Does High-Intensity Exercise Cause Acute Liver Injury in Patients with Fontan Circulation? A Prospective Pilot Study.

The Fontan procedure results in chronic hepatic congestion and Fontan-associated liver disease (FALD) characterized by progressive liver fibrosis and cirrhosis. Exercise is recommended in this population, but may accelerate the progression of FALD from abrupt elevations in central venous pressure. The aim of this study was to assess if acute liver injury occurs after high-intensity exercise in patients with Fontan physiology. Ten patients were enrolled. Nine had normal systolic ventricular function and one had an ejection fraction < 40%. During cardiopulmonary exercise testing, patients had near-infrared spectroscopy (NIRS) to measure oxygen saturation of multiple organs, including the liver, and underwent pre- and post-exercise testing with liver elastography, laboratory markers, and cytokines to assess liver injury. The hepatic and renal NIRS showed a statistically significant decrease in oxygenation during exercise, and the hepatic NIRS had the slowest recovery compared to renal, cerebral, and peripheral muscle NIRS. A clinically significant increase in shear wave velocity occurred after exercise testing only in the one patient with systolic dysfunction. There was a statistically significant, albeit trivial, increase in ALT and GGT after exercise. Fibrogenic cytokines traditionally associated with FALD did not increase significantly in our cohort; however, pro-inflammatory cytokines that predispose to fibrogenesis did significantly rise during exercise. Although patients with Fontan circulation demonstrated a significant reduction in hepatic tissue oxygenation based on NIRS saturations during exercise, there was no clinical evidence of acute increase in liver congestion or acute liver injury following high-intensity exercise.

Cumulative comorbid conditions influence mortality risk after staged palliation for hypoplastic left heart syndrome and variants.

OBJECTIVE: Prematurity, low birth weight, genetic syndromes, extracardiac conditions, and secondary cardiac lesions are considered high-risk conditions associated with mortality after stage 1 palliation. We report the impact of these conditions on outcomes from a prospective multicenter improvement collaborative. METHODS: The National Pediatric Cardiology Quality Improvement Collaborative Phase II registry was queried. Comorbid conditions were categorized and quantified to determine the cumulative burden of high-risk diagnoses on survival to the first birthday. Logistic regression was applied to evaluate factors associated with mortality. RESULTS: Of the 1421 participants, 40% (575) had at least 1 high-risk condition. The aggregate high-risk group had lower survival to the first birthday compared with standard risk (76.2% vs 88.1%, P < .001). Presence of a single high-risk diagnosis was not associated with reduced survival to the first birthday (odds ratio, 0.71; confidence interval, 0.49-1.02, P = .066). Incremental increases in high-risk diagnoses were associated with reduced survival to first birthday (odds ratio, 0.23; confidence interval, 0.15-0.36, P < .001) for 2 and 0.17 (confidence interval, 0.10-0.30, P < .001) for 3 to 5 high-risk diagnoses. Additional analysis that included prestage 1 palliation characteristics and stage 1 palliation perioperative variables identified multiple high-risk diagnoses, poststage 1 palliation extracorporeal membrane oxygenation support (odds ratio, 0.14; confidence interval, 0.10-0.22, P < .001), and cardiac reoperation (odds ratio, 0.66; confidence interval, 0.45-0.98, P = .037) to be associated with reduced survival odds to the first birthday. CONCLUSIONS: The presence of 1 high-risk diagnostic category was not associated with decreased survival at 1 year. Cumulative diagnoses across multiple high-risk diagnostic categories were associated with decreased odds of survival. Further patient accrual is needed to evaluate the impact of specific comorbid conditions within the broader high-risk categories.

Mathematical analysis of hemoglobin target in univentricular parallel circulation.

OBJECTIVE: The hemoglobin threshold for a decision to transfuse red blood cells in univentricular patients with parallel circulation is unclear. A pediatric expertise initiative put forth a "weak recommendation" for avoiding reflexive transfusion beyond a hemoglobin of 9 g/dL. We have created a mathematical model to assess the impact of hemoglobin thresholds in patients with parallel circulation. METHODS: A univentricular circulation was mathematically modeled. We examined the impact on oxygen extraction ratios and systemic and venous oxygen saturations by varying hemoglobin levels, pulmonary to systemic blood flow ratios, and total cardiac output. RESULTS: Applying a total cardiac index of 6 L/m2/min, oxygen consumption of 150 mL/min/m2, and a Qp/Qs ∼ 1, we found a hemoglobin level of 9 g/dL would lead to severe arterial (arterial oxygen saturation <70%) and venous (systemic venous oxygen saturation <40%) hypoxemia. To operate above the critical oxygen economy boundary (systemic venous oxygen saturation ∼40%) and maintain arterial oxygen saturation >70% would require either increasing the cardiac index to âˆ¼ 9 L/m2/min or increasing the hemoglobin to greater than 13 g/dL. Further, we found a greater improvement in arterial and venous saturation arises when hemoglobin is augmented from levels below 12 g/dL. CONCLUSIONS: Based on our model, a hemoglobin level of 9 g/dL would require a constricted set of features to sustain arterial saturations >70% and systemic venous saturations >40% and would risk unfavorable oxygen economy with elevations in oxygen consumption. Further prospective clinical studies are needed to delineate the impact of restrictive transfusion practices in univentricular circulation.

Impact of Reintervention During Stage 1 Palliation Hospitalization: A National, Multicenter Study.

BACKGROUND: Stage 1 palliation (S1P) for hypoplastic left heart syndrome remains associated with high morbidity and mortality. Previous studies on burden of reinterventions did not include patients who remain hospitalized before stage 2 palliation (S2P). This study described the rate of reintervention during S1P hospitalization and sought to determine the impact of reintervention on outcomes. METHODS: All participants enrolled in phase II of the National Pediatric Cardiology Quality Improvement Collaborative after S1P were included in this study. The primary outcome was the rate of reintervention during hospitalization after S1P and before hospital discharge or S2P. Reintervention was defined as 1 or more unplanned interventional cardiac catheterizations or surgical reoperations. RESULTS: Between March 1, 2016 and October 1, 2019, 1367 participants underwent S1P and 339 (24.8%) had a reintervention; most commonly to address the source of pulmonary blood flow. Gestational age, weight at S1P, atrioventricular septal defect, heterotaxy, preoperative pulmonary artery bands, hybrid S1P, and an additional bypass run or early extracorporeal membrane oxygenation were significantly associated with reintervention. Participants in the reintervention group experienced higher rates of nearly all postoperative complications, were less likely to be discharged before S2P (57.1% vs 86%; P < .001), and more likely to experience in-hospital mortality (17% vs 5%; P < .001). CONCLUSIONS: Unplanned reintervention during hospitalization after S1P palliation occurred in 25% of participants in a large, registry-based national cohort. Participants who underwent reintervention were more likely to remain as inpatient and were less likely to survive to S2P. Reintervention was associated with a multitude of postoperative complications that affect survival and long-term outcome.

Intranasal dexmedetomidine for transthoracic echocardiography in infants with shunt-dependent single ventricle heart disease.

OBJECTIVES: We investigated the efficacy and complication profile of intranasal dexmedetomidine for transthoracic echocardiography sedation in patients with single ventricle physiology and shunt-dependent pulmonary blood flow during the high-risk interstage period. METHODS: A single-centre, retrospective review identified interstage infants who received dexmedetomidine for echocardiography sedation. Baseline and procedural vitals were reported. Significant adverse events related to sedation were defined as an escalation in care or need for any additional/increased inotropic support to maintain pre-procedural haemodynamics. Minor adverse events were defined as changes from baseline haemodynamics that resolved without intervention. To assess whether sedation was adequate, echocardiogram reports were reviewed for completeness. RESULTS: From September to December 2020, five interstage patients (age 29-69 days) were sedated with 3 mcg/kg intranasal dexmedetomidine. The median sedation onset time and duration time was 24 minutes (range 12-43 minutes) and 60 minutes (range 33-60 minutes), respectively. Sedation was deemed adequate in all patients as complete echocardiograms were accomplished without a rescue dose. When compared to baseline, three (60%) patients had a >10% reduction in heart rate, one (20%) patient had a >10% reduction in oxygen saturations, and one (20%) patient had a >30% decrease in blood pressure. Amongst all patients, no significant complications occurred and haemodynamic changes from baseline did not result in need for intervention or interruption of study. CONCLUSIONS: Intranasal dexmedetomidine may be a reasonable option for echocardiography sedation in infants with shunt-dependent single ventricle heart disease, and further investigation is warranted to ensure efficacy and safety in an outpatient setting.

Nuclear Cell-Free DNA Predicts Adverse Events After Pediatric Cardiothoracic Surgery.

BACKGROUND: Preoperative risk stratification in cardiac surgery includes patient and procedure factors that are used in clinical decision-making. Despite these tools, unidentified factors contribute to variation in outcomes. Identification of latent physiologic risk factors may strengthen predictive models. Nuclear cell-free DNA (ncfDNA) increases with tissue injury and drops to baseline levels rapidly. The goal of this investigation is to measure and to observe ncfDNA kinetics in children undergoing heart operations with cardiopulmonary bypass (CPB), linking biomarkers, organ dysfunction, and outcomes. METHODS: This is a prospective observational study of 116 children <18 years and >3 kg undergoing operations with CPB. Plasma ncfDNA samples were collected and processed in a stepwise manner at predefined perioperative time points. The primary outcome measure was occurrence of postoperative cardiac arrest or extracorporeal membrane oxygenation. RESULTS: Data were available in 116 patients (median age, 0.9 years [range, 0-17.4 years]; median weight, 7.8 kg [range, 3.2-98 kg]). The primary outcome was met in 6 of 116 (5.2%). Risk of primary outcome was 2% with ncfDNA <20 ng/mL and 33% with ncfDNA >20 ng/mL (odds ratio, 25; CI, 3.96-158; P = .001). Elevated ncfDNA was associated with fewer hospital-free days (P < .01). CONCLUSIONS: This study analyzes ncfDNA kinetics in children undergoing operations with CPB for congenital heart disease. Elevated preoperative ncfDNA is strongly associated with postoperative arrest and extracorporeal membrane oxygenation. Further studies are needed to validate this technology as a tool to predict morbidity in children after cardiac surgical procedures.

Effects of Arterial Carbon Dioxide Tension on Cerebral and Somatic Regional Tissue Oxygenation and Blood Flow in Neonates After the Norwood Procedure With Deep Hypothermic Cardiopulmonary Bypass.

Neonates undergoing the Norwood procedure for hypoplastic left heart syndrome are at higher risk of impaired systemic oxygen delivery with resultant brain, kidney, and intestinal ischemic injury, shock, and death. Complex developmental, anatomic, and treatment-related influences on cerebral and renal-somatic circulations make individualized treatment strategies physiologically attractive. Monitoring cerebral and renal circulations with near infrared spectroscopy can help drive rational therapeutic interventions. The primary aim of this study was to describe the differential effects of carbon dioxide tension on cerebral and renal circulations in neonates after the Norwood procedure. Using a prospectively-maintained database of postoperative physiologic and hemodynamic parameters, we analyzed the relationship between postoperative arterial carbon dioxide tension and tissue oxygen saturation and arteriovenous saturation difference in cerebral and renal regions, applying univariate and multivariate multilevel mixed regression techniques. Results were available from 7,644 h of data in 178 patients. Increases in arterial carbon dioxide tension were associated with increased cerebral and decreased renal oxygen saturation. Differential changes in arteriovenous saturation difference explained these effects. The cerebral circulation showed more carbon dioxide sensitivity in the early postoperative period, while sensitivity in the renal circulation increased over time. Multivariate models supported the univariate findings and defined complex time-dependent interactions presented graphically. The cerebral and renal circulations may compete for blood flow with critical limitations of cardiac output. The cerebral and renal-somatic beds have different circulatory control mechanisms that can be manipulated to change the distribution of cardiac output by altering the arterial carbon dioxide tension. Monitoring cerebral and renal circulations with near infrared spectroscopy can provide rational physiologic targets for individualized treatment.

Elevated nuclear and mitochondrial cell-free deoxyribonucleic acid measurements are associated with death after infant cardiac surgery.

OBJECTIVES: Mortality rates following pediatric cardiac surgery with cardiopulmonary bypass have declined over decades, but have plateaued in recent years. This is in part attributable to persistent issues with postoperative global inflammation and myocardial dysfunction, commonly manifested by systemic inflammatory response syndrome and low cardiac output syndrome, respectively. Quantified cell-free DNA (cfDNA), of nuclear or mitochondrial origin, has emerged as a biomarker for both inflammation and myocardial injury. Recent data suggest that nuclear cfDNA (ncfDNA) may quantify inflammation, whereas mitochondrial cfDNA (mcfDNA) may correlate with the degree of myocardial injury. We hypothesize that threshold levels of ncfDNA and mcfDNA can be established that are sensitive and specific for postoperative mortality mediated through independent pathways, and that association will be enhanced with combined analysis. METHODS: Prospective observational study of infants younger than age 1 year undergoing planned surgery with cardiopulmonary bypass. The study received institutional review board approval. Samples were drawn before skin incision, immediately after completion of cardiopulmonary bypass, and subsequently at predetermined intervals postoperatively. Association of early postoperative ncfDNA and mcfDNA levels with mortality were assessed by logistic regression with cut-points chosen by receiving operating characteristic curve exploration. RESULTS: Data were available in 59 patients. Median age and weight were 122 days (interquartile range, 63-154 days) and 4.9 kg (interquartile range, 3.9-6.2 kg). Median STAT category was 3 (interquartile range, 1-4). The primary outcome of death was met in 3 out of 59 (5%). Combined analysis of ncfDNA and mcfDNA levels at 12 hours after the initiation of cardiopulmonary bypass with death at a threshold of 50 ng/mL ncfDNA and 17 copies/µL mcfDNA yielded 100% sensitivity and negative predictive value. The specificity (91%) and positive predictive value (38%) increased through combined analysis compared with univariate analysis. Combined analysis exhibited high specificity (93%) and negative predictive value (78%) for prolonged (>30 postoperative days) hospitalization. CONCLUSIONS: Combined analysis of early postoperative ncfDNA and mcfDNA can stratify risk of mortality and prolonged hospitalization following infant cardiac surgery. Evaluation of both ncfDNA and mcfDNA to identify states of generalized inflammation and myocardial injury may allow for targeted interventions and improved outcomes.

CropPol: A dynamic, open and global database on crop pollination.

Seventy five percent of the world's food crops benefit from insect pollination. Hence, there has been increased interest in how global change drivers impact this critical ecosystem service. Because standardized data on crop pollination are rarely available, we are limited in our capacity to understand the variation in pollination benefits to crop yield, as well as to anticipate changes in this service, develop predictions, and inform management actions. Here, we present CropPol, a dynamic, open, and global database on crop pollination. It contains measurements recorded from 202 crop studies, covering 3,394 field observations, 2,552 yield measurements (i.e., berry mass, number of fruits, and fruit density [kg/ha], among others), and 47,752 insect records from 48 commercial crops distributed around the globe. CropPol comprises 32 of the 87 leading global crops and commodities that are pollinator dependent. Malus domestica is the most represented crop (32 studies), followed by Brassica napus (22 studies), Vaccinium corymbosum (13 studies), and Citrullus lanatus (12 studies). The most abundant pollinator guilds recorded are honey bees (34.22% counts), bumblebees (19.19%), flies other than Syrphidae and Bombyliidae (13.18%), other wild bees (13.13%), beetles (10.97%), Syrphidae (4.87%), and Bombyliidae (0.05%). Locations comprise 34 countries distributed among Europe (76 studies), North America (60), Latin America and the Caribbean (29), Asia (20), Oceania (10), and Africa (7). Sampling spans three decades and is concentrated on 2001-2005 (21 studies), 2006-2010 (40), 2011-2015 (88), and 2016-2020 (50). This is the most comprehensive open global data set on measurements of crop flower visitors, crop pollinators and pollination to date, and we encourage researchers to add more datasets to this database in the future. This data set is released for non-commercial use only. Credits should be given to this paper (i.e., proper citation), and the products generated with this database should be shared under the same license terms (CC BY-NC-SA).

COVID-19 pre-procedural testing strategy and early outcomes at a large tertiary care children's hospital.

PURPOSE: With the emergence of the coronavirus disease-2019 (COVID-19) pandemic, institutions were tasked with developing individualized pre-procedural testing strategies that allowed for re-initiation of elective procedures within national and state guidelines. This report describes the experience of a single US children's hospital (Children's Wisconsin, CW) in developing a universal pre-procedural COVID-19 testing protocol and reports early outcomes. METHODS: The CW pre-procedural COVID-19 response began with the creation of a multi-disciplinary taskforce that sought to develop a strategy for universal pre-procedural COVID-19 testing which (1) maximized patient safety, (2) prevented in-hospital viral transmission, (3) conserved resources, and (4) allowed for resumption of procedural care within institutional capacity. RESULTS: Of 11,209 general anesthetics performed at CW from March 16, 2020 to October 31, 2020, 11,150 patients (99.5%) underwent pre-procedural COVID-19 testing. Overall, 1.4% of pre-procedural patients tested positive for COVID-19. By June 2020, CW was operating at near-normal procedural volume and there were no documented cases of in-hospital viral transmission. Only 0.5% of procedures were performed under augmented COVID-19 precautions (negative pressure environment and highest-level personal protective equipment). CONCLUSION: CW successfully developed a multi-disciplinary pre-procedural COVID-19 testing protocol that enabled resumption of near-normal procedural volume within three months while limiting in-hospital viral transmission and resource use.

Interventions Associated With Treatment of Low Cardiac Output After Stage 1 Norwood Palliation.

BACKGROUND: Mortality after stage 1 palliation of hypoplastic left heart syndrome remains significant. Both cardiac output (CO) and systemic vascular resistance (SVR) contribute to hemodynamic vulnerability. Simultaneous measures of mean arterial pressure and somatic regional near infrared spectroscopy saturation can classify complex hemodynamics into 4 distinct states, with a low-CO state of higher risk. We sought to identify interventions associated with low-CO state occupancy and transition. METHODS: Perioperative data were prospectively collected in an institutional review board-approved database. Hemodynamic state was classified as high CO, high SVR, low SVR, and low CO using bivariate analysis. Associations of static and dynamic support levels and state classifications over 48 postoperative hours were tested between states and across transitions using mixed regression methods in a quasi-experimental design. RESULTS: Data from 10,272 hours in 214 patients were analyzed. A low-CO state was observed in 142 patients for 1107 hours. Both low CO and extracorporeal membrane oxygenation had increased mortality risk. The low-CO state was characterized by lower milrinone but higher catecholamine dose. Successful transition out of low CO was associated with increased milrinone dose and hemoglobin concentration. Increasing milrinone and hemoglobin levels predicted reduced risk of low CO in future states. CONCLUSIONS: Bivariate classification objectively defines hemodynamic states and transitions with distinct support profiles. Maintaining or increasing inodilator and hemoglobin levels were associated with improved hemodynamic conditions and were predictive of successful future transitions from the low-CO state.

Innominate Vein Turn-down Procedure for Failing Fontan Circulation.

After the Fontan, systemic venous hypertension induces pathophysiologic changes in the lymphatic system that can result in complications of pleural effusion, ascites, plastic bronchitis, and protein losing enteropathy. Advances in medical therapy and novel interventional approaches have not substantially improved the poor prognosis of these complications. A more physiological approach has been developed by decompression of the thoracic duct to the lower pressure common atrium with a concomitant increase of preload. Diverting the innominate vein to the common atrium increases the transport capacity of the thoracic duct, which in most patients enters the circulation at the left subclavian-jugular vein junction. Contrary to the fenestrated Fontan circulation, in which the thoracic duct is drained into the high pressure Fontan circulation, turn down of the innominate vein to the common atrium effectively decompresses the thoracic duct to the lower pressure system with "diastolic suctioning" of lymph. Innominate vein turn-down may be considered for medical-refractory post-Fontan lymphatic complications of persistent chylothorax, plastic bronchitis, and protein losing enteropathy. Prophylactic innominate vein turn-down may also be considered at time of the Fontan operation for patients that are higher risk for lymphatic complications.

Identification of Time-Dependent Risks of Hemodynamic States After Stage 1 Norwood Palliation.

BACKGROUND: Mortality after stage 1 palliation of hypoplastic left heart syndrome remains significant. Hemodynamic changes result from interaction of cardiac output (CO) and systemic vascular resistance (SVR). We sought to identify time-dependent changes in postoperative hemodynamic states and their associations with mortality. METHODS: Perioperative data were prospectively collected in an institutional review board-approved database. Hemodynamic state was classified as high CO, high SVR, low SVR, and low CO using bivariate analysis of mean arterial pressure and somatic regional near-infrared spectroscopic oximetry saturation. State classifications over 48 postoperative hours were modelled using multinomial logistic regressions for association with mortality. RESULTS: Data from 9614 of 10,272 hours in 214 patients were analyzed. Operative survival was 91%. The predominant state was high CO (46% time). Low CO state without extracorporeal membrane oxygenation (ECMO) was found in 52% of patients for 9.7% time. ECMO was employed in 24 (11.2%) patients for 10.4% time. State stability was 33%, with high SVR the least stable (17%) and high CO the most stable (53%). Transition from high CO increased in hours 1 to 12, mainly to low SVR. Transition to low CO was 18.4%, increasing in hours 1 to 12, mainly from high SVR. The transition risk to ECMO was 0.32%, and 0.74% during hours 1 to 12, only from low CO. Both low CO and ECMO had increased mortality risk. CONCLUSIONS: Bivariate classification defines hemodynamic states with distinct physiologic, transition, and mortality risk profiles. High SVR state was unstable. Transition to ECMO occurred only from low CO, while the low SVR and high CO states were safest.

Norwood Procedure-Difficulty in Weaning From Cardiopulmonary Bypass and Implications for Outcomes.

Difficulty weaning from cardiopulmonary bypass (CPB) or the need to return to CPB (collectively D-CPB) may occur after the Norwood procedure. We sought to evaluate the relationship between D-CBP and survival. This was a retrospective chart review of all patients undergoing a Norwood procedure at our institution during the interval 2005-2017. Primary outcome was survival for the Norwood procedure. Secondary outcomes included various measures of morbidity. Successful wean from CBP (S-CPB) was defined as no need to return to full-flow CPB during the initial definitive wean or after separation from CPB; otherwise, the classification was difficulty with wean (D-CBP). Successful rescue in the D-CPB group was defined as not requiring extracorporeal life support either in the operating room or within the first 3 postoperative days. Of the 196 patients in the cohort, 49 were D-CPB. Survival for S-CPB was 92.5% (136/147) vs 71.4% (35/49) for D-CPB (P = 0.001). Major morbidity occurred in 29.9% (44/147) in S-CPB vs 69.4% (34/49) in D-CPB (P < 0.001). With multivariable analysis, D-CPB was significantly associated with mortality (odds ratio = 8.09; confidence interval 2.72-24.05; P < 0.001). Successful rescue occurred in 30 of 49 patients in the D-CPB group and demonstrated survival similar to the S-CPB group. In the Norwood patient, D-CPB is an important intraoperative event and prognostic factor for mortality and morbidity. Successful rescue appears to ameliorate the impact of D-CPB on survival.

Mismatched outcomes for biodiversity and ecosystem services: testing the responses of crop pollinators and wild bee biodiversity to habitat enhancement.

Supporting ecosystem services and conserving biodiversity may be compatible goals, but there is concern that service-focused interventions mostly benefit a few common species. We use a spatially replicated, multiyear experiment in four agricultural settings to test if enhancing habitat adjacent to crops increases wild bee diversity and abundance on and off crops. We found that enhanced field edges harbored more taxonomically and functionally abundant, diverse, and compositionally different bee communities compared to control edges. Enhancements did not increase the abundance or diversity of bees visiting crops, indicating that the supply of pollination services was unchanged following enhancement. We find that actions to promote crop pollination improve multiple dimensions of biodiversity, underscoring their conservation value, but these benefits may not be spilling over to crops. More work is needed to identify the conditions that promote effective co-management of biodiversity and ecosystem services.

Safety and Efficacy of Vasopressin After Fontan Completion: A Randomized Pilot Study.

BACKGROUND: Arginine vasopressin is a nonapeptide hormone with effects on intracellular water transport and arterial tone that is used in distributive shock and following cardiopulmonary bypass. We sought to evaluate the safety and efficacy of vasopressin infusion on hemodynamics and fluid balance in the early postoperative period after Fontan completion. METHODS: We conducted a randomized, double-blinded, placebo-controlled study of vasopressin infusion for 24 hours after cardiopulmonary bypass for Fontan completion. Patient characteristics, hospital outcomes, and measures of hemodynamic parameters, urine output, chest tube drainage, fluid balance, laboratory data, and plasma arginine vasopressin concentrations were collected at baseline and for 48 postoperative hours. Data were analyzed using mixed-effect regressions. RESULTS: Twenty patients were randomized, 10 to vasopressin and 10 to placebo. Transpulmonary gradient (6.4 ± 0.5 vs 8.3 ± 0.5 mm Hg, P = .011) and chest tube drainage (23 ± 20 vs 40 ± 20 mL/kg, P = .028) for 48 hours after surgery were significantly lower in the vasopressin arm compared to placebo. Arginine vasopressin concentrations were elevated above baseline after surgery until 4 hours post cardiac intensive care unit admission in both arms, and higher in the vasopressin arm during postoperative infusion. No differences in sodium concentration, liver function, or renal function were noted between groups. CONCLUSIONS: Vasopressin infusion after Fontan completion appears safe and was associated with reduced transpulmonary gradient and chest tube drainage in the early postoperative period. A larger multiinstitutional study may show further outcome benefit.

Impact of Anticoagulation and Circuit Technology on Complications During Extracorporeal Membrane Oxygenation.

The objective of this study is to evaluate the impact a change in anticoagulation protocol and circuit technology had on bleeding and thrombotic complications in patients supported on extracorporeal membrane oxygenation (ECMO). A retrospective review at a tertiary, academic pediatric intensive care unit was undertaken. The anticoagulation protocol changed from targeting an activated clotting time (ACT) to anti-Xa level. Significant changes in the ECMO circuit were undertaken concurrently. One-hundred and fifty-two ECMO runs in 129 patients in the ACT target group were compared with 122 ECMO runs in 101 patients in the anti-Xa target group. Improved probability of survival by ECMO duration, decreased rate of surgical exploration, increased time to first surgical exploration, decreased incidence of intracranial hemorrhage, increased time to identification of intracranial hemorrhage, decreased blood loss and transfused product volumes, decreased rate of circuit changes, and increased time to first circuit change were all observed in the anti-Xa targeted group. Heparin dosing was similar in both groups with fewer bolus doses of heparin and fewer changes in the infusion rate in the anti-Xa targeted group. The change in anticoagulation protocol and circuit technology was associated with an improvement in survival, a decrease in hemorrhagic complications, and a decrease in circuit changes.

Changes in Health Care Utilization for Pediatric Patients Treated at a Specialized Outpatient Pain Clinic.

INTRODUCTION: Pediatric pain clinics may be the most efficacious way to manage chronic and recurrent pain in children and adolescents, but families often rely heavily on nonspecialized care, such as the emergency department (ED). Health care utilization patterns for pediatric chronic pain have not been fully explored, particularly the patient-level factors that may contribute to underutilization or overutilization of certain services. OBJECTIVES: To identify health care utilization patterns before and after treatment at a pediatric pain clinic and the associations by primary diagnosis and patient sociodemographics. METHODS: Data were obtained for all pediatric patients with an initial visit at an outpatient pediatric pain clinic between 2005 and 2009. Individual-level data included patient demographics, insurance type, and diagnosis at first pain clinic visit. Rate of health care system utilization 3 months before and after the initial pain clinic visit was quantified. Health care utilization rates before and after the initial visit to the pain clinic were compared using Wilcoxon signed-rank test. RESULTS: Eight hundred twenty-six pediatric pain clinic patients were included. Overall, there were significant decreases in ED utilization (P < 0.001) and increases in outpatient service utilization (P < 0.001) after the initial pain clinic visit. Similar patterns were noted for patients by diagnosis (headache, musculoskeletal, or abdominal pain diagnoses) and among those who were female, white, 15 to 18 years old, privately insured, middle- or high-income (P < 0.05). CONCLUSIONS: Visits to an outpatient pediatric pain clinic were associated with shifts in health care utilization patterns. Important changes were an overall decrease in emergency visits and an increase in outpatient visits.

Staged biliary reconstruction after liver transplantation: A novel surgical strategy for high acuity pediatric transplant recipients.

INTRODUCTION: Biliary complications after pediatric orthotopic liver transplantation remain causes of significant patient morbidity. Staged operative approach in complex hepatobiliary surgery has improved postoperative outcomes but has not been evaluated in pediatric orthotopic liver transplantation. We sought to analyze the outcomes of staged biliary reconstruction after orthotopic liver transplantation in high acuity patients. METHODS: A retrospective analysis of 43 pediatric orthotopic liver transplantations at our center (January 2013 through December 2017). Median follow-up was 25 months. Variables were compared for group I: 1-stage orthotopic liver transplantation with biliary anastomosis (n = 6) versus group II: staged biliary reconstruction orthotopic liver transplantation (n = 37). RESULTS: Comparing groups I and II, median age (7.3 vs 4.8 years), weight (27 vs 19 kg), proportion of urgent orthotopic liver transplantation (50% vs 65%), partial graft orthotopic liver transplantation (33% vs 35%), and intraoperative red blood cell transfusion volume (11 vs 21 mL/kg) were comparable. Roux-en-Y hepaticojejunostomy was performed in 67% (group I) and 49% (group II). There was no biliary complication in both groups. For groups I and II, 3-year survival rates for graft (100% vs 92%, P = .477) and patient (100% vs 97%, P = .679) were comparable. CONCLUSION: Our study showed excellent outcomes with staged biliary reconstruction orthotopic liver transplantation in high acuity pediatric transplant recipients. This is the first report showing clinical applicability of staged biliary reconstruction orthotopic liver transplantation in children.

A Novel Pollen Transfer Mechanism by Honey Bee Foragers on Highbush Blueberry (Ericales: Ericaceae).

Honey bees (Apis mellifera L. (Hymenoptera: Apidae)) are effective pollinators of many crops but are thought to be inefficient in pollinating blueberries (Vaccinium corymbosum L.) due to their inability to buzz pollinate. Nonetheless, commercial growers rent honey bee hives for pollination, resulting in the dominance of honey bee workers visiting flowers during bloom. The objective of this study was to examine where on the honey bee pollen is carried and how it is transferred from flower to bee to the stigma of other flowers. Examination of 90 honey bee workers foraging on blueberry flowers documented that blueberry pollen tetrads were present on all body parts. Relative amounts were as follows: head 12%, body 6%, legs 19%, and tarsi 63%. Quantities on the body subregions ranged from an average of 400 tetrads on the basitarsi to 16 on the fore tarsal claws. Thus, a single contact between many of the pollen-carrying body parts and a stigma has the potential to transfer significant amounts of pollen. The study also revealed that bee behaviors unrelated to the intentional collection of nectar and pollen, such as the frequent touching of stigmas by the claws, tarsi, or legs, while foraging, grooming, and walking across flower clusters, could result in pollen transfer. These contacts occurred 65.9% of the time a honey bee landed on a flower cluster. These findings have broad implications for future assessments of the efficiencies of various bee species in pollinating diverse crops and plants.