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.

The utility of a structured, interactive cardiac anatomy teaching session for resident education.

BACKGROUND: Paediatric residents are often taught cardiac anatomy with two-dimensional images of heart specimens, or via imaging such as echocardiography or computed tomography. This study aimed to determine if the use of a structured, interactive, teaching session using heart specimens with CHD would be effective in teaching the concepts of cardiac anatomy. METHODS: The interest amongst paediatric residents of a cardiac anatomy session using heart specimens was assessed initially by circulating a survey. Next, four major cardiac lesions were identified to be of interest: atrial septal defect, ventricular septal defect, tetralogy of Fallot, and transposition. A list of key structures and anatomic concepts for these lesions was developed, and appropriate specimens demonstrating these features were identified by a cardiac morphologist. A structured, interactive, teaching session was then held with the paediatric residents using the cardiac specimens. The same 10-question assessment was administered at the beginning and end of the session. RESULTS: The initial survey demonstrated that all the paediatric residents had an interest in a cardiac anatomy teaching session. A total of 24 participated in the 2-hour session. The median pre-test score was 45%, compared to a median post-test score of 90% (p < 0.01). All paediatric residents who completed a post-session survey indicated that the session was a good use of educational time and contributed to increasing their knowledge base. They expressed great interest in future sessions. CONCLUSION: A 2-hour hands-on cardiac anatomy teaching session using cardiac specimens can successfully highlight key anatomic concepts for paediatric residents.

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.

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.

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.

Venous blood gases in pediatric patients: a lost art?

Blood oximetry provides a fundamental approach to blood gases for inpatients. Arterial blood gases (ABG) have been considered the gold standard for blood oximetry assessment. Venous blood gas (VBG) evaluation is frequently available and provides a source of a more comfortable method for the assessment of blood oximetry in pediatric patients. Some data provided by the venous blood gas can be additive and offer insights apart from the arterial blood gas. The purpose of this review was to provide an assessment of the performance of VBG in pediatric patients. The study concludes that VBG are helpful tools in assessing oxygenation and ventilation in critically ill children and can be used as a marker of adequacy of systemic oxygen delivery. In the setting of systemic oxygen delivery decrease or oxygen extraction increase, the partial pressure of oxygen on the VBG will decrease. Thus, the partial pressure of oxygen and the corresponding venous saturation can be a marker of systemic oxygen delivery in a variety of illnesses. Simultaneous ABG and VBG comparison can actually lend great insight to not only the respiratory status of a patient but provide an assessment of the adequacy of cardiac output and 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.

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.

Effects of Fenoldopam in the Pediatric Population: Fluid Status, Serum Biomarkers, and Hemodynamics: A Systematic Review and Meta-Analysis.

Fluid overload is a frequent complication in children during critical illness. Fluid restriction and diuretic agents have been the mainstay therapies so far. Fenoldopam, a selective dopamine-1 receptor agonist, is a diuretic agent with promising effects in the pediatric population. The purpose of this meta-analysis is to evaluate the outcomes of pediatric patients who received fenoldopam. We hypothesized that the administration of fenoldopam will cause an increase in urine output and decrease in serum creatinine in this patient population. A comprehensive database search of PubMed, EMBASE, and Cochrane libraries from the databases' inception through December 2018 was undertaken. Independent reviewers selected appropriate studies and the reviewed data. A meta-analysis was then conducted to determine the effects of fenoldopam on hemodynamics, the amount of vasoactive support, and renal function in children under the critical care setting. The selected end points were measured prior to the administration of fenoldopam and 24 hours after the initiation of the infusion: urine output, serum creatinine, serum sodium, inotrope score, heart rate, central venous pressure, systolic blood pressure, and mean blood pressure. Forest plots were generated to demonstrate individual study data as well as pooled data for each end point. A total of five studies (three retrospective cohort studies, two randomized trials) with 121 patients were included for analysis. No significant difference was observed in urine output, inotrope score, systolic blood pressure, or mean blood pressure. There was a statistically significant increase in serum creatinine and central venous pressure. There was statistically significant decrease in serum sodium and heart rate, and central venous pressure. This meta-analysis did not identify significant renoprotective or vasodilator effects from fenoldopam in this patient population. Although mild electrolyte and hemodynamic changes were identified, larger studies are warranted to determine the clinical significance of fenoldopam in this patient population.

Technical Modifications That Might Improve Long-term Outcomes of the Ross Procedure in Children.

BACKGROUND: Failure of the pulmonary valve autograft (PVA) after the Ross procedure (RP) has discouraged its widespread use and has led to modifications or alternatives to the procedure. We sought to analyze whether certain technical modifications could improve results of the RP in children. METHODS: Sixty-nine patients (median age, 12 years; range, 0.25-17.9) underwent the RP between January 1996 and December 2018. A concomitant Konno procedure was performed on 20 of 69 patients (29%). Prior interventions included balloon valvuloplasty in 30 (44%) and/or surgical valvuloplasty in 39 (57%). Technical modifications included using the native aortic root for external annuloplasty, implanting the autograft using uniplanar horizontal sutures through the aortic wall, normalizing the sinotubular junction, and wrapping the native root remnant around the PVA. RESULTS: Operative mortality was 1 of 69 patients (1.5%), with no late deaths. No patient had neoaortic valvar stenosis and 7 of 68 (10%) had mild regurgitation on discharge echocardiogram. At latest follow-up (median, 9.4 years; range, 0.4-21.3) there was no significant change in Z scores of annulus, sinus, or sinotubular junction diameters when compared with those at discharge. Three patients (4.4%) required late autograft replacement, 2 PVA repair, and 2 resection of a pseudoaneurysm. Actuarial freedom from PVA replacement was 87% at 20 years. Freedom from right ventricular outflow tract catheter reintervention or reoperation was 83% and 80%, respectively. CONCLUSIONS: Technical modifications of the RP used in this cohort might successfully prolong the life of the PVA without compromising its growth, an important advantage in pediatric patients.

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.

Troponin elevation in the setting of exercise-induced rhabdomyolysis in an athletic teenager.

Troponin levels are often obtained when chest pain is evaluated in the paediatric emergency department. Elevations in troponin levels can be due to different causes, and it is important to fully understand all of these possible causes to help streamline further evaluation and therapy. We present the case of a teenager who had two episodes of troponin elevation in the setting of rhabdomyolysis.

Neurally adjusted ventilatory assist versus conventional ventilation in the pediatric population: Are there benefits?

INTRODUCTION: Neurally-adjusted ventilator assist (NAVA) is a relatively new form of ventilation in which the electrical activity of the diaphragm is sensed by a catheter. The amplitude of this electrical signal is then used to deliver an appropriately proportioned pressure supported breath to the patient. Due to the synchronous nature of the breaths and the patient-adjusted nature of the support, NAVA has been shown to have benefits over conventional ventilation. Meta-analyses were conducted of published pediatric studies to compare ventilatory endpoints between NAVA and conventional ventilation. METHODS: Studies comparing ventilatory parameters between NAVA and conventional ventilation in pediatric patients were identified. These studies were reviewed for appropriateness for inclusion and studies of only pediatric patients with data for similar endpoints between both arms were then pooled. RESULTS: Statistically significant differences were noted in asynchrony, peak inspiratory pressure (PIP), and oxygen saturation by pulse oximetry. Asynchrony was 17% lower with NAVA, PIP was 1.74 cmH2 0 lower with NAVA, and oxygen saturation was 1.1% greater with NAVA. There was no statistically significant difference in peak expiratory pressure, mean airway pressure, electrical diaphragmatic activity, respiratory rate, hydrogen ion concentration, partial pressure of oxygen, or partial pressure of carbon dioxide. CONCLUSION: Statistically significant differences were noted in percent asynchrony, PIP, and oxygen saturation when comparing NAVA to conventional ventilation. These all tended to favor NAVA. Other than percent asynchrony, however, the other statistically significant findings were not clinically significant.