Periods of low renal perfusion pressure are associated with acute kidney injury following paediatric cardiac surgery.

INTRODUCTION: Acute kidney injury is associated with worse outcomes after cardiac surgery. The haemodynamic goals to ameliorate kidney injury are not clear. Low post-operative renal perfusion pressure has been associated with acute kidney injury in adults. Inadequate oxygen delivery may also cause kidney injury. This study evaluates pressure and oximetric haemodynamics after paediatric cardiac surgery and their association with acute kidney injury. MATERIALS AND METHODS: Retrospective case-control study at a children's hospital. Patients were < 6 months of age who underwent a Society of Thoracic Surgery-European Association for Cardio-Thoracic Surgery Congenital Heart Surgery categories ≥ 3. Low renal perfusion pressure was time and depth below several tested thresholds. The primary outcome was serum creatine-defined acute kidney injury in the first 7 days. RESULTS: Sixty-six patients (median age 8 days) were included. Acute kidney injury occurred in 36%. The time and depth of renal perfusion pressure < 42 mmHg in the first 24 hours was greater in acute kidney injury patients (94 versus 35 mmHg*minutes of low renal perfusion pressure/hour, p = 0.008). In the multivariable model, renal perfusion pressure < 42 mmHg was associated with acute kidney injury (aOR: 2.07, 95%CI: 1.25-3.82, p = 0.009). Mean arterial pressure, central venous pressure, and measures of inadequate oxygen delivery were not associated with acute kidney injury. CONCLUSION: Periods of low renal perfusion pressure (<42 mmHg) in the first 24 post-operative hours are associated with acute kidney injury. Renal perfusion pressure is a potential modifiable target that may mitigate the impact of acute kidney injury after paediatric cardiac surgery.

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.

A Near Real-Time Risk Analytics Algorithm Predicts Elevated Lactate Levels in Pediatric Cardiac Critical Care Patients.

BACKGROUND: Postoperative pediatric congenital heart patients are predisposed to develop low-cardiac output syndrome. Serum lactate (lactic acid [LA]) is a well-defined marker of inadequate systemic oxygen delivery. OBJECTIVES: We hypothesized that a near real-time risk index calculated by a noninvasive predictive analytics algorithm predicts elevated LA in pediatric patients admitted to a cardiac ICU (CICU). DERIVATION COHORT: Ten tertiary CICUs in the United States and Pakistan. VALIDATION COHORT: Retrospective observational study performed to validate a hyperlactatemia (HLA) index using T3 platform data (Etiometry, Boston, MA) from pediatric patients less than or equal to 12 years of age admitted to CICU (n = 3,496) from January 1, 2018, to December 31, 2020. Patients lacking required data for module or LA measurements were excluded. PREDICTION MODEL: Physiologic algorithm used to calculate an HLA index that incorporates physiologic data from patients in a CICU. The algorithm uses Bayes' theorem to interpret newly acquired data in a near real-time manner given its own previous assessment of the physiologic state of the patient. RESULTS: A total of 58,168 LA measurements were obtained from 3,496 patients included in a validation dataset. HLA was defined as LA level greater than 4 mmol/L. Using receiver operating characteristic analysis and a complete dataset, the HLA index predicted HLA with high sensitivity and specificity (area under the curve 0.95). As the index value increased, the likelihood of having higher LA increased (p < 0.01). In the validation dataset, the relative risk of having LA greater than 4 mmol/L when the HLA index is less than 1 is 0.07 (95% CI: 0.06-0.08), and the relative risk of having LA less than 4 mmol/L when the HLA index greater than 99 is 0.13 (95% CI, 0.12-0.14). CONCLUSIONS: These results validate the capacity of the HLA index. This novel index can provide a noninvasive prediction of elevated LA. The HLA index showed strong positive association with elevated LA levels, potentially providing bedside clinicians with an early, noninvasive warning of impaired cardiac output and oxygen delivery. Prospective studies are required to analyze the effect of this index on clinical decision-making and outcomes in pediatric population.

'Are Routine Post-discharge Diuretics Necessary After Pediatric Cardiac Surgery?'

A prospective, one-armed, safety non-inferiority trial with historical controls was performed at a single-center, quaternary, children's hospital. Inclusion criteria were children aged 3 months-18 years after pediatric cardiac surgery resulting in a two-ventricle repair between 7/2020 and 7/2021. Eligible patients were compared with patients from a 5-year historical period (selected using a database search). The intervention was that "regular risk" patients received no diuretics and pre-specified "high risk" patients received 5 days of twice per day furosemide at discharge. 61 Subjects received the intervention. None were readmitted for pleural effusions, though 1 subject was treated for a symptomatic pleural effusion with outpatient furosemide. The study was halted after an interim analysis demonstrated that 4 subjects were readmitted with pericardial effusion during the study period versus 2 during the historical control (2.9% versus 0.2%, P = 0.003). We found no evidence that limited post-discharge diuretics results in an increase in readmissions for pleural effusions. This conclusion is limited as not enough subjects were enrolled to definitively show that this strategy is not inferior to the historical practice. There was a statistically significant increase in readmissions for pericardial effusions after implementation of this study protocol which can lead to serious complications and requires further study before conclusions can be drawn regarding optimal diuretic regimens.

Use of Fenoldopam in Children with Congenital Heart Disease to Decrease Fluid Balance: A Retrospective, Descriptive Study and Insights into Predictors of Decreased Fluid Balance.

This retrospective study aimed to determine if fenoldopam is associated with a decrease in fluid balance and to define the factors that may promote this in children with a history of congenital heart disease at the cardiac intensive care unit (CICU). Patients cared from January 2014 to December 2018 in the CICU were reviewed, and those on fenoldopam infusion were identified. Patient cohort data included demographics, clinical information, laboratory results, hemodynamic and urine output measurements, and information regarding fenoldopam infusion were compared between those with and without decrease in fluid balance. Forty-six patients were identified. Patients received a starting dose of fenoldopam of 0.2 mcg/kg/h, a maximum dose of 0.3 mcg/kg/h, and duration of 64 hours. Over the 4-hour study period, statistically significant change was noted in systolic pressure (decrease of 5.4%; p < 0.001), diastolic pressure (decrease of 3.5%; p = 0.01), fluid balance, and urine output (decrease of 1.3%; p = 0.027). In the cohort, 34 patients (74%) had a decrease in fluid balance, 18 (39%) had an increase in urine output, and 25 (54%) had a decrease in fluid input after the initiation of fenoldopam. Patients that had a decrease in fluid balance tended to have a higher blood urea nitrogen level at the time of fenoldopam initiation. Fenoldopam was associated with decrease in fluid balance and fluid input, but not associated with an increase in urine output. The identification of factors that can decrease fluid balance may help identify those patients who can be benefited with this treatment.

Bleeding and Thrombosis With Pediatric Extracorporeal Life Support: A Roadmap for Management, Research, and the Future From the Pediatric Cardiac Intensive Care Society: Part 2.

OBJECTIVES: To make recommendations on improving understanding of bleeding and thrombosis with pediatric extracorporeal life support including future research directions. DATA SOURCES: Evaluation of literature and consensus conferences of pediatric critical care and extracorporeal life support experts. STUDY SELECTION: A team of 10 experts with pediatric cardiac and extracorporeal membrane oxygenation experience and expertise met through the Pediatric Cardiac Intensive Care Society to review current knowledge and make recommendations for future research to establish "best practice" for anticoagulation management related to extracorporeal life support. DATA EXTRACTION/DATA SYNTHESIS: This white paper focuses on clinical understanding and limitations of current strategies to monitor anticoagulation. For each test of anticoagulation, limitations of current knowledge are addressed and future research directions suggested. CONCLUSIONS: No consensus on best practice for anticoagulation monitoring exists. Structured scientific evaluation to answer questions regarding anticoagulation monitoring and bleeding and thrombotic events should occur in multicenter studies using standardized approaches and well-defined endpoints. Outcomes related to need for component change, blood product administration, healthcare outcome, and economic assessment should be incorporated into studies. All centers should report data on patient receiving extracorporeal life support to a registry.

Semi-automated speckle-tracking for quantitative right ventricular assessment in children and adolescents.

BACKGROUND: Assessment of right ventricular size and function is an important part of the clinical cardiac evaluation; however, these quantitative measures are challenging by echocardiography. Automated software could be useful in place of manual measurements and qualitative assessment. This study evaluates a semi-automated software by comparing automated to manual measures in normal children. METHODS: Neonates to adolescents with normal echocardiograms were prospectively enrolled. Measurements were performed using manual techniques and semi-automated software (EchoInsight®, Epsilon Imaging, Ann Arbor, Michigan, United States of America). Right ventricular measurements included end-diastolic and end-systolic area, fractional area change, chamber dimensions, and tricuspid annular plane systolic excursion. Agreement between manual and semi-automated measures was compared. RESULTS: Echocardiograms for 233 patients were included in the analysis. Intra- and inter-observer reliabilities for semi-automated measures were good with intraclass correlation coefficients all over 0.9 and 0.85, respectively. There was very strong correlation between manual and semi-automated methods for areas and dimensions (r = 0.93-0.99) and low bias (1.4-10.8%). For functional measures, tricuspid annular plane systolic excursion measures correlated well (r = 0.84), but fractional area change did not (r = 0.50). Both demonstrated significant bias (33.5-43.0%). The semi-automated method consistently underestimated fractional area change with a mean of 26.6% versus a manual mean of 36.1%. CONCLUSIONS: The semi-automated software is capable of generating quantitative right ventricular measures in children with good reliability. The software demonstrates very good correlation and low bias when compared to manual methods for right ventricular areas and dimensions. There is a significant difference between manual and semi-automated techniques for the functional measures.

Bleeding and Thrombosis With Pediatric Extracorporeal Life Support: A Roadmap for Management, Research, and the Future From the Pediatric Cardiac Intensive Care Society: Part 1.

OBJECTIVES: To make practical and evidence-based recommendations on improving understanding of bleeding and thrombosis with pediatric extracorporeal life support and to make recommendations for research directions. DATA SOURCES: Evaluation of literature and consensus conferences of pediatric critical care and extracorporeal life support experts. STUDY SELECTION: A team of 10 experts with pediatric cardiac and extracorporeal membrane oxygenation experience and expertise met through the Pediatric Cardiac Intensive Care Society to review current knowledge and make recommendations for future research to establish "best practice" for anticoagulation management related to extracorporeal life support. DATA EXTRACTION/SYNTHESIS: The first of a two-part white article focuses on clinical understanding and limitations of medications in use for anticoagulation, including novel medications. For each medication, limitations of current knowledge are addressed and research recommendations are suggested to allow for more definitive clinical guidelines in the future. CONCLUSIONS: No consensus on best practice for anticoagulation exists. Structured scientific evaluation to answer questions regarding anticoagulant medication and bleeding and thrombotic events should occur in multicenter studies using standardized approaches and well-defined endpoints. Outcomes related to need for component change, blood product administration, healthcare outcome, and economic assessment should be incorporated into studies. All centers should report data on patients receiving extracorporeal life support to a registry. The Extracorporeal Life Support Organization registry, designed primarily for quality improvement purposes, remains the primary and most successful data repository to date.

Results of international assistance for a paediatric heart surgery programme in a single Ukrainian centre.

BACKGROUND: Surgery for CHD has been slow to develop in parts of the former Soviet Union. The impact of an 8-year surgical assistance programme between an emerging centre and a multi-disciplinary international team that comprised healthcare professionals from developed cardiac programmes is analysed and presented.Material and methodsThe international paediatric assistance programme included five main components - intermittent clinical visits to the site annually, medical education, biomedical engineering support, nurse empowerment, and team-based practice development. Data were analysed from visiting teams and local databases before and since commencement of assistance in 2007 (era A: 2000-2007; era B: 2008-2015). The following variables were compared between periods: annual case volume, operative mortality, case complexity based on Risk Adjustment for Congenital Heart Surgery (RACHS-1), and RACHS-adjusted standardised mortality ratio. RESULTS: A total of 154 RACHS-classifiable operations were performed during era A, with a mean annual case volume by local surgeons of 19.3 at 95% confidence interval 14.3-24.2, with an operative mortality of 4.6% and a standardised mortality ratio of 2.1. In era B, surgical volume increased to a mean of 103.1 annual cases (95% confidence interval 69.1-137.2, p<0.0001). There was a non-significant (p=0.84) increase in operative mortality (5.7%), but a decrease in standardised mortality ratio (1.2) owing to an increase in case complexity. In era B, the proportion of local surgeon-led surgeries during visits from the international team increased from 0% (0/27) in 2008 to 98% (58/59) in the final year of analysis. CONCLUSIONS: The model of assistance described in this report led to improved adjusted mortality, increased case volume, complexity, and independent operating skills.

Tissue Motion Annular Displacement Predicts Mortality/Transplant After the Bidirectional Glenn.

BACKGROUND: Quantifying right ventricular function in patients with a systemic right ventricle (RV) is difficult but important for prognosis. Tissue motion annular displacement tracks displacement of the tricuspid annulus toward the apex. We evaluated this measure alongside fractional area change (FAC) on patients with single, RV prior to the bidirectional Glenn procedure. We tested both measures for correlation with outcomes. METHODS: Retrospective measurement of tissue motion annular displacement and FAC was performed on echocardiographic clips obtained prior to the bidirectional Glenn. A chart review included postoperative outcomes and midterm mortality/transplant. Bivariate correlations and Cox proportional hazards models were used for analyses. RESULTS: Fifty-one patients with dominant RV underwent the bidirectional Glenn procedure and all had image quality that allowed analysis. The age ranged from 3 to 11 months (median 4 months). Neither tissue motion annular displacement nor FAC correlated with short-term postoperative outcomes. Tissue motion annular displacement was independently predictive of mortality/transplant ( P = .03) in the Cox hazard model. The mean for survivors was 12.4% and for nonsurvivors/transplants was 10.0%. Tissue motion annular displacement intra-observer variability was 2.8% (1.2%-3.5%). Interobserver mean variability was 6.1% (3.3%-8.1%). Fractional area change was not predictive of mortality/transplant. CONCLUSION: Tissue motion annular displacement is an independent predictor of midterm mortality/transplant after the bidirectional Glenn procedure in patients with single, RV, in this study. It may outperform FAC in this regard and has good reproducibility. Tissue motion annular displacement may be a useful measure in identifying high-risk children in this population.

Intermittent Versus Continuous and Intermittent Medications for Pain and Sedation After Pediatric Cardiothoracic Surgery; A Randomized Controlled Trial.

OBJECTIVES: Compare continuous infusions of morphine and midazolam in addition to intermittent doses with an intermittent only strategy for pain and sedation after pediatric cardiac surgery. DESIGN: Randomized controlled trial. SETTING: Advocate Children's Hospital, Oak Lawn, IL. PATIENTS: Sixty patients 3 months to 4 years old with early extubation after pediatric cardiac surgery. INTERVENTIONS: Patients received a continuous infusion of morphine and midazolam or placebo for 24 hours. Both groups received intermittent morphine and midazolam doses as needed. MEASUREMENTS AND MAIN RESULTS: Gender, age, bypass time, and surgical complexity were not different between groups. Scheduled ketorolac and acetaminophen were used in both groups and were not associated with adverse events. The mean, median, and maximum Faces, Legs, Activity, Cry, And Consolability score were not different between groups. There was no significant difference in number of intermittent doses received between groups. The total morphine dose was higher in the continuous/intermittent group (0.90 vs 0.23 mg/kg; p < 0.01). The total midazolam dose was also higher in the continuous/intermittent group (0.90 vs 0.18 mg/kg; p < 0.01). The hospital length of stay was longer in the continuous/intermittent group (8.4 vs 4.9 d; p = 0.04). CONCLUSIONS: Pain was not better controlled with the addition of continuous infusions of morphine and midazolam when compared with intermittent dosing only. Use of continuous infusions resulted in a significantly higher total dosage of these medications and a longer length of stay.

Unscheduled Pediatric Intensive Care Unit Admissions in Patients With Cardiovascular Disease: Clinical Features and Outcomes.

BACKGROUND: An unscheduled readmission to the intensive care unit (ICU) is associated with increased morbidity and mortality in children. There is a paucity of data examining the impact of unscheduled admissions on outcomes in children with specific disease processes such as cardiovascular disease. We investigated the impact of scheduled versus unscheduled ICU admission on clinical outcomes and differences in patient characteristics in children with cardiovascular disease. METHODS: This was a retrospective analysis of contemporaneously collected clinical data using the Virtual PICU Systems database. All consecutive admissions at 102 participating pediatric ICUs in patients with cardiovascular disease were collected from October 2010 to September 2012. RESULTS: There were 48,653 admissions included in the analysis (44% scheduled and 56% unscheduled). The median patient age was 31 months. Unscheduled admissions were associated with longer ICU length of stay and increased mortality (both P < .001). Adjusting for age, weight, and primary ICU admission diagnosis (cardiovascular vs noncardiovascular), patients with unscheduled admissions had an increased odds of mortality (odds ratio = 4.8, P < .001). CONCLUSIONS: Unscheduled ICU admissions were associated with worse clinical outcomes including increased mortality. Efforts targeted at reducing unscheduled admissions in at-risk patients are warranted.

Unplanned admissions to a pediatric cardiac critical care unit: a review of 2 years' experience.

OBJECTIVES: Unplanned admissions to the pediatric cardiac ICU may be a large and high-risk group. Our study describes the frequency of unplanned pediatric cardiac ICU admissions, their admission data, and outcomes. DESIGN: All admissions to a pediatric cardiac ICU over 2 years were reviewed and those that were unplanned were identified for a detailed chart abstraction. Demographic, laboratory, diagnostic, and outcome data were collected. Readmission or admission for adverse event was noted. SETTING: Single, tertiary, pediatric cardiac center. PATIENTS: All patients admitted unexpectedly to the pediatric cardiac critical care unit between May 2008 and May 2010. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: There were 1,203 admissions to the cardiac ICU, and 426 (35%) were unplanned. The most common reasons for admission were new heart disease (25%), infection (19%), arrhythmia (13%), and congestive heart failure (11%). The majority of unplanned admissions (62%) occurred at night. Shock was present at admission in 18.5% of patients. Structural heart disease was present in 79%, and 39% of those were patients with single ventricle. Overall mortality among unplanned admissions was 7.3%, which is higher than that reported for elective surgical admissions. Mortality for the subset of patients readmitted within 30 days was 5.5%. Mean creatinine at admission was higher among nonsurvivors (0.7) than survivors (0.5). CONCLUSIONS: Unplanned admissions accounted for over one third of all admissions and had a high mortality rate. The majority of these occur at night, which may affect staffing models. Acute deterioration leading to unplanned admission, rather than readmission status, may be the driving factor in increased mortality. However, the risk of readmission, lower renal function, or other indices may identify patients at higher risk of an unplanned admission. Continued efforts to identify patients at risk for unplanned admissions are warranted given the outcomes in this cohort.

Echocardiography in pediatric infective endocarditis.

Transesophageal echocardiography is more sensitive than transthoracic echocardiography (TTE) in detecting endocarditis in adults; however, pediatric data are limited. Retrospectively, 39 subjects with endocarditis were divided into adult-sized (≥60 kg) and pediatric-sized (<60 kg). TTE was 97% sensitive in pediatric-sized subjects but 70% in adult-sized subjects (P < 0.05). TTE is usually sufficient for detection of endocarditis in children <60 kg.