patients in the operating room (0.72; 95% CI 0.67 to 0.75). The results indicated that the fluid type and measurement technique might not affect the diagnostic accuracy of Eadyn. Moreover, the AUHSROC for the sensitivity analysis of prospective studies was comparable to that in the primary analysis. CONCLUSIONS: Eadyn exhibits good performance for predicting MAP increases in response to fluid expansion in mechanically ventilated hypotensive adults, especially in the ICU setting.

Renal replacement therapy modality in critically ill patients with acute kidney injury - A network meta-analysis of randomized controlled trials.

PURPOSE: This network meta-analysis aims to compare the efficacy and safety of various renal replacement therapy (RRT) modalities in critically ill patients with acute kidney injury (AKI). MATERIALS AND METHODS: We searched the electronic databases for randomized controlled trials (RCTs) comparing different RRT modalities, including continuous RRT, intermittent RRT, hybrid RRT, and peritoneal dialysis (PD), in critically ill patients with AKI through July 26, 2020. The primary outcomes were renal recovery and short-term mortality. The study protocol was registered with PROSPERO (CRD42020188115). RESULTS: Twenty-three studies were included. No difference in the renal recovery or short-term mortality was observed among the four RRT modalities (low certainty). The four RRT modalities had similar effects on the incidence of infectious complications (low certainty). PD was associated with less fluid removal volume and lower incidence of hypotension compared with the extracorporeal modalities, yet no difference in the two outcomes was identified among the extracorporeal modalities (very low to moderate certainty). CONCLUSIONS: No superiority of one particular RRT modality over another in terms of renal recovery and short-term mortality in critically ill patients with AKI. PD exhibited worse fluid removal and better safety in the prevention of hypotension than the extracorporeal modalities.

Preventive use of respiratory support after scheduled extubation in critically ill medical patients-a network meta-analysis of randomized controlled trials.

BACKGROUND: Respiratory support has been increasingly used after extubation for the prevention of re-intubation and improvement of prognosis in critically ill medical patients. However, the optimal respiratory support method is still under debate. This network meta-analysis (NMA) aims to evaluate the comparative effectiveness of various respiratory support methods used for preventive purposes after scheduled extubation in critically ill medical patients. METHODS: A systematic database search was performed from inception to December 19, 2019, for randomized controlled trials (RCTs) that compared a preventive use of different respiratory support methods, including conventional oxygen therapy (COT), noninvasive ventilation (NIV), high-flow oxygen therapy (HFOT), and combinational use of HFOT and NIV (HFOT+NIV), after planned extubation in adult critically ill medical patients. Study selection, data extraction, and quality assessments were performed in duplicate. The primary outcomes included re-intubation rate and short-term mortality. RESULTS: Seventeen RCTs comprising 3341 participants with 4 comparisons were included. Compared with COT, NIV significantly reduced the re-intubation rate [risk ratio (RR) 0.55, 95% confidence interval (CI) 0.39 to 0.77; moderate quality of evidence] and short-term mortality (RR 0.66, 95% CI 0.48 to 0.91; moderate quality of evidence). Compared to COT, HFOT had a beneficial effect on the re-intubation rate (RR 0.55, 95% CI 0.35 to 0.86; moderate quality of evidence) but no effect on short-term mortality (RR 0.79, 95% CI 0.56 to 1.12; low quality of evidence). No significant difference in the re-intubation rate or short-term mortality was found among NIV, HFOT, and HFOT+NIV. The treatment rankings based on the surface under the cumulative ranking curve (SUCRA) from best to worst for re-intubation rate were HFOT+NIV (95.1%), NIV (53.4%), HFOT (51.2%), and COT (0.3%), and the rankings for short-term mortality were NIV (91.0%), HFOT (54.3%), HFOT+NIV (43.7%), and COT (11.1%). Sensitivity analyses of trials with a high risk of extubation failure for the primary outcomes indicated that the SUCRA rankings were comparable to those of the primary analysis. CONCLUSIONS: After scheduled extubation, the preventive use of NIV is probably the most effective respiratory support method for comprehensively preventing re-intubation and short-term death in critically ill medical patients, especially those with a high risk of extubation failure.

Stress ulcer prophylaxis with proton pump inhibitors or histamine 2 receptor antagonists in critically ill adults - a meta-analysis of randomized controlled trials with trial sequential analysis.

BACKGROUND: Proton pump inhibitors (PPI) and histamine 2 receptor antagonists (H2RA) have been widely used as stress ulcer prophylaxis (SUP) in critically ill patients, however, its efficacy and safety remain unclear. This study aimed to assess the effect of SUP on clinical outcomes in critically ill adults. METHODS: Literature search was conducted in PubMed, EMBASE, Web of Science, and the Cochrane database of clinical trials for randomized controlled trials (RCTs) that investigated SUP, with PPI or H2RA, versus placebo or no prophylaxis in critically ill patients from database inception through 1 June 2019. Study selection, data extraction and quality assessment were performed in duplicate. The primary outcomes were clinically important gastrointestinal (GI) bleeding and overt GI bleeding. Conventional meta-analysis with random-effects model and trial sequential analysis (TSA) were performed. RESULTS: Twenty-nine RCTs were identified, of which four RCTs were judged as low risk of bias. Overall, SUP could reduce the incident of clinically important GI bleeding [relative risk (RR) = 0.58; 95% confidence intervals (CI): 0.42-0.81] and overt GI bleeding (RR = 0.48; 95% CI: 0.36-0.63), these results were confirmed by the sub-analysis of trials with low risk of bias, TSA indicated a firm evidence on its beneficial effects on the overt GI bleeding (TSA-adjusted CI: 0.31-0.75), but lack of sufficient evidence on the clinically important GI bleeding (TSA-adjusted CI: 0.23-1.51). Among patients who received enteral nutrition (EN), SUP was associated with a decreased risk of clinically important GI bleeding (RR = 0.61; 95% CI: 0.44-0.85; TSA-adjusted CI: 0.16-2.38) and overt GI bleeding (RR = 0.64; 95% CI: 0.42-0.96; TSA-adjusted CI: 0.12-3.35), but these benefits disappeared after adjustment with TSA. Among patients who did not receive EN, SUP had only benefits in reducing the risk of overt GI bleeding (RR = 0.37; 95% CI: 0.25-0.55; TSA-adjusted CI: 0.22-0.63), but not the clinically important GI bleeding (RR = 0.27; 95% CI: 0.04-2.09). CONCLUSIONS: SUP has benefits on the overt GI bleeding in critically ill patients who did not receive EN, however, its benefits on clinically important GI bleeding still needs more evidence to confirm.

[Characteristics of Ozone Pollution Distribution and Source Apportionment in Zhoushan].

The processes affecting photochemical reactions and regional transport of ozone and its precursors in ambient air are very complicated. In this study, statistical analysis of the spatial and temporal distributions of ozone pollution in Zhoushan was carried out based on monitoring data from state monitoring stations in Zhoushan in 2014. Specifically, ozone formation was simulated by CMAQ (the community multiscale air quality) model, and the source contribution rate was calculated using the Integrated Source Apportionment Method (ISAM) source tracking algorithm. The results showed that ozone pollution was more severe in spring and autumn than in summer and winter, and the highest ozone concentrations mostly appeared during 13:00-15:00 in the afternoon. Putuo Station had the highest ozone concentration while Lincheng Station, located in the downtown area of the city, had the lowest ozone concentration. The overall average ozone concentration was not high; however, peak concentrations that exceeded the standards usually occurred, which occurs most often in May. Local ozone formation in Zhoushan City is controlled by the VOC concentration, and source tracking results showed that non-local sources accounted for 69.46% of the total contribution. Among local emission sources, fuel burning boiler sources, industry process sources, on-road mobile sources, and non-road mobile sources made similar contributions to ozone formation. Moreover, they showed significant characteristics of a port city. The contribution rates from shipping sources, petrochemical sources, and storage and transportation sources were 4.45%, 1.01%, and 1.80%, respectively. In conclusion, control of the ozone pollution in Zhoushan City should be based on simultaneous reduction and coordinated prevention involving multiple sources (VOCs as the main one) both locally and in surrounding areas.

The effects of deterioration and technological levels on pollutant emission factors for gasoline light-duty trucks.

Vehicle deterioration and technological change influence emission factors (EFs). In this study, the impacts of vehicle deterioration and emission standards on EFs of regulated pollutants (carbon monoxide [CO], hydrocarbon [HC], and nitrogen oxides [NOx]) for gasoline light-duty trucks (LDTs) were investigated according to the inspection and maintenance (I/M) data using a chassis dynamometer method. Pollutant EFs for LDTs markedly varied with accumulated mileages and emission standards, and the trends of EFs are associated with accumulated mileages. In addition, the study also found that in most cases, the median EFs of CO, HC, and NOx are higher than those of basic EFs in the International Vehicle Emissions (IVE) model; therefore, the present study provides correction factors for the IVE model relative to the corresponding emission standards and mileages. IMPLICATIONS: Currently, vehicle emissions are great contributors to air pollution in cities, especially in developing countries. Emission factors play a key role in creating emission inventory and estimating emissions. Deterioration represented by vehicle age and accumulated mileage and changes of emission standards markedly influence emission factors. In addition, the results provide collection factors for implication in the IVE model in the region levels.

Protection of retinal vasculature by losartan against apoptosis and vasculopathy in rats with spontaneous hypertension.

OBJECTIVES: Retinal blood vessels may develop vasculopathy and apoptosis in response to hypertension. The present study was aimed at testing the role of losartan, a specific antagonist of angiotensin II receptor type 1 receptor in regulation of vascular apoptosis in retinal vasculature with hypertension. METHODS: Losartan potassium was administered to spontaneously hypertensive rats (SHR). Blood pressure was measured in SHR as well as normotensive Wistar-Kyoto rats (WKY). Eye fundus was examined in living animals and then tissue specimens were collected for histochemistry by hematoxylin and eosin staining, terminal deoxynucleotidyl transferase-mediated 2'-deoxyuridine 5'-triphosphate nick end labeling (TUNEL), immunohistochemistry and transmission electron microscopy. RESULTS: Losartan treatment for 4-8 weeks reduced blood pressure of SHR to the normal levels seen in WKY. The losartan-treated SHR showed marked improvement of retinal vascular morphology compared with untreated SHR. The retinal blood networks of the treated SHR developed lower degrees of vasculopathy and apoptosis. TUNEL and transmission electron microscopy also revealed that losartan exerted its protective effects not only on endothelial cells but on pericytes as well. The blood vessels of losartan-treated animals also showed decreased expression of bax with elevation of B-cell CLL/lymphoma 2. CONCLUSION: Treatment with losartan, a medicine that lowers blood pressure by blocking angiotensin II receptor type 1 receptor, can protect the retinal vasculature against hypertensive vascular injury by inhibiting apoptosis of vascular cells and by preventing hypertensive retinopathy.