Contrast enhanced ultrasonography (CEUS) to detect abdominal microcirculatory disorders in severe cases of COVID-19 infection: First experience

Influence of Covid-19 disease on hemostasis dynamics during extracorporeal membrane oxygenation (ECMO)1

INTRODUCTION

COVID-19 causes a considerable degradation of pulmonary function to the point of an acute respiratory distress syndrome (ARDS). Over the course of the disease the gas exchange capability of the lung can get impaired to such an extent that extracorporeal membrane oxygenation (ECMO) is needed as a life-saving intervention. In patients COVID-19 as well as ECMO may cause severe coagulopathies which manifest themselves in micro and macro thrombosis. Previous studies established D-dimers as a marker for critical thrombosis of the ECMO system while on admission increased D-dimers are associated with a higher mortality in COIVD-19 patients. It is therefore crucial to determine if COVID-19 poses an increased risk of early thrombosis of the vital ECMO system.

METHODS

40 patients who required ECMO support were enrolled in a retrospective analysis and assigned into 2 groups. The COVID group consist of 20 COVID-19 patients who required ECMO support (n = 20), whereas 20 ECMO patients without COVID-19 were assigned to the control group. D-dimers, fibrinogen, antithrombin III (AT III), lactate dehydrogenase (LDH) and platelet count were analysed using locally weighted scatterplot smoothing and MANOVAs.

RESULTS

The analysis of both groups shows highly significant differences in the dynamics of hemostasis. The increase in D-dimers that is associated with thrombosis of the ECMO systems occurs in COVID-19 patients around 2 days earlier (p = 2,8115 10-11) while fibrinogen is consumed steadily. In the control group fibrinogen levels increase rapidly after ten days with a plateau phase of around five days (p = 1,407 10-3) . Both groups experience a rapid increase in AT III after start of support by ECMO (p = 5,96 10-15). In the COVID group platelet count decreased from 210 giga/l to 130 giga/l within eight days, while in the same time span in the control group platelets decreased from 180 giga/l to 105 giga/l (p = 1,1 10-15). In both groups a marked increase in LDH beyond 5000 U/l occurs (p = 3,0865 10-15).

CONCLUSION

The early increase in D-dimers and decrease in fibrinogen suggests that COVID-19 patients bear an increased risk of early thrombosis of the ECMO system compared to other diseases treated with ECMO. Additionally, the control group shows signs of severe inflammation 10 days after the start of ECMO which were absent in COVID-19 patients.

Morphology and Function of Red Blood Cells in COVID-19 Patients: Current Overview 2023

In severe cases, SARS-CoV-2 infection leads to severe respiratory failure. Although angiotensin-converting enzyme 2 (ACE2) receptors are not expressed in red blood cells, SARS-CoV-2 can interact with red blood cells (RBCs) via several receptors or auxiliary membrane proteins. Recent data show that viral infection causes significant damage to the RBCs, altering their morphology, deformability, and aggregability. Loss of RBC deformability and/or increased aggregability favors the development of thrombotic processes in the microcirculation, as has been described to occur in COVID-19 patients. In addition, many patients also develop systemic endotheliitis associated with generalized coagulopathy. This manifests itself clinically as obstructive microthrombi in the area of the medium and smallest vessels, which can affect all internal organs. It is thought that such changes in the RBCs may contribute to the microangiopathy/microthrombosis associated with COVID-19 and may result in impaired capillary blood flow and tissue oxygenation.

Potential Benefits of Omega-3 Polyunsaturated Fatty Acids (N3PUFAs) on Cardiovascular Health Associated with COVID-19: An Update for 2023

The accumulating literature demonstrates that omega-3 polyunsaturated fatty acid (n-3 polyunsaturated fatty acid, N3PUFA) can be incorporated into the phospholipid bilayer of cell membranes in the human body to positively affect the cardiovascular system, including improving epithelial function, decreasing coagulopathy, and attenuating uncontrolled inflammatory responses and oxidative stress. Moreover, it has been proven that the N3PUFAs, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are precursors of some potent endogenous bioactive lipid mediators that mediate some favorable effects attributed to their parent substances. A dose-response relationship between increased EPA and DHA intake and reduced thrombotic outcomes has been reported. The excellent safety profile of dietary N3PUFAs makes them a prospective adjuvant treatment for people exposed to a higher risk of cardiovascular problems associated with COVID-19. This review presented the potential mechanisms that might contribute to the beneficial effects of N3PUFA and the optimal form and dose applied.

Emerging Applications of Extracardiac Ultrasound in Critically Ill Cardiac Patients

Point-of-care ultrasound has evolved as an invaluable diagnostic modality and procedural guidance tool in the care of critically ill cardiac patients. Beyond focused cardiac ultrasound, additional extracardiac ultrasound modalities may provide important information at the bedside. In addition to new uses of existing modalities, such as pulsed-wave Doppler ultrasound, the development of new applications is fostered by the implementation of additional features in mid-range ultrasound machines commonly acquired for intensive care units, such as tissue elastography, speckle tracking, and contrast-enhanced ultrasound quantification software. This review explores several areas in which ultrasound imaging technology may transform care in the future. First, we review how lung ultrasound in mechanically ventilated patients can enable the personalization of ventilator parameters and help to liberate them from mechanical ventilation. Second, we review the role of venous Doppler in the assessment of organ congestion and how tissue elastography may complement this application. Finally, we explore how contrast-enhanced ultrasound could be used to assess changes in organ perfusion.

The efficacy of low molecular weight heparin is reduced in COVID-19

BACKGROUND

A significant degree of mortality and morbidity in COVID-19 is through thromboembolic complications, only partially mitigated by anticoagulant therapy. Reliable markers of infection severity are not fully established.

OBJECTIVES

This study investigated whether visco-elastic biomarkers predict disease severity on presentation to the Emergency Department (ED) and how they measure response to anticoagulationMETHODS:Patients testing positive for COVID-19 at a large University Teaching Hospital ED were recruited at presentation. Multiple blood samples were taken throughout hospital admission to monitor disease progression with end outcome recorded. Visco-elastic markers, fractal dimension (df) and Time to Gel Point (TGP) which measure the properties of the incipient clot were compared in patients with and without anticoagulation by Low Molecular Weight Heparin (LMWH).

RESULTS

TGP and df did not predict severity of infection with COVID-19. Although LMWH prolonged TGP, there was no change in df indicating LMWH did not change clot microstructure.

CONCLUSIONS

Therapeutic efficacy of LMWH appears blunted in COVID-19 infection. This may be due to the inflammatory state creating a resistance to LMWH activity, which may explain why LMWH appears less effective in COVID-19 compared to other disease states. COVID-19 was not predicted by visco-elastic testing at the time of ED presentation.

Association of coagulation factors profile with clinical outcome in patient with COVID-19 and acute stroke: A second wave cohort study

INTRODUCTION

The second wave of COVID-19 in Indonesia occurred due to delta variant transmission with up to 2266 cases. This variant could cause higher rate of morbidities and mortalities. This study reported coagulation profile of COVID-19 patients with acute stroke and its association with patients' outcome.

METHOD

This is a cohort-retrospective study conducted during the second wave of COVID-19, June-August 2021 in Cipto Mangunkusumo General Hospital. Inclusion criteria were adult patients with confirmed COVID-19 and diagnosed with acute stroke confirmed by radiological evidences. Exclusion criteria were COVID-19 patients with prior diagnosis of acute stroke. Coagulation factors were analyzed and presented with tables and graphs.

RESULTS

A total of 33 patients included in this study with majority experienced ischemic stroke (84.8%), followed by ischemic with haemorrhagic transformation (9.1%), and the rest with haemorrhagic stroke. The median of fibrinogen and D-dimer was 487.1(147-8,943)mg/dL and 2,110(250-35,200)ug/L respectively. Prothrombin time (PT) ratio was 0.95(0.82-1.3) and activated partial thromboplastin time (APTT) ratio was 1.01(0.64-2.72). On observation, 33.3% died during hospitalization, D-dimer value in these patients was significantly higher with 9,940ug/L compared to those who survived with 1,160ug/L(p = 0.009). The highest D-dimer value during hospitalization was also significantly higher with the median of 14,395ug/L compared to 3,740 ug/L (p = 0.014).

DISCUSSION

D-dimer value on initial assessment and its highest value during hospitalization were significantly higher in patient with poor outcome, showing that D-dimer can be one predictor of mortality in COVID-19 patients with acute stroke.

COVID-19 hemodynamic and thrombotic effect on the eye microcirculation after hospitalization: A quantitative case-control study

BACKGROUND & OBJECTIVE

To quantify the hemodynamic and thrombotic effect of COVID-19 on the eye microcirculation of patients with thromboprophylaxis, shortly after hospital discharge.

METHODS

This case-control study included 17 COVID-19 survivors (named "COVID-19 Group") and 17 healthy volunteers (named "Control Group"). Axial blood velocity (Vax) and percentage of occluded vessels (POV) were quantified by Conjunctival Video Capillaroscopy (CVC). Microvessels were identified and classified as "capillaries" (CAP), "postcapillary venules of size 1" (PC1), and "postcapillary venules of size 2" (PC2).

RESULTS

The COVID-19 Group did not differ significantly in basic demographics from the Control Group. In the COVID-19 Group, there was a statistically significant (p < 0.001) reduction of Vax (39%, 49% and 47%, for CAP, PC1, and PC2, respectively) in comparison to the Control Group and a sizeable (p < 0.001) increase of POV (600%) in comparison to the Control Group.

CONCLUSIONS

COVID-19 not only reduces significantly axial blood velocity in the capillaries and postcapillary venules of the eye but has also a devastating effect on microthrombosis (POV) despite thromboprophylaxis treatment. This gives a possible explanation for long COVID and a hint about the existence of a possibly unknown coagulation factor.

Multimodal ultrasound imaging with conventional B-mode, elastography, and parametric analysis of contrast-enhanced ultrasound (CEUS): A novel approach to assess small bowel manifestation in severe COVID-19 disease

The aim was to describe the small bowel morphology with conventional B-mode and elastography and additionally to evaluate dynamic effects of COVID-19 associated small bowel microvascularization using CEUS with color coded perfusion parameters.Thirteen patients with severe COVID-19 acute respiratory distress syndrome (ARDS) were investigated. 13 patients required intensive care treatment with mechanical ventilation. Five patients required extracorporeal membrane oxygenation (ECMO). Contrast-enhanced ultrasound (CEUS) was performed by an experienced investigator as a bolus injection of up to 2.4 ml sulfur hexafluoride microbubbles via a central venous catheter. In the parametric analysis of CEUS, the flare of microbubbles over time is visualized with colors. This is the first work using parametric analysis of CEUS to detect perfusion differences in the small bowel.Parametric analysis of CEUS in the intestinal phase was carried out, using DICOM loops for 20 seconds. In 5 patients, parametric analysis revealed intraindividual differences in contrast agent behavior in the small bowel region. Analogous to the computed tomography (CT) images parametric analysis showed regions of simultaneous hyper- and hypoperfusion of the small intestine in a subgroup of patients. In 5 patients, the parametric image of transmural global contrast enhancement was visualized.Our results using CEUS to investigate small bowel affection in COVID-19 suggest that in severe COVID-19 ARDS systemic inflammation and concomitant micro embolisms may lead to disruption of the epithelial barrier of the small intestine.This is the first study using parametric analysis of CEUS to evaluate the extent of small bowel involvement in severe COVID-19 disease and to detect microemboli. In summary, we show that in COVID-19 the small bowel may also be an important interaction site. This is in line with the fact that enterocytes have been shown to a plenitude of angiotensin converting enzyme (ACE)-2 receptors as entry sites of the virus.

Probing Red Blood Cell Membrane Microviscosity Using Fluorescence Anisotropy Decay Curves of the Lipophilic Dye PKH26

Red blood cell (RBC) aggregation and deformation are governed by the molecular processes occurring on the membrane. Since several social important diseases are accompanied by alterations in RBC aggregation and deformability, it is important to develop a diagnostic parameter of RBC membrane structural integrity and stability. In this work, we propose membrane microviscosity assessed by time-resolved fluorescence anisotropy of the lipophilic PKH26 fluorescent probe as a diagnostic parameter. We measured the fluorescence decay curves of the PKH26 probe in the RBC membrane to establish the optimal parameters of the developed fluorescence assay. We observed a complex biphasic profile of the fluorescence anisotropy decay characterized by two correlation times corresponding to the rotational diffusion of free PKH26, and membrane-bounded molecules of the probe. The developed assay allowed us to estimate membrane microviscosity ηm in the range of 100-500 cP depending on the temperature, which paves the way for assessing RBC membrane properties in clinical applications as predictors of blood microrheological abnormalities.

Blood hyperviscosity in acute and recent COVID-19 infection

BACKGROUND

Elevated estimated blood viscosity (EBV), derived from hematocrit and globulins, is associated with thrombotic complications, organ failure, and higher mortality in COVID-19 patients. Although informative, EBV does not account for cellular interactions or fibrinogen.

OBJECTIVE

Investigate whether patients with acute and recent COVID-19 have altered whole blood viscosity (WBV) when measured at both high and low shear rates using in vitro blood samples from patients.

METHODS

Cross-sectional study of 58 patients: 15 in the intensive care unit with acute COVID-19, 32 convalescent (9 < 8weeks [W] from acute infection, 23 > 8 W), and 11 controls without COVID-19. WBV was measured at high (300 s-1) and low (5 s-1) shear rates (HSR, LSR) using a scanning capillary viscometer.RESULTSAcute and convalescent patients < 8 W had mean WBV at LSR (16.0 centipoise [cP] and 15.1 cP) and HSR (5.1 cP and 4.7 cP). Mean WBV of convalescent > 8 W and control patients were 12.3 cP and 13.0 cP at LSR, and 4.1 cP and 4.2 cP at HSR. Acute and < 8 W patients had significantly higher WBV at both HSR and LSR compared to patients > 8 W (all p≤0.01). No significant differences in WBV were observed between acute and < 8 W patients, or between patients > 8 W and controls.

CONCLUSIONS

Hyperviscosity provides a possible explanation for thrombotic risk in acute and convalescent (< 8 W) patients. These findings have important implications for thromboprophylaxis.

Skin microcirculation reactivity to local thermal hyperaemia in patients with COVID-19 - A pilot observational study

BACKGROUND

Endothelial dysfunction and microvascular disturbances are suggested to play a key role in higher morbidity and worse prognosis in patients with COVID-19 and cardiometabolic diseases.

OBJECTIVE

Study was aimed to establish relationships between the skin microcirculation parameters and various clinical and laboratory indicators.

METHODS

The study included 18 patients with moderate disease according to WHO criteria. Skin microcirculation measurements were performed by laser Doppler flowmetry using a heating test on the hairy skin of the right forearm.

RESULTS

Baseline perfusion only correlated with C-reactive protein (Rs = 0.5, p = 0.034). Microcirculation indices characterising the development of hyperaemia during the first minute of heating (LTH1 and AUC60) showed significant correlations (Rs from 0.48 to 0.67, p < 0.05) with indices of general blood analysis and blood coagulation (fibrinogen, D-dimer, haemoglobin, erythrocyte count and haematocrit). Indexes characterising the dynamics of hyperaemia development over longer time intervals showed correlation with the glomerular filtration rate (Rs = 0.6, p = 0.009).

CONCLUSION

Known COVID-19 risk factors (haemorheological parameters, age) are correlated with the microvascular reactivity to heating in patients with COVID 19. We suggest that, prospectively, the method of laser Doppler flowmetry could be used for non-invasive instrumental assessment of microcirculatory disorders in patients with COVID-19.

Abdominal Imaging Findings in Patients with COVID-19 Part 2: Solid Organs

Since severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) first appeared in China in December 2019, the globe has been dealing with an ever-increasing incidence of coronavirus disease 2019 (COVID-19). In addition to respiratory disorders, 40% of patients present with gastrointestinal (GI) involvement. Abdominal pain is the most common indication for computed tomography (CT) and ultrasonography. After GI tract involvement, solid visceral organ infarction is the most prevalent abdominal abnormality in COVID-19. This review aims to gather the available data in the literature about imaging features of solid abdominal organs in patients with COVID-19. Gallbladder wall thickening and distension, cholelithiasis, hyperdense biliary sludge, acalculous cholecystitis, periportal edema, heterogeneous liver enhancement, and liver hypodensity and infarction are among hepatobiliary imaging findings in CT, particularly in patients admitted to ICU. Pancreatic involvement can develop as a result of direct SARS-CoV2 invasion with signs of acute pancreatitis in abdominal CT, such as edema and inflammation of the pancreas. Infarction was the most prevalent renal and splenic involvement in patients with COVID-19 who underwent abdominal CT presenting with areas of parenchymal hypodensity. In conclusion, although solid abdominal organs are rarely affected by COVID-19, clinicians must be familiar with the manifestations since they are associated with the disease severity and poor outcome.

Findings of Abdominal Imaging in Patients with COVID-19 - Part 1: Hollow Organs

Since COVID-19 has spread worldwide, the role of imaging for early detection of the disease has become more prominent. Abdominal symptoms in COVID-19 are common in addition to respiratory manifestations. This review collected the available data about abdominal computed tomography (CT) and ultrasonography indications in hollow abdominal organs in patients with COVID-19 and their findings. Since abdominal imaging is less frequently used in COVID-19, there is limited information about the gastrointestinal findings. The most common indications for abdominal CT in patients with COVID-19 were abdominal pain and sepsis. Bowel wall thickening and fluid-filled colon were the most common findings in abdominal imaging. Acute mesenteric ischemia (AMI) was one of the COVID-19 presentations secondary to coagulation dysfunction. AMI manifests with sudden abdominal pain associated with high morbidity and mortality in admitted patients; therefore, CT angiography should be considered for early diagnosis of AMI. Ultrasonography is a practical modality because of its availability, safety, rapidity, and ability to be used at the bedside. Clinicians and radiologists should be alert to indications and findings of abdominal imaging modalities in COVID-19 to diagnose the disease and its potentially serious complications promptly.

ADAMTS13 factor deficiency in severe COVID-19 may not be immune mediated-report from a pilot study

BACKGROUND

The assessment of ADAMTS13 factor activity and inhibitor levels was conducted in severe COVID-19 patients as an observational study.

RESULTS

A total of 14 patients were included and the average ADAMTS13 activity level at the time of admission was 28.54±30.74% (range 1.83-86.67%) which was reduced compared to controls (88.09±14.77). Nine patients had reduced ADAMTS13 factor activity (<40%) and 77.7% among them had severe deficiency (<10% activity). ADAMTS13 inhibitor was positive (>15 IU/mL) only in two patients and an overall mean value was 8.15±5.8. Elevated D-Dimer and length of hospital stay had significant correlation with ADAMTS13 activity (-0.247 and 0.306 respectively). No features of thrombotic microangiopathy were observed and hence no plasma exchange was performed.

CONCLUSION

Reduced ADAMTS13 factor activity without inhibitor development may give a clue to the disease progress in COVID19.

Impaired fibrinolysis in severe Covid-19 infection is detectable in early stages of the disease

BACKGROUND

A significant degree of mortality and morbidity in Covid-19 is due to thromboembolic disease. Coagulopathy has been well described in critically unwell patients on ICU. There is less clear evidence regarding these changes at the time of presentation to the Emergency Department and the progression of disease over time.

OBJECTIVE

We sought to investigate whether coagulation markers can predict severity and how they change over the disease course.

METHODS

Patients presenting to a single University Teaching Hospital were recruited and followed up if PCR was positive. Alongside routine blood testing, Rotational Thromboelastometry (ROTEM) was performed. Outcome data was recorded for all patients, and ROTEM values were compared across outcome groups.

RESULTS

Extem and Intem Maximum Lysis were significantly reduced in those who died or required an ICU admission, indicating a reduced ability to break down clot mass in the most critically unwell patients.

CONCLUSION

Comparisons between groups demonstrated that one distinguishing feature between those who require ICU admission or die of Covid-19 compared with those who survive a hospital stay to discharge was the extent to which fibrinolysis could occur. Mortality and morbidity in Covid-19 infection appears in part driven by an inability to break down clot mass.

Association of serum homocysteine and folic acid levels with coagulation functions of cancer patients with venous thromboembolism

Venous thromboembolism (VTE) is a common coagulative dysfunctional complication of cancer patients. The present study aimed to determine the association and diagnostic values of serum homocysteine (Hcy) and folic acid levels with VTE in cancer patients. We enrolled 700 cancer patients and 100 healthy subjects in our study. All cancer patients, with or without VTE, underwent measurement of serum Hcy and folic acid levels and coagulative markers including D-Dimer, factor VIII, fibrinogen and tissue plasminogen activator. The diagnostic values of Hcy and folic acid were assessed by receiver operative characteristic (ROC) analysis. Correlations between Hcy and folic acid and coagulative factors were determined. Among the 700 patients with malignant tumors recruited in our study, a total of 89 patients had VTE combined within three months, and 611 patients did not have VTE. Cancer patients with VTE had significantly higher levels of Hcy and significantly lower levels of folic acid in serum. Both Hcy and folic acid in serum demonstrated high sensitivity and specificity in diagnosing VTE in cancer patients and showed strong correlations to coagulative markers. Hcy and folic acid, which have strong correlations to coagulative markers, are potential novel serum markers for stratifying VTE risk in cancer patients.

The value of contrast-enhanced ultrasound in the diagnosis of BI-RADS-US 4a lesions less than 2 cm in diameter

BACKGROUND: Breast cancer is the most common malignant tumor in women. Early diagnosis of benign and malignant breast tumors is of great significance. OBJECTIVE: To retrospectively analyze the value of contrast-enhanced ultrasonography (CEUS) in the diagnosis of Breast Imaging-Reporting and Data System (BI-RADS) 4a breast lesions less than 2 cm in diameter. METHODS: CEUS was performed for 143 breast masses less than 2 cm in diameter that were diagnosed as BI-RADS 4a by ultrasound and reclassified. Considering pathological diagnosis as the gold standard, the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of reclassified lesions after CEUS for the diagnosis of benign and malignant masses were analyzed. RESULTS: BI-RADS 4a breast masses with a diameter less than 2 cm (n = 143) were confirmed by pathology; 103 and 40 were classified as benign and malignant, respectively. The sensitivity, specificity, PPV, and NPV of CEUS for the diagnosis were 90%, 86%, 72%, and 95%, respectively. The area under the receiver operating characteristic (ROC) curve of CEUS for the diagnosis of benign and malignant tumors after CEUS was 0.904. CONCLUSION: CEUS can help to improve the diagnostic accuracy of BI-RADS 4a masses with a diameter less than 2 cm.

Endothelial glycocalyx damage in patients with severe COVID-19 on mechanical ventilation - a prospective observational pilot study

BACKGROUND

Coronavirus disease (COVID-19) associated endotheliopathy and microvascular dysfunction are of concern.

OBJECTIVE

The objective of the present single-center observational pilot study was to compare endothelial glycocalyx (EG) damage and endotheliopathy in patients with severe COVID-19 (COVID-19 group) with patients with bacterial pneumonia with septic shock (non-COVID group).

METHODS

Biomarkers of EG damage (syndecan-1), endothelial cells (EC) damage (thrombomodulin), and activation (P-selectin) were measured in blood on three consecutive days from admission to the intensive care unit (ICU). The sublingual microcirculation was studied by Side-stream Dark Field (SDF) imaging with automatic assessment.

RESULTS

We enrolled 13 patients in the non-COVID group (mean age 70 years, 6 women), and 15 in the COVID-19 group (64 years old, 3 women). The plasma concentrations of syndecan-1 were significantly higher in the COVID-19 group during all three days. Differences regarding other biomarkers were not statistically significant. The assessment of the sublingual microcirculation showed improvement on Day 2 in the COVID-19 group. Plasma levels of C-reactive protein (CRP) were significantly higher on the first two days in the COVID-19 group. Plasma syndecan-1 and CRP were higher in patients suffering from severe COVID-19 pneumonia compared to bacterial pneumonia patients.

CONCLUSIONS

These findings support the role of EG injury in the microvascular dysfunction in COVID-19 patients who require ICU.

Vascular endotheliitis associated with infections: Its pathogenetic role and therapeutic implication

Vascular endothelial cells are major participants in and regulators of immune responses and inflammation. Vascular endotheliitis is regarded as a host immune-inflammatory response of the endothelium forming the inner surface of blood vessels in association with a direct consequence of infectious pathogen invasion. Vascular endotheliitis and consequent endothelial dysfunction can be a principle determinant of microvascular failure, which would favor impaired perfusion, tissue hypoxia, and subsequent organ failure. Emerging evidence suggests the role of vascular endotheliitis in the pathogenesis of coronavirus disease 2019 (COVID-19) and its related complications. Thus, once initiated, vascular endotheliitis and resultant cytokine storm cause systemic hyperinflammation and a thrombotic phenomenon in COVID-19, leading to acute respiratory distress syndrome and widespread organ damage. Vascular endotheliitis also appears to be a contributory factor to vasculopathy and coagulopathy in sepsis that is defined as life-threatening organ dysfunction due to a dysregulated response of the host to infection. Therefore, protecting endothelial cells and reversing vascular endotheliitis may be a leading therapeutic goal for these diseases associated with vascular endotheliitis. In this review, we outline the etiological and pathogenic importance of vascular endotheliitis in infection-related inflammatory diseases, including COVID-19, and possible mechanisms leading to vascular endotheliitis. We also discuss pharmacological agents which may be now considered as potential endotheliitis-based treatment modalities for those diseases.

Contrast enhanced ultrasonography (CEUS) a novel tool to detect intestinal epithelial barrier dysfunction in severe COVID-19 disease

Ten patients with confirmed COVID-19 disease were studied. Nine patients required intensive care treatment, among them four needed extracorporeal membrane oxygenation (ECMO). Contrast enhanced ultrasonography (CEUS) was performed by one experienced investigator as a bolus injection of up to 2.4 ml of sulphur hexafluoride microbubbles via a central venous catheter. B-Mode evaluation and strain elastography showed mural edema of the small bowel with a thickness of up to 10 mm in all patients. We applied color coded Doppler sonography (CCDS) and power mode with flow-adapted parameters and early, dynamic capillary arterial contrast enhancement of bowel wall structures <10 s to assess perfusion of the small bowel. In all patients, reactive hyperemia was seen in the entire small bowel. In a subgroup of seven patients microbubbles translocated into the intestinal lumen. Thus, high-grade intestinal barrier disruption secondary to SARSCoV-2 infection can be postulated in these patients. This is the first description of perfusion changes and a disruption of the small bowel epithelial barrier in COVID-19 Patients using contrast ultrasonography and elastography.

Advanced respiratory monitoring in mechanically ventilated patients with coronavirus disease 2019-associated acute respiratory distress syndrome

PURPOSE OF REVIEW

To summarize the current knowledge about the application of advanced monitoring techniques in coronavirus disease 2019 (COVID-19).

RECENT FINDINGS

Due to the heterogeneity between patients, management of COVID-19 requires daily monitoring of and/or aeration and inspiratory effort. Electrical impedance tomography can be used to optimize positive end-expiratory pressure, monitor the response to changes in treatment or body position and assess pulmonary perfusion and ventilation/perfusion matching. Lung ultrasound is more readily available and can be used to measure and monitor recruitment, provide an indication of diaphragm function and pulmonary perfusion disturbances. Esophageal pressure measurements enable the calculation of the transpulmonary pressure and inspiratory effort in order to prevent excessive stress on the lung. While esophageal pressure measurements are the golden standard in determining inspiratory effort, alternatives like P0.1, negative pressure swing during a single airway occlusion and change in central venous pressure are more readily available and capable of diagnosing extreme inspiratory efforts.

SUMMARY

Although there is little data on the effectiveness of advanced monitoring techniques in COVID-19, regular monitoring should be a central part of the management of COVID-19-related acute respiratory distress syndrome (C-ARDS).

The Value of Contrast-Enhanced Ultrasound (CEUS) in the Detection of Perfusion Disturbances in Abdominal Wall Hernias Compared with Surgical and Histological Assessment

Purpose: This study aimed to evaluate the value of contrast-enhanced ultrasound (CEUS) in the evaluation of perfusion disturbance in irreducible abdominal wall hernias (AWHs). Methods: From 2006 to 2018, 50 patients with an irreducible AWH were examined using B-mode ultrasound (B-US) and CEUS. The ultrasound findings were correlated with subsequent surgical and histological results. The presence of non-enhanced areas (NEAs) in hernia contents on CEUS and the presence of non-perfused areas (NPAs) on surgical and histological evaluation were analyzed retrospectively. Results: On CEUS, 13/50 hernia contents (26.0%) revealed NEAs during complete CEUS examination and 37/50 (74.0%) revealed no NEAs during CEUS examination. On surgical and histological evaluation, NPAs in hernia contents were identified in 11/13 cases (93.3%) with NEAs on CEUS. CEUS was found to have a sensitivity of 100.0%, a specificity of 94.9%, a positive predictive value of 84.6%, and a negative predictive value of 100.0% for the identification of perfusion disturbance in AWHs. Conclusions: The findings of this study demonstrate that using CEUS as an imaging method may be helpful for evaluating the perfusion of hernia contents in incarcerated AWHs. On CEUS, the presence of NEAs may suggest perfusion disturbance in hernia contents.

Application of dynamic contrast enhanced ultrasound in distinguishing focal-type autoimmune pancreatitis from pancreatic ductal adenocarcinoma

OBJECTIVE

To explore the value of dynamic contrast enhanced ultrasound (DCE-US) in preoperative differential diagnosis of focal-type autoimmune pancreatitis (AIP) and pancreatic ductal adenocarcinoma (PDAC).

PATIENTS AND METHODS

From May 2016 to March 2020, patients with biopsy and histopathologically confirmed focal-type AIP (n = 9) were retrospectively included. All patients received contrast enhanced ultrasound (CEUS) examinations one week before surgery/biopsy. Dynamic analysis was performed by VueBox® software (Bracco, Italy). Eighteen cases of resection and histopathologically proved PDAC lesions were also included as control group. B mode ultrasound (BMUS) features, CEUS enhancement patterns, time intensity curves (TICs) and CEUS quantitative parameters were obtained and compared between AIP and PDAC lesions.

RESULTS

After injection of ultrasound contrast agents, most focal-type AIP lesions displayed hyper-enhancement (2/9, 22.2%) or iso-enhancement (6/9, 66.7%) during arterial phase of CEUS, while most of PDAC lesions showed hypo-enhancement (88.9%) (P < 0.01). During late phase, most of AIP lesions showed iso-enhancement (8/9, 88.9%), while most of PDAC lesions showed hypo-enhancement (94.4%) (P < 0.001). Compared with PDAC lesions, TICs of AIP lesions showed delayed and higher enhancement. Among all CEUS perfusion parameters, ratio of PE (peak enhancement), WiAUC (wash-in area under the curve), WiR (wash-in rate), WiPI (wash-in perfusion index, WiPI = WiAUC/ rise time), WoAUC (wash-out area under the curve), WiWoAUC (wash-in and wash-out area under the curve) and WoR (wash-out rate) between pancreatic lesion and surrounding normal pancreatic tissue were significantly higher in AIP lesions than PDAC lesions (P < 0.05).

CONCLUSION

DCE-US with quantitative analysis has the potential to make preoperative differential diagnosis between focal-type AIP and PDAC non-invasively.

Perfusion Patterns of Peripheral Pulmonary Lesions in COVID-19 Patients Using Contrast-Enhanced Ultrasound (CEUS): A Case Series

PURPOSE

To describe perfusion patterns of peripheral pulmonary lesions (PPLs) in COVID-19 patients using contrast-enhanced ultrasound (CEUS).

PATIENTS AND METHODS

From April 2020 until July 2020, 11 consecutive patients with RT-PCR-confirmed COVID-19 and PPLs sized over 5 mm were investigated by B-mode ultrasound (B-US) and CEUS. The homogeneity of enhancement (homogeneous and inhomogeneous) was examined retrospectively using CEUS. An inhomogeneous enhancement was defined as a perfused lesion with coexisting non-perfused areas (NPA).

RESULTS

On B-US, all 11 patients showed an interstitial syndrome (B-lines) with PPLs between 0.5 and 6 cm. On CEUS, all cases showed peripheral NPA during the complete CEUS examination. One patient underwent a partial lung resection with subsequent histopathological examination. The histological examination showed vasculitis, microthrombus in the alveolar capillary, and small obliterated vessels.

CONCLUSION

In our case series, PPLs in patients with RT-PCR-confirmed COVID-19 infection presented a CEUS pattern with NPA during the complete CEUS examination. Our findings suggest a peripheral pulmonary perfusion disturbance in patients with COVID-19 infection. In 1 case, the histopathological correlation with the perfusion disturbance in the PPL was proven.

Is SARS-CoV-2 infection an emerging risk factor for splanchnic venous thrombosis?

OBJECTIVE

Thrombosis represents one of the most feared complications of the COronaVIrus Disease-2019 (COVID-19). Although pulmonary embolism and deep venous thrombosis are the most described complications, some investigations reported thrombotic localization also in the splanchnic venous district.

METHODS

We describe the case of a patient with SARS-CoV-2 infection presenting with abdominal pain and diagnosed with portal vein thrombosis. In addition, we shortly review available literature supporting the possible role of COVID-19 as leading cause of splanchnic venous thrombosis.

RESULTS

After in-depth diagnostic workup, we excluded the commonest causes of portal thrombosis and concluded that SARS-CoV-2 infection represented the main explanation of this finding.

CONCLUSIONS

Our study warns the clinicians to maintain a high index of suspicion for thrombosis in patients diagnosed with SARS-CoV-2 infection manifesting gastrointestinal symptoms. An appropriate diagnostic work-up could allow to obtain an early diagnosis and consequently improve the clinical outcome of patients.

Resveratrol as an Adjunctive Therapy for Excessive Oxidative Stress in Aging COVID-19 Patients

The coronavirus disease 2019 (COVID-19) pandemic continues to burden healthcare systems worldwide. COVID-19 symptoms are highly heterogeneous, and the patient may be asymptomatic or may present with mild to severe or fatal symptoms. Factors, such as age, sex, and comorbidities, are key determinants of illness severity and progression. Aging is accompanied by multiple deficiencies in interferon production by dendritic cells or macrophages in response to viral infections, resulting in dysregulation of inflammatory immune responses and excess oxidative stress. Age-related dysregulation of immune function may cause a more obvious pathophysiological response to SARS-CoV-2 infection in elderly patients and may accelerate the risk of biological aging, even after recovery. For more favorable treatment outcomes, inhibiting viral replication and dampening inflammatory and oxidative responses before induction of an overt cytokine storm is crucial. Resveratrol is a potent antioxidant with antiviral activity. Herein, we describe the reasons for impaired interferon production, owing to aging, and the impact of aging on innate and adaptive immune responses to infection, which leads to inflammation distress and immunosuppression, thereby causing fulminant disease. Additionally, the molecular mechanism by which resveratrol could reverse a state of excessive basal inflammatory and oxidative stress and low antiviral immunity is discussed.

Early evaluation of organ failure using MELD-XI in critically ill elderly COVID-19 patients

PURPOSECritically ill elderly patients who suffer from Sars-CoV-2 disease are at high risk for organ failure. The modified MELD-XI score has not been evaluated for outcome prediction in these most vulnerable patients.METHODSThe Corona Virus disease (COVID19) in Very Elderly Intensive Care Patients study (COVIP, NCT04321265) prospectively recruited patients on intensive care units (ICU), who were = 70 years. Data were collected from March 2020 to February 2021. The MELD-XI score was calculated using the highest serum bilirubin and creatinine on ICU admission. Univariate and multivariable logistic regression analyses were performed to assess associations between the MELD-XI score and mortality. The primary outcome was 30-day-mortality, the secondary outcomes were ICU- and 3-month-mortality.RESULTSIn total, data from 2,993 patients were analyzed. Most patients had a MELD-XI <12 on admission (76%). The patients with MELD-XI = 12 had a significantly higher 30-day-, ICU- and 3-month-mortality (44%vs 64%, and 42%vs. 59%, and 57%vs. 76%, p < 0.001). After adjustment for multiple confounders, MELD-XI = 12 remained significantly associated with 30-day- (aOR 1.572, CI 1.268-1.949, p < 0.001), ICU-, and 3-month-mortality.CONCLUSIONIn critically ill elderly intensive care patients with COVID-19, the MELD-XI score constitutes a valuable tool for an early outcome prediction.

Contrast-enhanced ultrasound perfusion imaging of organs

In multimodal radiologic imaging, contrast-enhanced ultrasound (CEUS) is increasingly used. One of the advantages of CEUS is the possibility of repeated application of contrast media without decreasing renal function or affecting the thyroid gland. Small solid liver lesions can be diagnosed and detected with high accuracy. Moreover, solid lesions in other abdominal organs can also be characterized. Frequent applications for solid lesions in the near field concern thyroid tumors and lymph nodes. For prostate diagnostics, CEUS can be used with an endorectal probe and perfusion imaging. This review explains how the additional (semi-)quantitative perfusion analysis, especially time-intensity curve (TIC) analyses, and wash-in/wash-out kinetics of integrated or external perfusion software programs facilitate new options in dynamic assessment of microvascularization during tumor follow-up care and even minimally invasive tumor therapy.

High resolution flow (HR Flow) and glazing flow in cases of hepatic flow changes: Comparison to color-coded Doppler sonography (CCDS)

AIM

To evaluate the possibilities of flow detection using high resolution flow (HR Flow) and Glazing Flow technique in patients with liver parenchymal changes and flow changes in comparison to colour coded Doppler sonography (CCDS).

MATERIAL AND METHODS

All examinations were performed using a multi frequency matrix convex probe with high resolution technique (SC6-1U/Resona7, Mindray, Shenzhen, China) by one experienced examiner to evaluate the venous, portal venous and arterial liver flow with digital documentation of the dynamic flow parameters like peak systolic flow, end-diastolic flow and resistance index. For liver parenchymal stiffness changes shear wave elastography was performed with at least 10 measurements. By two independent readers an elevation was performed to evaluate the image quality and the degree of flow artefacts, from 0 = not available to 5 points with excellent image quality without flow artefacts.

RESULTS

All 40 patients (24 men, 16 women, age 27-83 years, mean 56±5 years) showed morphology changes from B-Mode of the liver parenchyma to inhomogeneous tissue with higher stiffness evaluated by the shear wave elastography (1.45 m/s up to 2.79 m/s±1.79 m/s, considering F1 up to F4 fibrosis) and in 15 cases histopathologically proven liver cirrhosis. In 9 cases after non-acute thrombosis flow reduction of the portal vein was the reason for the diameter less than 5 mm. Flow parameters for the venous flow were between 8 cm/s up to 29 cm/s, mean 14±4 cm/s, for the hepatic portal vein 5 cm/s up to 57 cm/s, mean 17±5 cm/s, for the hepatic artery systolic flow between 50 cm/s up to 127±33 cm/s, end-diastolic flow from 22 cm/s up to 47 cm/s±8 cm/s. Resistance index for the hepatic artery was between 0.41 up to 0.73, mean 0.67±0.25. The image quality for CCDS over all cases was evaluated for CCDS between 1 up to 4. The mean quality was 2.5±0.5, for HR Flow in combination with Glazing flow 3±0.5, with significant differences for the 2 readers (P <  0.01).

CONCLUSION

Combination of HR Flow with Glazing Flow could be helpful to evaluate morphological und hemodynamic changes of liver arterial flow, portal venous and venous flow. Reduction of flow artefacts in combination with a higher image quality could be helpful for optimizing the digital measurements also for follow up examinations.

Abdominal imaging in COVID-19

Initially thought of as a respiratory infection, coronavirus disease-2019 (COVID-19) is now recognized as a complex disease with a wide clinical spectrum, including digestive involvement. While several studies have evaluated chest imaging findings in COVID-19, few papers have looked at the abdominal imaging features of these patients. Liver, biliary, pancreas and bowel involvement have been reported in COVID-19 infected patients. In this review, we aim to summarize currently available data related to abdominal imaging techniques in COVID-19, in accordance with relevant clinical and laboratory workup of these patients. Underlying mechanisms, indications and imaging findings related to COVID-19 are discussed based on published data. Also, practice points for clinicians are highlighted in order to adequately recognize digestive-related injuries of severe acute respiratory syndrome coronavirus 2 infection. While there’s been a steady accumulation of data with respect to abdominal imaging findings in COVID-19, currently available recommendations are based on limited research. There is a wide spectrum of abdominal imaging findings in COVID-19, which includes hepato-biliary, pancreatic and luminal pathology.

Acute mesenteric ischemia and small bowel imaging findings in COVID-19: A comprehensive review of the literature

BACKGROUND

Coronavirus disease 2019 (COVID-19), an infectious condition caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has rapidly spread worldwide since its first description in Wuhan in December 2019. Even though respiratory manifestations are the most prevalent and responsible for disease morbidity and mortality, extrapulmonary involvement has progressively gained relevance. In particular, gastrointestinal (GI) signs and symptoms, reported in up to two-thirds of patients with COVID-19, might represent the first and, in some cases, the only disease presentation. Their presence has been associated in some studies with an increased risk of a severe disease course. Proposed pathogenic mechanisms explaining GI tract involvement are either direct viral access to intestinal cells via angiotensin-converting enzyme 2 or indirect damage of the intestinal wall through mesenteric ischemia induced by the hypercoagulable state associated with COVID-19 infection. Although not typical of SARS-CoV-2 infection, several small bowel manifestations have been described in infected patients who underwent any form of abdominal imaging. The radiological findings were mainly reported in patients with abdominal symptoms, among which abdominal pain was the most common.

AIM

To discuss small bowel radiological manifestations of SARS-CoV-2 infection in abdominal imaging studies.

METHODS

Bibliographical searches were performed in PubMed, using the following keywords: “COVID-19” AND “imaging” AND “gastrointestinal” OR “abdominal” OR “small bowel”.

RESULTS

Of 62 patients with described radiologic small bowel alterations, mesenteric ischemia was diagnosed in 31 cases (50%), small bowel wall thickening in 10 cases (16%), pneumatosis in nine cases (15%), intussusception in eight cases (13%), pneumoperitoneum in two cases (3%) and paralytic ileus in two cases (3%). We also reported mesenteric adipose tissue hypertrophy and lymph nodes enlargement in a young woman.

CONCLUSION

So far it is difficult to establish whether these manifestations are the direct consequence of SARS-CoV-2 infection or collateral findings in infected patients, but their recognition would be pivotal to set a closer follow-up and to reduce missed diagnoses.

Can erythrocytes behavior in microcirculation help the understanding the physiopathology and improve prevention and treatment for covid-19?

Low plasma estrogens, vitamin D deficiency, obesity, diabetes, cardiovascular diseases, thromboembolism, and impaired microcirculation are linked to the severity of covid-19. Studies have suggested that these comorbidities also are related to erythrocyte factors linked to increased blood viscosity in microcirculation such as erythrocyte aggregation and erythrocyte deformability. Increased blood viscosity in microcirculation can lead to a decrease in oxygenation and nutrition of tissues. Therefore erythrocyte aggregation and erythrocyte deformability may be involved in covid-19 severity, leading to tissue hypoxia and a decrease of drug concentration in affected organs. If this relationship is demonstrated, erythrocytes factors can be used to monitor treatments for improve microcirculatory fluidity that may decrease covid-19 severity. Lifestyle improvement and treatments such as vitamin D and estrogens supplementation are some possible approaches to improve microcirculation and covid-19 prevention and treatment.

Contrast-enhanced ultrasound (CEUS) and perfusion imaging using VueBox®

The external perfusion software (VueBox™) for contrast-enhanced ultrasound (CEUS), enables the quantitative analysis of micro-vascularization within non-cystic lesions in terms of characterization and detection. This review summarizes our work about parathyroid gland, thyroid gland, liver, prostate and other tissues as well as original studies in the use of parametric perfusion imaging. Useful perfusion parameters are introduced.

COVID-19 and Delayed Cerebral Ischemia-More in Common Than First Meets the Eye

Since the arrival of the global COVID-19 pandemic scientists around the world have been working to understand the pathological mechanisms resulting from infection. There has gradually been an understanding that COVID-19 triggers a widespread endotheliopathy and that this can result in a widespread thrombosis and in particular a microthrombosis. The mechanisms involved in the microthrombosis are not confined to infection and there is evidence that patients with aneurysmal sub-arachnoid haemorrhage (SAH) also suffer from an endotheliopathy and microthrombosis. In this article we attempt to shed light on similarities in the underlying processes involved in both diseases and suggest potential treatment options.

Role of contrast-enhanced ultrasound guidance in core-needle biopsy for diagnosis of cervical tuberculous lymphadenitis

OBJECTIVE

To investigate the diagnostic value of core-needle biopsy (CNB) guided by contrast-enhanced ultrasound (CEUS) in cervical tuberculous lymphadenitis (CTL).

METHODS

178 patients with pathological confirmation of CTL were retrospectively enrolled. All of them had undergone CNB prior to the final surgery. According to the different ways of puncture guidance, they were divided into two groups: conventional ultrasound (US) group (n = 81) and CEUS group (n = 97). The comparison of diagnostic efficacy between two groups was compared and analyzed.

RESULTS

Among the 178 patients, 146 were directly diagnosed as CTL by CNB, including 59 patients in CEUS group and 87 patients in US group. The diagnostic accuracy were 89.7% (87/97) and 72.8% (59/81), respectively (P < 0.01). For subgroup analyses, differences among diagnostic efficacy ascribed to the different guiding methods were significant in medium size group (>2.0 cm and ≤3.0 cm) and large size group (>3.0 cm), 91.7% for CEUS group vs. 69.0% for US group (P < 0.05) and 84.4% for CEUS group vs. 57.7% for US group (P < 0.05), respectively.

CONCLUSIONS

In the diagnosis of CTL, compared with the US-guided CNB, CEUS-guided CNB have certain advantages, especially for larger lymph nodes.

Interstitial lung opacities in patients with severe COVID-19 pneumonia by bedside high-resolution ultrasound in association to CO2 retention

BACKGROUND

Coronavirus disease 2019 (COVID-19) can cause acute respiratory distress syndrome (ARDS).

OBJECTIVE

This single centre cross-section study aimed to grade the severity of pneumonia by bed-side lung ultrasound (LUS).

METHODS

A scoring system discriminates 5 levels of lung opacities: A-lines (0 points),≥3 B-line (1 point), coalescent B-lines (2 points), marked pleural disruptions (3 points), consolidations (4 points). LUS (convex 1-5 MHz probe) was performed at 6 defined regions for each hemithorax either in supine or prone position. A lung aeration score (LAS, maximum 4 points) was allocated for each patient by calculating the arithmetic mean of the examined lung areas. Score levels were correlated with ventilation parameters and laboratory markers.

RESULTS

LAS of 20 patients with ARDS reached from 2.58 to 3.83 and was highest in the lateral right lobe (Mean 3.67). Ferritin levels (Mean 1885μg/l; r = 0.467; p = 0.051) showed moderate correlation in spearman roh calculation. PaCO2 level (Mean 46.75 mmHg; r = 0.632; p = 0.005) correlated significantly with LAS, while duration of ventilation, Horovitz index, CRP, LDH and IL-6 did not.

CONCUSIONS

The proposed LAS describes severity of lung opacities in COVID-19 patients and correlates with CO2 retention in patients with ARDS.

Cerebrovascular comorbidity, high blood levels of C-reactive protein and D-dimer are associated with disease outcomes in COVID-19 patients

The emerging coronavirus disease (COVID-19) swept the world, affecting more than 200 countries and territories. As of August 22, 2020, the pandemic infected more than 23,329,752 including 807,054 patients who have died. Although the main clinical features of the pandemic disease are respiratory, cerebrovascular comorbidities emerged as one of the leading causes of death associated with COVID-19. Different case reports have indicated that C-reactive protein (CRP) and D-dimer (pro-inflammatory biomarkers) were elevated in COVID-19 patients, which can significantly increase the risk of ischemic stroke. Available data on cerebrovascular complications in COVID-19 patients were collected and a meta-analysis was designed and carried out to evaluate the risk of severity and mortality associated with high levels of CRP and D-dimer levels in COVID-19 patients. In addition, we aimed to describe the overall event rate of pre-existing cerebrovascular disease in COVID-19 patients. In our analysis, 5,614 cases have been studied, out of these patients 164 cases have developed cerebrovascular comorbities. Cerebrovascular comorbidity increased the risk of disease severity (odd ratio = 4.4; 95% CI: 1.48 to 12.84) and mortality (odd ratio = 7.0; 95% CI: 2.56 to 18.99). Statistical analyses showed that CRP and D-dimer serum levels were elevated by six-folds in the severe cases of COVID-19 patients. This significant increase in these two proteins levels can serve as a vital indicator for COVID-19 patients who are at increased risk of severe COVID-19 cerebrovascular complications, such as stroke.

Critically Ill COVID-19 Patients With Acute Kidney Injury Have Reduced Renal Blood Flow and Perfusion Despite Preserved Cardiac Function: A Case-Control Study Using Contrast-Enhanced Ultrasound

BACKGROUND

Acute kidney injury (AKI) is a common complication of COVID-19 critical illness but the pathophysiology is uncertain. Some evidence has indicated that a vascular aetiology may be implicated. We used contrast-enhanced ultrasound (CEUS) and echocardiography to study renal perfusion and global blood flow and compared our findings with measurements taken in a group of septic shock patients and healthy volunteers.

METHODS

Prospective case-control study. Renal perfusion variables were assessed with CEUS; macrovascular blood flow was assessed using Doppler analysis of large renal vessels; echocardiography was used to assess right and left heart function and cardiac output.

RESULTS

CEUS-derived parameters were reduced in COVID-19 associated AKI compared with healthy controls (perfusion index 3,415 vs. 548 a.u., P = 0·001; renal blood volume 7,794 vs. 3,338 a.u., P = 0·04). Renal arterial flow quantified using time averaged peak velocity was also reduced compared with healthy controls (36·6 cm/s vs. 20·9 cm/s, P = 0.004) despite cardiac index being similar between groups (2.8 L/min/m2 vs. 3.7 L/min/m2, P = 0.07). There were no differences in CEUS-derived or cardiac parameters between COVID-19 and septic shock patients but patients with septic shock had more heterogeneous perfusion variables.

CONCLUSION

Both large and small vessel blood flow is reduced in patients with COVID-19 associated AKI compared with healthy controls, which does not appear to be a consequence of right or left heart dysfunction. A reno-vascular pathogenesis of COVID-19 AKI seems likely.

Elevated fibrinogen and fibrin degradation product are associated with poor outcome in COVID-19 patients: A meta-analysis

INTRODUCTION

COVID-19 is a systemic infection with a significant impact on coagulation which manifests in thromboembolism. There is an unknown relationship of which coagulation profile parameter at presentation has an association with poor outcome in COVID-19.

OBJECTIVE

This meta-analysis aimed to determine the relationship between fibrinogen and FDP with poor outcome in COVID-19 patients.

METHODS

A systematic search of all observational studies or trials involving adult patients with COVID-19 that had any data fibrinogen or FDP on admission was carried out using the PubMed, Science Direct, Scopus, ProQuest, and MedRxiv databases. We assessed the methodological quality assessment using the NIH Quality Assessment Tool. We performed random-effects inverse-variance weighting analysis using mean difference (MD).

RESULTS

A total of 17 studies (1,654 patients) were included in this meta-analysis. It revealed a higher mean of fibrinogen levels on admission in patients with severe case compared to those with non-severe case (MD = 0.69, [95% CI: 0.44 to 0.94], p < 0.05; I2 = 72%, p < 0.05). Non-survivor group had a pooled higher mean difference of fibrinogen values on admission (MD = 0.48 [95% CI: 0.13 to 0.83], p < 0.05; I2 = 38%, p = 0.18). Higher FDP on admission was found in poor outcome (composite of severity, critically ill, and mortality) compared to good outcome (4 studies, MD = 4.84 [95% CI: 0.75 to 8.93], p < 0.05; I2 = 86%, p < 0.05).

CONCLUSION

Elevated fibrinogen and FDP level on admission were associated with an increase risk of poor outcome in COVID-19 patients.

Assessment of celiac artery compression using color-coded duplex sonography

BACKGROUND

Median arcuate ligament syndrome (MALS) is a rare condition due to compression of the celiac artery (CA) by an anatomically abnormal median arcuate ligament. With ultrasonography (US) as first-line diagnostic modality in patients with unclear abdominal pain, there is limited data on its diagnostic performance in MALS.

OBJECTIVE

To investigate the value of CA peak systolic velocity (PSV) in the workup of patients with suspected MALS.

METHODS

Patients with diagnosis of MALS between 2009 and 2019 were referred by Department of Visceral Surgery after clinical and gastroenterological workup. Diagnosis was confirmed by surgery or further cross-sectional imaging. B-mode US findings and PSV in the CA during various respiratory states were compared between patients with a final MALS diagnosis and patients not meeting the diagnostic criteria.

RESULTS

Patients with proven MALS (n = 10) had higher median CA PSV during normal inspiratory breath-hold (239 [IQR, 159-327] vs. 138 [IQR, 116-152] cm/s; p < #x003C;< #x200A;0.001), and expiratory breath-hold (287 [IQR, 191-412] vs. 133 [IQR, 115-194] cm/s; p < #x003C;< #x200A;0.001) compared to patients without MALS (n = 26). CA PSV in both inspiratory breath-hold (AUC 0.88, 95% CI 0.77-1.00) and expiratory breath-hold (AUC 0.89, 95% CI 0.78-1.00) was of diagnostic value for confirming MALS. The best diagnostic performance (100% sensitivity, 80% specificity) was found for the combination of CA PSVexpiration + 2.4 · PSVinspiration > 550 cm/s .

CONCLUSIONS

Since results on optimal cutoff values are inconsistent, a combination of CA PSVs during breathing maneuvers may help to diagnose or rule out MALS.

Application of dynamic contrast enhanced ultrasound in the assessment of kidney diseases

PURPOSE OF REVIEW

Many forms of acute and chronic disease are linked to changes in renal blood flow, perfusion, vascular density and hypoxia, but there are no readily available methods to assess these parameters in clinical practice. Dynamic contrast enhanced ultrasound (DCE-US) is a method that provides quantitative assessments of organ perfusion without ionising radiation or risk of nephrotoxicity. It can be performed at the bedside and is suitable for repeated measurements. The purpose of this review is to provide updates from recent publications on the utility of DCE-US in the diagnosis or assessment of renal disease, excluding the evaluation of benign or malignant renal masses.

RECENT FINDINGS

DCE-US has been applied in clinical studies of acute kidney injury (AKI), renal transplantation, chronic kidney disease (CKD), diabetic kidney disease and to determine acute effects of pharmacological agents on renal haemodynamics. DCE-US can detect changes in renal perfusion across these clinical scenarios and can differentiate healthy controls from those with CKD. In sepsis, reduced DCE-US measures of perfusion may indicate those at increased risk of developing AKI, but this requires confirmation in larger studies as there can be wide individual variation in perfusion measures in acutely unwell patients. Recent studies in transplantation have not provided robust evidence to show that DCE-US can differentiate between different causes of graft dysfunction, although it may show more promise as a prognostic indicator of graft function 1 year after transplant. DCE-US can detect acute haemodynamic changes in response to medication that correlate with changes in renal plasma flow as measured by para-aminohippurate clearance.

SUMMARY

DCE-US shows promise and has a number of advantages that make it suitable for the assessment of patients with various forms of kidney disease. However, further research is required to evidence its reproducibility and utility before clinical use can be advocated.

The novel iron chelator, DIBI, attenuates inflammation and improves outcome in colon ascendens stent peritonitis-induced experimental sepsis

BACKGROUND

Sepsis is the result of a dysregulated host immune response to an infection. An ideal therapy would target both the underlying infection and the dysregulated immune response. DIBI, a novel iron-binding polymer, was specifically developed as an antimicrobial agent and has also demonstrated in vivo anti-inflammatory properties.

OBJECTIVE

This study aimed to further investigate the effects of DIBI with and without the antibiotic imipenem (IMI) in colon ascendens stent peritonitis (CASP)-induced experimental sepsis.

METHODS

Vehicle, DIBI and/or IMI were administered in C57BL/6 mice after CASP surgery. Intestinal leukocyte activation and capillary perfusion was evaluated by intravital microscopy. Moreover, bacterial load in peritoneal lavage fluid and blood, and plasma cytokine levels were assessed. In a second series of experiments, surgery to repair the colon was performed at 5 hr and these mice were followed for long-term survival over 7 days.

RESULTS

DIBI reduced leukocyte adhesion, improved capillary blood flow, and decreased key plasma cytokines levels. DIBI also improved survival of infected mice and greatly improved IMI efficacy. Survivors treated with IMI and DIBI were found to be free of systemic infection.

CONCLUSIONS

DIBI has promising potential for sepsis treatment including its use as a sole or an adjunct therapeutic with antibiotics.

Contrast-enhanced ultrasound (CEUS) in the diagnostic evaluation of popliteal artery aneurysms, a single-center study

BACKGROUND

Popliteal artery aneurysms (PAA) are the most common peripheral artery aneurysms. Most common cause is arteriosclerosis. Acute thromboembolic limb ischemia and rupture of the PAA depict severe complications. Diagnostic tools for identifying PAAs are (Doppler) ultrasound, CT/MR angiography and DSA.

PURPOSE

The aim of the present retrospective single-center study is to assess the application and safety of CEUS for assessing untreated and treated PAAs.

MATERIALS AND METHODS

13 patients were included in this study on whom CEUS was performed between 2007-2016. CEUS examinations were performed and interpreted by an experienced single radiologist (EFSUMB Level 3).

RESULTS

CEUS allowed for the detection of PAAs in all cases. CEUS allowed for detection of partial thrombosis of PAA in 7/8 of untreated patients, proper exclusion of PAA upon femoro-popliteal bypass in 3 patients, incomplete exclusion of PAA upon femoro-popliteal bypass in 1 patient and ruling out of in-stent stenosis in 1 patient.

CONCLUSION

CEUS is a useful and safe tool for in real-time evaluation of PAAs in the pre-/post-treatment status. In addition to conventional (Doppler) ultrasound and as an alternative tool to more elaborate imaging modalities, CEUS might be integrated in the future diagnostic work-up and follow-up of PAA patients.

Herd immunity or suppression strategy to combat COVID-19

Some months ago, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) broke out in Wuhan, China, and spread rapidly around the world. Some states, such as the Netherlands, Germany, Great Britain, Sweden and the USA initially focused on keeping the restrictions for economy and society as low as possible. The responsible authorities were of the opinion - and still are e.g. in Sweden - that it is sufficient enough to protect particularly vulnerable persons such as the elderly or people with pre-existing conditions. The idea behind this is that as soon as 60 to 70 percent of the population is infected with a pathogen, a so-called “herd immunity” has developed. However, the increasing numbers of deaths and modelling studies showed the expected overload of the hospitals. Therefore, most countries decided for a temporary lockdown with the exception of Sweden.

Based on the number of the total population, three times more people died from COVID-19 in Sweden (2679 deaths per 10 million inhabitants) compared to Germany (6848 deaths per 80 million inhabitants). The comparison Sweden versus Taiwan is even worse because 1072 times more people died in Sweden based on the number of the population (6 deaths per 24 million inhabitants).

In the face of the lack of an antiviral treatment and the lack of a protective vaccine one must state Taiwan has made the best out of the pandemic situation whereas Sweden failed completely.

COVID-19 and the endothelium

There is growing evidence that COVID-19 not only affects the lungs but beyond that the endothelial system. Recent studies showed that this can lead to microcirculatory impairments and in consequence to functional disorders of all inner organs. The combination of endothelial dysfunction with a generalized inflammatory state and complement elements may together contribute to the overall pro-coagulative state described in COVID-19 patients leading to venular as well as to arteriolar occlusions.

The compelling arguments for the need of microvascular investigation in COVID-19 critical patients

The burden of pandemic COVID-19 is growing worldwide, as the continuous increases of contagion. Only 10–15% of the entire infected population has the necessity of intensive care unit (ICU) treatments. But, this relatively low rate of patients has absorbed almost the whole availability of ICU during few days, becoming at least in Italy, an emergency for the national health system. In COVID-19 ICU patients massive aggression of lung with severe pulmonary failure, as well as kidney and liver injuries, heart, brain, bowel and spleen damages with lymph nodes necrosis and even cutaneous manifestations have been observed. Moreover, increased levels of cytokines so-called “cytokines storm (CS), and overt intravascular disseminated coagulation have been also reported. The hypercoagulation and CS would speculate about a microvascular dysfunction. Unfortunately, no specific observations have been performed on microcirculatory dysfunction in COVID-19 patients. Hence the presumed pathophysiological pathways and models about a microvascular involvement can be gathered by sepsis models studies. But despite this lack of evidence, the COVID-19 has emphasized the compelling need for microcirculation monitoring at the bedside in ICU patients.