Relationship between kalemia and intensive care unit admission or death in hospitalized COVID-19 patients: A cohort study.

BACKGROUND: SARS-CoV-2 uses Angiotensin-Converting Enzyme 2 as a viral gateway to the cell and could interact with the renin-angiotensin-aldosterone system. Other studies have shown kalemia abnormalities in patients with severe forms of coronavirus disease 2019. Our goal was to assess the prognosis value of kalemia within ten days of symptom offset in the COVID-19 hospitalized population. METHODS: We analyzed data from a prospective cohort that included 65 patients with COVID-19, admitted between March 15, 2020, and March 21, 2020. The study aimed at determining the relationship between baseline kalemia and the admission to an intensive care unit (ICU) or death. RESULTS: The median age of the patients was 65 [54-79] years old, and 66.2% of the patients were men. Baseline kalemia under 3.8mmol/l occurred in 31 patients (48%), including 11 patients (35.5%) who were admitted to an ICU and one patient (3.2%) who died before ICU admission. In the primary end-point analysis, the adjusted hazard ratios for admission to an ICU or death were 3.52 [95% confidence interval (CI), 1.12 to 11.04] among patients with low baseline kalemia. CONCLUSION: Our study suggests that low kalemia levels within ten days of the first symptom onset might be associated with an increased risk of intensive care unit admission or death. The future perspective should be to better understand this relationship.

Ergotism with acute limb ischemia, provoked by HIV protease inhibitors interaction with ergotamine, rescued by multisite transluminal balloon angioplasty.

Acute limb ischemia induced by arterial vasospasm remains an exceptional situation, favoured by the use of arterial vasoconstrictors. The risk of these substances is largely underestimated in the general population, especially with the co-administration of strong cytochrome inhibitors like human immunodeficiency virus (HIV) protease inhibitors. A 33-year-old woman, who used to take dihydroergotamine for orthostatic hypotension, was prescribed a post-exposure HIV prophylaxis including lopinavir and ritonavir. One day later, she presented an acute bilateral limb ischemia with a sudden pain in both calves, initially while walking and then at rest with bilateral ischemic toes. Angiography confirmed diffuse arterial vasospasm of the lower limb arteries. A first-line therapy with isosorbide dinitrate and amlodipine was ineffective, with rapid clinical worsening. A combination of intra-arterial injections and intra-venous infusions of vasodilators, transluminal balloon angioplasty and bilateral 4-Compartment fasciotomies permitted rapid improvement and finally resulted in both lower limbs rescue. This case and literature review illustrate ergotism due to ergotamine overdose after taking HIV protease inhibitors. It also demonstrates the benefit of an interventional procedure besides medical therapy with vasodilators in severe arterial vasospasm. All along the lower limb arterial tree, transluminal balloon angioplasty restored the blood flow, without vasospasm recurrence. CONCLUSION: In case of ergotism with acute lower limbs ischemia, combining medical vasodilator therapy with interventional procedure can restore the arterial blood flow, thus allowing to save lower limbs.

Respiratory mechanics and gas exchanges in the early course of COVID-19 ARDS: a hypothesis-generating study.

RATIONALE: COVID-19 ARDS could differ from typical forms of the syndrome. OBJECTIVE: Pulmonary microvascular injury and thrombosis are increasingly reported as constitutive features of COVID-19 respiratory failure. Our aim was to study pulmonary mechanics and gas exchanges in COVID-2019 ARDS patients studied early after initiating protective invasive mechanical ventilation, seeking after corresponding pathophysiological and biological characteristics. METHODS: Between March 22 and March 30, 2020 respiratory mechanics, gas exchanges, circulating endothelial cells (CEC) as markers of endothelial damage, and D-dimers were studied in 22 moderate-to-severe COVID-19 ARDS patients, 1 [1-4] day after intubation (median [IQR]). MEASUREMENTS AND MAIN RESULTS: Thirteen moderate and 9 severe COVID-19 ARDS patients were studied after initiation of high PEEP protective mechanical ventilation. We observed moderately decreased respiratory system compliance: 39.5 [33.1-44.7] mL/cmH2O and end-expiratory lung volume: 2100 [1721-2434] mL. Gas exchanges were characterized by hypercapnia 55 [44-62] mmHg, high physiological dead-space (VD/VT): 75 [69-85.5] % and ventilatory ratio (VR): 2.9 [2.2-3.4]. VD/VT and VR were significantly correlated: r2 = 0.24, p = 0.014. No pulmonary embolism was suspected at the time of measurements. CECs and D-dimers were elevated as compared to normal values: 24 [12-46] cells per mL and 1483 [999-2217] ng/mL, respectively. CONCLUSIONS: We observed early in the course of COVID-19 ARDS high VD/VT in association with biological markers of endothelial damage and thrombosis. High VD/VT can be explained by high PEEP settings and added instrumental dead space, with a possible associated role of COVID-19-triggered pulmonary microvascular endothelial damage and microthrombotic process.

Quantitative imaging of coronary flows using 3D ultrafast Doppler coronary angiography.

Coronary flow rate remains complex to assess in clinical practice using non-invasive, non-ionizing imaging tools. In this study, we introduce 3D ultrafast Doppler coronary angiography (3D UDCA), an ultrasound-based method to assess coronary blood flows in three-dimensions at high volume-rate and in one single heartbeat. We demonstrate that 3D UDCA can visualize the coronary vasculature with high temporal and spatial resolution and quantify the absolute flow. The feasibility of the technique was demonstrated in an open-chest swine model. The flow rate of the left-anterior descending artery (LAD) assessed by 3D UDCA was reconstructed successfully at the early diastolic and late diastolic phases and was in good agreement with an invasive gold-standard flowmeter during baseline, reactive hyperemia and coronary stenosis (r2 = 0.84). Finally, we demonstrate that a coronary stenosis on the LAD can be visualized as well as its associated flow acceleration.

4D simultaneous tissue and blood flow Doppler imaging: revisiting cardiac Doppler index with single heart beat 4D ultrafast echocardiography.

The goal of this study was to demonstrate the feasibility of semi-automatic evaluation of cardiac Doppler indices in a single heartbeat in human hearts by performing 4D ultrafast echocardiography with a dedicated sequence of 4D simultaneous tissue and blood flow Doppler imaging. 4D echocardiography has the potential to improve the quantification of major cardiac indices by providing more reproducible and less user dependent measurements such as the quantification of left ventricle (LV) volume. The evaluation of Doppler indices, however, did not benefit yet from 4D echocardiography because of limited volume rates achieved in conventional volumetric color Doppler imaging but also because spectral Doppler estimation is still restricted to a single location. High volume rate (5200 volume s-1) transthoracic simultaneous tissue and blood flow Doppler acquisitions of three human LV were performed using a 4D ultrafast echocardiography scanner prototype during a single heartbeat. 4D color flow, 4D tissue Doppler cineloops and spectral Doppler at each voxel were computed. LV outflow tract, mitral inflow and basal inferoseptal locations were automatically detected. Doppler indices were derived at these locations and were compared against clinical 2D echocardiography. Blood flow Doppler indices E (early filling), A (atrial filling), E/A ratio, S (systolic ejection) and cardiac output were assessed on the three volunteers. Simultaneous tissue Doppler indices e' (mitral annular velocity peak), a' (late velocity peak), e'/a' ratio, s' (systolic annular velocity peak), E/e' ratio were also estimated. Standard deviations on three independent acquisitions were averaged over the indices and was found to be inferior to 4% and 8.5% for Doppler flow and tissue Doppler indices, respectively. Comparison against clinical 2D echocardiography gave a p  value larger than 0.05 in average indicating no significant differences. 4D ultrafast echocardiography can quantify the major cardiac Doppler indices in a single heart beat acquisition.

Pulsed cavitational therapy using high-frequency ultrasound for the treatment of deep vein thrombosis in an in vitro model of human blood clot.

Post-thrombotic syndrome, a frequent complication of deep venous thrombosis, can be reduced with early vein recanalization. Pulsed cavitational therapy (PCT) using ultrasound is a recent non-invasive approach. We propose to test the efficacy and safety of high-frequency focused PCT for drug-free thrombolysis (thrombotripsy) in a realistic in vitro model of venous thrombosis. To reproduce venous thrombosis conditions, human whole blood was allowed to clot by stasis in silicone tubes (6 mm internal diameter) at a 30 cm H2O pressure, maintained during the whole experiment. We engineered an ultrasound device composed of dual 2.25 MHz transducers centered around a 6 MHz imaging probe. A therapeutic focus was generated at a 3.2 cm depth from the probe. Thrombotripsy was performed by longitudinally scanning the thrombus at three different speeds: 1 mm s-1 (n = 6); 2 mm s-1 (n = 6); 3 mm s-1 (n = 12). Restored outflow was measured every three passages. Filters were placed to evaluate the debris size. Twenty-four occlusive thrombi, of 2.5 cm mean length and 4.4 kPa mean stiffness, were studied. Flow restoration was systematically obtained by nine subsequent passages (4.5 min maximum). By varying the device's speed, we found an optimal speed of 1 mm s-1 to be efficient for effective recanalization with 90 s (three passages). Within 90 s, flow restoration was of 80, 62 and 74% at respectively 1, 2 and 3 mm s-1. For all groups, cavitation cloud drilled a 1.7 mm mean diameter channel throughout the clot. Debris analysis showed 92% of debris <10 µm, with no fragment > 200 µm.

[Recanalization procedure of the common femoral vein following iatrogenic femoral chronic occlusion: 3 cases]. / Recanalisation veineuse des membres inférieurs sur occlusion fémorale chronique iatrogène : à propos de 3 cas.

Common femoral vein occlusion (CFVO) is frequently found in patients with chronic venous insufficiency. The iatrogenic form, secondary to either central catheter or surgery, is very rare but highly symptomatic. Classical compression therapy barely improves the clinical status of these patients, making them suitable candidates for an interventional procedure for venous recanalization. METHODS: We report here three consecutive cases of iatrogenic CFVO referred to our outpatient clinic because the disease had an impact on daily life activities. We detail the recanalization procedure, the Doppler control and the short-term outcome. RESULTS: In each case, endovascular recanalization required rigid material (rigid guide or Colapinto needle) to cross the fibrous adhesions before angioplasty could be performed with stenting. The procedure required two attempts in each case, underlining its complexity, but eventually enabled effective recanalization. No major complication occurred per- or post-procedure. One month later, a duplex Doppler control confirmed the permeability of the common femoral vein. The patients had experienced rapid and significant symptom improvement. CONCLUSION: Patients suffering from severe chronic venous insufficiency caused by iatrogenic CFVO can benefit from endovascular recanalization. Although these procedures may be complex due to the extensive fibrosis at the Scarpa and require specialized equipment, no major complications were observed. Patency of the recanalization persisted at least one month after the procedure. Symptom relief was good.