Project description:ObjectivesDuring severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, dramatic endothelial cell damage with pulmonary microvascular thrombosis have been was hypothesized to occur. The aim was to assess whether pulmonary vascular thrombosis (PVT) is due to recurrent thromboembolism from peripheral deep vein thrombosis or to local inflammatory endothelial damage, with a superimposed thrombotic late complication.DesignObservational study.SettingMedical and intensive care unit wards of a teaching hospital.ParticipantsThe authors report a subset of patients included in a prospective institutional study (CovidBiob study) with clinical suspicion of pulmonary vascular thromboembolism.InterventionsComputed tomography pulmonary angiography and evaluation of laboratory markers and coagulation profile.Measurements and main resultsTwenty-eight of 55 (50.9%) patients showed PVT, with a median time interval from symptom onset of 17.5 days. Simultaneous multiple PVTs were identified in 22 patients, with bilateral involvement in 16, mostly affecting segmental/subsegmental pulmonary artery branches (67.8% and 96.4%). Patients with PVT had significantly higher ground glass opacity areas (31.7% [22.9-41] v 17.8% [10.8-22.1], p < 0.001) compared with those without PVT. Remarkably, in all 28 patients, ground glass opacities areas and PVT had an almost perfect spatial overlap. D-dimer level at hospital admission was predictive of PVT.ConclusionsThe findings identified a specific radiologic pattern of coronavirus disease 2019 (COVID-19) pneumonia with a unique spatial distribution of PVT overlapping areas of ground-glass opacities. These findings supported the hypothesis of a pathogenetic relationship between COVID-19 lung inflammation and PVT and challenged the previous definition of pulmonary embolism associated with COVID-19 pneumonia.
Project description:BackgroundPulmonary manifestations of COVID-19 pneumonia are well known. However, COVID-19 is also associated with a range of vascular manifestations such as embolism, congestion, and perfusion changes. Regarding congestion, research from different groups has suggested arteriovenous anastomosis dysregulation as a contributing factor. In this study, we aim to better describe the changes in vascular volume in affected lung zones and to relate them to pathophysiological hypotheses.MethodsWe performed automatic vascular volume extraction in 10 chest CTs of patients, including 2 female and 8 male with a mean age of 63.5 ± 9.3 years, diagnosed with COVID-19 pneumonia. We compared the proportion of vascular volumes between manually segmented regions of lung parenchyma with and without signs of pneumonia.ResultsThe proportion of vascular volume was significantly higher in COVID (CVasc) compared to non-COVID (NCVasc) areas. We found a mean difference (DVasc) of 5% and a mean ratio (RVasc) of 3.7 between the two compartments (p < 0.01).ConclusionVascular volume in COVID-19 affected lung parenchyma is augmented relative to normal lung parenchyma, indicating venous congestion and supporting the hypothesis of pre-existing intra-pulmonary arteriovenous shunts.
Project description:Background and purposeStroke may complicate coronavirus disease 2019 (COVID-19) infection based on clinical hypercoagulability. We investigated whether transcranial Doppler ultrasound has utility for identifying microemboli and clinically relevant cerebral blood flow velocities (CBFVs) in COVID-19.MethodsWe performed transcranial Doppler for a consecutive series of patients with confirmed or suspected COVID-19 infection admitted to 2 intensive care units at a large academic center including evaluation for microembolic signals. Variables specific to hypercoagulability and blood flow including transthoracic echocardiography were analyzed as a part of routine care.ResultsTwenty-six patients were included in this analysis, 16 with confirmed COVID-19 infection. Of those, 2 had acute ischemic stroke secondary to large vessel occlusion. Ten non-COVID stroke patients were included for comparison. Two COVID-negative patients had severe acute respiratory distress syndrome and stroke due to large vessel occlusion. In patients with COVID-19, relatively low CBFVs were observed diffusely at median hospital day 4 (interquartile range, 3-9) despite low hematocrit (29.5% [25.7%-31.6%]); CBFVs in comparable COVID-negative stroke patients were significantly higher compared with COVID-positive stroke patients. Microembolic signals were not detected in any patient. Median left ventricular ejection fraction was 60% (interquartile range, 60%-65%). CBFVs were correlated with arterial oxygen content, and C-reactive protein (Spearman ρ=0.28 [P=0.04]; 0.58 [P<0.001], respectively) but not with left ventricular ejection fraction (ρ=-0.18; P=0.42).ConclusionsIn this cohort of critically ill patients with COVID-19 infection, we observed lower than expected CBFVs in setting of low arterial oxygen content and low hematocrit but not associated with suppression of cardiac output.
Project description:ObjectiveTo report six consecutive patients with confirmed coronavirus disease-2019 (COVID-19) who underwent Transcranial Doppler (TCD) ultrasonography evaluation for cerebral microemboli in the setting of suspected or confirmed acute ischemic stroke.MethodsPatient data were obtained from medical records from Northwestern Memorial Hospital, Chicago, IL between May and June 2020. All patients with confirmed COVID-19 who underwent clinical TCD ultrasonography for microemboli detection were included.ResultsA total of eight TCD studies were performed in six patients with COVID-19 (4 men and 2 women, median age 65±5), four with confirmed ischemic stroke and two with refractory encephalopathy. Microemboli were detected in three male patients, two patients had suffered a confirmed ischemic stroke and one who developed prolonged encephalopathy. Microemboli of varying intensity were identified in multiple vascular territories in two patients, and microemboli persisted despite therapeutic anticoagulation in a third patient. Of the three patients without evidence of microemboli on TCD ultrasonography, two patients had suffered a confirmed ischemic stroke, while one remained with refractory encephalopathy.ConclusionsTCD ultrasonography for microemboli detection identified three patients with confirmed COVID-19 with evidence of cerebral arterial microemboli, including one who was therapeutically anticoagulated. TCD ultrasonography provides a non-invasive method for evaluating cerebral microemboli in patients with COVID-19 and may be useful in assessing response to treatment in cases with suspected or confirmed disorders of hypercoagulability. Further studies investigating the prevalence of cerebral microemboli and associated risk factors are needed to characterize their pathogenic mechanism and guide therapeutic interventions in hospitalized COVID-19 patients.
Project description:Metatranscriptomic analysis identifies a state of pathogen dominance and suppressed pulmonary immune signaling in critically ill COVID-19 patients with secondary bacterial pneumonia.
Project description:BackgroundAlthough cerebral white matter lesions (WMLs) are considered as a risk factor for vascular dementia, data on their impact on cerebral hemodynamics are scarce. We test and compare transcranial Doppler (TCD) features in WML patients with or without associated cognitive impairment.MethodsA sample of non-demented elderly patients with WMLs was consecutively recruited. Mean blood flow velocity (MBFV), pulsatility index (PI), peak systolic blood flow velocity (PSV), end-diastolic blood flow velocity (EDV), and resistivity index (RI) were recorded from the middle cerebral artery bilaterally. Global cognitive functioning, frontal lobe abilities, functional status, and WML severity were also assessed.Results161 patients satisfying the clinical criteria for vascular cognitive impairment-no dementia (VCI-ND) were age-matched with 97 presenting WMLs without any cognitive deficit. VCI-ND patients exhibited a decrease in MBFV and EDV, as well as an increase in PI, RI, and PSV. Moreover, a significant correlation between all TCD parameters and the severity of executive dysfunction was observed, whereas PI, RI, and EDV were significantly correlated with the WML load.ConclusionsVCI-ND showed a hemodynamic pattern indicative of cerebral hypoperfusion and enhanced vascular resistance. These changes may be considered as the TCD correlate of VCI-ND due to microcirculation pathology. TCD provides useful indices of the occurrence and severity of small vessel disease and executive dysfunction in elderly patients at risk of future dementia.
Project description:BackgroundRight ventricle dilatation (RVD) is a common complication of non-intubated COVID-19 pneumonia caused by pro-thrombotic pneumonitis, intra-pulmonary shunting, and pulmonary vascular dysfunction. In several pulmonary diseases, RVD is routinely measured on computed tomography pulmonary angiogram (CTPA) by the right ventricle-to-left ventricle (LV) diameter ratio > 1 for predicting adverse events.ObjectiveThe aim of the study was to evaluate the association between RVD and the occurrence of adverse events in a cohort of critically ill non-intubated COVID-19 patients.MethodsBetween February 2020 and February 2022, non-intubated patients admitted to the Amiens University Hospital intensive care unit for COVID-19 pneumonia with CTPA performed within 48 h of admission were included. RVD was defined by an RV/LV diameter ratio greater than one measured on CTPA. The primary outcome was the occurrence of an adverse event (renal replacement therapy, extracorporeal membrane oxygenation, 30-day mortality after ICU admission).ResultsAmong 181 patients, 62% (n = 112/181) presented RVD. The RV/LV ratio was 1.10 [1.05-1.18] in the RVD group and 0.88 [0.84-0.96] in the non-RVD group (p = 0.001). Adverse clinical events were 30% and identical in the two groups (p = 0.73). In Receiving operative curves (ROC) analysis, the RV/LV ratio measurement failed to identify patients with adverse events. On multivariable Cox analysis, RVD was not associated with adverse events to the contrary to chest tomography severity score > 10 (hazards ratio = 1.70, 95% CI [1.03-2.94]; p = 0.04) and cardiovascular component (> 2) of the SOFA score (HR = 2.93, 95% CI [1.44-5.95], p = 0.003).ConclusionRight ventricle (RV) dilatation assessed by RV/LV ratio was a common CTPA finding in non-intubated critical patients with COVID-19 pneumonia and was not associated with the occurrence of clinical adverse events.