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Purpose: Echocardiography is considered essential during cannulation placement and manipulations. Literature evaluating transthoracic echocardiography (TTE) usage during pediatric VV‐ECMO is scant. The purpose of this study is to describe the use of echocardiography during VV‐ECMO at a large, quaternary children's hospital. Methods: A retrospective, single‐year cohort study was performed of pediatric patients on VV‐ECMO via dual‐lumen cannula at our institution from January 2019 through December 2019. For each echocardiogram, final cannula component (re‐infusion port (ReP), distal tip, proximal port and distal port) positions were evaluated by one echocardiographer. For TTEs with ReP in the right atrium, two echocardiographers independently evaluated ReP direction using 2‐point (Yes/No) and 4‐point scales, which were semi‐quantitative protocols using color Doppler images to estimate ReP jet direction to the tricuspid valve. Cohen's kappa or weighted kappa was used to measure interrater agreement. Results: During study period, 11 patients (64% male) received VV‐ECMO with 49 TTEs and one transesophageal echocardiogram performed. The median patient age was 4.3 years [IQR: 1.1–11.5] and median VV‐ECMO run time of 192 h [90–349]. The median time between TTEs on VV‐ECMO was 34 h [8.3–65]. Most common position for the ReP was the right atrium (n = 33, 67%), and ReP location was not identified in five TTEs (10%). For ReP flow direction, echocardiographers agreed on 82% of TTEs using 2‐point evaluation. There was only moderate agreement between echocardiographers on the 2‐point and 4‐point assessments (k =.54, kw =.46 respectively). Conclusions: TTE is the predominant cardiac ultrasound modality used during VV‐ECMO for pediatric respiratory failure. Subjective evaluation of VV‐ECMO ReP jet direction in the right atrium is challenging, regardless of assessment method. [ABSTRACT FROM AUTHOR]

G protein-coupled receptors (GPCRs) are intensely studied as drug targets and for their role in signaling. With the determination of the first crystal structures, interest in structure-based ligand discovery increased. Unfortunately, for most GPCRs no experimental structures are available. The determination of the D(3) receptor structure and the challenge to the community to predict it enabled a fully prospective comparison of ligand discovery from a modeled structure versus that of the subsequently released crystal structure. Over 3.3 million molecules were docked against a homology model, and 26 of the highest ranking were tested for binding. Six had affinities ranging from 0.2 to 3.1 μM. Subsequently, the crystal structure was released and the docking screen repeated. Of the 25 compounds selected, five had affinities ranging from 0.3 to 3.0 μM. One of the new ligands from the homology model screen was optimized for affinity to 81 nM. The feasibility of docking screens against modeled GPCRs more generally is considered.

This paper describes computer models of three interventions used for treating refractory pulmonary hypertension (RPH). These procedures create either an atrial septal defect, a ventricular septal defect or, in the case of a Potts shunt, a patent ductus arteriosus. The aim in all three cases is to generate a right-to-left shunt, allowing for either pressure or volume unloading of the right side of the heart in the setting of right ventricular failure, while maintaining cardiac output. These shunts are created, however, at the expense of introducing de-oxygenated blood into the systemic circulation, thereby lowering the systemic arterial oxygen saturation. The models developed in this paper are based on compartmental descriptions of human hemodynamics and oxygen transport. An important parameter included in our models is the cross-sectional area of the surgically created defect. Numerical simulations are performed to compare different interventions and various shunt sizes and to assess their impact on hemodynamic variables and oxygen saturations. We also create a model for exercise and use it to study exercise tolerance in simulated pre-intervention and post-intervention RPH patients. [ABSTRACT FROM AUTHOR]

Introduction: The aim of the study was to characterize the changes in fetal lung volume following fetoscopic endoluminal tracheal occlusion (FETO) that are associated with infant survival and need for extracorporeal membrane oxygenation (ECMO) in congenital diaphragmatic hernia (CDH). Methods: Fetuses with CDH who underwent FETO at a single institution were included. CDH cases were reclassified by MRI metrics [observed-to-expected total lung volume (O/E TLV) and percent liver herniation]. The percent changes of MRI metrics after FETO were calculated. ROC-derived cutoffs of these changes were derived to predict infant survival to discharge. Regression analyses were done to determine the association between these cutoffs with infant survival and ECMO need, adjusted for site of CDH, gestational age at delivery, fetal sex, and CDH severity. Results: Thirty CDH cases were included. ROC analysis demonstrated that post-FETO increases in O/E TLV had an area under the curve of 0.74 (p = 0.035) for the prediction of survival to hospital discharge; a cutoff of less than 10% was selected. Fetuses with a <10% post-FETO increase in O/E TLV had lower survival to hospital discharge [44.8% vs. 91.7%; p = 0.018] and higher ECMO use [61.1% vs. 16.7%; p = 0.026] compared to those with an O/E TLV increase ≥10%. Similar results were observed when the analyses were restricted to left-sided CDH cases. A post-FETO <10% increase in O/E TLV was independently associated with lower survival at hospital discharge (aOR: 0.073, 95% CI: 0.008–0.689; p = 0.022) and at 12 months of age (aOR: 0.091, 95% CI: 0.01–0.825; p = 0.036) as well as with higher ECMO use (aOR: 7.88, 95% CI: 1.31–47.04; p = 0.024). Conclusion: Fetuses with less than 10% increase in O/E TLV following the FETO procedure are at increased risk for requiring ECMO and for death in the postnatal period when adjusted for gestational age at delivery, CDH severity, and other confounders. [ABSTRACT FROM AUTHOR]