Outcomes for Children With Vascular Ring Repair Using a Simple Surgical Approach.

INTRODUCTION: Vascular Rings (VRs) are congenital malformations of the aortic arch that can compress the trachea and esophagus producing symptoms. Approximately, 5%-10% of patients experience persistent symptoms postrepair and 9% require reintervention. There are various approaches to repair-simple ligation and division of the ring or more complex procedures. Our objective was to describe outcomes for VR repair using a "simple" surgical approach. METHODS: We identified patients who underwent VR repair from 2012 to 2022 at our institution. Clinical and surgical data, demographics, intraoperative, and postoperative outcomes were extracted from their electronic medical records. Outcomes were analyzed and regression analysis was used to identify risk factors for residual symptoms after repair. RESULTS: Ninety three patients with VR repair were included. Prevalence of symptoms were reduced following surgery (80% preoperative versus 13% postoperative, P 0.03). Tracheomalacia also decreased from 16% to 7% postrepair. No deaths were reported in our cohort and 2% of our patients required reintervention. Multivariable regression analysis showed that preoperative tracheomalacia was associated with having persistent symptoms after VR repair (odds ratio 6.2, 95% CI 1.02-37.6). CONCLUSIONS: Our institutional experience using a simple surgical approach showed a significant decrease in symptoms, a very low reintervention rate and no mortality. Preoperative tracheomalacia can be a risk factor for persistent symptoms postrepair. We believe a simple surgical approach for children with complete VR repair can be effective in relieving symptoms.

Health-Related Quality of Life After Single Ventricle Palliation or Tetralogy of Fallot Repair.

Single ventricle (SV) cardiac lesions and tetralogy of Fallot (TOF) are both common forms of cyanotic congenital heart disease. With advances in perioperative care and longitudinal follow-up, survival of these patients has dramatically improved and the majority survive to adulthood. This study compares health-related quality of life (HRQoL) of adult SV and TOF patients to each other and the general population. HRQoL of all surviving, non-transplanted SV and TOF patients 21 years of age and older at our institution was assessed with the SF-36 questionnaire via phone. Additional data including demographic parameters and information related to comorbidities and healthcare utilization were also analyzed. Among 81 eligible SV patients and 207 TOF patients, 33 (41%) and 75 (36%) completed the SF-36 phone survey, respectively. The mean age of SV patients was 32 vs. 38 years in the TOF group (p=0.01). SV patients reported more hepatic, pulmonary, and renal comorbidities. TOF patients were more likely to complete advanced degrees and more likely to have children (p=0.03). SV physical functioning scores were worse compared to TOF. In other domains of the SF-36 questionnaire, SV and TOF scores were similar. Compared to the general population, both groups reported worse bodily pain and mental health, but other aspects of psychosocial and general health were comparable. Overall HRQoL is good for both SV and TOF patients through early and mid-adulthood. Some QoL metrics were modestly worse in the SV patients. While these patients may have some physical limitations, psychosocial wellbeing appears preserved.

Racial differences in attitudes to clinical pig organ Xenotransplantation.

INTRODUCTION: In addition to an organ donor shortage, racial disparities exist at different stages of the transplantation process. Xenotransplantation (XTx) could alleviate these issues. This study describes racial differences in attitudes to XTx among populations who may need a transplant or are transplant recipients. METHODS: A Likert-scale survey was distributed at outpatient clinics to parents of children with congenital heart disease (CHD) and kidney patients on their attitudes to pig organ XTx. Data from these two groups were stratified by race and compared. RESULTS: Ninety-seven parents of children with CHD (74.2% White and 25.8% Black) and 148 kidney patients (50% White and 50% Black) responded to our survey. Black kidney patients' acceptance of XTx although high (70%) was lower than White kidney patients (91%; P .003). White kidney patients were more likely to accept XTx if results are similar to allotransplantation (OR 4.14; 95% CI 4.51-11.41), and less likely to be concerned with psychosocial changes when compared to Black kidney patients (receiving a pig organ would change your personality OR 0.08; 95% CI 0.01-0.67 and would change social interaction OR 0.24; 95% CI 0.07-0.78). There were no racial differences in attitudes to XTx among parents of children with CHD. CONCLUSION: There are differences in attitudes to XTx particularly among Black kidney patients. Because kidneys may be the first organ for clinical trials of XTx, future studies that decrease scientific mistrust and XTx concerns among the Black community are needed to prevent disparities in uptake of possible future organ transplant alternatives.

Evaluating the Highest- and Lowest-cited Research Articles in the Cardiothoracic Surgery Literature.

BACKGROUND: Understanding the differences between articles that amass a high number of citations and those that receive very few allows investigators to write journal articles that maximize the impact of their research. There are minimal data regarding these two cohorts in the cardiothoracic surgery literature. METHODS: We identified all primary research articles from 1998 to 2008 from The Journal of Thoracic and Cardiovascular Surgery, The Journal of Cardiac Surgery, The Annals of Thoracic Surgery, and The European Journal of Cardio-Thoracic Surgery (n = 4276). Eighty-seven of these articles accrued 0 or only 1 citation within 10 y of publication. We compared this "low citation" cohort to the "high citation" cohort made up of the 87 highest-cited articles from the same journals over the same time period. RESULTS: When compared with the low-citation articles, high-citation articles were significantly more likely to be clinical in nature (P < 0.0001), have observational study design (P < 0.0001), involve multidisciplinary authorship (P < 0.0001), and have more funding reported (P = 0.0039). With regard to technical aspects of the article, the high-citation articles were likely to have longer titles (P = 0.0086), punctuation in the title (P = 0.0027), longer abstracts (P = 0.0007), more words in the manuscript (P < 0.0001), more authors (P < 0.0001), more declared conflict of interests (P = 0.0167), more references (P < 0.0001), more tables (P < 0.0001), more figures (P = 0.0024), and more pages (P < 0.0001). There was no significant difference in the year of publication among both cohorts. CONCLUSIONS: This review suggests that there are several important distinguishing characteristics that should be considered by investigators when designing and implementing cardiothoracic research studies to maximize the impact of their published research.

Examining racial and socioeconomic disparity in the pediatric heart transplant evaluation.

Racial disparities have been reported among pediatric patients waitlisted for and undergoing heart transplantation but have not been studied further upstream in the transplant candidate evaluation process. We retrospectively studied our single-center experience in order to investigate any potential biases in the evaluation process. Results of the heart transplant evaluation in children ≤18 years old at our institution were analyzed. Primary outcome was final disposition to waitlist or not. Race was defined by family self-identification. Descriptive and comparative statistical analyses were performed. From 2013 to 2019, 133 unique patients were referred for listing consideration. While Black patients comprised 44% of the referral population and had more markers of socioeconomic disadvantage, they comprised 43% of the patients who were listed for transplantation with no significant difference between these proportions (p = .96). Black and White patients made up a similar proportion of patients deemed too well or too ill for listing. Black patients had lower annual household income estimates and rates of household marriage. Despite identifying significant social challenges in 27 patients (18 of them Black), only five patients (3 Black and 2 White) were turned down for listing due to social barriers. While limited by the small number of patients turned down for social barriers, our transplant evaluation process does not appear to result in racial disparities in access to listing. Further studies are needed using national cohorts to explore possible racial disparities upstream from waitlisting and transplantation, such as during the referral and evaluation.

Attitudes toward xenotransplantation: A survey of parents and pediatric cardiac providers.

BACKGROUND: Scientific advancements are occurring in cardiac xenotransplantation (XTx). However, there have been religious and social concerns surrounding this allotransplantation alternative. The purpose of this study was to explore the acceptance of XTx among stakeholders of the congenital heart disease (CHD) community. METHODS: A Likert-scale anonymous survey was distributed to physicians and nurses who care for children with CHD and parents of children with CHD. Psychosocial and clinical attitudes were compared across all groups to identify differences, and regression analysis was performed to identify factors associated with XTx acceptance. RESULTS: A total of 297 responded to the survey: 134 physicians, 62 nurses, and 101 parents. Potential acceptance of XTx if outcomes were similar to allotransplantation was high overall (75.3%), but different between the groups (physicians 86%; nurses 71%, parents 64%; P < .0001). Regression analysis showed respondents who reported religion would influence medical decision making (OR 0.48; 95%CI 0.24-0.97) and those who would not use a pig heart transplant as a bridge until a human heart became available were less likely to accept XTx (OR 0.09; 95%CI 0.04-0.21). Psychosocial concerns to XTx were minimal but were also associated with XTx acceptance particularly among parents (OR 0.17; 95%CI 0.03-0.80). CONCLUSIONS: Potential acceptance of XTx is high, assuming results are similar to allotransplantation. Religious beliefs and attitudes toward the use of XTx as a bridge to allotransplant may present barriers to XTx acceptance. Future research is needed to assess potential attitude differences in light of ethical, psychosocial, and religious objections to XTx.

Tachyarrhythmia as a possible symptom of coronavirus in a neonate diagnosed with transposition of the great arteries.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic poses broad challenges to healthcare systems and providers. The manifestations of this disease are still being described in a variety of different contexts and patient populations. RESULTS: We report the case of a neonate who demonstrated COVID-19 after surgical correction of transposition of the great arteries. In addition, the patient demonstrated an evolving and persistent tachyarrhythmia consistent with neither the most likely postoperative complications nor typical COVID-19. DISCUSSION: The patient had negative preoperative testing for the virus and presented with profound oxygen desaturation and respiratory failure several days postoperatively. This raised concern for a complication of his arterial switch operation. It was found that one of the patient's caregivers was an asymptomatic carrier of COVID-19, and imaging ruled out intracardiac shunting. After initiating treatment for COVID-19, the patient's oxygen requirements and need for anti-arrhythmic agents improved. CONCLUSION: We propose that, despite negative preoperative testing, coronavirus infection may present as refractory tachyarrhythmia, and may be considered along with surgical complications as a cause for unexplained hypoxemia postoperatively.

A large ventricular fibroma requiring surgical resection in a symptomatic 3-month-old infant.

Cardiac Fibromas are primary cardiac tumours more common in children than in adults. Surgical intervention is often not required except in the case of limited cardiac output or significant arrhythmia burden. We present a symptomatic 3-month-old infant who had successful surgical intervention for a giant right ventricle fibroma found on prenatal imaging.

Postoperative Hydrocortisone Infusion Reduces the Prevalence of Low Cardiac Output Syndrome After Neonatal Cardiopulmonary Bypass.

OBJECTIVE: Neonatal cardiac surgery with cardiopulmonary bypass is often complicated by morbidity associated with inflammation and low cardiac output syndrome. Hydrocortisone "stress dosing" is reported to provide hemodynamic benefits in some patients with refractory shock. Development of cardiopulmonary bypass-induced adrenal insufficiency may provide further rationale for postoperative hydrocortisone administration. We sought to determine whether prophylactic, postoperative hydrocortisone infusion could decrease prevalence of low cardiac output syndrome after neonatal cardiac surgery with cardiopulmonary bypass. DESIGN: Double-blind, randomized control trial. SETTING: Pediatric cardiac ICU and operating room in tertiary care center. PATIENTS: Forty neonates undergoing cardiac surgery with cardiopulmonary bypass were randomized (19 hydrocortisone and 21 placebo). Demographics and known risk factors were similar between groups. INTERVENTIONS: After cardiopulmonary bypass separation, bolus hydrocortisone (50 mg/m²) or placebo was administered, followed by continuous hydrocortisone infusion (50 mg/m²/d) or placebo tapered over 5 days. Adrenocorticotropic hormone stimulation testing (1 µg) was performed before and after cardiopulmonary bypass, prior to steroid administration. Blood was collected for cytokine analysis before and after cardiopulmonary bypass. MEASUREMENTS AND MAIN RESULTS: Subjects receiving hydrocortisone were less likely to develop low cardiac output syndrome (5/19, 26% vs 12/21, 57%; p = 0.049). Hydrocortisone group had more negative net fluid balance at 48 hours (-114 vs -64 mL/kg; p = 0.01) and greater urine output at 0-24 hours (2.7 vs 1.2 mL/kg/hr; p = 0.03). Hydrocortisone group weaned off catecholamines and vasopressin sooner than placebo, with a difference in inotrope-free subjects apparent after 48 hours (p = 0.033). Five placebo subjects (24%) compared with no hydrocortisone subjects required rescue steroids (p = 0.02). Thirteen (32.5%) had adrenal insufficiency after cardiopulmonary bypass. Patients with adrenal insufficiency randomized to receive hydrocortisone had lower prevalence of low cardiac output syndrome compared with patients with adrenal insufficiency randomized to placebo (1/6 vs 6/7, respectively; p = 0.02). Hydrocortisone significantly reduced proinflammatory cytokines. Ventilator-free days, hospital length of stay, and kidney injury were similar. CONCLUSIONS: Prophylactic, postoperative hydrocortisone reduces low cardiac output syndrome, improves fluid balance and urine output, and attenuates inflammation after neonatal cardiopulmonary bypass surgery. Further studies are necessary to show if these benefits lead to improvements in more important clinical outcomes.

Mechanical circulatory support: strategies and outcomes in pediatric congenital heart disease.

Patients with acute or progressive heart failure in the setting of congenital heart disease may need mechanical circulatory support (MCS) to enhance survival while awaiting cardiac transplantation. Because the majority of MCS devices are implanted after prior cardiac operations, special precautions are necessary at the time of implant. MCS in single ventricle patients usually requires ventricular and aortic cannulation, with a systemic to pulmonary artery shunt for pulmonary blood flow. Limited outcomes data is available, with less than 15% of pediatric MCS patients having congenital heart disease. The Berlin EXCOR is the only durable device currently available for infants. Neurologic complications are the major cause of mortality, and survival during support is poor for infants <5 kg. Patients post-Fontan with acute cardiac failure and/or respiratory failure are at high risk for death before transplant and should be considered for MCS therapy. Several emerging miniature continuous flow devices will soon broaden the landscape of available pediatric devices.

Standardization of the Norwood Procedure Improves Outcomes in a Medium-Sized Volume Center.

The Norwood operation has become common practice to palliate patients with hypoplastic left heart structures. Surgical technique and postoperative care have improved; yet, there remains significant attrition prior to stage II palliation. The objective of this study is to report outcomes before and after standardizing our approach to the Norwood operation. Patients who underwent the Norwood operation at Children's of Alabama were identified, those who underwent hybrid palliation operations were excluded. Pre- (2015-2020) and post- (2020-January 2023) standardization groups were compared and outcomes analyzed. Ninety-one patients were included (pre-standardization 44 (48.3%) and 47 (51.7%) post-standardization). There were no differences in baseline and intraoperative characteristics at Norwood between the pre- and post-standardization groups. Compared with pre-standardization, post-standardization was associated with decreased time to extubation (OR 0.87, 95%CI 0.79-0.96), inotrope duration (OR 0.92, 95%CI 0.86-0.98) and hospital length of stay (OR 0.98, 95%CI 0.96-0.99). There was a trend toward decreased cardiac arrest, reintervention rates, and interstage mortality for the post-standardization group. A standardized approach to complex neonatal cardiac operations such as the Norwood procedure may improve morbidity and decrease hospital resource utilization. We recommend establishing protocols at an institutional level to optimize outcomes in such high-risk patient populations.

Hybrid Thrombectomy and Central Extracorporeal Membrane Oxygenation for Massive Pulmonary Embolism in a Child.

We describe a hybrid thrombectomy and central extracorporeal membrane oxygenation for a child in cardiogenic shock due to a massive pulmonary embolism.

A Multidisciplinary Surgical Approach to Mediastinal Masses in Children.

The aim of this study is to demonstrate the safety and advantages of a multidisciplinary approach to surgical resection of mediastinal masses in children. Eight patients underwent resection of a mediastinal mass by a team involving both a pediatric general surgeon and pediatric cardiothoracic surgeon. One patient required rapid initiation of cardiopulmonary bypass to complete the tumor resection and repair an aortic injury that occurred when removing adherent tumor from the structure. Perioperative outcomes were excellent for all patients. This series shows that a multidisciplinary surgical approach can be potentially life saving.

Surgical Experience With Nine Cases of Obstructed Right Aortic Arch.

BACKGROUND: Right-sided aortic arch obstruction is an extremely rare congenital anomaly. A variety of surgical approaches have been described. This study reviews our institutional experience over the last 30 years. METHODS: Our surgical database at the University of Alabama at Birmingham and Children's Hospital of Alabama from 1992 to 2022 was reviewed to include all patients who underwent surgical repair for right-sided aortic arch obstruction. RESULTS: A total of nine patients underwent surgical repair for right-sided aortic arch obstruction. Surgical approach was via thoracotomy (n = 2, 22%), sternotomy (n = 5, 56%), or combined (n = 2, 22%). Primary extended end-to-end anastomosis was utilized for patients with discrete coarctation (n = 1, 11%), reverse subclavian flap for coarctation with associated distal arch hypoplasia (n = 2, 22%), GORE-TEX® tube graft for circumflex aorta (n = 1, 11%), and aortic arch advancement (n = 5, 56%) with or without patch augmentation for those with an interrupted or severely hypoplastic aortic arch. Reintervention was required in one patient (11%) for recoarctation. All patients were discharged in good condition. There was no hospital mortality and at 10.5 years (mean) follow-up there was one late death. CONCLUSION: Right aortic arch obstruction is a rare entity. Surgical approach should be tailored to the anatomy and associated intracardiac defects. Preoperative imaging with a CT angiogram is useful for operative planning. Sternotomy with single-stage primary repair is safe, effective, and our preferred surgical approach for patients with right aortic arch obstruction and associated intracardiac pathology.

Hybrid Norwood for Hypoplastic Left Heart Syndrome With Rare Aortic Arch Anatomy.

We describe the hybrid Norwood as first-stage palliation for a patient with hypoplastic left heart syndrome, right aortic arch, right descending aorta, bilateral ductus arteriosus, and left innominate artery arising from the left ductus.

Norwood Operation: Immediate vs Delayed Sternal Closure.

BACKGROUND: The Norwood operation is a complex neonatal surgery. There are limited data to inform the timing of sternal closure. After the Norwood operation, delayed sternal closure (DSC) is frequent. We aimed to examine the association of DSC with outcomes, with a particular interest in how sternal closure at the time of surgery compared with the timing of DSC. Our outcomes included mortality, length of ventilation, length of stay, and postoperative complications. METHODS: This retrospective study included neonates who underwent a Norwood operation reported in the Pediatric Cardiac Critical Care Consortium registry from February 2019 through April 2021. Outcomes of patients with closed sternum were compared to those with sternal closure prior to postoperative day 3 (early closure) and prior to postoperative day 6 (intermediate closure). RESULTS: The incidence of DSC was 74% (500 of 674). The median duration of open sternum was 4 days (interquartile range 3-5 days). Comparing patients with closed sternum to patients with early sternal closure, there was no statistical difference in mortality rate (1.1% vs 0%) and the median hospital postoperative stay (30 days vs 31 days). Compared with closed sternum, patients with intermediate sternal closure required longer mechanical ventilation (5.9 days vs 3.9 days) and fewer subsequent sternotomies (3% vs 7.5%). CONCLUSIONS: For important outcomes following the Norwood operation there is no advantage to chest closure at the time of surgery if the chest can be closed prior to postoperative day 3.

Association Between Venous Homografts and Allosensitization After Norwood Procedure.

BACKGROUND: Right ventricle (RV) to pulmonary artery (PA) shunts have become the shunt of choice at many centers for use during the Norwood procedure for single ventricle palliation. Some centers have begun to use cryopreserved femoral or saphenous venous homografts as an alternative to polytetrafluoroethylene (PTFE) for shunt construction. The immunogenicity of these homografts is unknown, and potential allosensitization could have significant implications on transplant candidacy. METHODS: All patients undergoing Glenn procedure at our center between 2013 and 2020 were screened. Patients who initially underwent Norwood procedure with either PTFE or venous homograft RV-PA shunt and had available pre-Glenn serum were included in the study. The primary outcome of interest was panel reactive antibody (PRA) level at the time of Glenn surgery. RESULTS: Thirty-six patients met inclusion criteria (N = 28 PTFE, N = 8 homograft). Patients in the homograft group had significantly higher median PRA levels at the time of Glenn surgery (0% [IQR 0-18] PTFE vs 94% [IQR 74-100] homograft, P = .003). There were no other differences between the two groups. CONCLUSIONS: Despite potential improvements in PA architecture, the use of venous homografts for RV-PA shunt construction at the time of Norwood procedure is associated with significantly elevated PRA level at the time of Glenn surgery. Centers should carefully consider the use of currently available venous homografts given the high percentage of these patients who may require future transplantation.

Central Extracorporeal Membrane Oxygenation Support Following Calcium Channel Blocker Overdose in Children.

Refractory vasodilatory shock (RVS) following massive calcium channel blocker (CCB) overdose remains a challenging clinical entity. Peripheral venoarterial extracorporeal membrane oxygenation (ECMO) has proven useful in several cases of CCB intoxication, however, its use in the pediatric population poses unique challenges given the generally small size of pediatric peripheral vasculature in comparison to the high flow rates necessary for adequate mechanical circulatory support. As a result of these challenges, our group has adopted a "primary" central ECMO cannulation approach to the treatment of children and adolescents admitted to our center with profound RVS after CCB ingestion. We present four cases within the last year using this approach. All patients were successfully discharged from the hospital with no late morbidity at most recent follow-up. Central ECMO support in cases of massive vasodilatory shock following CCB overdose is safe and effective and should be considered early in the clinical course of these critically ill patients.

Report of the 2022 Society of Thoracic Surgeons Congenital Heart Surgery Practice Survey.

BACKGROUND: The Society of Thoracic Surgeons Workforce on Congenital Surgery performed a practice survey to analyze contemporary data. METHODS: An electronic survey was sent to congenital heart surgeons in North America. Details on demographics, training paradigm, clinical practice, and work satisfaction were queried, tabulated, and analyzed. RESULTS: Of 312 unique contacts, 201 (64.4%) responded. Of these, 178 (89%) were practicing. The median age was 52 years (interquartile range, 43, 59 years), and 157 (88%) were male. The number of female respondents increased from 12 (7%) in 2015 to 18 (11%) at present. Practice composition was predominantly mixed pediatric and adult (141; 79%), although 15 (8%) surgeons practiced exclusively pediatric surgery. Most surgeons (154; 87%) reported performing the Society of Thoracic Surgeons-European Association for Cardio-Thoracic Surgery category 4 and 5 procedures. One-fourth (42; 24%) reported performing fewer than 50 pediatric cases per year, and 18 (10%) stated that their primary role was as a surgical assistant. Individual surgeon case volume was most commonly 100 to 149 total cases (29%). Although one-half (91; 51%) reported their volume as being "just right," 74 (42%) reported that their case volume was "too small." Seventy-six (43%) reported too many surgeons in their region. Of the 201 practicing surgeons, 30 (14.9%) plan retirement in the next 5 years. Most described career satisfaction, with 102 (57%) being very satisfied and 48 (27%) somewhat satisfied. CONCLUSIONS: Although most congenital heart surgeons in North America are satisfied with their careers, more than 40% believe that their caseload is inadequate and that there are too many surgeons in their region. Further analysis is warranted regarding career dissatisfaction and diversity.

Early initiation of arginine vasopressin infusion in neonates after complex cardiac surgery.

OBJECTIVE: To describe our experience with low-dose arginine vasopressin infusions (0.0003 U/kg/min) initiated in the operating room after the Norwood procedure or arterial switch operation. DESIGN: Retrospective cohort study of 37 consecutive neonates. SETTING: Pediatric cardiovascular intensive care unit in a tertiary hospital. SUBJECTS: Nineteen patients that received low-dose arginine vasopressin infusion instituted in the operating room (arginine vasopressin+) were compared to 18 patients that did not receive early arginine vasopressin infusion (arginine vasopressin-). INTERVENTIONS: None. RESULTS: When comparing arginine vasopressin+ and arginine vasopressin- in the first 24 hrs after cardiovascular intensive care unit admission, there was no difference in demographic variables, heart rate, blood pressure, central venous pressure, maximum lactate, maximum arterial and central venous saturation difference, urine output, chest tube output, or peritoneal drain output. Mean fluid resuscitation in the first 24 hrs was significantly lower in the arginine vasopressin+ group compared to the arginine vasopressin- group (182 ± 61 mL/kg vs. 223 ± 53 mL/kg, p = .03). The arginine vasopressin+ group also reached median net negative cumulative fluid balance sooner (55 hrs: interquartile range 45, 74 vs. 76 hrs: interquartile range 69, 92; p = .02). Median maximum inotrope score in the first 24 hrs was significantly lower in arginine vasopressin+ (9: interquartile range 5, 12.5 vs. 16.5: interquartile range 10.3, 22.1; p = .02). There was a nonsignificant trend toward shorter duration of mechanical ventilation and cardiovascular intensive care unit length of stay in the arginine vasopressin+ group. The lowest serum sodium in the first 48 hrs was significantly lower in arginine vasopressin+ (132 vs. 137 mmol/L, p = .01). CONCLUSION: Low-dose arginine vasopressin infusion initiated in the operating room after complex neonatal cardiac surgery was associated with decreased fluid resuscitation and catecholamine requirements in the first 24 postoperative hours.