Effect of the COVID-19 pandemic on CT scans ordered from the emergency department for abdominal complaints

Emergency Radiology - The COVID-19 pandemic has affected healthcare systems and patients alike across the USA. We seek to elucidate changes in abdominal imaging ordered from the emergency...     

Challenges of acute phase neuroimaging in VA-ECMO,pitfalls and alternative imaging options

Large vessel occlusion in patients on ECMO is challenging to appreciate clinically secondary to sedation or induced paralysis, thus placing more emphasis on neurovascular imaging. However, emergent CTA and CTP are both inaccurate and unreliable in ECMO patients due to altered circuitry and interference with normal physiologic hemodynamics. In this review, the utility of DSA is discussed in evaluating the altered hemodynamics of VA-ECMO circuits and patency of major vasculature. In addition, the potential use of TCD in ECMO patients is discussed.     

Rapid Increase in Marrow Fat Content and Decrease in Marrow Perfusion in Lumbar Vertebra Following Bilateral Oophorectomy: An MR Imaging-Based Prospective Longitudinal Study

ObjectiveBilateral oophorectomy leads to reduced bone mineral density (BMD), and reduced BMD is associated with increased marrow fat and reduced marrow perfusion. Purpose of this study was to investigate how soon these changes occur following surgical oophorectomy.ResultsReduced BMD, increased marrow FF, and reduced marrow perfusion occurred synchronously post-oophorectomy. There was a sharp decrease of 12.5 ± 7.2% in BMD (n = 6), a sharp increase of 92.2 ± 46.3% (n = 6) in FF, a sharp decrease of 23.6 ± 3.9% in maximum contrast enhancement (n = 5), and of 45.4 ± 7.7% for enhancement slope (n = 5) during the initial 3 months post surgery. BMD and marrow perfusion continued to decrease, and marrow FF continued to increase at a slower rate during the following 18 months. Friedman test showed a significant trend for these changes (p < 0.05).ConclusionBilateral oophorectomy leads to a rapid decrease in lumbar BMD, an increase in marrow fat content, and a decrease in marrow blood perfusion.     

Effects of Cardiopulmonary Support With a Novel Pediatric Pump‐Lung in a 30‐Day Ovine Animal Model

The scarcity of donor organs has led to the development of devices that provide optimal long‐term respiratory or cardiopulmonary support to bridge recipients as they wait for lung and/or heart transplantation. This study was designed to evaluate the 30‐day in vivo performance of the newly developed pediatric pump‐lung (PediPL) for cardiopulmonary support using a juvenile sheep model. The PediPL device was placed surgically between the right atrium and descending aorta in eight sheep (25.4–31.2 kg) and evaluated for 30 days. Anticoagulation was maintained with continuous heparin infusion (activated clotting time 150–200 s). The flow rate was measured continually, and gas transfer was measured daily. Plasma free hemoglobin, platelet activation, hematologic data, and blood biochemistry were assessed twice a week. Sheep were euthanized after 30 days. The explanted devices were examined for gross thrombosis. Six sheep survived for 30–32 days. During the study, the oxygen transfer rate of the devices was 54.9 ± 13.2 mL/min at a mean flow rate of 1.14 ± 0.46 L/min with blood oxygen saturation of 95.4% ± 1.7%. Plasma free hemoglobin was 8.2 ± 3.7 mg/dL. Platelet activation was 5.35 ± 2.65%. The animals had normal organ chemistries except for surgery‐related transient alterations in kidney and liver function. Although we found some scattered thrombi on the membrane surfaces of some explanted devices during the necropsy, the device function and performance did not degrade. The PediPL device was capable of providing cardiopulmonary support with long‐term reliability and good biocompatibility over the 30‐day duration and offers the potential option for bridging pediatric patients with end‐stage heart or lung disease to heart and/or lung transplantation.     

Flecainide: electrophysiologic and antiarrhythmic properties in refractory ventricular tachycardia

Twenty-two patients with coronary artery disease and spontaneous ventricular tachycardia (VT) or ventricular fibrillation (VF) underwent intracardiac electrophysiologic evaluation and, when possible, ambulatory monitoring before and after therapy with flecainide (mean dose 418 +/- 87 mg [mean +/- standard deviation]). An average of 4 antiarrhythmic agents were used and were unsuccessful before therapy with flecainide was begun. During 64 +/- 16 hours of control Holter monitoring in 16 patients, all had 1 or more salvos of VT, as well as ventricular premature complexes (VPCs). Programmed stimulation during the control period induced VT in 17 of 22 patients. After flecainide therapy, Holter monitoring showed elimination of all forms of VT in all but 1 patient, as well as significant reduction of paired VPCs by 95% (p less than 0.03) and single VPCs by 70% (p less than 0.005). Electrophysiologic study during flecainide therapy showed significant increases in AH, HV, PR, QRS and QTc intervals, and the ventricular effective refractory period. Programmed stimulation in 17 patients taking flecainide, with a mean plasma level of 1,075 +/- 521 ng/ml, showed ablation of inducible VT in only 2 patients, a worsening in 5 and continued VT inducibility in 10. Adverse effects that required drug withdrawal were infrequent and encountered in patients who received higher drug levels: 1 patient with congestive heart failure and 1 with severe sinus bradycardia. Thus, although flecainide suppresses complex ventricular arrhythmias on Holter recordings, it rarely alters the response to programmed stimulation. Caution is recommended in its use for recurrent sustained VT or VF and in the interpretation of electrophysiologic studies until the predictive value of programmed stimulation with flecainide therapy is established.     

Experimental herpes simplex virus encephalitis: Comparative effects of treatment with cytosine arabinoside and adenine arabinoside.

Experimental herpesvirus encephalitis in weanling mice was treated with either cytosine arabinoside or adenine arabinoside to determine the comparative effectiveness of the two compounds on survival and on the concentration of virus in the brain. The uniformly fatal course of the encephalitis was not altered by any dosage of cytosine arabinoside. In contrast, treatment with adenine arabinoside resulted in long-term survival of the majority of the infected animals. The concentration of virus measured in the brains of animals treated with two different dosages of cytosine arabinoside indicated initial suppression of viral replication with a subsequent rise to levels higher than those in the untreated controls. In the brains of adenine arabinoside-treated animals, titers of virus gradually diminished to undetectable levels by the eighth day after institution of therapy.