Variation in outcomes with extracorporeal membrane oxygenation in the era of coronavirus: A multicenter cohort evaluation.

Extracorporeal membrane oxygenation (ECMO) is used in critically ill patients with coronavirus disease 2019 (COVID-19) with acute respiratory distress syndrome unresponsive to other interventions. However, a COVID-19 infection may result in a differential tolerance to both medical treatment and ECMO management. The aim of this study was to compare outcomes (mortality, organ failure, circuit complications) in patients on ECMO with and without COVID-19 infection, either by venovenous (VV) or venoarterial (VA) cannulation. This is a multicenter, retrospective analysis of a national database of patients placed on ECMO between May 2020 and January 2022 within the United States. Nine-hundred thirty patients were classified as either Pulmonary (PULM, n = 206), Cardiac (CARD, n = 279) or COVID-19 (COVID, n = 445). Patients were younger in COVID groups: PULM = 48.4 ± 15.8 years versus COVID = 44.9 ± 12.3 years, p = 0.006, and CARD = 57.9 ± 15.4 versus COVID = 46.5 ± 11.8 years, p < 0.001. Total hours on ECMO were greatest for COVID patients with a median support time two-times higher for VV support (365 [101, 657] hours vs 183 [63, 361], p < 0.001), and three times longer for VA support (212 [99, 566] hours vs 70 [17, 159], p < 0.001). Mortality was highest for COVID patients for both cannulation types (VA-70% vs 51% in CARD, p = 0.041, and VV-59% vs PULM-42%, p < 0.001). For VA supported patients hepatic failure was more often seen with COVID patients, while for VV support renal failure was higher. Circuit complications were more frequent in the COVID group as compared to both CARD and PULM with significantly higher circuit change-outs, circuit thromboses and oxygenator failures. Anticoagulation with direct thrombin inhibitors was used more often in COVID compared to both CARD (31% vs 10%, p = 0.002) and PULM (43% vs 15%, p < 0.001) groups. This multicenter observational study has shown that COVID patients on ECMO had higher support times, greater hospital mortality and higher circuit complications, when compared to patients managed for either cardiac or pulmonary lesions.

Characterizing Polyoxovanadate-Alkoxide Clusters Using Vanadium K-Edge X-Ray Absorption Spectroscopy.

A number of technologies would benefit from developing inorganic compounds and materials with specific electronic and magnetic exchange properties. Unfortunately, designing compounds with these properties is difficult because metal⋅⋅⋅metal coupling schemes are hard to predict and control. Fully characterizing communication between metals in existing compounds that exhibit interesting properties could provide valuable insight and advance those predictive capabilities. One such class of molecules are the series of Lindqvist iron-functionalized and hexavanadium polyoxovanadate-alkoxide clusters, which we characterized here using V K-edge X-ray absorption spectroscopy. Substantial changes in the pre-edge peak intensities were observed that tracked with the V 3d-electron count. The data also suggested substantial delocalization between the vanadium cations. Meanwhile, the FeIII cations were electronically isolated from the polyoxovanadate core.

The influence of ultrafiltration on red blood cell transfusion during cardiopulmonary bypass.

BACKGROUND: Ultrafiltration during cardiopulmonary bypass (CPB) reduces fluid overload and inflammatory mediators in open-heart surgery and is thought to reduce the risk of red blood cell (RBC) transfusion. We evaluated its effectiveness in reducing RBC transfusions in a large population undergoing cardiac surgery, among patients in general as well as by gender. METHODS: We analyzed 40,650 propensity-matched adult cardiac surgery cases conducted over a 61-month period at 195 hospitals. We assessed the risk of intraoperative transfusion (⩾1 unit RBC) according to body surface area (BSA)-normalized ultrafiltration volume via mixed-effects binary logistic regression. Our statistical model controlled for 12 demographic and operative variables as well as for center level tendencies in ultrafiltration use and intraoperative RBC transfusion. In light of recent findings on gender and risk of transfusion, we also included an interaction effect between gender and ultrafiltration volume (UV). RESULTS: Ultrafiltration was associated with an increased crude rate of RBC transfusion (32.1% vs. 28.1%, p<0.001), but equivalent crude median hematocrit change from first in operating room to nadir on bypass (-11% in both groups, p = 0.133). After controlling for patient, operative and site-level characteristics, we found no statistically significant effect on transfusion rate by volume of ultrafiltrate removed nor did we find statistical support for any gender-specific effect of ultrafiltration. CONCLUSIONS: Ultrafiltration is not associated with a reduction of risk of RBC transfusion during cardiac surgery. The use of ultrafiltration as a method for reducing intraoperative RBC transfusion warrants further study.

Does the Type of Cardioplegia Solution Affect Intraoperative Glucose Levels? A Propensity-Matched Analysis.

Myocardial protection during cardiac surgery is a multifaceted process that is structured to limit injury and preserve function. Evolving techniques use solutions with varying constituents that enter the systemic circulation and alter intrinsic systemic concentrations. This study compared two distinct cardioplegia solutions on affecting intraoperative glucose levels. Data were abstracted from a multi-institutional perfusion registry, including a total of 1,188 propensity-matched cases performed from January through October 2016, at 17 cardiac surgical centers across the United States in which both del Nido and 4:1 cardioplegia were used during the study period. Covariate data included insulin administration, crystalloid cardioplegia volume, diabetes history, glucose at operating room entry, and nine additional variables. Primary and secondary endpoints were the highest intraoperative glucose level and maximum glucose in excess of 180 mg/dL. Mixed-effects multivariable linear and logistic regression models were used to assess the primary and secondary endpoints, respectively, allowing for statistical control of center and surgeon effects. Greater median crystalloid cardioplegia volume was given in the del Nido group (n = 594) 1,040 mL [interquartile range (IQR) = {800, 1,339}] compared with the 4:1 group (n = 594) 466 mL [IQR = {360, 660}] in the 4:1 group (p < .001) despite these groups being statistically indistinguishable in terms of bypass and cross-clamp times as well as seven other patient covariates. More patients required intraoperative insulin drip in the 4:1 group compared with del Nido (65.7% vs. 56.2%, p < .001). Multivariable linear mixed-effects analysis yielded an estimated maximum intraoperative glucose for the del Nido group of 177.8 mg/dL compared with that of the 4:1 group, 183.5 mg/dL-a statistically significant reduction of 5.7 mg/dL (p = .03). Multivariable logistic mixed-effects analysis showed a statistically nonsignificant reduction in the likelihood of crossing the 180 mg/dL threshold for del Nido compared with 4:1 (odds ratio [OR] = .79, p = .214). After controlling for known confounding variables, intraoperative maximum glucose levels for the del Nido group were 5.7 mg/dL lower than that of the 4:1 group; there was limited evidence suggesting a difference between methods in the likelihood of exceeding the threshold of 180 mg/dL intraoperatively. Further research is warranted to examine the differential effects of cardioplegia solution on intraoperative glucose levels.

The effect of ultrafiltration on end-cardiopulmonary bypass hematocrit during cardiac surgery.

OBJECTIVE: Ultrafiltration (UF) during cardiopulmonary bypass (CPB) is a well-accepted method for hemoconcentration to reduce excess fluid and increase hematocrit, platelet count and plasma constituents. The efficacy of this technique may confer specific benefit to certain patients presenting with acquired cardiac defects. The purpose of this study was to retrospectively evaluate the effect of UF on end-CPB hematocrit by cardiac surgical procedure type. METHODS: A review of 73,506 cardiac procedures from a national registry (SCOPE) was conducted between April 2012 and October 2016 at 197 institutions. Cases included in this analysis were those completed without intraoperative red blood cell transfusion and where zero-balance UF was not used. The primary end point was the last hematocrit reading taken before the end of CPB, with a secondary end point of urine output during CPB. In order to isolate the effect of the UF volume removed, we controlled for a number of confounding factors, including: first hematocrit on CPB, total asanguineous volume, estimated circulating blood volume, CPB urine output, total volume of crystalloid cardioplegia, total volume of other asanguineous fluids administered by both perfusion and anesthesia, type of cardiac procedure, acuity, gender, age and total time on CPB. Descriptive statistics were calculated among five subgroups according to the UF volume removed: no volume removed and quartiles across the range of UF volume removed. The effect of UF volume on primary and secondary end points was modeled using ordinary least squares and restricted cubic splines in order to assess possible non-linearity in the effect of the UF volume while controlling for the above-named confounding factors. An interaction term was included in each model to account for possible differences by procedure type. RESULTS: The study found a statistically significant non-linear pattern in the relationship between the UF volume removed and the last hematocrit on bypass (X2 = 172.5, df=24, p<0.001). For most procedure types, UF was most effective at increasing the last hematocrit on CPB, from 1 mL to approximately 2.5 L, with continued improvements in hematocrit coming more slowly as the UF volume was increased above 2.5 L. There were statistically significant interactions between UF and procedure type (X2 = 78.5, df=24, p<0.0001) as well as UF and starting hematocrit on CPB (X2 = 234.0, df=4, p<0.0001). In a secondary end-point model, there was a statistically significant relationship between the ultrafiltration volume removed and urine output on bypass (X2 = 598.9, df=28, p<0.001). CONCLUSION: The use of UF during CPB resulted in significant increases in end-hematocrit, with the greatest benefit shown when volumes were under 2.5 L. We saw a positive linear benefit up to 2.5 L removed and, thereafter, in most procedures, the benefit leveled off. However, of note is markedly decreased urine output on bypass as the ultrafiltration volumes increase.

Does the Type of Cardioplegic Technique Influence Hemodilution and Transfusion Requirements in Adult Patients Undergoing Cardiac Surgery?

During cardiac surgery, myocardial protection is performed using diverse cardioplegic (CP) solutions with and without the presence of blood. New CP formulations extend ischemic intervals but use high-volume, crystalloid-based solutions. The present study evaluated four commonly used CP solutions and their effect on hemodilution during cardiopulmonary bypass (CPB). Records from 16,670 adult patients undergoing cardiac surgery with CPB between February 2016 and January 2017 were reviewed. Patients were classified into one of four groups according to CP type: 4-1 blood to crystalloid (4:1), microplegia (MP), del Nido (DN) and histidine-tryptophan-ketoglutarate (HTK). Covariate-adjusted estimates of group differences were calculated using multivariable logistic and linear mixed effects regression models. The primary end point was intraoperative transfusion of allogeneic red blood cells (RBCs), with a secondary end point of intraoperative hematocrit change. Among all patients, 8,350 (50.1%) received 4:1, 4,606 (27.6%) MP, 3,344 (20.1%) DN, and 370 (2.2%) HTK. Both 4:1 and MP were more likely to be used in patients undergoing coronary revascularization surgery, whereas DN and HTK were seen more often in patients undergoing valve surgery (p < .001). The highest volume of crystalloid CP solution was seen in the HTK group, 2,000 [1,754, 2200], whereas MP had the lowest, 50 [32, 67], p < .001. Ultrafiltration usage was as follows: HTK-84.9%. DN-83.7%, MP-40.1%, and 4:1-34.0%, p < .001. There were no statistically significant differences on the primary outcome risk of intraoperative RBC transfusion. However, statistically significant differences among all but one of the pair-wise comparisons of CP methods on hematocrit change (p < .05 or smaller), with MP having the lowest predicted drift (-7.8%) and HTK having the highest (-9.4%). During cardiac surgery, the administration of different CP formulations results in varying intraoperative hematocrit changes related to the volume of crystalloid solution administered.

The Influence of Intraoperative Autotransfusion on Postoperative Hematocrit after Cardiac Surgery: A Cross-Sectional Study.

Utilization of intraoperative autotransfusion (IAT) during cardiac surgery with cardiopulmonary bypass (CPB) has been shown to reduce allogeneic red blood cell transfusion. Previous research has emphasized the benefits of using IAT in the intraoperative period. The present study was designed to evaluate the effects of using IAT on overall hematocrit (Hct) drift between initiation of CPB and the immediate postoperative period. We reviewed 3,225 adult cardiac procedures occurring between February 2016 and January 2017 at 84 hospitals throughout the United States. Data were collected prospectively from adult patients undergoing cardiac surgery with CPB, and stored in the SpecialtyCare Operative Procedural rEgistry (SCOPE), a large quality improvement database. Patients receiving allogeneic transfusion and those with missing covariate data were excluded from analysis. The effect of IAT volume returned to patients on the primary endpoint, hematocrit change from CPB initiation to intensive care unit (ICU) entry, was assessed using a multivariable linear mixed effects regression model controlling for patient demographics, operative characteristics, surgeon, and hospital. Descriptive analysis showed greater positive hematocrit change with increasing autotransfusate volume returned. Those patients with no IAT volume returned saw a median hematocrit change of +2.00%, whereas those with more than 380 mL/m2 BSA had a median Hct drift of +5.00% (p < .001). After controlling for known confounds, our regression estimate of the effect of IAT volume returned on Hct drift was +.0045% per 1 mL/m2 BSA (p < .001). For a patient with the median autotransfusate volume returned (273 mL/m2 BSA), and all other covariate values at their respective medians, this translates to a predicted hematocrit change of +3.6% (95% CI +3.1 to +4.1). These findings lend further support to the notion that autotransfusate volume is positively associated with increases in postoperative hematocrit.

The effectiveness of acute normolvolemic hemodilution and autologous prime on intraoperative blood management during cardiac surgery.

OBJECTIVE: Intraoperative blood management during cardiac surgery is a multifaceted process incorporating various interventions directed at optimizing oxygen delivery and enhancing hemostasis. The purpose of this study was to evaluate the effects of acute normovolemic hemodilution (ANH) and autologous priming (AP) on preserving the hematocrit during cardiopulmonary bypass (CPB). METHOD: Case records from a national registry of adult patients who underwent cardiac surgery between January and October 2016 were reviewed. Groups were determined as follows: ANH, AP, ANH+AP or Neither. Primary endpoint was first the hematocrit on CPB with secondary endpoints of hematocrit drift and red blood cell (RBC) transfusion rate. RESULTS: Eighteen thousand and twenty-four (18,024) consecutive patients were reviewed. The first CPB hematocrit was lowest in the ANH group (26.5%±4.4%) and highest in ANH+AP patients (27.5%±4.8%) (p<0.001). The change in hematocrit was greatest in the ANH group (8.3%±3.9%) compared to both the AP (6.4%±3.8%) and ANH+AP (6.9%±4.1%) groups (p<0.001). Intraoperative RBC transfusions were as follows: ANH 26 (7.8%), AP 2,531 (20.0%), ANH+AP 287 (10.3%) and Neither 592 (26.7%) (p<0.001). CONCLUSIONS: Regression results show that the use of ANH will result in the greatest decline in hematocrit values. When combined with AP, higher hematocrits and lower transfusions were seen.

Anti-factor Xa assay is a superior correlate of heparin dose than activated partial thromboplastin time or activated clotting time in pediatric extracorporeal membrane oxygenation*.

OBJECTIVE: To assess the utility of activated clotting time, activated partial thromboplastin time, and anti-Factor Xa assay for the monitoring and dosing of heparin in pediatric patients requiring support with extracorporeal membrane oxygenation. DESIGN: Retrospective chart review. SETTING: PICU in a single, tertiary care, academic children's hospital. PATIENTS: Seventeen patients (age 1 d to 13.9 yr, median 0.83 yr) managed on pulmonary and cardiac extracorporeal membrane oxygenation between March 2010 and August 2012 by a single surgeon. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Twice daily measurements of anti-Factor Xa assay, activated clotting time, and activated partial thromboplastin time were determined from the same blood specimen. Data were analyzed using SAS system v9.2. Fourteen patients (82.4%) were successfully weaned from extracorporeal membrane oxygenation and 12 (70.6%) were discharged from the hospital. Pearson correlations were used to compare heparin dose and activated clotting time, activated partial thromboplastin time, and anti-Factor Xa assay. Analysis showed negative Pearson correlations in 11 of 17 patients between the activated clotting time and heparin, as compared with seven of 17 for activated partial thromboplastin time and only one for heparin and anti-Factor Xa assay. Only four patients had moderate to strong positive correlations between activated clotting time and heparin as compared with a moderate to strong positive correlation in 10 patients for anti-Factor Xa assay and heparin. CONCLUSIONS: The anti-Factor Xa assay correlated better with heparin dosing than activated clotting time or activated partial thromboplastin time. Activated clotting time has a poor correlation to heparin doses commonly associated with extracorporeal membrane oxygenation. In pediatric extracorporeal membrane oxygenation, anti-Factor Xa assay may be a more valuable monitor of heparin administration.

Vitamin D and prebiotics for intestinal health in cystic fibrosis: Rationale and design for a randomized, placebo-controlled, double-blind, 2 x 2 trial of administration of prebiotics and cholecalciferol (vitamin D3) (Pre-D trial) in adults with cystic fibrosis.

Individuals with cystic fibrosis (CF) have dysfunctional intestinal microbiota and increased gastrointestinal (GI) inflammation also known as GI dysbiosis. It is hypothesized that administration of high-dose cholecalciferol (vitamin D3) together with a prebiotic (inulin) will be effective, and possibly additive or synergistic, in reducing CF-related GI and airway dysbiosis. Thus, a 2 x 2 factorial design, placebo-controlled, double-blinded, pilot and feasibility, clinical trial was proposed to test this hypothesis. Forty adult participants with CF were block-randomized into one of four groups: 1) high-dose oral vitamin D3 (50,000 IU weekly) plus oral prebiotic placebo daily; 2) oral prebiotic (12 g inulin daily) plus oral placebo vitamin D3 weekly; 3) combined oral vitamin D3 weekly and oral prebiotic inulin daily; and 4) oral vitamin D3 placebo weekly and oral prebiotic placebo. The primary endpoints included 12-week changes in the microbial bacterial communities, gut and airway microbiota richness and diversity before and after the intervention. This pilot study examined whether vitamin D3 with or without prebiotics supplementation was feasible, changed airway and gut microbiota, and reduced dysbiosis, which in turn, may improve health outcomes and quality of life of patients with CF.

Vitamin D and Prebiotics for Intestinal Health in Cystic Fibrosis: Rationale and design for a randomized, placebo-controlled, double-blind, 2 × 2 trial of administration of prebiotics and cholecalciferol (vitamin D3) (Pre-D Trial) in adults with cystic fibrosis.

Individuals with cystic fibrosis (CF) have dysfunctional intestinal microbiota and increased gastrointestinal (GI) inflammation also known as GI dysbiosis. It is hypothesized that administration of high-dose cholecalciferol (vitamin D3) together with a prebiotic (inulin) will be effective, and possibly additive or synergistic, in reducing CF-related GI dysbiosis and improving intestinal functions. Thus, a 2 × 2 factorial design, placebo-controlled, double-blind, clinical trial was proposed to test this hypothesis. Forty adult participants with CF will be block-randomized into one of four groups: 1) high-dose oral vitamin D3 (50,000 IU weekly) plus oral prebiotic placebo daily; 2) oral prebiotic (12 g inulin daily) plus oral placebo vitamin D3 weekly; 3) combined oral vitamin D3 weekly and oral prebiotic inulin daily; and 4) oral vitamin D3 placebo weekly and oral prebiotic placebo. The primary endpoints will include 12-week changes in the reduced relative abundance of gammaproteobacteria, and gut microbiota richness and diversity before and after the intervention. This clinical study will examine whether vitamin D3 with or without prebiotics will improve intestinal health and reduce GI dysbiosis, which in turn, should improve health outcomes and quality of life of patients with CF.

Impact of high-dose cholecalciferol (vitamin D3) and inulin prebiotic on intestinal and airway microbiota in adults with cystic fibrosis: A 2 × 2 randomized, placebo-controlled, double-blind pilot study.

Background: Cystic fibrosis (CF) is a multi-organ disease caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR). Individuals with CF often have gastrointestinal (GI) dysbiosis due to chronic inflammation and antibiotic use. Previous studies suggested a role for vitamin D in reversing the GI dysbiosis found in CF. Objective: To explore the potential role of a combination of high-dose oral cholecalciferol (vitamin D3) and fermentable dietary fiber, inulin, to impact bacterial composition, richness, and diversity of intestinal and airway microbiota in adults with CF. Methods: This was a 2 × 2 factorial, double-blinded, placebo-controlled, randomized, pilot clinical trial in which adults with CF received oral cholecalciferol (vitamin D3) (50,000 IU/week) and/or inulin (12 g/day) for 12 weeks. Thus, there were 4 study groups (n = 10 subjects per group); 1) placebo 2) vitamin D3 3) inulin 4) vitamin D3 plus inulin. Stool and sputum samples were collected at baseline (just before) and after the intervention and were analysed using 16S ribosomal RNA gene sequencing for gut and airway microbiota composition. Statistical analyses assessed alpha and beta diversity to evaluate microbial community changes. Results: Of a total of 254 screened participants, 40 eligible participants were randomized to one of the 4 treatment arms. Participants receiving vitamin D3 plus inulin exhibited greater changes in microbiome indexes in both intestinal and airway relative to those in the other study groups. Specific taxonomic changes supported the potential beneficial influence of this combination to mitigate both intestinal and airway dysbiosis in adults with CF. Conclusion: This pilot study established that the combination of oral vitamin D3 and the prebiotic inulin was well tolerated over 12 weeks in adults with CF and altered gut and airway bacterial communities. Future research appear warranted to define clinical outcomes and the role of microbiota changes therein with this approach.

Predicting glycemic control status and high blood glucose levels through voice characteristic analysis in patients with cystic fibrosis-related diabetes (CFRD).

Cystic fibrosis-related diabetes (CFRD) is associated with reduced life expectancy in adults with cystic fibrosis (CF). Voice analysis may be a convenient method for diagnosing and monitoring CFRD. This study aims to determine the relationship between voice characteristics and markers of glucose and glycemic control and to identify if voice analysis can predict high blood glucose levels and glycemic control in adults with CFRD. We conducted a prospective cross-sectional study in adults with CF from March to December 2021. We recorded 3-second voice samples of a sustained /a/ vowel and analyzed voice characteristic using the Computerized Speech Lab with the Multi-Dimensional Voice Program. In female participants with CFRD, the noise-to-harmonic ratio was significantly lower in those with HbA1c ≥ 7. Furthermore, fundamental frequency variation was significantly lower in both male and female participants with CFRD who had a glucose level of 200 mg/dL or higher at the time of collection. This finding was also associated with a high level of point-of-care glucose. The human voice has potential as a non-invasive tool for measuring glucose levels and glycemic control status in CFRD patients in the future.

Variation in survival in patients with Coronavirus Disease 2019 supported with extracorporeal membrane oxygenation: A multi-institutional analysis of 594 consecutive patients with Coronavirus Disease 2019 supported with extracorporeal membrane oxygenation at 49 hospitals within 21 states.

OBJECTIVES: We reviewed 594 consecutive patients with Coronavirus Disease 2019 supported with extracorporeal membrane oxygenation at 49 hospitals within 21 states and examined patient characteristics, treatments, and variation in outcomes over the course of the pandemic. METHODS: A multi-institutional database was used to assess all patients with Coronavirus Disease 2019 cannulated for extracorporeal membrane oxygenation between March 17, 2020, and December 20, 2021, inclusive, and separated from ECMO on or prior to January 14, 2022. Descriptive analysis was stratified by 4 time categories: group A = March 2020 to June 2020, group B = July 2020 to December 2020, group C = January 2021 to June 2021, group D = July 2021 to December 2021. A Bayesian mixed-effects logistic regression was used to assess continuous trends in survival where time was operationalized as the number of days between each patient's cannulation and that of the first patient in March 2020, controlling for multiple variables and risk factors. RESULTS: At hospital discharge, of 594 patients, 221 survived (37.2%) and 373 died. Throughout the study, median age [interquartile range] declined (group A = 51.0 [41.0-60.0] years, group D = 39.0 [32.0-48.0] years, P < .001); median days between Coronavirus Disease 2019 diagnosis and intubation increased (group A = 4.0 [1.0-8.5], group D = 9.0 [5.0-14.5], P < .001); and use of medications (glucocorticoids, interleukin-6 blockers, antivirals, antimalarials) and convalescent plasma fluctuated significantly (all P < .05). Estimated odds of survival varied over the study period with a decline between April 1, 2020, and November 21, 2020 (odds ratio, 0.39, 95% credible interval, 0.18-0.87, probability of reduction in survival = 95.7%), improvement between November 21, 2020, and May 17, 2021 (odds ratio, 1.85, 95% credible interval, 0.86-4.09, probability of improvement = 93.4%), and decline between May 17, 2021, and December 1, 2021 (odds ratio, 0.49, 95% credible interval, 0.19-1.44, probability of decrease = 92.1%). CONCLUSIONS: Survival for patients with Coronavirus Disease 2019 supported with extracorporeal membrane oxygenation has fluctuated during the stages of the pandemic. Minimizing variability by adherence to best practices may refine the optimal use of extracorporeal membrane oxygenation in a pandemic response.

First reported use of the heartware HVAD in the US as bridge to transplant in an adolescent.

Limited options exist for mechanical circulatory support as a bridge to transplantation in pediatric patients with advanced heart failure. This is particularly true when it comes to intracorporeal technologies. We describe the first reported experience with the use of the HVAD in the US as a successful bridge to transplantation in a 13-yr-old patient.

Late onset renal failure and nephrotic syndrome after autologous stem cell transplant for Al amyloidosis.

We present a patient with AL amyloidosis who had an autologous stem cell transplant (ASCT) over 9 years ago. She has since then developed slowly progressive renal insufficiency and the nephrotic syndrome. Hematologic evaluation has failed to identify recurrent disease and a renal biopsy demonstrated extensive amyloid deposition and substantial glomerulosclerosis. We suggest that the patient has chronic glomerulosclerosis as a consequence of renal damage associated with her disease process and her treatment.

Prolonged hemodialysis for severe metformin intoxication.

Lactic acidosis is a rare and often lethal complication of metformin therapy. We describe a patient who ingested at least 52 g, and possibly more, of metformin and presented with severe lactic acidosis and acute renal failure. He was treated with prolonged hemodialysis: a 3.5 h treatment that did not result in significant clinical improvement, followed by an additional 31 h treatment. With this treatment regimen, his lactate levels gradually decreased and his clinical status improved. A metformin level drawn approximately 25 h after the initiation of the second hemodialysis treatment was still elevated at about five times the upper therapeutic limit. It is suggested that prolonged dialysis is indicated in patients with severe metformin overdose, particularly those with renal failure. In patients whose cardiovascular status permits, prolonged hemodialysis should be strongly considered.

Henoch-Schönlein purpura and recurrent renal failure.

We present an 18-year-old patient with Henoch-Schönlein purpura (HSP) who had multiple episodes of severe acute renal failure, including one episode for which he required hemodialysis for 2 months and a second episode for which dialysis was considered before his spontaneous recovery of renal function. Multiple treatment options, including steroids, mycophenolate mofetil, cyclophosphamide, and plasmapheresis, were tried but we could not confidently point to the utility of any of these measures. We highlight the unusual severity and lability of our patient's clinical course and how such a course makes the evaluation of treatment effectiveness extraordinarily difficult.

Comparison of ultrasound and CT in the evaluation of pneumonia complicated by parapneumonic effusion in children.

OBJECTIVE: The purpose of our study was to compare chest ultrasound and chest CT in children with complicated pneumonia and parapneumonic effusion. MATERIALS AND METHODS: We retrospectively compared chest ultrasound and chest CT in 19 children (nine girls and 10 boys; age range, 8 months-17 years) admitted with complicated pneumonia and parapneumonic effusion between December 2006 and January 2009. Images were evaluated for effusion, loculation, fibrin strands, parenchymal consolidation, necrosis, and abscess. In the subset of patients who underwent surgical management, imaging findings were correlated with operative findings. RESULTS: Eighteen of 19 patients had an effusion on both chest ultrasound and chest CT. The findings of effusion loculation as well as parenchymal consolidation and necrosis or abscess were similar between the two techniques. Chest ultrasound was better able to visualize fibrin strands within the effusions. Of the 14 patients who underwent video-assisted thoracoscopy, five had surgically proven parenchymal abscess or necrosis. Preoperatively, chest ultrasound was able to show parenchymal abscess or necrosis in four patients, whereas chest CT was able to show parenchymal abscess or necrosis in three. CONCLUSION: In our series, chest ultrasound and chest CT were similar in their ability to detect loculated effusion and lung necrosis or abscess resulting from complicated pneumonia. Chest CT did not provide any additional clinically useful information that was not also seen on chest ultrasound. We suggest that the imaging workup of complicated pediatric pneumonia include chest radiography and chest ultrasound, reserving chest CT for cases in which the chest ultrasound is technically limited or discrepant with the clinical findings.