Venous Doppler ultrasound in critically Ill COVID-19 patients: game changer in anticoagulation therapy.

BACKGROUND: COVID-19 infection has been associated with a high rate of thrombotic events, such as deep vein thrombosis (DVT) and acute pulmonary embolism (APE). METHODS: The purpose of our retrospective study was to evaluate the prevalence of asymptomatic DVT in lower limbs in critically ill COVID-19 patients (n = 23) with severe respiratory failure and high levels of D-dimer by bedside Doppler ultrasound (DU). RESULTS: DVT was diagnosed in 14 cases (60.87%), 5 in proximal venous territory and 9 in infrapopliteal veins. Computed Tomography Pulmonary Angiography (CTPA) was performed in six patients and all of them showed acute pulmonary embolism (APE) at segmental or subsegmental branches of pulmonary arteries. These patients (APE or DVT confirmed) were treated with therapeutic doses of anticoagulant therapy. CONCLUSION: In critically COVID-19 ill ICU patients with severe respiratory failure and elevated D-dimer, the incidence of asymptomatic DVT is high. We propose that DU allows detection of DVT in asymptomatic patients, adding a factor that may balance the decision to fully anticoagulate these patients.

Normal values of liver shear wave velocity in healthy children assessed by acoustic radiation force impulse imaging using a convex probe and a linear probe.

Acoustic radiation force impulse (ARFI) is an image-guided ultrasound elastography method that allows quantification of liver stiffness by measurement of shear wave velocity. One purpose of the work described in this article was to determine the normal liver stiffness values of healthy children using ARFI with two different probes, 4 C1 and 9 L4. Another purpose was to evaluate the effects of site of measurement, age, gender and body mass index on liver stiffness values. This prospective study included 60 healthy children (newborn to 14 y) divided into four age groups. One thousand two hundred ARFI measurements were performed, that is, 20 measurements per patient (5 measurements in each lobe, with each probe). Means, standard deviations (SD) and confidence intervals for velocity were calculated for each hepatic lobe and each probe in each age group and for the whole group. Mean shear wave velocity measured in the right lobe was 1.19 ± 0.04 m/s (SD = 0.13) with the 4 C1 transducer and 1.15 ± 0.04 m/s (SD = 0.15) with the 9 L4 transducer. Age had a small effect on shear wave measurements. Body mass index and sex had no significant effects on ARFI values, whereas site of measurement had a significant effect, with lower ARFI values in the right hepatic lobe. ARFI is a non-invasive technique that is feasible to perform in children with both the 4 C1 and 9 L4 probes. The aforementioned velocity values obtained in the right lobe may be used as reference values for normal liver stiffness in children.

Contrast-enhanced ultrasound of liver lesions related to arterial thrombosis in adult liver transplantation.

PURPOSE: To describe the contrast-enhanced ultrasound (CEUS) features of liver and biliary lesions related to hepatic artery thrombosis in adult patients with orthotopic liver transplantation. METHODS: Gray-scale ultrasound (US), Doppler US, and CEUS using a hexafluoride-based US contrast media were performed on a series of eight patients with liver transplantation and hepatic artery thrombosis. RESULTS: Six of the cases presented infarctions, seen as parenchymal geographic areas of lack of enhancement. Biliary necrosis, seen as nonenhancing periportal cuff, was seen in one case. Infected biloma, seen as a nonenhancing hilar collection, was present in two cases. Infarction and biloma coexisted in one patient. Two abscesses were seen as a late complication in one case. One of them was seen as a typical necrotic abscess with a central nonenhancing area and peripheral rim enhancement higher than the surrounding liver. The other one was seen as a partially liquefied abscess. CONCLUSION: CEUS was useful to diagnose lesions related to hepatic artery thrombosis in liver transplantation. It enabled distinguishing between them and to define their size and extension better than conventional gray-scale US.