Successful venoarterial extracorporeal membrane oxygenation for prolonged hepatopulmonary syndrome following pediatric liver transplantation: A case report and review of the literature.

HPS is a major complicating feature of end-stage liver disease. Diagnosis is clinical, and LT is the only definitive treatment. While the general impression is that HPS improves quickly after transplantation, it may not always be the case. We describe the smallest reported child with HPS prior to LT and requiring prolonged venoarterial extracorporeal membrane oxygenation after LT; especially as it is a rare occurrence, physician managing such cases should be aware of the circumstances under which HPS may require specific treatment.

Great vessel root and artery dimensions in transposition of the great arteries repaired with atrial switch operation.

To describe great-vessel dimensions in patients with D-loop transposition of the great arteries (TGA) who have undergone atrial switch operation (ATSO). Patients who have undergone arterial switch operation for TGA have a high incidence of dilation of the neoaortic root. The incidence and degree of great artery dilation in patients who have undergone ATSO for TGA has not previously been described. A retrospective database review identified patients with TGA and intact ventricular septum who underwent ATSO at <1 year of age with cardiac magnetic resonance (CMR) within the previous 5 years (n = 39). A control group of patients referred for CMR with normal findings was identified for comparison (n = 40). Measurements of the annulus, root, sinotubular junction, and great vessels were performed, and interobserver/intraobserver variability was assessed. Median age of subjects at ATSO was 3 months (range 1-12) with median age at CMR of 29 years (range 18-40). For aortic measurements, mean z scores (± SDs) for patients relative to body surface area (BSA)-adjusted normal controls were as follows: annulus 1.41 (0.80), root 2.04 (1.48), sinotubular junction 2.16 (1.26), and great vessel 1.86 (1.53). For pulmonary measurements, similar values were as follows: annulus 1.82 (1.42), root 3.25 (2.01), sinotubular junction 2.47 (1.79), and great vessel 3.96 (3.08). In all cases, the p value was <0.001, and no confidence interval included the value 0. Adult patients with TGA repaired with ATSO in infancy have a greater incidence of dilation of both great vessels, particularly the pulmonary artery. These results may indicate abnormalities in the vascular structure of both great arteries in TGA that may predispose to progressive arterial dilation.

Interprofessional Extracorporeal Membrane Oxygenation Cardiopulmonary Resuscitation Simulations Aimed at Decreasing Actual Cannulation Times: A Longitudinal Study.

BACKGROUND: Since 2013, the cardiac intensive care unit (CICU) at Children's National has conducted annual extracorporeal membrane oxygenation cardiopulmonary resuscitation (ECPR) simulations that focus on team dynamics, room setup, and high-quality CPR. In 2019 and 2020, the simulations were expanded to include the surgical and extracorporeal membrane oxygenation (ECMO) teams in an effort to better understand and improve this process. METHODS: During a 4-week period in 2019, 7 peripheral ECPR simulations were conducted, and through a 3-week period in 2020, 7 central ECPR simulations were conducted. Participants in each session included: 8 to 10 CICU nurses, 1 CICU attending, 1 to 2 ICU or cardiology fellows, 1 cardiovascular surgery fellow or attending, and 1 ECMO specialist. For each session, the scenario continued until the simulated patient was on full cardiopulmonary bypass. An ECMO trainer was used for peripheral simulations and a 3-dimensionally-printed heart was used for central cannulations. An ECMO checklist was used to objectively determine when the patient and room were fully prepared for surgical intervention, and simulated cannulation times were recorded for both groups. A retrospective chart review was conducted to compare actual cannulation times before and after the intervention period, and video was used to review the events and assist in dividing them into medical versus surgical phases. Control charts were used to trend the total ECPR times before and after the intervention period, and mean and P values were calculated for both ECPR times and for all other categorical data. RESULTS: Mean peripheral ECPR times decreased significantly from 71.7 to 45.1 minutes ( P = 0.036) after the intervention period, and this was reflected by a centerline shift. Although we could not describe a similar decrease in central ECPR times because there were only 6 postintervention events, the times for each of these events were shorter than the historical mean of 37.8 minutes. There was a trend in improved survival, which did not meet significance both among patients undergoing peripheral ECPR (15.4% ± 10% to 43.8% ± 12.4%, P = 0.10) and central ECPR (36.4% ± 8.4% to 50% ± 25%, P = 0.60). The percentage of time dedicated to the medical phases of the actual versus simulated procedures was very consistent among both peripheral (33.0% vs. 31.9%) and central (39.6% vs. 39.8%) cannulations. CONCLUSIONS: We observed a significant decrease in peripheral cannulation times at our institution after conducting interprofessional ECPR simulations taken to the establishment of full cardiopulmonary bypass. The use of an ECMO trainer and a 3-dimensionally-printed heart allowed for both the medical and surgical phases of the procedure to be studied in detail, providing opportunities to streamline and improve this complex process. Larger multisite studies will be needed in the future to assess the effect of efforts like these on patient survival.

Transposition With Hypertrophic Cardiomyopathy and Persistent Pulmonary Hypertension of the Newborn.

The contemporaneous presentation of transposition of the great arteries and hypertrophic cardiomyopathy is rare and complicates optimal surgical timing. We present a newborn with transposition and severe hypertrophic cardiomyopathy with a postnatal course complicated by persistent pulmonary hypertension who was supported with extracorporeal membrane oxygenation until successful arterial switch operation on the day of life 8.

Use of Virtual Reality for Pediatric Cardiac Critical Care Simulation.

Simulation is a key component of training in the pediatric cardiac intensive care unit (CICU), a complex environment that lends itself to virtual reality (VR)-based simulations. However, VR has not been previously described for this purpose. Two simulations were developed to test the use of VR in simulating pediatric CICU clinical scenarios, one simulating junctional ectopic tachycardia and low cardiac output syndrome, and the other simulating acute respiratory failure in a patient with suspected coronavirus disease 2019. Six attending pediatric cardiac critical care physicians were recruited to participate in the simulations as a pilot test of VR's feasibility for educational and practice improvement efforts in this highly specialized clinical environment. All participants successfully navigated the VR environment and met the critical endpoints of the two clinical scenarios. Qualitative feedback was overall positive with some specific critiques regarding limited realism in some mechanical aspects of the simulation. This is the first described use of VR in pediatric cardiac critical care simulation.

Further studies on the interaction of nonpolyglutamatable aminopterin analogs with dihydrofolate reductase and the reduced folate carrier as determinants of in vitro antitumor activity.

Thirteen structural analogs of the potent nonpolyglutamatable dihydrofolate reductase inhibitor N(alpha)-(4-amino-4-deoxypteroyl)-N(delta)-hemiphthaloyl-L-ornithine (PT523) with modifications in the side chain, the para-aminobenzoyl moiety, or the 9,10-bridge were evaluated for the ability to inhibit human recombinant dihydrofolate reductase (DHFR), to utilize the reduced folate carrier (RFC) for influx, and to inhibit the growth of CCRF-CEM human leukemia cells in culture. In spectrophotometric assays of the kinetics of the reduction of dihydrofolate by DHFR in the presence of NADPH, these compounds had K(i) values ranging from 0.2 to 1.3pM, and thus were not greatly different in potency from the parent drug PT523. By comparison, the K(i) values of aminopterin (AMT), methotrexate (MTX), and 10-ethyl-10-deazaaminopterin (EDX) were 3.7, 4.8, and 11pM. In assays of competitive inhibition of [3H]MTX influx into CCRF-CEM cells, the K(i) values ranged from 0.21 to 7.3 micro M, as compared with 0.71, 5.4, and 1.1 micro M for PT523, AMT, and EDX. The K(t) for MTX was also re-analyzed and found to be 4.7 micro M, in better agreement with the literature than our previously reported value of 7.1 micro M. The IC(50) values of these compounds as inhibitors of the growth of CCRF-CEM cells after 72hr of drug exposure ranged from 0.53 to 55nM, and were qualitatively consistent with the other results.