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Background As a formative step toward development of adult congenital heart disease (ACHD) risk-adjusted metrics, we describe the STS ACHD population, procedural frequency, and early mortality. Methods Adults ( > 18 years) with CHD (2014-2019) were identified in the STS Adult Cardiac Surgery (ASCD) and the Congenital Heart Surgery (CHSD) Databases. Following deduplication, variable mapping, data concatenation, and harmonization of pre-procedure factors, procedures were grouped and unadjusted mortality catalogued for overall cohort and the cohort excluding patients with isolated bicuspid aortic valve (BAV). Results Among 171,186 ACSD and 18,281 CHSD records, 152,731 unique records met inclusion criteria. Twenty-eight congenital diagnoses accounted for 86% of the overall cohort, and prevalence of ACHD increased over the study timeframe. ACHD patients underwent operations to treat both acquired and CHD. Most common procedures overall and after excluding isolated BAV were: aortic valve replacement (AVR), ascending aortic surgery, and coronary artery bypass grafting (CABG). After excluding isolated BAV, major procedure combinations occurred in 46% (31% had 2 and 3% > 4 major procedures) and most prevalent combinations included: AVR + CABG (n=2,352), AVR + subaortic stenosis repair (n=1,481) and AVR + ascending aortic surgery (n=1,239). Unadjusted 30-day mortality was procedure dependent, 2.8% overall and 3.6% with isolated BAV excluded. Conclusions The ACHD surgical population is heterogenous, and patients undergo surgery for CHD-related and adult/acquired procedure combinations. Early mortality is variable and influenced by surgical complexity. Excluding isolated BAV patients and developing procedure-based ACHD mortality risk models may be ideal but will require empirically-derived grouping and collaboration.

Background Contemporary practice patterns and outcomes for aortic valve replacement (AVR) among young and middle-aged adults are unknown given guideline modifications for surgical AVR (SAVR) and increasing transcatheter AVR (TAVR) acceptance. This study describes SAVR and TAVR use and outcomes using The Society of Thoracic Surgeons (STS) National Databases. Methods Adults 18 to 55 years of age in the Congenital Heart Surgery Database (CHSD) and the Adult Cardiac Surgery Database (ACSD) who underwent SAVR or TAVR from 2013 to 2018 were included. Perioperative characteristics and early outcomes were described by valve type. Multivariable regression identified determinants of death, length of hospital stay, and a composite end point of renal failure, persistent neurologic deficit, readmission, and reoperation. Results The study analyzed 1580 unique CHSD and 44,173 ACSD operations, 16% of which were performed in patients with congenital heart disease. Valve use included the following: TAVR, 1%; mechanical, 42%; bioprosthetic, 55%; autograft, 0.6%; homograft, 1.2%; and Ozaki, 0.4%. Over time, TAVR volumes increased by 167%. The 30-day mortality was as follows: TAVR, 3.8%; mechanical, 3.2%; bioprosthetic, 3.7%; autograft, 0.6%; homograft, 9%; and Ozaki, 3.4%. Stroke rate was lower for isolated SAVR vs isolated TAVR (0.9% vs 2.4%; P = .002). In multivariable analyses, mortality risk was lower with mechanical valves, congenital morbidity risk was higher with TAVR, and length of stay was shorter with TAVR. Conclusions TAVR is increasingly used for adults younger than 55 years of age. Given the uniformly excellent results with SAVR, including both mortality and morbidity—particularly regarding stroke, our data favor SAVR in this population, but a prospective trial is needed. Ongoing efforts to harmonize variables and outcomes definitions between the ACSD and CHSD are valuable.

Case Presentation A previously healthy 22-month-old girl presented to the ED with a 3-week history of dyspnea on exertion. A chest radiograph showed a right upper-lobe opacity suspicious for pneumonia ( Fig 1 A). The patient was prescribed amoxicillin but returned to the ED 7 days later with cough and persistent dyspnea and tachypnea. At that time, a repeat chest radiograph was concerning for worsening pneumonia ( Fig 1 B). Treatment with azithromycin and albuterol was initiated, and amoxicillin was discontinued. Her symptoms briefly improved; however, she returned to the ED 10 days later because of worsening cough and tachypnea, and a 2-day history of increased irritability, decreased oral intake, decreased urine output, and intermittent perioral cyanosis. She was afebrile throughout this period per parent report and vital sign documentation at each ED visit.

Aberrant right subclavian artery, or arteria lusoria, is a common congenital anomaly of the aortic arch and may be associated with dysphagia. Surgical treatment, particularly in children, remains controversial. Current surgical interventions include supraclavicular and thoracotomy approaches, as well as hybrid endovascular techniques. However, these techniques have significant limitations and varying degrees of success. This case report describes a 2-site operation whereby the arteria lusoria is transected via a left thoracotomy and subsequently re-implanted into the right common carotid artery via a median sternotomy. This approach has provided complete symptom resolution for dysphagia lusoria in 2 children.

We investigated the safety and efficacy of surfactant during extracorporeal membrane oxygenation (ECMO) in children with cardiac disease. ECMO patients administered surfactant (surfactant group) were compared with patients who did not receive (control). Criteria to administer surfactant were based on a decreased lung compliance of

Respiratory failure is a significant problem within the pediatric population. A means of respiratory support that readily allows ambulation could improve treatment. The Pittsburgh Pediatric Ambulatory Lung (P-PAL) is being developed as a wearable pediatric pump-lung for long-term respiratory support and has previously demonstrated positive benchtop results. This study aimed to evaluate acute (4-6 hours) in vivo P-PAL performance, as well as develop an optimal implant strategy for future long-term studies. The P-PAL was connected to healthy sheep (n = 6, 23-32 kg) via cannulation of the right atrium and pulmonary artery. Plasma-free hemoglobin (PfHb) and animal hemodynamics were measured throughout the study. Oxygen transfer rates were measured at blood flows of 1-2.5 L/min. All animals survived the complete study duration with no device exchanges. Flow limitation because of venous cannula occlusion occurred in trial 2 and was remedied via an altered cannulation approach. Blood exiting the P-PAL had 100% oxygen saturation with the exception of trial 4 during which inadequate device priming led to intrabundle clot formation. Plasma-free hemoglobin remained low (

BACKGROUND New drugs may further decrease the need for lung transplant (LTx) in pediatric patients with cystic fibrosis (CF), but few studies highlight pediatric non-CF LTx characteristics and outcomes. METHODS The ISHLT registry was used to report morbidity, graft failure, and survival for primary pediatric (

There is evidence that reducing opioid exposure in children undergoing cardiac surgery may enhance postoperative recovery. We aimed to describe a minimal opioid postoperative management protocol in children undergoing cardiac surgery and our early outcomes with this strategy. We reviewed the medical records of children (6 months-18 years) who underwent elective cardiac surgery through a median sternotomy with cardiopulmonary bypass at our institution between 2016 and 2018. All patients were managed postoperatively using a standardized protocol. 101 children (median age 5 years) were included and 85% were extubated in the operating room. Although most patients (96%) received opioids postoperatively, opioid requirements decreased steadily over time, with 88%, 58%, and 18% of children receiving opioids on postoperative day 1, 2, and 3, respectively; 41% received no opioids after postoperative day 1. The median cumulative opioid exposure was 0.25 morphine milligram equivalents per kg (interquartile range, 0.10-0.75). Greater than mild pain was rare (10%) at each time point. The rates of operative mortality and major complication were 0% and 3%, respectively. The median postoperative length of stay was 3 days, and 13% required readmission within 30 days. Age, cardiopulmonary bypass time, and number of benzodiazepine doses were independently associated with cumulative opioid exposure. Any complication, chest tube time, and higher STAT Category were independently associated with prolonged postoperative length of stay. A minimal opioid postoperative management protocol can be safe and effective in children undergoing cardiac surgery. Future prospective studies are needed to determine optimal practice and patient selection.

Extracorporeal membrane oxygenation (ECMO) circuit volume, patient size, and blood flow may influence coagulation and hemolysis complications. We performed a single-center retrospective analysis of ECMO patients over a 6.5 year period. In 299 ECMO runs, 13% required coagulation-associated circuit changes. Respiratory ECMO was associated with coagulation-associated circuit changes [odds ratio (O/R) 2.8, p0.05] and developed severe (plasma-free hemoglobin [pfHb]100 mg/dl) hemolysis (O/R 2.3, p0.05). Severe hemolysis and component changes were associated with hospital mortality (O/R 2.3 and 2.5, respectively, p0.05). The activated partial thromboplastin time (aPTT) to residence time (RT) ratio (aPTT/RT) was used as a surrogate for coagulation risk. We found that aPTT/RT2.5 more than doubled time to circuit change (3-8 days, p0.05), but aPTT/RT3 increased bleeding risks and hospital mortality (O/R 1.8; p0.1). Hemolysis was associated with patient weight and circuit to patient volume ratio (CPVR) (p0.05), but not pump type. Hemolysis slightly increased with transfusion (p = 0.08), and transfusion requirements increased for CPVR50% (p0.1).Our data suggest that pediatric respiratory ECMO patients are more likely to develop coagulation and hemolysis complications, which are associated with increased mortality. This may result from higher inflammatory processes, which affect coagulation and red cell fragility. Minimizing circuit volume, inflammation, and red cell stress may help to reduce these two complications and their associated mortality.

There are no established neuroprotective guidelines during pediatric extracorporeal membrane oxygenation (ECMO) after cardiac arrest. We report a case of unknown duration, out-of-hospital cardiac arrest after drowning in a toddler. The patient experienced severe cardiopulmonary failure shortly after return of spontaneous circulation and required veno-arterial ECMO. Clinical outcome was excellent. This report outlines a neuroprotective strategy using high-dose erythropoietin, dexmedetomidine, and therapeutic hypothermia that was implemented during ECMO. Risk factors related to pediatric drowning with cardiac arrest are also discussed.

To determine the relationship between the production of cell-free plasma hemoglobin and acute kidney injury in infants and children undergoing cardiopulmonary bypass for cardiac surgery.Prospective observational study.Twelve-bed cardiac ICU in a university-affiliated children's hospital.Children were prospectively enrolled during their preoperative outpatient appointment with the following criteria: greater than 1 month to less than 18 years old, procedures requiring cardiopulmonary bypass, no preexisting renal dysfunction.None.Plasma and urine were collected at baseline (in a subset), the beginning and end of cardiopulmonary bypass, and 2 hours and 24 hours after cardiopulmonary bypass in 60 subjects. Levels of plasma hemoglobin increased during cardiopulmonary bypass and were associated (p0.01) with cardiopulmonary bypass duration (R = 0.22), depletion of haptoglobin at end and 24 hours after cardiopulmonary bypass (R = 0.12 and 0.15, respectively), lactate dehydrogenase levels at end cardiopulmonary bypass (R = 0.27), and change in creatinine (R = 0.12). Forty-three percent of patients developed acute kidney injury. There was an association between plasma hemoglobin level and change in creatinine that varied by age (overall [R = 0.12; p0.01]; in age2 yr [R = 0.22; p0.01]; and in2 yr [R = 0.03; p = 0.42]). Change in plasma hemoglobin and male gender were found to be risk factors for acute kidney injury (odds ratio, 1.02 and 3.78, respectively; p0.05).Generation of plasma hemoglobin during cardiopulmonary bypass and male gender are associated with subsequent renal dysfunction in low-risk pediatric patients, especially in those older than 2 years. Further studies are needed to determine whether specific subgroups of pediatric patients undergoing cardiopulmonary bypass would benefit from potential treatments for hemolysis and plasma hemoglobin-associated renal dysfunction.

We present the case of a 17-year-old boy with a cardiac venous malformation. This case highlights the diagnostic challenges of such tumours and demonstrates the potential efficacy of a watch-and-wait management approach.

Several options exist for aortic valve replacement (AVR) in children and teens, but contemporary practice patterns and outcome data are lacking. We describe national AVR practice patterns and early outcomes.Children (aged 1 to 18 years) in The Society of Thoracic Surgeons Congenital Heart Surgery Database undergoing AVR from 2000 to 2016 were included. Preoperative characteristics, operative data, and outcomes were described. To evaluate practice patterns, centers were assigned tertiles by aortic valve surgical volume. Statistical comparisons included Mann-Whitney U statistic, Kruskal-Wallis, χIn total, 3446 operations (46% children aged 1 to 12 years; 54% teens aged 12 to 18 years) were included. Preoperative risk factors were present in 23%, and 46% had a prior sternotomy. Valve utilization included autograft (64% child, 37% teen), mechanical (19% child, 35% teen), bioprosthetic (8% child, 20% teen), and homograft (9% child, 7% teen). Autografts were utilized more often for teenage girls than for teenage boys (odds ratio 1.3, 95% confidence interval: 1.05 to 1.66, P.05). Overall, inpatient mortality and major complications affected 1% and 10%, respectively, and these rates were highest for homografts (5%, P.001, and 13%, P.05). Autograft utilization varied widely across centers (10th to 90th percentile: 21% to 71% of total AVR volume). More autografts were utilized at high-volume centers vs low- or medium-volume centers (53% ± 2.3% vs 46% ± 2.6%, P.001).Practice patterns for AVR in children and teens vary across centers, age groups, and sexes. Although early outcomes were similar across valve types, homografts had higher morbidity and mortality. Valve choice was related to aortic valve surgical volume. Further efforts are needed to understand and optimize AVR practice patterns and long-term outcomes.

Venoarterial extracorporeal membrane oxygenation (VA-ECMO) has saved thousands of newborns. Population comparisons for research and quality initiatives require risk-matching, but no indices exist for this population. We sought to create a pre-ECMO risk index using the registry data from the Extracorporeal Life Support Organization. We analyzed 5,455 neonatal (

Intraoperative transesophageal echocardiography (TEE) plays an integral role in the modern era of congenital heart surgery. Pre- and post-repair imaging obtained in the operating room by a pediatric cardiologist is now routine for most cardiac operations. This intraoperative collaboration is unique among the subspecialties, and, in many cases, influences the next step of the operation. Although TEE is an invaluable tool for providing detailed anatomical information, the surgical decisions based on that information are a reflection of the working relationship between the surgeon and the echocardiographer. As equally-invested stakeholders, pediatric cardiologists and surgeons share the responsibility for outcomes in congenital heart surgery. Optimizing communication in the operating room between surgeons and physicians performing echocardiograms is critical to providing the best possible outcomes for patients. Although published guidelines describe the technical conduct of TEE, they fail to describe what the surgeon is looking for and why. Just as surgeons may be unfamiliar with the technical aspects of echocardiography, cardiologists may be unfamiliar with the technical aspects of certain cardiac surgery procedures, and generally do not observe the entire operation. Because the surgeon looks at the echocardiogram from the unique perspective of having recently handled the involved structures, he or she will place priority on some aspects over others. Common priorities can be described by operation type. Herein, we provide an overview of intraoperative TEE for six benchmark operations, from the perspective of the surgeon.

Objective We sought to assess the relationship between serious infections and fever, white blood cell count (WBC), and C-reactive protein (CRP) levels in children on ventricular assist device (VAD). Methods We retrospectively reviewed all children who underwent VAD placement from 2006 to 2014 at Children's Hospital of Pittsburgh. Daily maximum temperature, maximum WBC, CRP levels, microbiologic data and antibiotic use were abstracted from the electronic health record. Serious infection was defined as bacteremia, mediastinitis and/or driveline infection. Results Thirty-six consecutive patients underwent VAD placement with mean age of 7.1 years ±6.3 years (range 9 days −18.1 years). The median duration of VAD support was 24 days (1–102 days). Patients were on antibiotics for 58% of total VAD days. We found no drive line infections or mediastinitis and only 5 episodes of blood stream infections in 4 patients (11%) during 1167 total days. Fever was present on 23% of total VAD days and nearly all (35/36) patients had at least one day of fever. CRP was elevated in 298 of 318 (94%) of all samples tested. 53% (448/851) of the total WBC assessments were elevated. On detailed analysis of confirmed bloodstream infection, only 2 of the 5 episodes were associated with fever within 24 h of the positive culture. WBC and CRP levels (drawn within 24 h of positive culture) were normal in 2/5 (40%). Conclusions Despite a low prevalence of serious infection in our pediatric VAD cohort, we found that fever, elevated WBC and CRP were common. This suggests that traditional markers of infection are unreliable. Fever, elevated WBC count and elevated CRP were poorly predictive of serious bacterial infection in our pediatric VAD cohort. Their presence alone should not be an indication for long-term antibiotics.

Extracorporeal Membrane Oxygenation (ECMO) is a resource intensive, life-preserving support system that has seen ever-expanding clinical indications as technology and collective experience has matured. Clinicians caring for patients who develop pulmonary failure secondary to cardiac failure can find themselves in unique situations where traditional ECMO may not be the ideal clinical solution. Existing paracorporeal ventricular assist device (VAD) technology or unique patient physiologies offer the opportunity for thinking “outside the box.” Hybrid ECMO approaches include splicing oxygenators into paracorporeal VAD systems and alternative cannulation strategies to provide a staged approach to transition a patient from ECMO to a VAD. Alternative technologies include the adaptation of ECMO and extracorporeal CO2 removal systems for specific physiologies and pediatric aged patients. This chapter will focus on: (1) hybrid and alternative approaches to extracorporeal support for pulmonary failure, (2) patient selection and, (3) technical considerations of these therapies. By examining the successes and challenges of the relatively select patients treated with these approaches, we hope to spur appropriate research and development to expand the clinical armamentarium of extracorporeal technology.

Mechanical circulatory support encompasses technology that can provide cardiac and cardiopulmonary support for patients from short-term devices used in the operating room or intensive care units to long-term devices used by patients in an outpatient setting. While the experience and available devices have focused predominantly on the adult population, recent interest in pediatric usage has seen clinicians adapting adult devices for this population. Such adaptation necessitates a strong understanding of the mechanics of these devices to promote proper patient management and to remain vigilant for signs of blood damage arising from operation off-design. This chapter aims to provide clinicians with a working understanding of the basic principles that separate the various devices and the various conditions that can alter pump mechanics. A greater understanding of the current pumps will help to shape the development of new pumps geared toward the pediatric population.

Acute and chronic respiratory failure are a significant source of pediatric morbidity and mortality. Current respiratory support options used to bridge children to lung recovery or transplantation typically render them bedridden and can worsen long-term patient outcomes. The Pittsburgh Pediatric Ambulatory Lung (P-PAL) is a wearable pediatric blood pump and oxygenator (0.3 m(2) surface area) integrated into a single compact unit that enables patient ambulation. The P-PAL is intended for long-term use and designed to provide up to 90% of respiratory support in children weighing 5 to 25 kg. Computational fluid dynamics and numerical gas exchange modeling were used to design the P-PAL and predict its performance. A P-PAL prototype was then used to obtain pressure versus flow curves at various impeller rotation rates using a blood analog fluid. In vitro oxygen exchange rates were obtained in blood in accordance with ISO standard 7199. The normalized index of hemolysis (NIH) was measured over a 6-hour period at blood flow rates of 1 and 2.5 L/min. The P-PAL provided blood flows of 1–2.5 L/min against the pressure drop associated with its intended-use pediatric cannulas. The oxygen exchange rate reached a maximum of 108 mL/min at a blood flow rate of 2.5 L/min and met our respiratory support design target. Device-induced hemolysis was low with NIH values of 0.022–0.027 g/100L in the intended blood flow rate range. In conclusion, the current P-PAL design met our pumping, oxygenation, and hemolysis specifications and has the potential to improve treatment for pediatric respiratory failure.

Destination ventricular assist device therapy (DT-VAD) is well accepted in select adults with medically refractory heart failure (HF) who are not transplant candidates; however, its use in younger patients with progressive diseases is unclear. We sought to evaluate the cost-effectiveness of DT-VAD in Duchenne muscular dystrophy (DMD) patients with advanced HF. We created a Markov-state transition model (5-year horizon) to compare survival, costs, and quality of life (QOL) between medical management and DT-VAD in DMD with advanced HF. Model input parameters were derived from the literature. We used sensitivity analyses to explore uncertainty around model assumptions. DT-VAD had higher costs ($435,602 vs. $125,696), survival (3.13 vs. 0.60 years), and quality-adjusted survival (1.99 vs. 0.26 years) than medical management. The incremental cost-effectiveness ratio (ICER) for DT-VAD was $179,086 per quality-adjusted life year (QALY). In sensitivity analyses that were widely varied to account for uncertainty in model assumptions, the DT-VAD strategy generally remained more costly and effective than medical management. Only when VAD implantation costs were

Purpose Cystic fibrosis (CF) is a common indication for pediatric lung transplant (LTx), but new CF drug therapies may decrease the need for LTx. Studies of CF vs. non-CF LTx outcomes are rare. We report practice patterns and outcomes for pediatric LTx in CF and non-CF patients. Methods The ISHLT registry was used to report morbidity, graft failure, and survival for primary LTx performed in children ( Results In total, 2,218 primary LTx were performed, 88% in children ≥6yrs. CF was the primary diagnosis in 61%; common non-CF diagnoses were: pulmonary hypertension (28%), pulmonary fibrosis (15%), and obliterative bronchiolitis (12%). CF patients were older (median 15 vs 11yrs, p Conclusion Mid-term mortality and graft failure rates are higher for pediatric LTx recipients with CF, and important gender differences exist. Long-term outcomes are similar between groups. Further study is needed to understand these differences.

Ventricular assist devices (VADs) are increasingly being used in pediatric patients to support cardiac failure. As more centers adopt this technology, there may be a need to transport these patients over long distances to facilitate patient care and organ transplantation. Food and Drug Administration indications for use state only that the patient must be a candidate for transplantation and does not place restrictions on the transplant capabilities of the implanting medical center. Nontransplanting institutions are able to use this technology with a predetermined agreement to transfer the patient to a partnering transplant center. We report the first two cases of interhospital air and ground transport of nonambulatory or intubated pediatric (

The current prevalence and severity of heart defects requiring functional replacement of cardiac tissue pose a serious clinical challenge. Biologic scaffolds are an attractive tissue engineering approach to cardiac repair because they avoid sensitization associated with homograft materials and theoretically possess the potential for growth in similar patterns as surrounding native tissue. Both urinary bladder matrix (UBM) and cardiac ECM (C-ECM) have been previously investigated as scaffolds for cardiac repair with modest success, but have not been compared directly. In other tissue locations, bone marrow derived cells have been shown to play a role in the remodeling process, but this has not been investigated for UBM in the cardiac location, and has never been studied for C-ECM. The objectives of the present study were to compare the effectiveness of an organ-specific C-ECM patch with a commonly used ECM scaffold for myocardial tissue repair of the right ventricle outflow tract (RVOT), and to examine the role of bone marrow derived cells in the remodeling response. A chimeric rat model in which all bone marrow cells express green fluorescent protein (GFP) was generated and used to show the ability of ECM scaffolds derived from the heart and bladder to support cardiac function and cellular growth in the RVOT. The results from this study suggest that urinary bladder matrix may provide a more appropriate substrate for myocardial repair than cardiac derived matrices, as shown by differences in the remodeling responses following implantation, as well as the presence of site appropriate cells and the formation of immature, myocardial tissue.

Tracheomalacia is a relatively rare problem, but can be challenging to treat, particularly in pediatric patients. Due to the presence of mechanically deficient cartilage, the trachea is unable to resist collapse under physiologic pressures of respiration, which can lead to acute death if left untreated. However, if treated, the outcome for patients with congenital tracheomalacia is quite good because the cartilage tends to spontaneously mature over a period of 12 to 18 months. The present study investigated the potential for the use of degradable magnesium-3% yttrium alloy (W3) to serve as an extraluminal tracheal stent in a canine model. The host response to the scaffold included the formation of a thin, vascularized capsule consisting of collagenous tissue and primarily mononuclear cells. The adjacent cartilage structure was not adversely affected as observed by bronchoscopic, gross, histologic, and mechanical analysis. The W3 stents showed reproducible spatial and temporal fracture patterns, but otherwise tended to corrode quite slowly, with a mix of Ca and P rich corrosion product formed on the surface and observed focal regions of pitting. The study showed that the approach to use degradable magnesium alloys as an extraluminal tracheal stent is promising, although further development of the alloys is required to improve the resistance to stress corrosion cracking and improve the ductility. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 611–620, 2014.

OBJECTIVES: Single ventricle with apicocaval juxtaposition (ACJ) is a rare, complex anomaly, in which the optimal position of the conduit for completion of total cavopulmonary connection (TCPC) is still controversial. The purpose of this study was to identify a preoperative method for optimal conduit position using the IVC anatomy and computational fluid dynamics (CFD). METHODS: Twenty-four patients with ACJ (5.3 ± 5.7 years) who underwent TCPC were enrolled. A conduit was placed ipsilateral to the cardiac apex in each of 11 patients, of which 9 were intra-atrial and 2 extracardiac (group A) and, in a further 13 patients, extracardiac on the contralateral side (group B). As control, 10 patients with tricuspid atresia were also enrolled (group C). The location of the IVC in relation to the spine was evaluated from the frontal view of preoperative angiogram, using the following index: IVC-index = IVC width overlapping the vertebra/width of the vertebra × 100%. Energy loss was calculated by CFD simulation. RESULTS: IVC-index of group B was larger than groups A and C (45 ± 26 vs. 20 ± 21 and 28 ± 19%, P = 0.03). Postoperative catheterizations showed that, due to its curvature, conduit length in group B was significantly longer than the others (65 ± 12 vs. 36 ± 14 and 44 ± 10 mm, P < 0.001), although there was no statistical difference in central venous pressure or cardiac output. CFD studies revealed less energy loss in group A conduits compared with group B (1.6 ± 0.3 vs. 3.6 ± 0.6 mW, P = 0.05), although this did not appear to be clinically significant. Moreover, CFD simulation showed significant energy loss within the Fontan circulation when the conduit was either compressed or kinked: 4.9 and 18.2 mW respectively. CONCLUSIONS: In patients with ACJ, placement of a straighter and shorter conduit on the ventricular apical side provides better laminar blood flow with less energy loss. However, conduit compression and kinking are far more detrimental to the Fontan circulation. A preoperative IVC-index is pivotal for avoiding these factors and deciding the optimal conduit route.

It is now recognized that a majority of single ventricle patients, those with functionally univentricular hearts, who have survived palliative cavopulmonary connection will experience circulatory failure and end-organ dysfunction due to intrinsic inadequacies of a circulation supported by a single ventricle. Thus, there are an increasing number of patients with functional single ventricles presenting with failing circulations that may benefit from mechanical circulatory support (MCS). The paucity of experience with MCS in this population, even at high volume cardiac centers, contributes to limited available data to guide MCS device selection and management. Thus, a registry of MCS in this population would be beneficial to the field. A conference was convened in January 2012 of pediatric and adult cardiologists, pediatric cardiac intensivists, congenital heart surgeons, and adult cardiothoracic surgeons to discuss the current state of MCS, ventricular assist device, and total artificial heart therapy for patients who have undergone cavopulmonary connection, either superior cavopulmonary connection or total cavopulmonary connection. Specifically, individual experience and challenges with VAD therapy in this population was reviewed and creation of a multiinstitutional registry of MCS/ventricular assist device in this population was proposed. This document reflects the consensus from the meeting and provides a descriptive overview of the registry referred to as Mechanical Support as Failure Intervention in Patients with Cavopulmonary Shunts.

The incorporation of complex medical device technologies into clinical practice is governed by critical oversight of the US Food and Drug Administration. This regulatory process requires a judicious balance between assuring safety and efficacy, while providing efficient review to facilitate access to innovative therapies. Recent contrasting views of the regulatory process have emphasized the difficulties in obtaining an optimal balance. Mechanical circulatory support has evolved to become an important therapy for patients who have advanced heart failure with the advent of more durable, implantable ventricular assist devices. The regulatory oversight of these new technologies has been difficult owing to the complexities of these devices, associated adverse event profile, and severity of illness of the intended patient population. Maintaining a regulatory environment to foster efficient introduction of safe and effective technologies is critical to the success of ventricular assist device therapy and the health of patients with advanced heart failure. Physicians representing key surgical and cardiology societies, and representatives from the Food and Drug Administration, National Heart, Lung, and Blood Institute, Centers for Medicare and Medicaid Services, Interagency Registry of Mechanically Assisted Circulatory Support, and industry partners gathered to discuss relevant issues regarding the current regulatory environment assessing ventricular assist devices. The goal of the meeting was to explore innovative ways to foster the introduction of technologically advanced, safe, and effective ventricular assist devices. The following summary reflects opinions and conclusions endorsed by The Society of Thoracic Surgeons, American Association for Thoracic Surgery, American Heart Association, Heart Failure Society of America, International Society for Heart and Lung Transplantation, and Interagency Registry of Mechanically Assisted Circulatory Support.

The incorporation of complex medical device technologies into clinical practice is governed by critical oversight of the US Food and Drug Administration. This regulatory process requires a judicious balance between assuring safety and efficacy, while providing efficient review to facilitate access to innovative therapies. Recent contrasting views of the regulatory process have emphasized the difficulties in obtaining an optimal balance. Mechanical circulatory support has evolved to become an important therapy for patients with advanced heart failure with the advent of more durable, implantable ventricular assist devices. The regulatory oversight of these new technologies has been difficult owing to the complexities of these devices, associated adverse event profile, and severity of illness of the intended patient population. Maintaining a regulatory environment to foster efficient introduction of safe and effective technologies is critical to the success of ventricular assist device therapy and the health of patients with advanced heart failure. Physicians representing key surgical and cardiology societies, and representatives from the Food and Drug Administration, National Heart, Lung, and Blood Institute, Centers for Medicare and Medicaid Services, Interagency Registry of Mechanically Assisted Circulatory Support, and industry partners gathered to discuss relevant issues regarding the current regulatory environment assessing ventricular assist devices. The goal of the meeting was to explore innovative ways to foster the introduction of technologically advanced, safe, and effective ventricular assist devices. The following summary reflects opinions and conclusions endorsed by The Society of Thoracic Surgeons, American Association for Thoracic Surgery, American Heart Association, Heart Failure Society of America, International Society for Heart and Lung Transplantation, and the Interagency Registry of Mechanically Assisted Circulatory Support.

Objectives The PediaFlow (HeartWare International, Inc, Framingham, Mass) is a miniature, implantable, rotodynamic, fully magnetically levitated, continuous-flow pediatric ventricular assist device. The fourth-generation PediaFlow was evaluated in vitro and in vivo to characterize performance and biocompatibility. Methods Supported by 2 National Heart, Lung, and Blood Institute contract initiatives to address the limited options available for pediatric patients with congenital or acquired cardiac disease, the PediaFlow was developed with the intent to provide chronic cardiac support for infants as small as 3 kg. The University of Pittsburgh–led Consortium evaluated fourth-generation PediaFlow prototypes both in vitro and within a preclinical ovine model (n = 11). The latter experiments led to multiple redesigns of the inflow cannula and outflow graft, resulting in the implantable design represented in the most recent implants (n = 2). Results With more than a decade of extensive computational and experimental efforts spanning 4 device iterations, the AA battery–sized fourth-generation PediaFlow has an operating range of 0.5 to 1.5 L/min with minimal hemolysis in vitro and excellent hemocompatibility (eg, minimal hemolysis and platelet activation) in vivo. The pump and finalized accompanying implantable components demonstrated preclinical hemodynamics suitable for the intended pediatric application for up to 60 days. Conclusions Designated a Humanitarian Use Device for “mechanical circulatory support in neonates, infants, and toddlers weighing up to 20 kg as a bridge to transplant, a bridge to other therapeutic intervention such as surgery, or as a bridge to recovery” by the Food and Drug Administration, these initial results document the biocompatibility and potential of the fourth-generation PediaFlow design to provide chronic pediatric cardiac support.

Purpose The objective of this study was to demonstrate the safety and performance of a unique extracorporeal carbon dioxide removal system (Hemolung, ALung Technologies, Pittsburgh, PA) which incorporates active mixing to improve gas exchange efficiency, reduce exposure of blood to the circuit, and provide partial respiratory support at dialysis-like settings. Methods An animal study was conducted using eight domestic crossbred sheep, 6–18 months of age and 49–115 kg in weight. The sheep were sedated and intubated, and a 15.5-Fr dual lumen catheter was inserted into the right jugular vein. The catheter was connected to the extracorporeal circuit primed with heparinized saline, and flow immediately initiated. The animals were then awakened and encouraged to stand. The animals were supported in a stanchion and monitored around the clock. Anticoagulation was maintained with heparin to achieve an aPTT of 46–70 s. Results Measurements included blood flow rate through the device, carbon dioxide exchange rate, pump speed and sweep gas flow rate. Safety and biocompatibility measurements included but were not limited to plasma-free hemoglobin, hematocrit, white blood cell count, platelet count and fibrinogen. The Hemolung removed clinically significant amounts of carbon dioxide, more than 50 ml/min, at low blood flows of 350–450 ml/min, with minimal adverse effects. Conclusions The results of 8-day trials in awake and standing sheep supported by the Hemolung demonstrated that this device can consistently achieve clinically relevant levels of carbon dioxide removal without failure and without significant risk of adverse reactions.

Intravascular hemolysis and resulting plasma-free hemoglobin elevation has been associated with acute kidney injury via several mechanisms. Proximal tubular injury due to iron compound deposition and nitric oxide sequestration with subsequent impairment of the microcirculation and hypoperfusion are specific adverse effects of intravascular hemolysis that may contribute to acute kidney injury. Therefore, removal of plasma-free hemoglobin and restoration of normal nitric oxide vasodilatory mechanisms may play a beneficial role in treating acute kidney injury secondary to acute intravascular hemolysis. We report herein the case of a 13-year-old patient with severe intravascular hemolysis and acute kidney injury and describe the role of plasma exchange with plasma replacement in his successful recovery. J. Clin. Apheresis 27:274–277, © 2012 Wiley Periodicals, Inc.

Objectives. The current drug of choice for reentrant supraventricular tachycardia (SVT) is adenosine followed by verapamil or diltiazem. Although limitations and significant adverse events have been encountered over the years, an alternative effective and safe agent has not been available. Dexmedetomidine has recently been shown to have potential antiarrhythmic effects, and here we describe our experience in the acute termination of reentrant SVT. Design. Retrospective case series. Setting: Quaternary University Children's Hospital, Cardiac Intensive Care Unit. Patients: Patients who received dexmedetomidine for SVT in the past 5 years. Interventions: None. Outcome Measures: SVT episodes terminated with dexmedetomidine were compared with episodes terminated with adenosine. Results. Fifteen patients, median age of 10 days (6–16), were given 27 doses of dexmedetomidine, mean dose 0.7 ± 0.3 mcg/kg, for a total of 27 episodes of SVT. Successful termination occurred in 26 episodes (96%) at a median time of 30 seconds (20–35). Duration of sinus pause was 0.6 ± 0.2 seconds, there was one episode of hypotension and no bradycardia and sedation lasted for 34 ± 8 minutes. Five patients received 27 doses of adenosine, with an overall successful cardioversion in 17 patients (63%) (P= .0017). Transient bradycardia and hypotension was seen in three patients (11%), agitation in 16 patients (59%), and broncospasm in one patient. Median sinus pause was 2.5 seconds (2–9) (P < .001). Conclusions. Dexmedetomidine appears to have novel antiarrhythmic properties for the acute termination of reentrant SVT. Although adenosine is very effective, dexmedetomidine may prove to possess a more favorable therapeutic profile with increased effectiveness and fewer side effects.

Objective. Infants with critical congenital heart disease (CHD) can have genetic and other extracardiac malformations, which add to the short- and long-term risk of morbidity and perhaps mortality. We sought to examine our center's practice of screening for extracardiac anomalies and to determine the yield of these tests among specific cardiac diagnostic categories. Design. Retrospective review of infants admitted to the cardiac intensive care unit with a new diagnosis of CHD. Subjects were categorized into six groups: septal defects (SD), conotruncal defects (CTD), single-ventricle physiology (SV), left-sided obstructive lesions (LSO), right-sided obstructive lesions (RSO), and “other” (anomalous pulmonary venous return, Ebstein's anomaly). Screening modalities included genetic testing (karyotype and fluorescent in situ hybridization for 22q11.2 deletion), renal ultrasound (RUS), and head ultrasound (HUS). Results. One hundred forty-one patients were identified. The incidence of cardiac anomalies was: CTD (36%), SD (18%), SV (18%), LSO (14%), RSO (3%), and “other” (8%). Overall 14% had an abnormal karyotype, 5% had a deletion for 22q11.2, 28% had an abnormal RUS and 22% had abnormal HUS. Patients in SD and SV had the highest incidence of abnormal karyotype (36% and 17%); 22q11.2 deletion was present only in CTD and LSO groups (9% and 7%, respectively); abnormal RUS and HUS were seen relatively uniformly in all categories. Premature infants had significantly higher incidence of renal 43% vs. 24%, and intracranial abnormalities 46% vs. 16%. Conclusion. Infants with critical CHD and particularly premature infants have high incidence of genetic and other extracardiac anomalies. Universal screening for these abnormalities with ultrasonographic and genetic testing maybe warranted because early detection could impact short and long-term outcomes.

The Levitronix PediVAS is an extracorporeal magnetically levitated pediatric ventricular assist system with an optimal flow rate range of 0.3 – 1.5 L/min. The system is being tested in preclinical studies to assess hemodynamic performance and biocompatibility. The PediVAS was implanted in 9 ovines for 30 days duration using either commercially available cannulae (N = 3) or customized Levitronix cannulae (N = 6). Blood biocompatibility in terms of circulating activated platelets was measured by flow cytometric assays to detect P-selectin. Platelet activation was further examined following exogenous agonist stimulation. Platelet activation rose following surgery and eventually returned to baseline in animal studies where minimal kidney infarcts were observed. Platelet activation remained elevated for the duration of the study in animals where a moderate number of kidney infarcts with or without thrombotic deposition in the cannulae were observed. When platelet activation did return to baseline, platelets appropriately responded to agonist stimulation signifying conserved platelet function following PediVAS implant. Platelet activation returned to baseline in the majority of studies, representing a promising biocompatibility result for the Levitronix PediVAS.

The PediVAS blood pump is a magnetically levitated centrifugal pump designed for bridge-to-decision or bridge-to-recovery in pediatric patients from 3 to 20 kg in weight. In preparation for submission of an investigational device exemption (IDE) application, we completed a final six-animal series of pre-clinical studies. The studies were conducted under controlled conditions as prescribed by the recently released FDA guidance document for animal studies for cardiovascular devices. Three 30-day chronic left ventricular support studies were completed in a juvenile lamb model to demonstrate the safety and hemocompatibility of the PediVAS pump. Three additional 8-h acute biventricular support studies were performed to demonstrate the feasibility of this approach from a hemodynamic and systems standpoint. It is estimated that 50% of pediatric patients who require left ventricular support also require right ventricular support. All studies were successfully completed without complications, device malfunctions, or adverse events. End-organ function was normal for the chronic studies. We noted small surface lesions on one kidney from each chronic study as well as the presence of ring thrombus on connectors, as expected for these types of studies in animal models. The strategy and challenges imposed by performing a controlled cardiovascular device study in a juvenile lamb model are discussed. We believe that these successful implants demonstrate safety and performance for the PediVAS device for support of an IDE application to initiate human clinical trials and provide a roadmap for other researchers.

Ventricular assist devices (VADs) have significantly impacted the treatment of adult cardiac failure, but few options exist for pediatric patients. This has motivated our group to develop an implantable magnetically levitated rotodynamic VAD (PediaFlow®) for 3–20 kg patients. The second prototype design of the PediaFlow (PF2) is 56% smaller than earlier prototypes, and achieves 0.5–1.5 L/min blood flow rates. In vitro hemodynamic performance and hemolysis testing were performed with analog blood and whole ovine blood, respectively. In vivo evaluation was performed in an ovine model to evaluate hemocompatibility and end-organ function. The in vitro normalized index of hemolysis was 0.05–0.14 g/L over the specified operating range. In vivo performance was satisfactory for two of the three implanted animals. A mechanical defect caused early termination at 17 days of the first in vivo study, but two subsequent implants proceeded without complication and electively terminated at 30 and 70 days. Serum chemistries and plasma free hemoglobin were within normal limits. Gross necropsy revealed small, subclinical infarctions in the kidneys of the 30 and 70 day animals (confirmed by histopathology). The results of these experiments, particularly the biocompatibility demonstrated in vivo encourage further development of a miniature magnetically levitated VAD for the pediatric population. Ongoing work including further reduction of size will lead to a design freeze in preparation for of clinical trials.

Background Postoperative tachyarrhythmias remain a common complication after congenital cardiac operations. Dexmedetomidine (DEX), an α-2 adrenoreceptor agonist, can have a therapeutic role in supraventricular tachyarrhythmias for cardioversion to sinus rhythm or heart rate control. Whether routine perioperative use of DEX decreases the incidence of supraventricular and ventricular tachyarrhythmias was studied. Methods In this prospective cohort study, 32 pediatric patients undergoing cardiothoracic operations received DEX and were compared with 20 control patients who did not receive DEX. Results Dexmedetomidine was started after anesthesia induction and continued intraoperatively and postoperatively for 38 ± 4 hours (mean dose, 0.76 ± 0.04 μg/kg/h). Ten control patients and 2 DEX patients sustained 16 episodes of tachyarrhythmias ( p = 0.001), including a 25% vs 0% ( p = 0.01) incidence of ventricular tachycardia and 25% vs 6% ( p = 0.05) of supraventricular arrhythmias in the control and DEX group, respectively. Transient complete heart block occurred in 2 control patients and in 1 DEX patient. Control patients had a higher heart rate (141 ± 5 vs 127 ± 3 beats/min, p = 0.03), more sinus tachycardia episodes (40% vs 6%; p = 0.008), required more antihypertensive drugs with nitroprusside (20 ± 7 vs 4 ± 1 μg/kg; p = 0.004) and nicardipine (13 ± 5 vs 2 ± 1 μg/kg; p = 0.02), and required more fentanyl (39 ± 8 vs 19 ± 3 μg/kg; p = 0.005). Conclusions Perioperative use of dexmedetomidine is associated with a significantly decreased incidence of ventricular and supraventricular tachyarrhythmias, without significant adverse effects.

The PediaFlow™ pediatric ventricular assist device (VAD) is a magnetically levitated turbodynamic pump under development for circulatory support of small children with a targeted flow rate range of 0.3 - 1.5 L/min. As the design of this device is refined, ensuring high levels of blood biocompatibility is essential. In this study we characterized platelet activation during the implantation and operation of a second generation prototype of the PediaFlow VAD (PF2) and also performed a series of surgical sham studies to examine purely surgical effects on platelet activation. In addition, a newly available monoclonal antibody was characterized and shown to be capable of quantifying ovine platelet activation. The PF2 was implanted in 3 chronic ovine experiments of 16, 30, and 70 days, while surgical sham procedures were performed in 5 ovines with 30 d monitoring. Blood biocompatibility in terms of circulating activated platelets was measured by flow cytometric assays with and without exogenous agonist stimulation. Platelet activation following sham surgery returned to baseline in approximately 2 weeks. Platelets in PF2 implanted ovines returned to baseline activation levels in all three animals, and showed an ability to respond to agonist stimulation. Late term platelet activation was observed in one animal corresponding with unexpected pump stoppages related to a manufacturing defect in the percutaneous cable. The results demonstrated encouraging platelet biocompatibility for the PF2 in that basal platelet activation was achieved early in the pump implant period. Furthermore, this first characterization of the effect of a major cardiothoracic procedure on temporal ovine platelet activation provides comparative data for future cardiovascular device evaluation in the ovine model.

Kounis syndrome is coronary vasospasm because of mast cell degranulation in the context of an allergic reaction. The syndrome has known associations with several drugs used during anesthesia, including rocuronium and isoflurane. In this case report, we discuss a 2-year-old patient who developed signs and symptoms of an acute coronary syndrome soon after anesthesia for atrial septal defect repair. A diagnostic angiography after the episode revealed diffusely small coronary arteries. Subsequent angiography after clinical improvement showed essentially normal coronary anatomy. We report the clinical course of this patient and postulate that Kounis syndrome was the explanation for his transient coronary vasospasm. To date, this is the youngest known patient with reported Kounis syndrome.

The PediaFlow pediatric ventricular assist device is a miniature magnetically levitated mixed flow pump under development for circulatory support of newborns and infants (3-15 kg) with a targeted flow range of 0.3-1.5 L/min. The first generation design of the PediaFlow (PF1) was manufactured with a weight of approximately 100 g, priming volume less than 2 mL, length of 51 mm, outer diameter of 28 mm, and with 5-mm blood ports. PF1 was evaluated in an in vitro flow loop for 6 h and implanted in ovines for three chronic experiments of 6, 17, and 10 days. In the in vitro test, normalized index of hemolysis was 0.0087 ± 0.0024 g/100L. Hemodynamic performance and blood biocompatibility of PF1 were characterized in vivo by measurements of plasma free hemoglobin, plasma fibrinogen, total plasma protein, and with novel flow cytometric assays to quantify circulating activated ovine platelets. The mean plasma free hemoglobin values for the three chronic studies were 4.6 ± 2.7, 13.3 ± 7.9, and 8.8 ± 3.3 mg/dL, respectively. Platelet activation was low for portions of several studies but consistently rose along with observed animal and pump complications. The PF1 prototype generated promising results in terms of low hemolysis and platelet activation in the absence of complications. Hemodynamic results validated the magnetic bearing design and provided the platform for design iterations to meet the objective of providing circulatory support for young children with exceptional biocompatibility.

Objectives. Abnormal diaphragmatic motion secondary to phrenic nerve injury is not uncommon after pediatric cardiothoracic surgery. Fluoroscopy is the most frequent method of diagnosis but it carries risks associated with transportation of critically ill children and exposure to ionizing radiation. Ultrasonography, a reliable diagnostic method in adults, eliminates both concerns. Since most cardiac intensivists are trained in echocardiography, we tested the hypothesis that chest ultrasound performed by a cardiac intensivist is faster than fluoroscopy, and is highly accurate in predicting fluoroscopy results, therefore serving as an equally useful diagnostic test. Design. Prospective study in consecutive pediatric patients with suspected abnormal diaphragmatic motion after cardiothoracic surgery. All patients underwent fluoroscopy and ultrasound study of the diaphragm. Ultrasound was performed by a pediatric cardiac intensivist and a trainee. Kappa statistic was calculated to assess concordance between both ultrasound readings. Sensitivity, specificity, and positive and negative predictive values (PPV and NPV) were calculated to assess accuracy of each ultrasound test in predicting fluoroscopy results. Results. Twenty-five patients with median age 3 months (12 days–11 years) and median weight of 3.8 kg (2.5–29 kg) were included. The ultrasound diagnosis of the cardiac intensivist was perfectly accurate (100% sensitivity, specificity, and PPV and NPV) in predicting fluoroscopy results. The ultrasound performed by the trainee achieved 85.7% sensitivity, 94.4% NPV, and 100% specificity relative to fluoroscopy. The interoperator reliability of chest ultrasound was 0.89 (95% confidence interval 0.69–1). Delay between clinical suspicion and the diagnostic tests was 15 minutes (5 minutes–2.5 hours) for ultrasound and 17 hours (60 minutes–82 hours) for fluoroscopy (P < 0.001). Conclusions. Chest ultrasound performed by cardiac intensivists allows for an early and accurate diagnosis of abnormal diaphragmatic motion, as evidenced by their ability to predict fluoroscopy findings in pediatric cardiothoracic patients. Training in ultrasound-guided assessment of diaphragmatic motion should be reinforced during pediatric cardiac intensive care fellowship.

Conduits available for right ventricular outflow tract (RVOT) reconstruction eventually become stenotic and/or insufficient due to calcification. In order to reduce the incidence of reoperations we have developed and used a bicuspid valved polytetrafluoroethylene (PTFE) conduit for the RVOT reconstruction. The purpose of this study is to investigate the hemodynamic performance of the new design using a pediatric in vitro right heart mock loop. PTFE conduit has been used for the complete biventricular repair of 20 patients (age 1.7±6 years) with cyanotic congenital defects. To account for the large variability of conduit sizes, 14, 16, 22, and 24-mm conduit sizes were evaluated using an in vitro flow loop comprised of a pulsatile pump with cardiac output (CO) of 1.2-3.2L/min, bicuspid valved RVOT conduit, pulmonary artery, venous compartments, and the flow visualization setup. We recorded the diastolic valve leakage and pre- and post-conduit pressures in static and pulsatile settings. In vitro valve function and overall hemodynamic performance was evaluated using high-speed cameras and ultrasonic flow probes. Three-dimensional flow fields for different in vivo conduit curvatures and inflow regimes were calculated by computational fluid dynamics (CFD) analysis to further aid the conduit design process. The average pressure drop over the valved conduits was 0.8±1.7mm Hg for the CO range tested. Typical values for regurgitant fraction, peak-to-peak pressure gradient, and effective office area were 23±2.1%, 13±2.4mm Hg, and 1.56±0.2 cm(2) , respectively. High-speed videos captured the intact valve motion with asymmetrical valve opening during the systole. CFD simulations demonstrated the flow skewness toward the major curvature of the conduit based on the pulmonic curvature. In vitro evaluation of the bicuspid valved PTFE conduit coincides well with acceptable early clinical performance (mild insufficiency), with relatively low pressure drop, and intact valve motion independent from the conduit curvature, orientation or valve location, but at the expense of increased diastolic flow regurgitation. These findings benchmark the baseline performance of the bicuspid valved conduit and will be used for future designs to improve valve competency.

Assessment of electrocardiographic (ECG) effects of dexmedetomidine.Prospective observational study including children 0-17 years of age with congenital heart disease (CHD) and children following cardiothoracic surgery. Patients who did not receive dexmedetomidine were used as a control group. All patients had two ECGs: one baseline, pre-dexmedetomidine (T1) and one during dexmedetomidine infusion (T2).Fifty-one patients, median age of 0.5 years (IQR = 3.4), and 25 patients, age 0.25 (IQR = 2.9), were included in the dexmedetomidine and control groups, respectively. Forty received a dexmedetomidine-loading dose of 1 microg/kg (IQR = 0.5). At T2, the dexmedetomidine infusion was 1 microg/kg/h (IQR = 0.5). In the dexmedetomidine group, heart rate (HR) decreased from 140 +/- 22 to 115 +/- 23 (P0.001); PR, PRc and PR index changed from 115 +/- 28 to 122 +/- 29 ms (P = 0.01), 174 +/- 38 to 167 +/- 35 ms (P = 0.07) and 15,882 +/- 3,565 to 13,792 +/- 3,311 (P0.001), respectively. QRS decreased from 84 +/- 21 to 80 +/- 21 ms (P = 0.02), and QTc had no change (433 +/- 47 to 435 +/- 36 ms). When compared to the control group, none of the ECG intervals had any difference other than a trend towards lower HR (P = 0.08). Neonates and infants had a bigger drop in the HR compared to older children (P0.001), while other parameters were similar. At T2 none of the dexmedetomidine group patients had atrioventricular block or other arrhythmia. Four patients in the control group had accelerated junctional rhythm.Use of dexmedetomidine in patients with CHD and patients following cardiothoracic surgery is not associated with any significant ECG interval abnormalities other than a trend towards lower HR.

BackgroundThromboembolic events are a serious complication occurring in critically ill children admitted to the cardiac intensive care unit. Although enoxaparin is one of the current anticoagulants of choice, dosages in children are extrapolated from adult guidelines. Recent data suggest that this population may need a higher dose than what is currently recommended to achieve target anti-factor Xa levels. The purpose of this study was to evaluate whether children less than 2 years old admitted to the cardiac intensive care unit require a higher enoxaparin dose than that currently recommended to achieve target anti-factor Xa levels.MethodsRetrospective chart review including patients who received enoxaparin for the treatment or prophylaxis of venous thrombosis between January, 2005 and October, 2007. Patients were classified as younger and older as well as prophylactic and therapeutic on the basis of age and enoxaparin dose, respectively. Younger patients were those 2 month old or less and older patients were those older than 2 months of age.ResultsA total of 31 patients were identified; 13 (42%) were 2 months or younger and 25 (81%) were postoperative patients. Ten (32%) received prophylactic and 21 (68%) received therapeutic enoxaparin doses. To achieve optimal anti-factor Xa levels, enoxaparin dose was increased in all groups and reached statistical significance in all patients except those older than 2 months who received prophylactic enoxaparin. An average of 2.8 dosage adjustments was needed. No bleeding complications were reported.ConclusionsYoung children, infants, and neonates admitted to the cardiac intensive care unit required a significantly higher enoxaparin dose than that currently recommended to achieve target anti-factor Xa levels.