David M. Kwiatkowski

Dexmedetomidine Is Associated With Lower Incidence of Acute Kidney Injury After Congenital Heart Surgery.

Objectives: Recent data have suggested an association between the use of dexmedetomidine and a decreased incidence of acute kidney injury in adult patients after cardiopulmonary bypass. However, no study has focused on this association among pediatric populations where the incidence of acute kidney injury is particularly high and of critical significance. The primary objective of this study was to assess the relationship between the use of postoperative dexmedetomidine and the incidence of acute kidney injury in pediatric patients undergoing cardiopulmonary bypass. The secondary objective was to determine whether there was an association between dexmedetomidine use and duration of mechanical ventilation or cardiovascular ICU stay. Design: Single-center retrospective matched cohort study. Setting: A 20-bed quaternary cardiovascular ICU in a university-based pediatric hospital in California. Patients: Children less than 18 years old admitted after cardiac surgery with cardiopulmonary bypass between January 1, 2012, and May 31, 2014. Interventions: None. Measurements and Main Results: Data from a cohort of 102 patients receiving dexmedetomidine during the first postoperative day after cardiac surgery were compared to an age- and procedure-matched cohort not receiving dexmedetomidine. Cohorts had similar baseline and demographic characteristics. Patients receiving dexmedetomidine were less likely to develop acute kidney injury (24% vs 36%; odds ratio, 0.54; 95% CI, 0.29–0.99; p = 0.046). After adjusting for age, bypass time, nephrotoxin use, and vasoactive inotropic score, the use of dexmedetomidine was associated with a lower incidence of acute kidney injury with adjusted odds ratio of 0.43 (95% CI, 0.27–0.98; p = 0.048). There was no difference between the cohorts with respect to the duration of mechanical duration (1 d each; p = 0.98) or cardiovascular ICU stays (5 vs 6 d; p = 0.91). Conclusions: The use of a dexmedetomidine infusion in pediatric patients after congenital heart surgery was associated with a decreased incidence of acute kidney injury; however, it was not associated with changes in clinical outcomes. Further prospective study is necessary to validate these findings.

Peritoneal Dialysis vs Furosemide for Prevention of Fluid Overload in Infants After Cardiac Surgery: A Randomized Clinical Trial

Importance Fluid overload after congenital heart surgery is frequent and a major cause of morbidity and mortality among infants. Many programs have adopted the use of peritoneal dialysis (PD) for fluid management; however, its benefits compared with those of traditional diuretic administration are unknown. Objective To determine whether infants randomized to PD vs furosemide for the treatment of oliguria have a higher incidence of negative fluid balance on postoperative day 1, as well as avoidance of 10% fluid overload; shorter duration of mechanical ventilation, intensive care unit stay, and inotrope use; and fewer electrolyte abnormalities. Design, Setting, and Participants This single-center, unblinded, randomized clinical trial compared methods of fluid removal after cardiac surgery from October 1, 2011, through March 13, 2015, in a large tertiary pediatric hospital in Ohio. The parents or guardians of all eligible infants (aged <6 months) undergoing cardiac surgery with catheter placement for PD were approached for inclusion. No patients were withdrawn for adverse effects. Recruitment was powered for the primary outcome, and analysis was based on intention to treat. Patients randomized to PD were hypothesized to have superior outcomes. Interventions Infants received intravenous furosemide (1 mg/kg every 6 hours) or a standardized PD regimen. Main Outcomes and Measures The primary end point was incidence of negative fluid balance on postoperative day 1. Secondary end points included incidence of fluid overload, duration of mechanical ventilation and intensive care unit stay, electrolyte abnormalities and repletion doses, duration of inotropic administration, and mortality. Results Seventy-three patients (47 boys [64%] and 26 girls [35%]; median age, 8 [interquartile range (IQR), 6-14] days) received treatment and completed the trial. No difference was found between the PD and furosemide groups in the incidence of negative fluid balance on the first postoperative day. The furosemide group was 3 times more likely to have 10% fluid overload (odds ratio [OR], 3.0; 95% CI, 1.3-6.9), was more likely to have prolonged ventilator use (OR, 3.1; 95% CI, 1.2-8.2), and had a longer duration of inotrope use (median, 5.5 [IQR, 4-8] vs 4.0 [IQR, 3-6] days) and higher electrolyte abnormality scores (median, 6 [IQR, 4-7] vs 3 [IQR, 2-5]) compared with the PD group. No statistically significant differences in mortality (3 patients [9.4%] in the furosemide group vs 1 patient [3.1%] in the PD group) or length of cardiac intensive care unit (median, 7 [IQR, 6-12] vs 9 [IQR, 5-15] days) or hospital (15 [IQR, 10-28] vs 14 [IQR, 9-22] days) stay were observed. No serious complications were observed. Dialysis was discontinued early in 9 of 41 patients in the PD group for pleural-peritoneal communication. Conclusions and Relevance Use of PD is safe and allows for superior fluid management with improved clinical outcomes compared with diuretic administration. Use of PD should be strongly considered among infants at high risk for postoperative acute kidney injury and fluid overload. Trial Registration clinicaltrials.gov Identifer: NCT01709227

Biomarkers of acute kidney injury in pediatric cardiac patients

Acute kidney injury is a common and significant complication among pediatric patients with congenital heart disease, occurring most commonly after cardiopulmonary bypass. Current laboratory methods of diagnosis are not timely enough to guide management decisions, thus spurring interest in discovering new biomarkers of acute injury. Several promising candidates, including NGAL, IL-18 and KIM-1, have been the subject of recent investigation and may facilitate earlier and more accurate diagnosis of renal injury within this cohort. There is little evidence demonstrating that it will be possible to rely upon one particular biomarker as a single agent, and evidence supports that the use of biomarker panels will be most effective. Further clinical validation and broader commercial availability of these novel biomarkers will probably revolutionize the care of pediatric cardiac patients with renal injury.

The utility of outpatient echocardiography for evaluation of asymptomatic murmurs in children.

OBJECTIVE   The purpose of this study is to review sedated outpatient echocardiograms performed to evaluate asymptomatic murmurs in children between the ages of 1 month and 4 years and describe outcomes of tests done to determine if utility varies among age of study and referral type (primary care physician vs. pediatric cardiologist.) We aim to describe the yield in a contemporary cohort which has increased availability and quality of diagnostic aids such as fetal ultrasound, newborn pulse oximetry, and neonatal echocardiography. DESIGN   Retrospective cohort study. SETTING   Cincinnati Childrens Hospital Medical Center: Outpatient Echocardiography Laboratory. PATIENTS   Children between 1 month and 4 years of age with asymptomatic murmurs who are referred for outpatient echocardiogram for evaluation of murmur. OUTCOME MEASURES   Primary diagnosis of echocardiography studies, classified into severity score. Results.  Four hundred sixty-two sedated echocardiograms were studied. Six (1%) echocardiograms showed severe pathology, and no severe pathology was shown in the echocardiograms ordered at the age of over 6 months old. The yield of studies decreased as age increased. The incidence of abnormal pathology was higher among tests ordered by cardiologists, across all severity levels (P < .0001). CONCLUSIONS   Among echocardiograms ordered for children over 1 year of age with an asymptomatic murmur, there was no severe and little moderate disease. Cardiac disease is significantly less likely when echocardiograms are ordered without referral to a pediatric cardiologist. The workup for asymptomatic murmurs does not require an echocardiogram, and these results may aid clinicians when deciding whether evaluation of a child should include this study.

Short QT Interval Prevalence and Clinical Outcomes in a Pediatric Population

Background—Risk associated with short QT interval has recently received recognition. European studies suggest a prevalence of 0.02% to 0.1% in the adult population, but similar studies in pediatric patients are limited. We sought to determine the prevalence of short QT interval in a pediatric population and associated clinical characteristics and outcomes. Methods and Results—Retrospective review of an ECG database at a single pediatric institution. The database was queried for ECGs on patients ⩽21 years with electronically measured QTc of 140 to 340 ms. Patients with QTc of 140 to 340 ms confirmed by a pediatric electrophysiologist were identified for chart review for associated clinical characteristics, symptoms, and outcome. Patients with and without symptoms were compared in an attempt to identify variables associated with outcome. The query included 272 504 ECGs on 99 380 unique patients. Forty-five patients (35 men, 76%) had QTc ⩽340 ms, for a prevalence of 0.05%. Median age was 15 years (interquartile range, 2–17), median QT 330 ms (interquartile range, 280–360), and median QTc 323 ms (IQR, 313–332). Women had significantly shorter QTc compared with men (312 versus 323 ms; P=0.03). Two deaths were noted in chart review—one from respiratory failure and the second of unknown pathogenesis in a patient with dilated cardiomyopathy. Conclusions—Short QT interval was a rare finding in this pediatric population, with a prevalence of 0.05%. Male predominance was identified, although the median QT interval was significantly shorter in women. There seem to be no unifying clinical characteristics for this pediatric patient cohort with short QT interval.

A Teenager with Marfan Syndrome and Left Ventricular Noncompaction

We report a teenager with Marfan syndrome who presented to Cincinnati Children’s Hospital Medical Center as part of a preoperative evaluation for an orthopedic procedure after asymptomatic arrhythmia was recognized. Continuous cardiac monitoring showed frequent premature ventricular contractions and nonsustained runs of ventricular tachycardia. Cardiac magnetic resonance imaging showed left ventricular noncompaction (LVNC), prompting insertion of an implantable cardiac defibrillator. Although Marfan syndrome is associated with cardiac lesions, it has not previously been described with LVNC. Likewise LVNC has been seen in association with other cardiac lesions; however, this report represents the first reference of LVNC in the context of Marfan syndrome.

Incidence, risk factors, and outcomes of acute kidney injury in adults undergoing surgery for congenital heart disease.

BACKGROUND Acute kidney injury after cardiac surgery is a frequent and serious complication among children with congenital heart disease (CHD) and adults with acquired heart disease; however, the significance of kidney injury in adults after congenital heart surgery is unknown. The primary objective of this study was to determine the incidence of acute kidney injury after surgery for adult CHD. Secondary objectives included determination of risk factors and associations with clinical outcomes. METHODS This single-centre, retrospective cohort study was performed in a quaternary cardiovascular ICU in a paediatric hospital including all consecutive patients ⩾18 years between 2010 and 2013. RESULTS Data from 118 patients with a median age of 29 years undergoing cardiac surgery were analysed. Using Kidney Disease: Improving Global Outcome creatinine criteria, 36% of patients developed kidney injury, with 5% being moderate to severe (stage 2/3). Among higher-complexity surgeries, incidence was 59%. Age ⩾35 years, preoperative left ventricular dysfunction, preoperative arrhythmia, longer bypass time, higher Risk Adjustment for Congenital Heart Surgery-1 category, and perioperative vancomycin use were significant risk factors for kidney injury development. In multivariable analysis, age ⩾35 years and vancomycin use were significant predictors. Those with kidney injury were more likely to have prolonged duration of mechanical ventilation and cardiovascular ICU stay in the univariable regression analysis. CONCLUSIONS We demonstrated that acute kidney injury is a frequent complication in adults after surgery for CHD and is associated with poor outcomes. Risk factors for development were identified but largely not modifiable. Further investigation within this cohort is necessary to better understand the problem of kidney injury.

Acute Kidney Injury and Cardiorenal Syndromes in Pediatric Cardiac Intensive Care

Objectives: The objectives of this review are to discuss the definition, diagnosis, and pathophysiology of acute kidney injury and its impact on immediate, short-, and long-term outcomes. In addition, the spectrum of cardiorenal syndromes will be reviewed including the pathophysiology on this interaction and its impact on outcomes. Data Source: MEDLINE and PubMed. Conclusion: The field of cardiac intensive care continues to advance in tandem with congenital heart surgery. As mortality has become a rare occurrence, the focus of cardiac intensive care has shifted to that of morbidity reduction. Acute kidney injury adversely impact outcomes of patients following surgery for congenital heart disease as well as in those with heart failure (cardiorenal syndrome). Patients who become fluid overloaded and/or require dialysis are at a higher risk of mortality, but even minor degrees of acute kidney injury portend a significant increase in mortality and morbidity. Clinicians continue to seek methods of early diagnosis and risk stratification of acute kidney injury to prevent its adverse sequelae.

Acute Kidney Injury in Children

Acute kidney injury (AKI) has become one of the more common complications seen among hospitalized children. The development of a consensus definition has helped refine the epidemiology of pediatric AKI, and we now have a far better understanding of its incidence, risk factors, and outcomes. Strategies for diagnosing AKI have extended beyond serum creatinine, and the most current data underscore the diagnostic importance of oliguria as well as introduce the concept of urinary biomarkers of kidney injury. As AKI has become more widespread, we have seen that it is associated with a number of adverse consequences including longer lengths of stay and greater mortality. Though effective treatments do not currently exist for AKI once it develops, we hope that the diagnostic and definitional strides seen recently translate to the testing and development of more effective interventions.

Right Ventricular Outflow Tract Obstruction: Pulmonary Atresia With Intact Ventricular Septum, Pulmonary Stenosis, and Ebstein’s Malformation

Objectives: The objectives of this review are to discuss the anatomy, pathophysiology, clinical course, and current treatment strategies for pulmonary atresia with intact ventricular septum, pulmonary stenosis, and Ebstein’s anomaly. Data Source: MEDLINE and PubMed. Conclusions: Considerable advances have been made in management strategies for these complex congenital heart lesions, which have led to improved outcomes.