Factors that mediate change in creatinine and acute kidney injury after the Norwood operation: insights from high-fidelity haemodynamic monitoring data.

BACKGROUND: Acute kidney injury is a common postoperative complication of paediatric cardiac surgery associated with increased morbidity and mortality. The purpose of this study is to characterise associations between haemodynamic parameters, clinical parameters, and medical interventions, on acute kidney injury. METHODS: Nine patients with univentricular physiology undergoing the Norwood procedure from a single-centre tertiary care paediatric cardiac ICU were included (September 2022 to March 2023). Patients were monitored with the T3 software. Data were analysed using a Fisher exact test, Mann-Whitney-U test, LASSO-based machine learning techniques, and receiver operator curve analyses. RESULTS: Over 27,000 datapoints were included. Acute kidney injury occurred in 2 patients (22%) during this period. Net fluid balance and renal oxygen extraction were independently associated with acute kidney injury, while commonly used metrics of pressure (systolic, diastolic, or mean arterial blood pressure) were not. The resulting acute kidney injury risk score was (4.1 × fluid balance) + (1.9 × renal oxygen extraction). The risk score was significantly higher in acute kidney injury with a score of 32.9 compared to 7.9 (p < 0.01). Optimal cut-offs for fluid balance (7 mL/hr) and renal oxygen extraction (29%) were identified. Higher serum creatinine:baseline creatinine ratio was associated with a higher mean airway pressure, higher renal oxygen extraction, higher mean arterial blood pressure, higher vasoactive inotropic score, and fluid balance. CONCLUSION: Among patients with univentricular physiology undergoing the Norwood procedure, renal oxygen extraction and a higher net fluid balance are independently associated with increased risk of acute kidney injury. Renal perfusion pressure is not significantly associated with acute kidney injury.

Postoperative Atrioventricular Block in Pediatric Patients: Impact of Congenital Cardiac Malformations and Medications.

Postoperative atrioventricular block may occur after pediatric cardiac surgery. A small proportion of those who develop atrioventricular block will require pacemaker placement. The primary aim of this study was to determine factors associated with postoperative atrioventricular block. Secondary aims included determining factors associated with pacemaker placement in those with atrioventricular block. Data from the PHIS data were utilized to identify patients under 18 years of age who underwent cardiac surgery. Those who did and did not develop atrioventricular block. Univariable analyses and regression analyses were conducted to determine factors associated with postoperative atrioventricular block. Similar analyses were conducted to determine factors associated with pacemaker placement in those with atrioventricular block. A total of 43,716 admissions were identified. Of these, 2093 (5%) developed atrioventricular block and 480 (1% of total admissions) underwent pacemaker placement. Approximately 70% of those with atrioventricular block received steroids but this was not associated with a decrease in pacemaker placement. Risk factors (congenital malformations of the heart, comorbidities, medications) associated with increased risk of atrioventricular block and pacemaker placement were identified. Postoperative atrioventricular block occurred in 5% of pediatric admissions for cardiac surgery. Of these admissions with postoperative atrioventricular block, 23% required pacemaker placement. Isoproterenol and steroids were not associated with a reduction in the likelihood of pacemaker placement.

Reduced length of stay after implementation of a clinical pathway following repair of ventricular septal defect.

BACKGROUND: There is variation in care and hospital length of stay following surgical repair of ventricular septal defects. The use of clinical pathways in a variety of paediatric care settings has been shown to reduce practice variability and overall length of stay without increasing the rate of adverse events. METHODS: A clinical pathway was created and used to guide care following surgical repair of ventricular septal defects. A retrospective review was done to compare patients two years prior and three years after the pathway was implemented. RESULTS: There were 23 pre-pathway patients and 25 pathway patients. Demographic characteristics were similar between groups. Univariate analysis demonstrated a significantly shorter time to initiation of enteral intake in the pathway patients (median time to first enteral intake after cardiac ICU admission was 360 minutes in pre-pathway patients and 180 minutes in pathway patients, p < 0.01). Multivariate regression analyses demonstrated that the pathway use was independently associated with a decrease in time to first enteral intake (-203 minutes), hospital length of stay (-23.1 hours), and cardiac ICU length of stay (-20.5 hours). No adverse events were associated with the use of the pathway, including mortality, reintubation rate, acute kidney injury, increased bleeding from chest tube, or readmissions. CONCLUSIONS: The use of the clinical pathway improved time to initiation of enteral intake and decreased length of hospital stay. Surgery-specific pathways may decrease variability in care while also improving quality metrics.

Expert Consensus Statement: Anatomy, Imaging, and Nomenclature of Congenital Aortic Root Malformations.

Over the past 2 decades, several categorizations have been proposed for the abnormalities of the aortic root. These schemes have mostly been devoid of input from specialists of congenital cardiac disease. The aim of this review is to provide a classification, from the perspective of these specialists, based on an understanding of normal and abnormal morphogenesis and anatomy, with emphasis placed on the features of clinical and surgical relevance. We contend that the description of the congenitally malformed aortic root is simplified when approached in a fashion that recognizes the normal root to be made up of 3 leaflets, supported by their own sinuses, with the sinuses themselves separated by the interleaflet triangles. The malformed root, usually found in the setting of 3 sinuses, can also be found with 2 sinuses, and very rarely with 4 sinuses. This permits description of trisinuate, bisinuate, and quadrisinuate variants, respectively. This feature then provides the basis for classification of the anatomical and functional number of leaflets present. By offering standardized terms and definitions, we submit that our classification will be suitable for those working in all cardiac specialties, whether pediatric or adult. It is of equal value in the settings of acquired or congenital cardiac disease. Our recommendations will serve to amend and/or add to the existing International Paediatric and Congenital Cardiac Code, along with the Eleventh iteration of the International Classification of Diseases provided by the World Health Organization.

Fluid Overload and AKI After the Norwood Operation: The Correlation and Characterization of Routine Clinical Markers.

The purpose of this study was to determine the correlation of different methods of assessing fluid overload and determine which metrics are associated with development of acute kidney injury (AKI) in the period immediately following Norwood palliation. This was a retrospective single-center study of Norwood patients from January 2011 through January 2021. AKI was defined using the Kidney Disease Improving Global Outcomes (KDIGO). Patients were separated into two groups: those with AKI and those without. A logistic regression analysis was conducted with AKI at any point in the study period as the dependent variable and clinical and laboratory data as independent variables. Analysis was conducted as a stepwise regression. The coefficients from the logistic regression were then used to develop a cumulative AKI risk score. Spearman correlations were conducted to analyze the correlation of fluid markers. 116 patients were included, and 49 (42.4%) developed AKI. The duration of open chest, duration of mechanical ventilation, need for dialysis, need for extracorporeal membrane oxygenation, and inpatient mortality were associated with AKI (p ≤ 0.05). Stepwise logistic regression demonstrated the following significant independent associations AKI: age at Norwood in days (p < 0.01), blood urea nitrogen (p < 0.01), central venous pressure (p = 0.04), and renal oxygen extraction ratio (p < 0.01). The area under the receiver operating characteristic curve for the logistic regression was 0.74. The fluid markers had weak R-value. Urea, central venous pressure, and renal oxygen extraction ratio are associated with AKI after the Norwood operation. Common clinical metrics used to assess fluid overload are poorly correlated with each other for postoperative Norwood patients.

The effect of clinical and haemodynamic variables on post-operative length of stay immediately upon admission after biventricular repair with Yasui operation following an earlier Norwood operation.

BACKGROUND: There are a variety of approaches to biventricular repair in neonates and infants with adequately sized ventricles and left-sided obstruction in the presence of a ventricular septal defect. Those who undergo this in a staged manner initially undergo a Norwood procedure followed by a ventricular septal defect closure such that the neo-aorta is entirely committed to the left ventricle and placement of a right ventricular to pulmonary artery conduit (Yasui operation). This study aimed to determine clinical and haemodynamic factors upon paediatric cardiac ICU admission immediately after the two-stage Yasui operation that was associated with post-operative length of stay. METHODS: This was a retrospective review of patients who underwent the Yasui procedure after the initial Norwood operation between 1 January 2011 and 31 December 2020. Patients with complete data on admission were identified and analysed using Bayesian regression analysis. RESULTS: A total of 15 patients were included. The median age was 9.0 months and post-operative length of stay was 6days. Bayesian regression analysis demonstrated that age, weight, heart rate, mean arterial blood pressure, central venous pressure, pulse oximetry, cerebral near infrared spectroscopy, renal near infrared spectroscopy, pH, pCO2, ionised calcium, and serum lactate were all associated with post-operative length of stay. CONCLUSION: Discrete clinical and haemodynamic factors upon paediatric cardiac ICU admission after staged Yasui completion are associated with post-operative length of stay. Clinical target ranges can be developed and seem consistent with the notion that greater systemic oxygen delivery is associated with lower post-operative length of stay.

Association Between Seasonal Fontan Timing, Viral Infection Burden, and Post-Operative Length of Stay.

The Fontan procedure (FP) is typically a semi-elective surgery performed between 2 and 5 years of age to complete staged single ventricle palliation. Optimal timing for the FP, particularly in relation to seasonal infectious burden, remains unclear. We queried the Pediatric Health Information System (PHIS) database for all admissions for viral respiratory infections (VRI) from January 2006 to September 2015 and separately for all admissions with a primary procedure code of FP. The PHIS query generated 2,767,142 admissions for VRI and 6349 admissions for the FP from 45 children's hospitals. Of all FP, 2124 (33.5%) were performed from October through March. The median length of stay after Fontan procedure was 9 days (IQR 7-15). Median length of stay after FP was correlated with VRI burden (correlation coefficient = 0.3, p = 0.03). April through August (weeks 18 through 35) had the lowest VRI admission burden and FP length of stay was significantly shorter during this time (13.6 ± 14.8 days vs 14.9 ± 20.3 days, p = 0.03). The FP is frequently performed during the viral respiratory season. This timing is associated with an increased post-operative length of stay after the FP. For elective FP, ideal timing that avoids the viral respiratory season and minimizes post-operative LOS is April through August.

Association of Immediate Postoperative Hemodynamic and Laboratory Values in Predicting Norwood Admission Outcomes.

The primary objective of this study was to determine whether or not hemodynamic parameters and laboratory values at the time of admission to the pediatric cardiac intensive care unit after the Norwood operation were associated with a composite outcome of either need for extracorporeal membrane oxygenation or inpatient mortality. This was a single-center retrospective study of infants with functionally univentricular hearts admitted to intensive care after the Norwood procedure from January 2011 to January 2020. Data were obtained at a single point (after a Norwood procedure) and then compared between two subsets of patients based on the presence or not of the composite outcome of interest. In univariate and multiple regression analyses, a series of receiver operator curves were generated to assess the relationship between the variables of interest and the composite outcome. Eight (7.6%) experienced the composite outcome out of a total of 104 patients. Those who experienced the composite endpoint had significantly higher oxygen extraction ratio (0.43 vs. 0.31, p = 0.01), lower systemic blood flow (2.5 L/min versus 3.1 L/min, p = 0.01), and higher systemic vascular resistance (20.2 indexed woods units versus 14.8 indexed woods units, p = 0.01). Those with systemic blood flow of less than 2.5 L/min/m2 had a 17% risk of experiencing the composite endpoint AUC = 0.79. Those with systemic vascular resistance of greater than 19 indexed woods units had a 22% risk of experiencing the composite endpoint AUC 0.80. Systemic blood flow and systemic vascular resistance are independently associated with this composite outcome.

Propofol in the Pediatric Intensive Care Unit, a Safe and Effective Agent in Reducing Pain and Sedation Infusions: A Single-Center Retrospective Study.

Introduction Propofol has long been used as an anesthetic agent during pediatric surgery. Its use in pediatric intensive care units has been largely controversial. A beneficial use of propofol is to facilitate weaning of other pain and sedation infusions such as opiates and benzodiazepines. However, some have advocated to not use propofol due to fear of possible adverse effects including propofol infusion syndrome and hemodynamic instability. The purpose of this study was to determine both the safety of propofol infusions in critically ill pediatric patients, as well as the change in the requirement of other pain and sedation infusions by use of a propofol infusion. Methods Single-center, retrospective data (January 2011 to January 2020) was obtained manually using a study-specific data extraction tool created for electronic medical records. The data obtained included variables of interest that measured physiological parameters and pain/sedation infusion (morphine, fentanyl, hydromorphone, midazolam, and dexmedetomidine) rates during three time periods: before propofol initiation, immediately after discontinuation, and four hours after discontinuation. The physiological parameters were then compared to the pain and sedation infusion rates using paired Wilcoxon signed-rank tests. Results There was a total of 33 patients with an average age of 11.1 years who were given a median initial propofol infusion of 50 mcg/kg/min with a peak dose of 75 mcg/kg/min over an average of eight hours. Age had a weak and insignificant correlation with initial rate and duration and a moderate and significant correlation with peak rate and duration. Physiological parameters did not vary at any time point measured. There was a significant reduction in other pain and sedation infusions after discontinuation of propofol. Conclusion Propofol infusions are hemodynamically tolerated and the majority of patients who are on other pain and sedation infusions tolerate complete discontinuation of these infusions following propofol discontinuation.

Serum Lactate and Mortality during Pediatric Admissions: Is 2 Really the Magic Number?

The primary objective of this study was to determine if serum lactate level at the time of hospital admission can predict mortality in pediatric patients. A systematic review was conducted to identify studies that assessed the utility of serum lactate at the time of admission to predict mortality in pediatric patients. The areas under the curve from the receiver operator curve analyses were utilized to determine the pooled area under the curve. Additionally, standardized mean difference was compared between those who survived to discharge and those who did not. A total of 12 studies with 2,099 patients were included. Out of these, 357 (17%) experienced mortality. The pooled area under the curve for all patients was 0.74 (0.67-0.80, p < 0.01). The pooled analyses for all admissions were higher in those who experienced mortality (6.5 vs. 3.3 mmol/L) with a standardized mean difference of 2.60 (1.74-3.51, p < 0.01). The pooled area under the curve for cardiac surgery patients was 0.63 (0.53-0.72, p < 0.01). The levels for cardiac surgery patients were higher in those who experienced mortality (5.5 vs. 4.1 mmol/L) with a standardized mean difference of 1.80 (0.05-3.56, p = 0.04). Serum lactate at the time of admission can be valuable in identifying pediatric patients at greater risk for inpatient mortality. This remained the case when only cardiac surgery patients were included.

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.

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

The purpose of this study is to assess the effect of fluid bolus in response to a hypotensive episode by evaluating high-fidelity hemodynamic data obtained from children with single-ventricle anatomy and parallel circulation. Single center, retrospective analysis of hemodynamic and oximetric data after fluid bolus administrations within the first 2 weeks post-surgery. A baseline (- 60 to - 10 min), hypotensive episode (- 10 to 0 min), and response interval (0 to 60 min) were defined to quantify the dynamics of vital signs. The responses assessed include heart rate, blood pressure, oxygen saturation, oxygen extraction ratios, and pulmonary-to-systemic flow ratios. Mixed effects models were used to account for the repeated measures over the response interval. The analysis included 67 fluid boluses. There is a decrease in heart rate and an increase in blood pressure during the response in comparison to the hypotensive time. These vitals rapidly return to the baseline values. The boluses induced a significant decrease in renal and cerebral oxygen extraction ratios, with no significant change in arterial oxygen saturation or pulmonary-to-systemic flow ratio. The type of bolus (normal saline versus albumin) did not affect the response in blood pressure. However, in comparison with albumin, normal saline had a more favorable effect on the renal and cerebral oxygen extraction ratios. This study demonstrates that fluid boluses are an effective rescue medication for hypotensive episodes in children with parallel circulation by improving hemodynamics, as well as markers of oxygen delivery. The type of bolus (normal saline versus albumin) did not affect the blood pressure response. However, normal saline had a more pronounced effect on the renal and cerebral oxygen extraction ratios than albumin.

Inferior and Superior Vena Cava Saturation Monitoring After Neonatal Cardiac Surgery.

OBJECTIVES: Superior vena cava oxygen saturation (SVC O 2 ) monitoring is well described for early detection of hemodynamic deterioration after neonatal cardiac surgery but inferior vena cava vein oxygen saturation (IVC O 2 ) monitoring data are limited. DESIGN: Retrospective cohort study of 118 neonates with congenital heart disease (52 single ventricle) from February 2008 to January 2014. SETTING: Pediatric cardiac ICU. PATIENTS: Neonates (< 30 d) with concurrent admission IVC O 2 and SVC O 2 measurements after cardiac surgery with cardiopulmonary bypass. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The primary aim was to correlate admission IVC O 2 and SVC O 2 . Secondary aims included: correlate flank or cerebral near-infrared spectroscopy with IVC O 2 and SVC O 2 , respectively, and exploratory analysis to evaluate associations between oximetry data and a composite adverse outcome defined as any of the following: increasing serum lactate or vasoactive support at 2 hours post-admission, cardiac arrest, or mortality. Admission IVC O 2 and SVC O 2 correlated ( r = 0.54; p < 0.001). However, IVC O 2 measurements were significantly lower than paired SVC O 2 (mean difference, -6%; 95% CI, -8% to -4%; p < 0.001) with wide variability in sample agreement. Logistic regression showed that each 12% decrease in IVC O 2 was associated with a 12-fold greater odds of the composite adverse outcome (odds ratio [OR], 12; 95% CI, 3.9-34; p < 0.001). We failed to find an association between SVC O 2 and increased odds of the composite adverse outcome (OR, 1.8; 95% CI, 0.99-3.3; p = 0.053). In an exploratory analysis, the area under the receiver operating curve for IVC O 2 and SVC O 2 , and the composite adverse outcome, was 0.85 (95% CI, 0.77-0.92) and 0.63 (95% CI, 0.52-0.73), respectively. Admission IVC O 2 had strong correlation with concurrent flank near-infrared spectroscopy value ( r = 0.74; p < 0.001). SVC O 2 had a weak association with cerebral near-infrared spectroscopy ( r = 0.22; p = 0.02). CONCLUSIONS: In postoperative neonates, admission IVC O 2 and SVC O 2 correlate. Lower admission IVC O 2 may identify a cohort of postsurgical neonates at risk for low cardiac output and associated morbidity.

Impact of Medical Interventions and Comorbidities on Norwood Admission for Patients with Hypoplastic Left Heart Syndrome.

The purpose of these analyses was to determine how specific comorbidities and medical interventions impact risk of inpatient mortality in those with hypoplastic left heart syndrome undergoing Norwood procedure. The secondary aims were to determine the impact of these on billed charges, postoperative length of stay, and risk of cardiac arrest. Admissions from 2004 to 2015 in the Pediatric Health Information System database with hypoplastic left heart syndrome and Norwood procedure were identified. Admission characteristics, patient interventions, and the presence of comorbidities were captured. A total of 5,138 admissions were identified meeting inclusion criteria. Of these 829 (16.1%) experienced inpatient mortality, and 352 (6.7%) experienced cardiac arrest. The frequency of inpatient mortality did not significantly change over the course of the study era. The frequency of cardiac arrest significantly decreased from 7.4% in 2004 to 4.3% in 2015 (p = 0.04). The frequency of pharmacologic therapies, particularly vasoactive use, decreased as the study period progressed. Regression analyses demonstrated a significant association between cardiac arrest and inpatient mortality with arrhythmias, acute kidney injury, and pulmonary hypertension. Similarly, regression analyses demonstrated a significant association between increase in billed charges and length of stay with year of surgery, presence of heart failure, syndromes, and acute kidney injury. For patients with hypoplastic left heart syndrome undergoing the Norwood procedure, the frequency of pharmacologic therapies and cardiac arrest has decreased over time. There are significant associations between acute kidney injury, arrythmias, and pulmonary hypertension with cardiac arrest and mortality.

Rates of depression, anxiety, and stress in parents of children with congenital heart disease using the Depression Anxiety Stress Scale.

Context and Background: The Cardiac Neurodevelopmental Outcome Collaborative has recommended using the Depression Anxiety Stress Scale (DASS) to evaluate for depression, anxiety, and stress in parents of children with congenital heart disease (CHD). There has not been a longitudinal study investigating its utility in these parents. Aims: The aim of this study was to determine the trend of depression, anxiety, and stress in parents of patients with CHD. Methods: Our center uses this self-reported survey at every visit between 6 and 36 months of age. This was a single-centered, retrospective study from January 1, 2018, to June 1, 2020. Statistical Analysis: Cox regression analysis was conducted using a composite end point of having an abnormal score in any of the three domains. Results: Two hundred and seventy-three mothers and 139 fathers were included in the study. For mothers, scores in each domain were elevated at 12 and 24 months. For fathers, scores in each domain were elevated at 6 months, followed by a decrease before peaking again, with depression increasing at 36 months and anxiety and stress increasing at 30 months. Increased length of stay for the index surgery was associated with an abnormal score for mothers (B = 0.02, P < 0.01) and fathers (B = 0.01, P = 0.04). Being in a relationship with the father (B = -0.8, P < 0.01) was associated with freedom of an abnormal score for mothers. Conclusions: Scores concerning for depression, anxiety, and stress peak at different points for parents. Length of stay for the index surgery and being in a relationship are important factors in the mental health of parents.

Impact of Noonan Syndrome on admissions for pediatric cardiac surgery.

BACKGROUND: Noonan Syndrome is the second most common genetic syndrome associated with congenital heart disease. Many patients with Noonan Syndrome will require a cardiac intervention. This study aimed to characterize the difference in cardiac surgery admissions in patients with and without Noonan Syndrome. METHODS: Data regarding hospital admissions was collected using the Kids' Inpatient Database from 1997 to 2012. A cross-sectional study was conducted comparing baseline characteristics, cardiac morphology, cardiac surgery, and other comorbidities between those with and without Noonan Syndrome. Regression analysis was conducted to determine factors related to Noonan Syndrome and risk factors for increased length of hospitalization, need for ECMO, and inpatient mortality using Noonan Syndrome as the independent variable. RESULTS: A total of 46,169 admissions with cardiac surgery under 18 years of age were included in the final analyses. Of these 778 (1.6%) had Noonan Syndrome. Pulmonary stenosis, coronary anomalies, and valvuloplasty without valve replacement were independently associated with Noonan Syndrome. Those with Noonan Syndrome were 90% more likely to have chylothorax. Pediatric cardiac surgery admissions tended to be 4.5 days longer and cost $54,296 more in total charges with Noonan Syndrome. Inpatient mortality is also increased by Noonan Syndrome. CONCLUSIONS: Noonan Syndrome is present in a relatively small proportion of pediatric cardiac surgery admissions. Noonan Syndrome is independently associated with increased length and cost of such admissions as well as inpatient mortality.

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.

The effect of dexmedetomidine on renal function after surgery: A systematic review and meta-analysis.

WHAT IS KNOWN AND OBJECTIVE: Acute kidney injury (AKI) is a complication following surgery and has been associated with worsened patient outcomes. Providers have used agents that may confer a degree of renal protection in the perioperative stage. Such is the case of dexmedetomidine, a selective alpha-2 adrenergic agonist used in the intensive care unit (ICU) as a sedative agent. The primary objective of this meta-analysis was to characterize the use of dexmedetomidine and to evaluate its impact on renal markers and outcomes in patients after surgery. METHODS: A systematic review of manuscripts was performed to identify patients who received dexmedetomidine after surgery by searching the PubMed, Embase, and Cochrane databases. The following parameters were captured: blood urea nitrogen (BUN), serum creatinine, creatinine clearance, neutrophil gelatinase-associated lipoprotein (NGAL), cystatin C, urine output, duration of mechanical ventilation, ICU length of stay, AKI, need for dialysis, and mortality. RESULTS AND DISCUSSION: Nineteen studies with 3,395 patients were included in the analyses. The mean bolus and infusion dose of dexmedetomidine were 0.82 µg/kg and 0.54 mcg/kg/hr, respectively. There was a significant difference in creatinine clearance and NGAL in favour of the dexmedetomidine group. In addition, the dexmedetomidine group had a shorter ICU length of stay, and a lower risk of acute kidney injury and mortality compared to the control. There was no difference in the rest of the parameters. WHAT IS NEW AND CONCLUSION: Dexmedetomidine appears to have postoperative renal protective effects. This is evidenced by lower NGAL levels and increased creatinine clearance in those who received dexmedetomidine. These effects are associated with decreases in ICU length of stay and risk of AKI and mortality.

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.