Application of Cardiovascular Physiology to the Critically Ill Patient.

OBJECTIVES: To use the ventricular pressure-volume relationship and time-varying elastance model to provide a foundation for understanding cardiovascular physiology and pathophysiology, interpreting advanced hemodynamic monitoring, and for illustrating the physiologic basis and hemodynamic effects of therapeutic interventions. We will build on this foundation by using a cardiovascular simulator to illustrate the application of these principles in the care of patients with severe sepsis, cardiogenic shock, and acute mechanical circulatory support. DATA SOURCES: Publications relevant to the discussion of the time-varying elastance model, cardiogenic shock, and sepsis were retrieved from MEDLINE. Supporting evidence was also retrieved from MEDLINE when indicated. STUDY SELECTION, DATA EXTRACTION, AND SYNTHESIS: Data from relevant publications were reviewed and applied as indicated. CONCLUSIONS: The ventricular pressure-volume relationship and time-varying elastance model provide a foundation for understanding cardiovascular physiology and pathophysiology. We have built on this foundation by using a cardiovascular simulator to illustrate the application of these important principles and have demonstrated how complex pathophysiologic abnormalities alter clinical parameters used by the clinician at the bedside.

Exploring the Possible Role of Cannabinoids in Managing Post-cardiac Surgery Complications: A Narrative Review of Preclinical Evidence and a Call for Future Research Directions.

ABSTRACT: Open-heart surgery with cardiopulmonary bypass often leads to complications including pain, systemic inflammation, and organ damage. Traditionally managed with opioids, these pain relief methods bring potential long-term risks, prompting the exploration of alternative treatments. The legalization of cannabis in various regions has reignited interest in cannabinoids, such as cannabidiol, known for their anti-inflammatory, analgesic, and neuroprotective properties. Historical and ongoing research acknowledges the endocannabinoid system's crucial role in managing physiological processes, suggesting that cannabinoids could offer therapeutic benefits in postsurgical recovery. Specifically, cannabidiol has shown promise in managing pain, moderating immune responses, and mitigating ischemia/reperfusion injury, underscoring its potential in postoperative care. However, the translation of these findings into clinical practice faces challenges, highlighting the need for extensive research to establish effective, safe cannabinoid-based therapies for patients undergoing open-heart surgery. This narrative review advocates for a balanced approach, considering both the therapeutic potential of cannabinoids and the complexities of their integration into clinical settings.

Standardized Training for Physicians Practicing Pediatric Cardiac Critical Care.

OBJECTIVES: In the vast majority of Children's Hospitals, the critically ill patient can be found in one of three locations: the PICU, the neonatal ICU, and the cardiac ICU. Training, certification, and maintenance of certification for neonatology and critical care medicine are over seen by the Accreditation Council for Graduate Medical Education and American Board of Pediatrics. There is no standardization of training or oversight of certification and maintenance of certification for pediatric cardiac critical care. DATA SOURCES: The curricula from the twenty 4th year pediatric cardiac critical care training programs were collated, along with the learning objectives from the Pediatric Cardiac Intensive Care Society published "Curriculum for Pediatric Cardiac Critical Care Medicine." STUDY SELECTION: This initiative is endorsed by the Pediatric Cardiac Intensive Care Society as a first step toward Accreditation Council for Graduate Medical Education oversight of training and American Board of Pediatrics oversight of maintenance of certification. DATA EXTRACTION: A taskforce was established of cardiac intensivists, including the directors of all 4th year pediatric cardiac critical care training programs. DATA SYNTHESIS: Using modified Delphi methodology, learning objectives, rotational requirements, and institutional requirements for providing training were developed. CONCLUSIONS: In the current era of increasing specialized care in pediatric cardiac critical care, standardized training for pediatric cardiac critical care is paramount to optimizing outcomes.

Fluid bolus administration in children, who responds and how? A systematic review and meta-analysis.

BACKGROUND: Fluid boluses are frequently utilized in children. Despite their frequency of use, there is little objective data regarding the utility of fluid boluses, who they benefit the most, and what the effects are. AIMS: This study aimed to conduct pooled analyses to identify those who may be more likely to respond to fluid boluses as well as characterize clinical changes associated with fluid boluses. METHODS: A systematic review of the literature and meta-analysis was conducted to identify pediatric studies investigating the response to fluid boluses and clinical changes associated with fluid boluses. RESULTS: A total of 15 studies with 637 patients were included in the final analyses with a mean age of 650 days ± 821.01 (95% CI 586 to 714) and a mean weight of 10.5 kg ± 7.19 (95% CI 9.94 to 11.1). The mean bolus volume was 12.14 ml/kg ± 4.09 (95% CI 11.8 to 12.5) given over a mean of 19.55 min ± 10.16 (95% CI 18.8 to 20.3). The following baseline characteristics were associated with increased likelihood of response [represented in mean difference (95% CI)]: greater age [207.2 days (140.8 to 273.2)], lower cardiac index [-0.5 ml/min/m2 (-0.9 to -0.3)], and lower stroke volume [-5.1 ml/m2 (-7.9 to -2.3)]. The following clinical parameters significantly changed after a fluid bolus: decreased HR [-5.6 bpm (-9.8 to -1.3)], increased systolic blood pressure [7.7 mmHg (1.0 to 14.4)], increased mean arterial blood pressure [5.5 mmHg (3.1 to 7.8)], increased cardiac index [0.3 ml/min/m2 (0.1 to 0.6)], increased stroke volume [4.3 ml/m2 (3.5 to 5.2)], increased central venous pressure [2.2 mmHg (1.1 to 3.3)], and increased systemic vascular resistance [2.1 woods units/m2 (0.1 to 4.2)]. CONCLUSION: Fluid blouses increase arterial blood pressure or cardiac output by 10% in approximately 56% of pediatric patients. Fluid blouses lead to significant decrease in HR and significant increases in cardiac output, stroke volume, and systemic vascular resistance. Limited published data are available on the effects of fluid blouses on systemic oxygen delivery.

Correlation of Near-Infrared Spectroscopy Oximetry and Corresponding Venous Oxygen Saturations in Children with Congenital Heart Disease.

Invasive and non-invasive monitoring allow for early detection of hemodynamic compromise, facilitating timely intervention and avoidance of further decline. While venous oximetry is useful for assessing the adequacy of systemic oxygen delivery (DO2), it is most often intermittent, invasive, and costly. Near-infrared spectroscopy (NIRS) oximetry allows for the non-invasive estimation of the adequacy of DO2. We assessed the correlation between cerebral NIRS oximetry and superior vena cava (SVC) and jugular venous (JV) oxygen saturations and between renal NIRS oximetry and inferior vena cava (IVC) oxygen saturations. Systematic review of the literature was conducted to identify studies with data regarding near-infrared spectroscopy and venous saturation. The PubMed, EMBASE, Medline, and Cochrane databases were queried using the following terms in isolation and various combinations: "congenital heart disease," "near infrared spectroscopy," "venous saturation," and "pediatric." Pediatric studies in which simultaneous NIRS oximetry and corresponding venous oxygen saturations were simultaneously collected after cardiac surgery or catheterization were identified. Data were pooled from these studies to analyze the correlation between NIRS oximetry and the corresponding venous oxygen saturations. A total of 16 studies with 613 patients were included in the final analyses. Data were present to compare cerebral and renal NIRS oximetry with corresponding venous oxygen saturation. Cerebral NIRS and SVC and JV oxygen saturations and renal NIRS and IVC oxygen saturations demonstrated strong degrees of correlation (r-value 0.70 for each). However, cerebral NIRS and IVC oxygen saturation had a week degree of correlation (r-value of 0.38). Pooled analyses demonstrate that cerebral NIRS oximetry correlates strongly with SVC or JV oxygen saturation while renal NIRS oximetry correlates strongly with IVC oxygen saturations. A weak correlation was noted between cerebral NIRS oximetry and IVC oxygen saturations.

Hemodynamic Response to Calcium Chloride Boluses in Single-Ventricle Patients with Parallel Circulation.

The purpose of this study is to assess the effect of calcium bolus in response to a hypotensive episode by assessing high-fidelity hemodynamic data obtained from children with single-ventricle physiology with parallel circulation. Single-center, retrospective analysis of hemodynamic data after calcium bolus administrations within the first 2 weeks post-surgery. Time intervals were the baseline (- 60 to - 10 min); the hypotensive episode (- 10 to 0 min); time point zero at the bolus administration; and the response (0 to 60 min). The main responses assessed were the peak increase in mean blood pressure (mBP), duration of the response after the bolus, and markers of oximetric effects. These analyses included 128 boluses in 63 patients. Of the total boluses analyzed, 80% increased the mBP by 5 mmHg or higher with the effect lasting at least 10 min, whereas 10% of the boluses analyzed increased the mBP by 20 mmHg or higher with the effect lasting at least 50 min. The boluses induced a significant increase in arterial oxygen saturation and an upward trend in pulmonary-to-systemic flow ratio, without increasing renal or cerebral oxygen extraction ratios. Calcium chloride boluses are an effective rescue medication for hypotensive episodes in children with parallel circulation. They lead to an improvement in mBP, as well as an increase in pulmonary-to-systemic blood flow ratio. More importantly, these boluses do not compromise systemic oxygen delivery.

Alpha-blockade during congenital heart surgery admissions: analysis from national database.

INTRODUCTION: The effects of alpha-blockade on haemodynamics during and following congenital heart surgery are well documented, but data on patient outcomes, mortality, and hospital charges are limited. The purpose of this study was to characterise the use of alpha-blockade during congenital heart surgery admissions and to determine its association with common clinical outcomes. MATERIALS AND METHODS: A cross-sectional study was conducted using the Pediatric Health Information System database. De-identified data for patients under 18 years of age with a cardiac diagnosis who underwent congenital heart surgery were obtained from 2004 to 2015. Patients were subdivided on the basis of receiving alpha-blockade with either phenoxybenzamine or phentolamine during admission or not. Continuous and categorical variables were analysed using Mann−Whitney U-tests and Fisher exact tests, respectively. Characteristics between subgroups were compared using univariate analysis. Regression analyses were conducted to determine the impact of alpha-blockade on ICU length of stay, hospital length of stay, billed charges, and mortality. RESULTS: Of the 81,313 admissions, 4309 (5.3%) utilised alpha-blockade. Phentolamine was utilised in 4290 admissions. In univariate analysis, ICU length of stay, total length of stay, inpatient mortality, and billed charges were all significantly higher in the alpha-blockade admissions. However, regression analyses demonstrated that other factors were behind these increased. Alpha-blockade was significantly, independently associated with a 1.5 days reduction in ICU length of stay (p < 0.01) and a 3.5 days reduction in total length of stay (p < 0.01). Alpha-blockade was significantly, independently associated with a reduction in mortality (odds ratio 0.8, 95% confidence interval 0.7−0.9). Alpha-blockade was not independently associated with any significant change in billed charges. CONCLUSIONS: Alpha-blockade is used in a subset of paediatric cardiac surgeries and is independently associated with significant reductions in ICU length of stay, hospital length of stay, and mortality without significantly altering billed charges.

Acute Effects of Vasopressin Arginine Infusion in Children with Congenital Heart Disease: Higher Blood Pressure Does Not Equal Improved Systemic Oxygen Delivery.

The use of vasopressin has been increased in recent years in children after congenital heart surgery. However, there is limited information regarding its effects on cardiac output, systemic oxygen delivery, and myocardial energetics. The purpose of this study is to characterize the effects of vasopressin infusions on hemodynamics and systemic oxygen delivery in children with congenital heart disease. A retrospective, single-center study of patients with congenital heart disease who received vasopressin infusions in a pediatric cardiac intensive care unit between January 2019 and May 2020. The measured values collected for study were systolic and diastolic blood pressure, heart rate, arterial oxygen saturation as determined by pulse oximetry, arterial pH, arterial partial pressure of oxygen, arterial partial pressure of carbon dioxide, serum lactate, serum sodium, and renal and cerebral oximetry based on near-infrared spectroscopy. The calculated values for this study were the difference between arterial and NIRS oximetry, the reno-cerebral near-infrared spectroscopy gradient and the vasoinotrope score. A Wilcoxon signed-rank test was utilized to compare values of paired continuous variables before and after initiation of the vasopressin infusion. Correlations were assessed using Spearman correlation analyses and stepwise regressions were completed. A total of 26 vasopressin infusions among 20 unique patients were included in the final analyses. Of these 26 vasopressin infusions, 18 were in patients with biventricular circulation and 8 were in patients with functionally univentricular circulation. The median vasopressin infusion dose at initiation was 0.4 (0.1-1) milliunits/kg/min. For the entire cohort 2 h after the initiation of vasopressin, systolic blood pressure increased to 8.4 mmHg, p < 0.01, but no significant correlation was found to markers of systemic oxygen delivery. Similar results were obtained when only those with biventricular circulation were considered. Those with functionally univentricular circulation were not found to have any statistically significant rise in blood pressure. Vasopressin infusions appear to statistically significantly increase systolic blood pressure in children with congenital heart disease who have a biventricular but not functionally univentricular circulation. Even when an increase in systolic blood pressure is present, systemic oxygen delivery did not improve.

Effects of Vasopressin Infusion After Pediatric Cardiac Surgery: A Meta-analysis.

Vasopressin has been used to augment blood pressure; however, cardiovascular effects after cardiac surgery have not been well established. The primary objective of this study was to survey the current literature and quantify the pooled effect of vasopressin on hemodynamic parameters in children after pediatric cardiac surgery. A systematic review was conducted to identify studies characterizing the hemodynamic effects of vasopressin after pediatric cardiac surgery. Studies were assessed and those of satisfactory quality with pre- and post-vasopressin hemodynamics for each patient were included in the final analyses. 6 studies with 160 patients were included for endpoints during the first 2 h of infusions. Patients who received vasopressin infusion had greater mean, systolic, and diastolic blood pressures and lower heart rates at 2 h after initiation. 8 studies with 338 patients were included for the effects at 24 h. Patients who received vasopressin infusion had lower central venous pressures and decreased lactate concentrations 24 h after initiation. A subset analysis for children with functionally univentricular hearts found significant decrease in inotrope score and central venous pressure. A subset analysis for neonates found significant decrease in inotrope score and fluid balance. Vasopressin leads to decrease in heart rate and increase in blood pressure in the first 2 h of initiation. Later effects include decrease in inotrope score, central venous pressure, fluid balance, and in lactate within the first 24 h. Findings vary in neonates and in those with functionally univentricular hearts although beneficial effects are noted in both.

The impact of medical interventions on admission characteristics in children with congenital heart disease and cardiomyopathy.

INTRODUCTION: Children with congenital heart disease and cardiomyopathy are a unique patient population. Different therapies continue to be introduced with large practice variability and questionable outcomes. The purpose of this study is to determine the impact of various medications on intensive care unit length of stay, total length of stay, billed charges, and mortality for admissions with congenital heart disease and cardiomyopathy. MATERIALS AND METHODS: We identified admissions of paediatric patients with cardiomyopathy using the Pediatric Health Information System database. The admissions were then separated into two groups: those with and without inpatient mortality. Univariate analyses were conducted between the groups and the significant variables were entered as independent variables into the regression analyses. RESULTS: A total of 10,376 admissions were included these analyses. Of these, 904 (8.7%) experienced mortality. Comparing patients who experienced mortality with those who did not, there was increased rate of acute kidney injury with an odds ratio (OR) of 5.0 [95% confidence interval (CI) 4.3 to 5.8, p < 0.01], cardiac arrest with an OR 7.5 (95% CI 6.3 to 9.0, p < 0.01), and heart transplant with an OR 0.3 (95% CI 0.2 to 0.4, p < 0.01). The medical interventions with benefit for all endpoints after multivariate regression analyses in this cohort are methylprednisolone, captopril, enalapril, furosemide, and amlodipine. CONCLUSIONS: Diuretics, steroids, angiotensin-converting enzyme inhibitors, calcium channel blockers, and beta blockers all appear to offer beneficial effects in paediatric cardiomyopathy admission outcomes. Specific agents within each group have varying effects.

Pediatric Cardiac Intensive Care Distribution, Service Delivery, and Staffing in the United States in 2018.

OBJECTIVES: To assess the distribution, service delivery, and staffing of pediatric cardiac intensive care in the United States. DESIGN: Based on a 2016 national PICU survey, and verified through online searching and clinician networking, medical centers were identified with a separate cardiac ICU or mixed ICU. These centers were sent a structured web-based survey up to four times, with follow-up by mail and phone for nonresponders. SETTING: Cardiac ICUs were defined as specialized units, specifically for the treatment of children with life-threatening primary cardiac conditions. Mixed ICUs were defined as separate units, specifically for the treatment of children with life-threatening conditions, including primary cardiac disease. PARTICIPANTS: Cardiac ICU or mixed ICU physician medical directors or designees. MEASUREMENTS AND MAIN RESULTS: One-hundred twenty ICUs were identified: 61 (51%) were mixed ICUs and 59 (49%) were cardiac ICUs. Seventy five percent of institutions at least sometimes used a neonatal ICU prior to surgery. The most common temporary cardiac support beyond extracorporeal membrane oxygenation was a centrifugal pump such as Centrimag. Durable cardiac support devices were far more common in separate cardiac ICUs (84% vs 20%; p < 0.0001). Significantly less availability of electrophysiology, heart failure, and cardiac anesthesia consultation was available in mixed ICUs (p = 0.0003, p < 0.0001, p = 0.042 respectively). ICU attending physicians were in-house day and night 98% of the time in mixed ICUs and 87% of the time in cardiac ICUs. Nurse practitioners were consistent front-line providers in the ICUs caring for children with primary cardiac disease staffing 88% of cardiac ICUs and 56% of mixed ICUs. Mixed ICUs were more commonly staffed with pediatric residents, and critical care fellows were found in more cardiac ICUs (83% vs 77%; p < 0.0001). CONCLUSIONS: Mixed ICUs and cardiac ICUs have statistically different staffing models and available services. More evaluation is needed to understand how this may impact patient outcomes and training programs of physicians and nurses.

Sodium nitroprusside versus nicardipine for hypertension management after surgery: A systematic review and meta-analysis.

BACKGROUND: Vasoactive medications are commonly administered for afterload reduction and arterial hypertension treatment in patients after cardiac surgery. A systematic review and meta-analysis were conducted to determine the effects of sodium nitroprusside and nicardipine on hemodynamics and cardiac performance in this population. METHODS: A systematic review of published manuscripts was performed to identify studies of patients who received sodium nitroprusside and nicardipine as part of the treatment for arterial hypertension or afterload reduction after cardiac surgery. A meta-analysis was then conducted to determine the effects of sodium nitroprusside and nicardipine on hemodynamics and cardiac performance. The following parameters were captured: blood pressure, heart rate, right atrial pressure, systemic vascular resistance, and stroke volume. RESULTS: In total, five studies with 571 patients were pooled for these analyses. Systolic blood pressure, diastolic blood pressure, and mean arterial blood pressure were similar in both groups. The cardiac index was greater with nicardipine while mean pulmonary artery pressure was lower with sodium nitroprusside. CONCLUSION: Nicardipine and sodium nitroprusside have similar abilities in reducing afterload in the postoperative cardiac population. Statistically significant differences were found in pulmonary artery pressure and cardiac index. It may be beneficial to consider nicardipine for afterload reduction in patients with a low cardiac index.

Peritoneal dialysis during congenital heart surgery admissions: insights from a large database.

BACKGROUND: The management of fluid overload after congenital heart surgery has been limited to diuretics, fluid restriction, and dialysis. This study was conducted to determine the association between peritoneal dialysis and important clinical outcomes in children undergoing congenital heart surgery. METHODS: A retrospective review was conducted to identify patients under 18 years of age who underwent congenital heart surgery. The data were obtained over a 16-year period (1997-2012) from the Kids' Inpatient Database. Data analysed consisted of demographics, diagnoses, type of congenital heart surgery, length of stay, cost of hospitalisation, and mortality. Logistic regression was performed to determine factors associated with peritoneal dialysis. RESULTS: A total of 46,176 admissions after congenital heart surgery were included in the study. Of those, 181 (0.4%) utilised peritoneal dialysis. The mean age of the peritoneal dialysis group was 7.6 months compared to 39.6 months in those without peritoneal dialysis. The most common CHDs were atrial septal defect (37%), ventricular septal defect (32.6%), and hypoplastic left heart syndrome (18.8%). Univariate analyses demonstrated significantly greater length of stay, cost of admission, and mortality in those with peritoneal dialysis. Regression analyses demonstrated that peritoneal dialysis was independently associated with significant decrease in cost of admission (-$57,500) and significant increase in mortality (odds ratio 1.5). CONCLUSIONS: Peritoneal dialysis appears to be used in specific patient subsets and is independently associated with decreased cost of stay, although it is associated with increased mortality. Further studies are needed to describe risks and benefit of peritoneal dialysis in this population.

Postoperative Pain Management in Pediatric Patients Undergoing Cardiac Surgery: Where Are We Heading?

OBJECTIVES: Adequate postoperative pain management is crucial in pediatric patients undergoing cardiac surgery because pain can lead to devastating short- and long-term consequences. This review discusses the limitations of current postoperative pain assessment and management in children after cardiac surgery, the obstacles to providing optimal treatment, and concepts to consider that may overcome these barriers. DATA SOURCE: MEDLINE and PubMed. CONCLUSIONS: Effective pain management in infants and young children undergoing cardiac surgery continues to evolve with innovative methods of both assessment and therapy using newer drugs or novel routes of administration. Artificial intelligence- and machine learning-based pain assessment and patient-tailored management in both pain measurement and prevention are already being integrated into the routine of current practice.

Postoperative Inhaled Nitric Oxide Does Not Decrease Length of Stay in Pediatric Cardiac Surgery Admissions.

Pulmonary hypertension is one of the most challenging complications in congenital heart surgery. The purpose of this study was to characterize inhaled nitric oxide administration in children with and without pulmonary hypertension who underwent congenital heart surgery and to describe the effect of nitric oxide administration on admission outcomes. This is a cross-sectional study utilizing data from the Pediatric Health Information System (PHIS) and PHIS + databases from 2004 to 2015. Pediatric patients with a congenital heart disease diagnosis were included and divided into groups with pulmonary hypertension that received and not received inhaled nitric oxide and patients without diagnosis of pulmonary hypertension who received and did not receive inhaled nitric oxide. For all admissions, the following were captured: age of admission, gender, year of admission, length of stay, billed charges, inpatient mortality, the presence of specific congenital malformations of the heart, specific cardiac surgeries, and comorbidities. Comparisons between groups were completed using a Mann-Whitney-U test and Fisher's exact test. Outcomes evaluation was completed using univariate and regression analyses. A total of 40,194 pediatric cardiac surgical admissions without pulmonary hypertension were identified. Of these, 726 (1.8%) received inhaled nitric oxide. Regression analyses demonstrated that inhaled nitric oxide was independently associated with increased length of stay, billed charges, and inpatient mortality. A total of 1678 pediatric cardiac surgical admissions with pulmonary hypertension were identified. Of these, 195 (11.6%) received inhaled nitric oxide. Regression analyses demonstrated that inhaled nitric oxide was independently associated with a significant increase in length of stay and billed charges. There was no statistically significant association between inhaled nitric oxide and decrease mortality. Administration of inhaled nitric oxide after pediatric cardiac surgery increases length of stay and billed charges while not providing improved inpatient mortality. In fact, administration of inhaled nitric oxide was associated with increased mortality in those without pulmonary hypertension while not impacting mortality in any way in those with pulmonary hypertension.

The Use of Nesiritide in Children With Congenital Heart Disease.

OBJECTIVE: We evaluated the use of nesiritide in children with critical congenital heart disease, pulmonary congestion, and inadequate urine output despite conventional diuretic therapy. DESIGN: We conducted a retrospective analysis of 26 consecutive patients, comprising 37 infusions occurring during separate hospitalizations. Hemodynamic variables, urine output, and serum creatinine levels were monitored prior to and throughout the duration of therapy with nesiritide. In addition, the stage of acute kidney injury was determined prior to and throughout the duration of the therapy using a standardized definition of acute kidney injury-The Kidney Disease: Improving Global Outcomes criteria. SETTING: Cardiac ICU. PATIENTS: Pediatric patients with critical congenital heart disease, pulmonary congestion, and inadequate urinary output despite diuretic therapy. INTERVENTION: Nesiritide infusion. MEASUREMENTS AND MAIN RESULTS: The use of nesiritide was associated with a significant decrease in the central venous pressure and heart rate with a trend toward a significant increase in urine output. During the course of therapy with nesiritide, the serum creatinine and stage of acute kidney injury decreased significantly. The decrease in stage of acute kidney injury became significant by day 4 (p = 0.006) and became more significant with time (last day of therapy compared with baseline; p < 0.001). During 12 of the 37 infusions, the stage of acute kidney injury decreased by two or more (p < 0.001). CONCLUSIONS: Nesiritide had a favorable impact on hemodynamics and urine output in children with critical congenital heart disease and pulmonary congestion, and there was no worsening of renal function.