Peritoneal dialysis after surgery for congenital heart disease in infants and young children

Evaluation of postoperative renal functions and its effect on body perfusion in patients with double aortic cannulation

BACKGROUND

The optimal visceral preservation method during aortic arch reconstruction is still controversial. It has been thought that double aortic cannulation is effective. Herein, it was aimed to evaluate this technique in providing distal perfusion.

METHODS

A total of 74 patients who underwent arch reconstruction between 2011 and 2019 were included. Patients were grouped according to ventricular physiology and cannulation strategies. Group 1 were univentricle patients, and all had double aortic cannulation. Group 2 were biventricular patients. Group 2A double aortic cannulation-done and Group 2B non-double aortic cannulation were included. Lactate, urea, creatinine values, renal functions, and need for peritoneal dialysis of patients were evaluated.

RESULTS

There were no complications observed due to descending aortic cannulation in any of the patients. A delayed sternal closure and the need for peritoneal dialysis were more common in the Group 1 (p < 0.01). The preoperative and postoperative 1st- and 2nd-day lactate, urea, and creatinine values in the Group 1 were higher (p < 0.05) when compared with the Group 2A and 2B. The same values were higher in Group 2A than the Group 2B (p < 0.05).

CONCLUSION

The positive effect of double aortic cannulation on renal dysfunction could not be demonstrated. This may be associated with a <1 month of age, low weight, complex surgical procedure, and high preoperative lactate, urea, and creatinine values in patients with double aortic cannulation.

Tools for managing childcare in the postoperative period of cardiac surgery: an integrative review

OBJECTIVE

To analyze the scientific literature on the application of management tools in the postoperative period of pediatric cardiac surgery.

METHODS

integrative review including studies published between 2004 and 2018 in the following databases: LILACS, BDENF, coleciona SUS, MEDLINE/PUBMED, CINAHL and SCOPUS, via Portal de Periódicos da Capes, Scientific Electronic Library Online (SciELO) and Academic Google research.

RESULTS

Twelve articles that met the inclusion criteria were analyzed. The studies demonstrated that strategies such as extracorporeal membrane oxygenation, renal replacement therapy and the risk scores for Risk Adjustment for Congenital Heart Surgery 1 and Aristotle Basic Score favored the stratification the demand for care and predicted the risk for mortality.

FINAL CONSIDERATIONS

The applicability of risk scores and emerging strategies for the management of childcare in the postoperative period of cardiac surgery was described by the evaluation of possibilities of performance and/or efficiency of the treatments developed.

Cell-Cycle Arrest Biomarkers: Usefulness for Cardiac Surgery-Related Acute Kidney Injury in Neonates and Infants

OBJECTIVES

Cell cycle arrest urine biomarkers have recently been shown to be early indicators of acute kidney injury in various clinical settings in critically ill adults and children. The product of tissue inhibitor metalloproteinase -1 and insulin-like growth factor binding protein-7 concentrations/1,000 (TIMP-1) × (IGFBP-7) provides stratification of acute kidney injury-risk in adults with critical illness. The present study explores the predictive accuracy of (TIMP-1) × (IGFBP-7) measured early after cardiopulmonary bypass for cardiac surgery-related acute kidney injury in neonates and infants, a population in whom such data are not yet available.

DESIGN

Prospective, observational.

SETTING

A tertiary referral pediatric cardiac ICU.

PATIENTS

Fifty-seven neonates and 110 infants undergoing surgery with cardiopulmonary bypass.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

(TIMP-1) × (IGFBP-7) was measured on the NephroCheck (Astute Medical, San Diego, CA) platform preoperatively, less than 1 hour of cardiopulmonary bypass and 1-3 hours of cardiopulmonary bypass. The incidence of postoperative acute kidney injury, dialysis, and/or death were compared among quintiles of postoperative (TIMP-1) × (IGFBP-7). Multivariable regression was used to assess the added predictive value for renal events of (TIMP-1) × (IGFBP-7) over clinical models. Basal (TIMP-1) × (IGFBP-7) increased with age at surgery (regression coefficient = 0.004 ± 0.001; p = 0.005). (TIMP-1) × (IGFBP-7) increased after cardiopulmonary bypass. Neonates had lower postoperative (TIMP-1) × (IGFBP-7) compared with older infants, despite undergoing longer surgeries and experiencing a higher incidence of postoperative renal events. (TIMP-1) × (IGFBP-7) was not associated with acute kidney injury, dialysis, and/or death and was not a predictor of the aforementioned events when added to a clinical acute kidney injury model including age, duration of cardiopulmonary bypass, and mechanical ventilation prior to surgery.

CONCLUSIONS

These findings question the usefulness of (TIMP-1) × (IGFBP-7) for the prediction of cardiac surgery-related acute kidney injury in neonates and infants when measured within 3 hours of cardiopulmonary bypass.

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

BACKGROUND

The management of fluid overload after congenital heart surgery has been limited to diuretics, fluid restriction, and dialysis. This study was conducted to determine the association between peritoneal dialysis and important clinical outcomes in children undergoing congenital heart surgery.

METHODS

A retrospective review was conducted to identify patients under 18 years of age who underwent congenital heart surgery. The data were obtained over a 16-year period (1997-2012) from the Kids' Inpatient Database. Data analysed consisted of demographics, diagnoses, type of congenital heart surgery, length of stay, cost of hospitalisation, and mortality. Logistic regression was performed to determine factors associated with peritoneal dialysis.

RESULTS

A total of 46,176 admissions after congenital heart surgery were included in the study. Of those, 181 (0.4%) utilised peritoneal dialysis. The mean age of the peritoneal dialysis group was 7.6 months compared to 39.6 months in those without peritoneal dialysis. The most common CHDs were atrial septal defect (37%), ventricular septal defect (32.6%), and hypoplastic left heart syndrome (18.8%). Univariate analyses demonstrated significantly greater length of stay, cost of admission, and mortality in those with peritoneal dialysis. Regression analyses demonstrated that peritoneal dialysis was independently associated with significant decrease in cost of admission (-$57,500) and significant increase in mortality (odds ratio 1.5).

CONCLUSIONS

Peritoneal dialysis appears to be used in specific patient subsets and is independently associated with decreased cost of stay, although it is associated with increased mortality. Further studies are needed to describe risks and benefit of peritoneal dialysis in this population.

Peritoneal Dialysis in Pediatric Postoperative Cardiac Surgical Patients

Background

We determined the prevalence of acute kidney injury requiring peritoneal dialysis (PD), the factors associated with early PD initiation, prolonged PD and mortality among pediatric postoperative cardiac surgical patients.

Materials and Methods

The hospital records of 23 children, aged 12 years or younger, who had undergone cardiac surgery and required PD subsequently, during a 1-year period were reviewed. Demographic data, intraoperative variables, and postoperative complications were compared between survivors and nonsurvivors of PD, between the short and long duration PD groups, and between the early and late PD initiation groups.

Results

Six hundred and eight pediatric patients who underwent open heart surgery were enrolled in this study. 23 (3.78%) of them required PD. When compared with survivors (n = 11), non survivors (n =12) were more likely to have a higher serum procalcitonin (p = 0.01), higher serum potassium on day 2 (p = 0.001), day 3 (p = 0.04), day of termination of PD (p = 0.001) and a lower urine output on day 3 of PD (p = 0.03). Prolonged PD was associated with time of PD initiation (p = 0.01), a higher postoperative serum creatinine on day 3 (p = 0.01) of PD initiation as well on the day of PD termination (p = 0.01) and the final outcome in terms of survival (p = 0.02). Factors significantly associated with an early PD initiation were CPB time (p = 0.04), sepsis (p = 0.02) and shorter PD duration (p = 0.003).

Conclusion

PD is very useful mode of renal replacement therapy among pediatric postoperative cardiac surgical patients. The intraoperative and postoperative variables have important association with the time of PD initiation, PD duration and patient survival.

How to cite this article

Sahu MK, Bipin C, Arora Y, Singh SP, Devagouru V, Rajshekar P, et al. Peritoneal Dialysis in Pediatric Postoperative Cardiac Surgical Patients. Indian J Crit Care Med 2019;23(8):371-375.

Renal replacement therapy in the pediatric cardiac intensive care unit

OBJECTIVE

There is an increased risk of mortality in patients in whom acute kidney injury and fluid accumulation develop after cardiothoracic surgery, and the risk is especially high when renal replacement therapy is needed. However, renal replacement therapy remains an essential intervention in managing these patients. The objective of this study was to identify risk factors for mortality in surgical patients requiring renal replacement therapy in a pediatric cardiac intensive care unit.

METHODS

We performed a retrospective review of patients requiring renal replacement therapy for acute kidney injury or fluid accumulation after cardiothoracic surgery between January 2009 and December 2017. Survivors and nonsurvivors were compared with respect to multiple variables, and a multivariable logistic regression analysis was performed to identify independent risk factors associated with mortality.

RESULTS

The mortality rate for the cohort was 75%. Nonsurvivors were younger (nonsurvivors: 0.8 years; interquartile range, 0.1-8.2; survivors: 14.6 years; interquartile range, 4.2-19.7; P = .002) and had a lower weight-for-age z-score (nonsurvivors: -1.5; interquartile range, -3.1 to -0.4; survivors: -0.5; interquartile range, -0.9 to 0.3; P = .02) compared with survivors. There was no difference with respect to fluid accumulation. In multivariable analysis, a longer duration of stage 3 acute kidney injury before initiation of renal replacement therapy was independently associated with mortality (adjusted odds ratio, 1.39; 95% confidence interval, 1.05-1.83; P = .021).

CONCLUSIONS

Mortality in patients requiring renal replacement therapy after congenital heart disease surgery is high. A longer duration of acute kidney injury before renal replacement therapy initiation is associated with increased mortality.

Early Peritoneal Dialysis and Major Adverse Events After Pediatric Cardiac Surgery: A Propensity Score Analysis

OBJECTIVES

Early peritoneal dialysis may have a role in modulating the inflammatory response after cardiopulmonary bypass. This study sought to test the effect of early peritoneal dialysis on major adverse events after pediatric cardiac surgery involving cardiopulmonary bypass.

DESIGN

In this observational study, the outcomes in infants post cardiac surgery who received early peritoneal dialysis (within 6 hr of completing cardiopulmonary bypass) were compared with those who received late peritoneal dialysis. The primary outcome was a composite of one or more of cardiac arrest, emergency chest reopening, requirement for extracorporeal membrane oxygenation, or death. Secondary outcomes included duration of mechanical ventilation, length of intensive care, and hospital stay. A propensity score methodology utilizing inverse probability of treatment weighting was used to minimize selection bias due to timing of peritoneal dialysis.

SETTING

Cardiac ICU, The Royal Children's Hospital, Melbourne, VIC, Australia.

PATIENTS

From 2012 to 2015, infants who were commenced on peritoneal dialysis after cardiac surgery were included.

MEASUREMENTS AND MAIN RESULTS

Among 239 eligible infants, 56 (23%) were commenced on early peritoneal dialysis and 183 (77%) on late peritoneal dialysis. At 90 days, early peritoneal dialysis as compared with late peritoneal dialysis was associated with a decreased risk of primary outcome (relative risk, 0.16; 95% CI, 0.05-0.47; p < 0.001 and absolute risk difference, -18.1%; 95% CI, -25.1 to -11.1; p < 0.001). Early peritoneal dialysis was also associated with a decrease in duration of mechanical ventilation and intensive care stay. Among infants with a cardiopulmonary bypass greater than 150 minutes, early peritoneal dialysis was also associated with a survival advantage (relative risk, 0.14; 95% CI, 0.03-0.84; p = 0.03 and absolute risk difference, -7.8; 95% CI, -13.6 to -2; p = 0.008).

CONCLUSIONS

Early peritoneal dialysis in infants post cardiac surgery is associated with a decrease in the rate of major adverse events. The role of early peritoneal dialysis warrants the conduct of randomized trials both in high and low-to-middle income countries; any beneficial effects if confirmed have the potential to strongly influence outcomes for children born with congenital heart disease.

Increased mortality, morbidities, and costs after heart transplantation in heterotaxy syndrome and other complex situs arrangements

OBJECTIVES

Identify pediatric heart transplant (HT) recipients with heterotaxy and other complex arrangements of cardiac situs (heterotaxy/situs anomaly) and compare mortality, morbidities, length of stay (LOS), and costs to recipients with congenital heart disease without heterotaxy/situs anomaly.

METHODS

Using linked registry data (2001-2016), we identified 186 HT recipients with heterotaxy/situs anomaly and 1254 with congenital heart disease without heterotaxy/situs anomaly. We compared post-HT outcomes in univariable and multivariable time-to-event analyses. LOS and cost from HT to discharge were compared using Wilcoxon rank-sum tests. Sensitivity analyses were performed using stricter heterotaxy/situs anomaly group inclusion criteria and through propensity matching.

RESULTS

HT recipients with heterotaxy/situs anomaly were older (median age, 5.1 vs 1.6 years; P < .001) and more often black, Asian, Hispanic, or "other" nonwhite (54% vs 32%; P < .001). Heterotaxy/situs anomaly was independently associated with increased mortality (hazard ratio, 1.58; 95% confidence interval, 1.19-2.09; P = .002), even among 6-month survivors (hazard ratio, 1.86; 95% confidence interval, 1.09-3.16; P = .021). Heterotaxy/situs anomaly recipients more commonly required dialysis (odds ratio, 2.58; 95% confidence interval, 1.51-4.42; P = .001) and cardiac reoperation (odds ratio, 1.91; 95% confidence interval, 1.17-3.11; P = .010) before discharge. They had longer ischemic times (19.2 additional minutes [range, 10.9-27.5 minutes]; P < .001), post-HT intensive care unit LOS (16 vs 13 days; P = .012), and hospital LOS (26 vs 23 days; P = .005). Post-HT hospitalization costs were also greater ($447,604 vs $379,357; P = .001).

CONCLUSIONS

Heterotaxy and other complex arrangements of cardiac situs are associated with increased mortality, postoperative complications, LOS, and costs after HT. Although increased surgical complexity can account for many of these differences, inferior late survival is not well explained and deserves further study.

Retrospective study of complete atrioventricular canal defects: Anesthetic and perioperative challenges

Objective:

The objective of this study was to highlight anesthetic and perioperative management and the outcomes of infants with complete atrioventricular (AV) canal defects.

Design:

This retrospective descriptive study included children who underwent staged and primary biventricular repair for complete AV canal defects from 1999 to 2013.

Setting:

A single-center study at a university affiliated heart center.

Participants:

One hundred and fifty-seven patients with a mean age at surgery of 125 ± 56.9 days were included in the study. About 63.6% of them were diagnosed as Down syndrome. Mean body weight at surgery was 5.6 ± 6.3 kg.

Methods:

Primary and staged biventricular repair of complete AV canal defects. Measurements and main results: A predefined protocol including timing of surgery, management of induction and maintenance of anesthesia, cardiopulmonary bypass, and perioperative intensive care treatment was used throughout the study. Demographic data as well as intraoperative and perioperative Intensive Care Unit (ICU) data, such as length of stay in ICU, total duration of ventilation including reintubations, and total length of stay in hospital and in hospital mortality, were collected from the clinical information system. Pulmonary hypertension was noted in 60% of patients from which 30% needed nitric oxide therapy. Nearly 2.5% of patients needed permanent pacemaker implantation. Thorax was closed secondarily in 7% of patients. In 3.8% of patients, reoperations due to residual defects were undertaken. Duration of hospital stay was 14.5 ± 4.7 days. The in-hospital mortality was 0%.

Conclusion:

Protocolized perioperative management leads to excellent outcome in AV canal defect repair surgery.

Pediatric Mechanical Circulatory Support

Over the past two decades clinicians and researchers have sought to bring mechanical circulatory support (MCS) to pediatric patients with heart failure. ECMO, IABPs, and VADs have all been used in infants and children as a bridge to myocardial recovery or as a bridge to transplant. However, until recently, a commitment by industry, government, and researchers towards the development of pediatric MCS has not been present, especially in the United States. Advancements in adult VAD design to smaller, quieter, and fully implantable pumps capable of complete outpatient support have sparked curiosity in the application of this technology to children. Also, the increasing success of palliating congenital heart disease is creating an ever-growing cohort of children and adolescents with heart failure. These changing demographics and technological advances have caused a refocus of attention. This is most clearly demonstrated by the international use of several established MCS pediatric and neonatal systems, by the FDA's increasing proclivity to allow the use of international pediatric VADs in the USA, and by the recent National Heart, Lung, and Blood Institute funding of several institutions to develop pediatric VADs. This review describes the different aspects of pediatric MCS including indications, the features of the various VADs, and their current application in children worldwide.

Acute kidney injury in congenital cardiac surgery: Pediatric risk-injury-failure-loss-end-stage renal disease and Acute Kidney Injury Network

BACKGROUND

Acute kidney injury (AKI) is associated with an increased risk of mortality, especially in pediatric intensive care units. The aim of this study was to determine the risk factors of AKI in children undergoing cardiac surgery for congenital heart disease and to compare two different classification systems: pediatric risk-injury-failure-loss-end-stage renal disease (pRIFLE) and Acute Kidney Injury Network (AKIN).

METHODS

We retrospectively analyzed 145 patients undergoing pediatric congenital heart surgery who were between 1 month and 18 years of years, and treated at a cardiovascular surgery department from January 2009 to October 2011.

RESULTS

One hundred and thirty-seven patients (mean age, 36.6 ± 43.3 months) were enrolled: 84 (61.3%) developed AKI according to the pRIFLE criteria (25.5%, risk; 20.4%, injury; 15.3%, failure); and 65 patients (47.4%) developed AKI according to the AKIN criteria (15.3%, stage I; 18.2%, stage II; and 13.9%, stage III). Children younger than 11 months were more likely to develop AKI (P < 0.005). Longer cardiopulmonary bypass time was associated with an increased risk of AKI (P < 0.05). pRIFLE identified AKI more frequently than AKIN (P < 0.0005). pRIFLE may help in the early identification of patient at risk for AKI and seems to be more sensitive in pediatric patients (P < 0.05). Any degree of AKI in both classifications was associated with increased mortality (pRIFLE: OR, 15.1; AKIN: OR, 11.2; P = 0.007).

CONCLUSION

pRIFLE identified AKI more frequently than the AKIN criteria. pRIFLE identified patients at risk for AKI earlier, and was more sensitive in pediatric patients. Any degree of AKI in both classifications was associated with increased mortality. Both sets of criteria had the same association with mortality.

Independent Risk Factors and 2-Year Outcomes of Acute Kidney Injury after Surgery for Congenital Heart Disease

BACKGROUND

Data are limited regarding risk factors for acute kidney injury (AKI) following cardiac surgery in children with congenital heart disease (CHD). This observational study was performed to examine temporal trends in AKI incidence according to the Pediatric Risk, Injury, Failure, Loss, End-Stage Renal Disease (pRIFLE) criteria, identify independent risk factors for AKI after cardiac surgery, and examine associations between AKI and long-term mortality.

METHODS

We retrospectively evaluated 418 patients (259 males, 159 females; median age, 5 months) who underwent cardiac surgery for CHD between April 2007 and August 2013. Patients were followed up for 2 years. AKI was defined according to the pRIFLE criteria as ≥25% decrease in estimated creatinine clearance.

RESULTS

AKI developed postoperatively in 104 cases (24.9%). Approximately 80% belonged to the "Risk" category according to the pRIFLE criteria, and only 21 cases (5%) required renal replacement therapy (peritoneal dialysis in all cases). Multivariate analysis revealed 3 independent risk factors for onset of AKI: young age (<1 year), surgery in Risk Adjustment in Congenital Heart Surgery (RACHS-1) category ≥4, and long cardiopulmonary bypass (CPB) time (≥90 min). Twenty-three patients (22%) with AKI died during the 2-year follow-up. In multivariate cox hazard regression analysis, the most significant contributor to risk of mortality was AKI.

CONCLUSIONS

Postoperative AKI was strongly associated with young age, high RACHS-1 category, and prolonged CPB time. In addition, mortality rate was higher in patients who survived after recovery from AKI than in those without AKI, even among the lower pRIFLE categories.

The Kidney in Critical Cardiac Disease: Proceedings From the 10th International Conference of the Pediatric Cardiac Intensive Care Society

The field of cardiac intensive care continues to advance in tandem with congenital heart surgery. The focus of intensive care unit care has now shifted to that of morbidity reduction and eventual elimination. Acute kidney injury (AKI) after cardiac surgery is associated with adverse outcomes, including prolonged intensive care and hospital stays, diminished quality of life, and increased long-term mortality. Acute kidney injury occurs frequently, complicating the care of both postoperative patients and those with heart failure. Patients who become fluid overloaded and/or require dialysis are at high risk of mortality, but even minor degrees of AKI portend a significant increase in mortality and morbidity. Clinicians continue to seek methods of early diagnosis and risk stratification of AKI to prevent its adverse sequelae. Previous conventional wisdom that survivors of AKI fully recover renal function without subsequent consequences may be flawed.

Structural equation modelling exploration of the key pathophysiological processes involved in cardiac surgery-related acute kidney injury in infants

Background

Uncertainties about the pathophysiological processes resulting in cardiac surgery-related acute kidney injury (AKI) in infants concern the relative impact of the most prominent risk factors, the clinical relevance of changes in glomerular filtration rate vs tubular injury, and the usefulness of available diagnostic tools. Structural equation modelling could allow for the assessment of these complex relationships.

Methods

A structural model was specified using data from a prospective observational cohort of 200 patients <1 year of age undergoing cardiopulmonary bypass surgery. It included four latent variables: AKI, modelled as a construct of perioperative creatinine variation, of oliguria and of urine neutrophil gelatinase-associated lipocalin (uNGAL) concentrations; the cardiopulmonary bypass characteristics; the occurrence of a post-operative low cardiac output syndrome and the post-operative outcome.

Results

The model showed a good fit, and all path coefficients were statistically significant. The bypass was the most prominent risk factor, with a path coefficient of 0.820 (95 % CI 0.527–0.979), translating to a 67.2 % explanation for the risk of AKI. A strong relationships was found between AKI and early uNGAL excretion, and between AKI and the post-operative outcome, with path coefficients of 0.611 (95 % CI 0.347–0.777) and 0.741 (95 % CI 0.610–0.988), respectively. The path coefficient between AKI and a >50 % increase in serum creatinine was smaller, with a path coefficient of 0.443 (95 % CI 0.273–0.596), and was intermediate for oliguria, defined as urine output <0.5 ml kg⁻¹ h⁻¹, with a path coefficient of 0.495 (95 % CI 0.250–0.864). A path coefficient of −0.229 (95 % CI −0.319 to 0.060) suggested that the risk of AKI during the first year of life did not increase with younger age at surgery.

Conclusions

These findings suggest that cardiac surgery-related AKI in infants is a translation of tubular injury, predominately driven by the cardiopulmonary bypass, and linked to early uNGAL excretion and to post-operative outcome.

Trial registration

ClinicalTrials.gov identifier NCT01219998. Registered 11 October 2010.

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-016-1350-1) contains supplementary material, which is available to authorized users.

Renal replacement therapy in adult and pediatric intensive care : Recommendations by an expert panel from the French Intensive Care Society (SRLF) with the French Society of Anesthesia Intensive Care (SFAR) French Group for Pediatric Intensive Care Emergencies (GFRUP) the French Dialysis Society (SFD)

Acute renal failure (ARF) in critically ill patients is currently very frequent and requires renal replacement therapy (RRT) in many patients. During the last 15 years, several studies have considered important issues regarding the use of RRT in ARF, like the time to initiate the therapy, the dialysis dose, the types of catheter, the choice of technique, and anticoagulation. However, despite an abundant literature, conflicting results do not provide evidence on RRT implementation. We present herein recommendations for the use of RRT in adult and pediatric intensive care developed with the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system by an expert group of French Intensive Care Society (SRLF), with the participation of the French Society of Anesthesia and Intensive Care (SFAR), the French Group for Pediatric Intensive Care and Emergencies (GFRUP), and the French Dialysis Society (SFD). The recommendations cover 4 fields: criteria for RRT initiation, technical aspects (access routes, membranes, anticoagulation, reverse osmosis water), practical aspects (choice of the method, peritoneal dialysis, dialysis dose, adjustments), and safety (procedures and training, dialysis catheter management, extracorporeal circuit set-up). These recommendations have been designed on a practical point of view to provide guidance for intensivists in their daily practice.

Short-term renal support in postoperative repair of tetralogy of Fallot in the paediatric intensive care unit: can we predict those who need it?

INTRODUCTION

Fluid balance and renal function can be difficult to manage in the postoperative infant with tetralogy of Fallot. High fluid volumes are often needed to maintain cardiac output. Aims To stratify patients at risk for advanced renal support following tetralogy of Fallot repair.

METHODS

Retrospective analysis of all consecutive tetralogy of Fallot cases operated at a single centre in a 3-year period.

RESULTS

A total of 41 children were identified. All cases had loop diuretics administered. Of the cases, 17% required support with a peritoneal dialysis catheter, with only one complication of peritoneal dialysis catheter blockage. The mean length of paediatric intensive care unit stay in those receiving peritoneal dialysis catheter insertion was prolonged by an additional mean of 6 days (p<0.001). No statistical significance was found between those children requiring peritoneal dialysis and those who did not when considering patient age and weight at time of repair, cardiopulmonary bypass and aortic cross clamp times, the presence of a transannular patch, or junctional ectopic tachycardia. However, volume requirement of more than 35 ml/kg in the first 12 hours following repair did increase the likelihood to need peritoneal dialysis (p<0.0001). Furthermore, the higher the peak creatinine, the longer the stay on intensive care (p<0.01).

CONCLUSIONS

Peritoneal dialysis is an effective method of dealing with fluid balance in children after tetralogy of Fallot repair, with minimal complications. Early consideration should be given to peritoneal dialysis when it is clear that high fluid volumes are required postoperatively.

Pre-operative renal volume predicts peak creatinine after congenital heart surgery in neonates

OBJECTIVE

Acute kidney injury is common in neonates following surgery for congenital heart disease. We conducted a retrospective analysis to determine whether neonates with smaller pre-operative renal volume were more likely to develop post-operative acute kidney injury.

DESIGN/SETTING

We conducted a retrospective review of 72 neonates who underwent congenital heart surgery for any lesion other than patent ductus arteriosus at our institution from January 2007 to December 2011. Renal volume was calculated by ultrasound using the prolate ellipsoid formula. The presence and severity of post-operative acute kidney injury was determined both by measuring the peak serum creatinine in the first 7 days post-operatively and by using the Acute Kidney Injury Network scoring system.

RESULTS

Using a linear change point model, a threshold renal volume of 17 cm³ was identified. Below this threshold, there was an inverse linear relationship between renal volume and peak post-operative creatinine for all patients (p = 0.036) and the subgroup with a single morphologic right ventricle (p = 0.046). There was a non-significant trend towards more acute kidney injury using Acute Kidney Injury Network criteria in all neonates with renal volume ≤17 cm³ (p = 0.11) and in the subgroup with a single morphologic right ventricle (p = 0.17).

CONCLUSIONS

Pre-operative renal volume ≤17 cm³ is associated with a higher peak post-operative creatinine and potentially greater risk for post-operative acute kidney injury for neonates undergoing congenital heart surgery. Neonates with a single right ventricle may be at higher risk.

Renal replacement therapy in neonates

The incidence of acute kidney injury (AKI) has steadily increased in the last decade in neonates and infants. Despite the extensive proposed pharmacologic approaches to treat or prevent AKI, renal replacement therapy is the only available therapeutic approach to manage the consequences of significant AKI and maintain electrolyte homeostasis and fluid balance in infants with AKI. The objective of this article is to summarize the different approaches and modalities of renal replacement therapy in neonatal intensive care units.

Prophylactic peritoneal dialysis catheter does not decrease time to achieve a negative fluid balance after the Norwood procedure: a randomized controlled trial

OBJECTIVE

Infants and children who undergo cardiopulmonary bypass and cardiac surgery are at risk of postoperative fluid overload. Peritoneal dialysis catheter (PDC) and peritoneal dialysis are reported to be effective means of postoperative fluid management. We sought to test the hypothesis that PDC insertion in the operating room at the time of Norwood palliation would decrease the time to achieve a negative fluid balance in a group of neonates with hypoplastic left heart syndrome.

METHODS

A single center randomized controlled trial was performed. We randomized neonates with hypoplastic left heart syndrome to prophylactic PDC, with or without dialysis, or standard care (ie, no PDC).

RESULTS

Twenty-two neonates were included; 10 were randomized to PDC and 12 were randomized to standard care. The mean time to first postoperative negative fluid balance was 2.70 ± 1.06 days for the prophylactic PDC group and 2.67 ± 0.65 days for the standard care group (P = .93). There was no difference between the 2 groups in time to lactate ≤ 2 mmol/L, maximum vasoactive-inotrope score on postoperative days 2 to 5, time to sternal closure, time to first extubation, modified clinical outcome score, or hospital length of stay. Twenty-one patients (95%) survived to hospital discharge. Four patients randomized to prophylactic PDC had 1 or more serious adverse events compared with no patients in the standard care group (P = .03).

CONCLUSIONS

Prophylactic PDC, with or without dialysis, did not decrease the time to achieve a negative fluid balance after the Norwood procedure, did not alter physiological variables postoperatively, and was associated with more severe adverse events.

Peritoneal dialysis does not adversely affect kidney function recovery after congenital heart surgery

PURPOSE

Acute kidney injury (AKI) after cardiopulmonary bypass surgery to correct congenital heart disease is common. We prevent fluid overload and further cardiac compromise in oliguric infants with continuous peritoneal dialysis (CPD). The effect of CPD on kidney recovery is unknown, thus indications to discontinue CPD are unclear. We aimed to determine if CPD affects kidney recovery, measured by urine output and novel urinary AKI biomarker concentrations.

METHODS

Twenty infants <90 days old with congenital heart disease who underwent bypass surgery and were post-operatively treated with CPD were randomized at the time of clinical readiness for CPD discontinuation to 1) discontinue CPD (control) or 2) continue 24 h more CPD (experimental). Urine output (ml/kg per h), total output (ml/kg per h) and urinary neutrophil gelatinase-associated lipocalin, interleukin-18, liver-type fatty acid binding protein, and kidney injury molecule-1 were assessed post-surgery until CPD catheter removal.

RESULTS

24 hours preceding randomization, there were no differences in mean urine output or total output; 24 hours post-randomization, the control group had higher mean urine output (4.2 ± 2.6 ml/kg per h vs. 2.8 ± 2.0 ml/kg per h, p = 0.02) but lower total output (6.3 ± 2.1 ml/kg per h vs. 4.7 ± 2.7 ml/kg per h, p = 0.01). Median biomarker concentrations did not differ significantly between groups at any time point.

CONCLUSIONS

Our results suggest renal replacement therapy does not change the time course of kidney function recovery.

Predictive performance of urine neutrophil gelatinase-associated lipocalin for dialysis requirement and death following cardiac surgery in neonates and infants

BACKGROUND AND OBJECTIVES

Urine neutrophil gelatinase-associated lipocalin (uNGAL) has been shown to accurately predict and allow early detection of AKI, as assessed by an increase in serum creatinine in children and adults. The present study explores the accuracy of uNGAL for the prediction of severe AKI-related outcomes in neonates and infants undergoing cardiac surgery: dialysis requirement and/or death within 30 days.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Prospective, observational cohort study conducted in a tertiary referral pediatric cardiac intensive care unit, including 75 neonates and 125 infants undergoing surgery with cardiopulmonary bypass between August 1, 2010, and May 31, 2011. Urine samples were collected before surgery and at median of five time points within 48 hours of bypass. Urine NGAL was quantified as absolute concentration, creatinine-normalized concentration, and absolute excretion rate, and a clusterization algorithm was applied to the individual uNGAL kinetics. The accuracy for the prediction of the outcome was assessed using receiver-operating characteristic areas, likelihood ratios, diagnostic odds ratios, net reclassification index, integrated reclassification improvement, and number needed to screen.

RESULTS

A total of 1176 urine samples were collected. Of all patients, 8% required dialysis and 4% died. Three clusters of uNGAL kinetics were identified, including patients with significantly different outcomes. The uNGAL level peaked between 1 and 3 hours of bypass and remained high in half of all patients who required dialysis or died. The uNGAL levels measured within 24 hours of bypass accurately predicted the outcome and performed best after normalization to creatinine, with varying cutoffs according to the time elapsed since bypass. The number needed to screen to correctly identify the risk of dialysis or death in one patient varied between 1.5 and 2.6 within 12 hours of bypass.

CONCLUSIONS

uNGAL is a valuable predictive tool of dialysis requirement and death in neonates and infants with AKI after cardiac surgery.

Indications and outcomes in children receiving renal replacement therapy in pediatric intensive care

PURPOSE

We aimed to describe patient characteristics, indications for renal replacement therapy (RRT), and outcomes in children requiring RRT. We hypothesized that fluid overload, not classic blood chemistry indications, would be the most frequent reason for RRT initiation.

MATERIALS AND METHODS

A retrospective cohort study of all patients receiving RRT at a single-center quaternary pediatric intensive care unit between January 2004 and December 2008 was conducted.

RESULTS

Ninety children received RRT. The median age was 7 months (interquartile range, 1-83). Forty-six percent of patients received peritoneal dialysis, and 54% received continuous renal replacement therapy. The median (interquartile range) PRISM-III score was 14 (8-19). Fifty-seven percent had congenital heart disease, and 32% were on extracorporeal life support. The most common clinical condition associated with acute kidney injury was hemodynamic instability (57%; 95% confidence interval [CI], 46-67), followed by multiorgan dysfunction syndrome (17%; 95% CI, 10-26). The most common indication for RRT initiation was fluid overload (77%; 95% CI, 66-86). Seventy-three percent (95% CI, 62-82) of patients survived to hospital discharge.

CONCLUSIONS

Hemodynamic instability and multiorgan dysfunction syndrome are the most common clinical conditions associated with acute kidney injury in our population. In the population studied, the mortality was lower than previously reported in children and much lower than in the adult population.

Limitations of early serum creatinine variations for the assessment of kidney injury in neonates and infants with cardiac surgery

Background

Changes in kidney function, as assessed by early and even small variations in serum creatinine (ΔsCr), affect survival in adults following cardiac surgery but such associations have not been reported in infants. This raises the question of the adequate assessment of kidney function by early ΔsCr in infants undergoing cardiac surgery.

Methodology

The ability of ΔsCr within 2 days of surgery to assess the severity of kidney injury, accounted for by the risk of 30-day mortality, was explored retrospectively in 1019 consecutive neonates and infants. Patients aged ≤ 10 days were analyzed separately because of the physiological improvement in glomerular filtration early after birth. The Kml algorithm, an implementation of k-means for longitudinal data, was used to describe creatinine kinetics, and the receiver operating characteristic and the reclassification methodology to assess discrimination and the predictive ability of the risk of death.

Results

Three clusters of ΔsCr were identified: in 50% of all patients creatinine decreased, in 41.4% it increased slightly, and in 8.6% it rose abruptly. Mortality rates were not significantly different between the first and second clusters, 1.6% [0.0–4.1] vs 5.9% [1.9–10.9], respectively, in patients aged ≤ 10 days, and 1.6% [0.5–3.0] vs 3.8% [1.9–6.0] in older ones. Mortality rates were significantly higher when creatinine rose abruptly, 30.3% [15.1–46.2] in patients aged ≤ 10 days, and 15.1% [5.9–25.5] in older ones. However, only 41.3% of all patients who died had an abrupt increase in creatinine. ΔsCr improved prediction in survivors, but not in patients who died, and did not improve discrimination over a clinical mortality model.

Conclusions

The present results suggest that a postoperative decrease in creatinine represents the normal course in neonates and infants with cardiac surgery, and that early creatinine variations lack sensitivity for the assessment of the severity of kidney injury.

Early initiation of peritoneal dialysis in neonates and infants with acute kidney injury following cardiac surgery is associated with a significant decrease in mortality

Association between early renal replacement therapy and better survival has been reported in adults with postoperative kidney injury, but not in children undergoing cardiac surgery. We conducted a retrospective cohort study of 146 neonates and infants requiring peritoneal dialysis following cardiac surgery in a tertiary referral hospital. A propensity score was used to limit selection bias due to timing of dialysis, and included baseline and intraoperative characteristics, requirement for postoperative extracorporeal membrane oxygenation, and creatinine clearance variation. Inverse probability of treatment weighting resulted in good balance between groups for all baseline and intraoperative variables. After weighting, 30-day and 90-day mortality were compared between the 109 patients placed on dialysis early, within the first day of surgery, and those with delayed dialysis, commencing on the second day of surgery or later, using logistic regression and survival analysis. Mortality was 28.1% at 30 days, and was 36.3% during follow-up. Early dialysis was associated with a 46.7% decrease in the 30-day and a 43.5% decrease in the 90-day mortality rate when compared with delayed dialysis. All other short-term outcome variables were similar. Thus, initiation of peritoneal dialysis on the day of or the first day following surgery was associated with a significant decrease in mortality in neonates and infants with acute kidney injury.

[Use of peritoneal dialysis in newborns undergoing cardiac surgery with cardiopulmonary bypass]

INTRODUCTION

Renal replacement therapy is required in up to 10% of children undergoing cardiac surgery. Peritoneal dialysis (PD) is the preferred treatment method in the neonatal period.

OBJECTIVE

To evaluate safety, efficacy and perioperative factors associated with the need for PD.

MATERIAL AND METHODS

Retrospective review of clinical charts over a two-year period of newborns undergoing cardiac surgery with cardiopulmonary bypass (CPB). The group of cases requiring PD were compared with a group of random controls that did not require any renal replacement therapy.

RESULTS

A total of 76 infants underwent cardiac surgery with CPB, of which 24 required PD. The need for PD was associated with low cardiac output in the immediate postoperative period and longer mechanical ventilation. The most frequent indication was fluid overload. The technique was effective in 66% of patients. Complications were only recorded in one patient.

CONCLUSIONS

The most common indication for PD after cardiac surgery with CPB in neonates is fluid overload. The need for renal replacement therapy is associated with low cardiac output and a longer duration of mechanical ventilation. PD is an effective technique with few complications in these patients.

Epidemiology of cardiac surgery-associated acute kidney injury in neonates: a retrospective study

BACKGROUND

Cardiac surgery is a known risk factor for acute kidney injury (AKI) in children. However, cardiac surgery-associated AKI (CS-AKI) in neonates has not been well studied. The objectives of this study were: (1) to describe the epidemiology of CS-AKI in neonates utilizing the Acute Kidney Injury Network (AKIN) definition, (2) to identify risk factors for neonatal CS-AKI, and (3) to determine if neonatal CS-AKI is associated with increased morbidity and mortality.

METHODS

This was a retrospective study involving 122 neonates (≤28 days) undergoing cardiac surgery from 2006 to 2009. Neonates with and without AKI were identified using serum creatinine (SCr) and urine output (UO) data.

RESULTS

Cardiac surgery-AKI occurred in 76 (62 %) neonates, of whom 22 (29 %) were AKIN stage 1, 19 (25 %) were stage 2, and 35 (46 %) were stage 3. AKI mostly occurred early as 75 % of patients achieved their maximal AKIN stage within the first 48 h post-operatively. In the multivariate analysis, cardiopulmonary bypass duration of ≥120 min was independently associated with AKI [odds ratio (OR) 2.53, 95 % confidence interval (CI) 1.03-6.30]. Severe AKI (AKIN stage 3) was independently associated with mortality (OR 6.70, 95 % CI 1.08-41.50) and a longer stay in the pediatric intensive care unit (hazard ratio 9.09, 95 % CI 1.35-60.95). The majority of severe AKI cases (65 %) were identified with AKIN UO criteria alone without significant rises in SCr.

CONCLUSIONS

Cardiac surgery-AKI is common in neonates when the AKIN definition is utilized and is associated with higher morbidity and mortality, especially in those with more severe AKI.

Near-infrared spectroscopy monitoring to predict postoperative renal insufficiency following repair of congenital heart disease

BACKGROUND

Infants undergoing repair or palliation of congenital heart disease are at risk of renal insufficiency. Development of renal insufficiency increases mortality. This project seeks to determine whether intra- and postoperative renal near-infrared spectroscopy (NIRS) monitoring can reliably predict renal insufficiency after cardiac surgery in infants.

METHODS

In this prospective, observational cohort study 48 patients undergoing repair or palliation of congenital heart disease in the first 6 months of life were studied intraoperatively and on postoperative day 1 and 2. The NIRS mean and nadir were recorded for the 3 time periods, as were urine output, fluid balance, and serum creatinine. Renal insufficiency was defined as rise in creatinine ≥40% from baseline or oliguria for >4 hours. Near-infrared spectroscopy data were compared to creatinine increase, oliguria, and fluid balance on postoperative day 0, 1, and 2 by regression analysis.

RESULTS

Mean renal regional saturation on postoperative day 1 has a strong correlation with increase in creatinine (P < .001 and R (2) = .6). Mean renal saturation less than 80% predicts renal insufficiency with a sensitivity of 100% and a specificity of 75% (P < .001).

CONCLUSION

Monitoring of intra- and postoperative renal regional saturation may provide an early, noninvasive marker of renal insufficiency after cardiac surgery in infants. This would be clinically significant if interventions to improve renal regional saturation prevent renal insufficiency.

Is serum cystatin C an early predictor for acute kidney injury following cardiopulmonary bypass surgery in infants and young children?

Acute kidney injury (AKI) is a potential complication following cardiopulmonary bypass (CPB) surgery in infants and young children with congenital heart disease (CHD). The current pilot study evaluates the predictive value of serum cystatin C (CysC) for AKI after pediatric CPB surgery. We prospectively enrolled 43 children with CHD (30 males and 13 females) who underwent CPB surgery. They were aged 3 years or younger. Serum CysC was measured at baseline and at 6 hours, 12 hours, 24 hours, and 48 hours after initiating CBP. Twenty-one (48.8%) patients developed AKI after cardiac surgery. Children who developed AKI had more complex cardiac surgical procedures (based on the Risk Adjustment for Congenital Heart Surgery 1 [RACHS-1] category), a longer CPB duration, and a longer aortic clamping time (ACT). Serum concentrations of CysC postoperatively demonstrated an initial decline at 6 hours, a subsequent increase at 12 hours, and stabilized at 24-48 hours. The best predictive performance was achieved 6 hours after CPB with an area under receiver operating characteristic curve (AUC) value of 0.69. The optimal cut-off value was 0.47 mg/L (sensitivity, 85.7%; specificity, 50%). By contrast, the RACHS-1 category, CPB duration, and ACT had higher AUC values at 0.735, 0.791, and 0.731, respectively. In conclusion, serum CysC had limited predictive capacity and was not superior to clinical risk factors for the early detection of AKI after CPB surgery in this pilot study, which focused on infants and young children.

Comparison of urinary biomarkers for early detection of acute kidney injury after cardiopulmonary bypass surgery in infants and young children

Acute kidney injury (AKI) is a potential complication for children with congenital heart disease (CHD) after cardiopulmonary bypass (CPB) surgery. This study was designed to investigate and compare the predictive values of urinary biomarkers for AKI after CPB surgery in infants and young children and to determine the optimal timing of testing and the cutoff value for each biomarker. The study prospectively enrolled 58 CHD children 3 years of age or younger who were undergoing CPB surgery. Urinary neutrophil gelatinase-associated lipocalin (NGAL), interleukin-18 (IL-18), microalbumin (MA), N-acetyl-ß-D-glucosaminidase (NAG), α1-microglobulin (α1-MG), and creatinine (UCr) were measured at baseline and at various time points after surgery. Children who experienced AKI had more complex cardiac surgical procedures as evaluated by Risk Adjustment for Congenital Heart Surgery 1 (RACHS-1), longer CPB and aortic clamping times, and worse clinical outcomes than those who did not. In the AKI group, all five urinary biomarkers increased substantially and peaked at 4 h after surgery. In contrast, in the non-AKI group, they increased slightly or had no significant changes during the first 24 h. All the biomarkers had the best predictive performances at 4 h after surgery. At this time point, NAG had the minimum area under the curve (AUC) (0.747), which was significantly lower than that of the others (AUC, 0.82-0.85; P < 0.05). The optimal cutoff value of each biomarker was 290 ng/mg UCr for NAGL, 1,477 pg/mg UCr for IL-18, 400 mg/g UCr for MA, 225 U/g UCr for NAG, and 290 mg/g UCr for α1-MG. In conclusion, urinary NGAL, IL-18, MA, and α1-MG had similar predictive performances for the early detection of AKI after CPB surgery in infants and young children.

Percutaneous Intraperitoneal Catheters in Neonates Following Open Heart Surgery

Objective:

Ascitic fluid in the peritoneal cavity may severely impair respiratory and renal function following neonatal heart surgery. It has been our practice to liberally insert percutaneous peritoneal catheters (PPCs) in order to manage fluid balance and thereby improve ventilatory function. We herein report our experience with PPC.

Methods:

Retrospective analysis of charts of all surviving neonates that underwent PPC insertion from January 2007 through March 2010. Charts were reviewed for demographic and clinical variables from the preoperative, operative, and postoperative periods.

Results:

A total of 1268 patients underwent surgery, 292 (23%) were neonates. 17 (5.8%) patients required PPC. Mean age and weight were 16 days and 3.1 kg, respectively. Mean amount drained upon insertion was 55 ± 46 ml. Catheters were maintained for a mean of 5 days and drained an average of 201 ml on the first postinsertion day. Ventilatory settings did not change significantly prior to and postcatheter insertion (respiratory rate [29 ± 3.8 vs 28.7 ± 3.9; P = .93], inspiratory pressures [26.3 ± 3.6 vs 26.1 ± 3.3 cm H2O; P = .34], and fraction of inspired oxygen [0.66 ± 0.21 vs 0.63 ± 0.18; P = .53]). Carbon dioxide values decreased significantly (43.2 ± 9.7 vs 37 ± 4.9 mm Hg; P = .01), and PO2 values increased (78 ± 69 vs 104 ± 57 mm Hg; P = .05).

Conclusions:

The PPC insertion can be easily performed at the bedside with minimal complications. Fluid balance management is facilitated, and ventilation is improved. The PPC insertion is a valuable addition to the armamentarium of the physician treating neonates in the intensive care unit after complex congenital heart surgery.

Pediatric renal replacement therapy in the intensive care unit

Renal replacement therapy (RRT) is used in a wide variety of pediatric populations. In this article, we will review the advantages and disadvantages of the different RRT modalities and the technical aspects of providing pediatric RRT. In addition, we will review the use of RRT with extracorporeal membrane oxygenation, the use of continuous RRT in the critically ill child with acute kidney injury and fluid overload, and the use of RRT for the removal of toxins and treatment of inborn errors of metabolism.

The impact of intraoperative vasopressin infusion in complex neonatal cardiac surgery

OBJECTIVES

Although recent advances have led to a better understanding of the beneficial effects of vasopressin on haemodynamics in paediatric cardiac surgery, not much information is available on the adverse effects. The objective of this study was to assess the impact of intraoperative vasopressin infusion on postoperative liver, renal and haemostatic function and lactate levels in neonates undergoing cardiac surgery.

METHODS

We reviewed data from 34 consecutive neonates who had undergone complex cardiac surgery. The cohort was divided into two groups according to the use of vasopressin. Seventeen patients received vasopressin [vasopressin (+) group], and 17 patients did not [vasopressin (-) group].

RESULTS

No differences between the groups in terms of age, weight, cardiopulmonary bypass time, Risk Adjustment for Congenital Heart Surgery-1 score or the comprehensive Aristotle score were seen. No differences in the systolic or diastolic arterial blood pressures, heart rate or inotropic score upon admission to the intensive care unit were observed between the groups. No adverse effects on the aminotransferase levels were seen. The vasopressin (+) group had higher urea and creatinine levels. All the patients except one received peritoneal dialysis on the day of surgery. Thirteen patients in the vasopressin (+) group and 7 patients in the vasopressin (-) group continued to require peritoneal dialysis on postoperative day 5 (POD 5) (P = 0.04). The platelet count had decreased to a significantly lower level in the vasopressin (+) group on POD 5 [97 x 10(3)/mm(3) (range: 40-132 x 10(3)/mm(3))]. A tendency toward a high lactate concentration was seen in the vasopressin (+) group. In comparison with the vasopressin (-) group, the number of patients whose lactate level remained above 2.0 mmol/l was higher in the vasopressin (+) group on PODs 2 and 3 (17 patients vs 8 patients, P < 0.01 and 15 patients vs 7 patients, P = 0.01, respectively).

CONCLUSIONS

These findings suggest that the intraoperative use of vasopressin extends the period of peritoneal dialysis, reduces platelet counts and delays the recovery of the lactate concentration. Intraoperative vasopressin infusion should not be used routinely, but only in catecholamine-refractory shock.

Aprotinin, transfusions, and kidney injury in neonates and infants undergoing cardiac surgery

BACKGROUND

A significantly increased risk of acute kidney injury (AKI) with the prophylactic use of aprotinin has been reported in adults undergoing cardiac surgery, but not in children. Blood product transfusions have also been shown to carry an independent risk of AKI. The present study assessed associations between AKI, aprotinin, and transfusions in neonates and infants undergoing cardiac surgery.

METHODS

All neonates and infants undergoing surgery with cardiopulmonary bypass over a 42 month period, before and after the withdrawal of aprotinin, were included retrospectively. AKI was assessed by the Acute-Kidney-Injury-Network classifications. A propensity score was used to balance treated and untreated groups.

RESULTS

Three hundred and ninety patients received aprotinin and 568 patients did not. Inverse probability of treatment weighting resulted in good balance between groups for baseline and surgical characteristics. Controls underwent surgery with smaller bypass circuits and fewer transfusions. After adjustment for the use of miniaturized circuits and for the year of surgery, no significant association between the incidence of AKI, dialysis, and aprotinin was noted. Red blood cell transfusions were associated with an increased risk of AKI and dialysis: odds ratios (ORs) 1.64 (1.12-2.41) and 2.07 (1.13-3.73), respectively; as were fresh frozen plasma transfusions, ORs 2.28 (1.68-3.09) and 3.11 (1.95-4.97), respectively. Platelet transfusions were associated with an increased risk of dialysis: OR 2.20 (1.21-4.01).

CONCLUSIONS

Blood product transfusions, but not the prophylactic use of aprotinin, are significantly associated with AKI after cardiac surgery in neonates and infants.

Cystatin C: influence of perfusion and myocardial injury on early (<24 h) renal function after pediatric cardiac surgery

BACKGROUND

Cardiopulmonary bypass (CPB)-associated renal dysfunction following cardiac surgery is well recognized. In patients with renal disease, cystatin C has emerged as a new biomarker which in contrast to creatinine (Cr) is sensitive to minor changes in glomerular filtration rate (GFR).

AIM

We utilized cystatin C to investigate the association of CPB perfusion parameters with acute renal injury after pediatric cardiac surgery.

METHODS

Twenty children, aged 4-58 months (AVSD, n = 7; VSD, n = 9; and ASD, n = 4), were prospectively studied. Glomerular filtration rate was quantified postoperatively by creatinine clearance (first and second 12-h periods; CrCl(0-12) and CrCl(12-24) ). Serum cystatin C and Cr were measured preoperatively and on days 0-3. Recorded CPB parameters included bypass duration (BP), perfusion pressure (PP), lowest pump flow (Q(min) ), lowest hematocrit, and corresponding lowest oxygen delivery (DO(2 min) ). Myocardial injury was determined by troponin-I.

RESULTS

Postoperatively, GFR remained unchanged (CrCl(0-12) 63.6 ± 37.0 vs CrCl(12-24) 65.1 ± 27.5; P = 0.51) and only correlated with cystatin C (CrCl(0-12) vs cystatin C(Day 0) [r = 0.58, P = 0.018] and Cr(Day 0) [r = 0.09, P = 0.735]). Cr and cystatin C increased postoperatively to peak on days 2 and 3, respectively (Cr(PreOp) 31 ± 6.9 vs Cr(Day 2) 36.9 ± 12.2, P = 0.03; cystatin C(Day 0) 0.83 ± 0.27 vs cystatin C(Day 3) 1.45 ± 0.53, P = 0.02). Increased cystatin C was significantly associated with BP (P = 0.001), mean PP (P = 0.029), Q(min) (P = 0.005), troponin-I (P < 0.001), and DO(2 min) <300 ml·min(-1) ·m(-2) (P = 0.007). Receiver-operator cutoff >1.044 mg·l(-1) for cystatin C exhibited 100% sensitivity and 67% specificity for detecting renal dysfunction, defined as GFR <55 ml·min(-1) ·1.73 m(-2).

CONCLUSIONS

Cystatin C is a sensitive marker of early renal dysfunction following pediatric heart surgery. Variations in bypass parameters, myocardial injury, and ultimately critical oxygen delivery are significantly associated with the degree of renal impairment.

Cardiopulmonary bypass and its direct effects on neonatal piglet kidney morphology

Renal failure after open heart surgery is a serious complication even in the pediatric population. The aim of the present study was to analyze morphological changes after cardiopulmonary bypass (CPB) surgery in a neonatal piglet model. The kidneys of newborn piglets sacrificed 6 h after CPB were examined (CPB; n = 4) regarding tubular dilatation, vacuole formation, leukocytic infiltration, epithelial destruction, and interstitial edema. Thereafter, the findings were compared with the morphology of normal (untreated) neonatal piglet kidneys (control; n = 4). All changes but the interstitial edema were statistically significant if compared with the normal renal tissue: tubular dilatation (CPB vs. control P < 0.05), vacuole formation (CPB vs. control P < .05), leukocytic infiltration (CPB vs. control P < 0.05), and epithelial destruction (CPB vs. control P < 0.001). In conclusion, CPB induces significant changes in the morphology of the neonatal piglet kidneys.

Factors associated with acute kidney injury or failure in children undergoing cardiopulmonary bypass: a case-controlled study

Acute kidney injury (AKI) is a serious complication that occurs commonly following cardiopulmonary bypass (CPB) in infants and children. Underlying risk factors for AKI remain unclear, given changes in CPB practices during recent years. This retrospective, case-control study examined the relationships between patient, perioperative factors, AKI, and kidney failure in children who underwent CPB.

METHODS

Cohorts of children with and without AKI were identified from the cardiac perfusion and nephrology consult databases. Demographic, perioperative, and postoperative outcome data were extracted from the databases and from medical records. Children were stratified into groups based on the Acute Dialysis Quality Initiative's RIFLE definitions for acute kidney risk or injury (AKI-RI) and kidney failure.

RESULTS

The study groups included 308 controls (no AKI-RI or failure), 161 with AKI-RI, and 89 with failure. Young age, preoperative need for mechanical ventilation, milrinone, or gentamicin; intraoperative use of milrinone and furosemide; durations of CPB and anesthesia; multiple cross-clamp and transfusion of blood products were significantly associated with AKI or failure. Young age, perioperative use of milrinone, multiple cross-clamps, extracorporeal membrane oxygenation, cardiac failure, neurological complications, sepsis, and failure significantly increased the odds of mortality.

CONCLUSION

This study identified multiple perioperative risk factors for AKI-RI, failure, and mortality in children undergoing CPB. In addition to commonly known risk factors, perioperative use of milrinone, particularly in young infants, and furosemide were independently predictive of poor renal outcomes in this sample. Findings suggest a need for the development of protocols aimed at renal protection in specific at risk patients.

Acute renal replacement therapy in pediatrics

Acute kidney injury (AKI) independently increases morbidity and mortality in children admitted to the hospital. Renal replacement therapy (RRT) is an essential therapy in the setting of AKI and fluid overload. The decision to initiate RRT is complex and often complicated by concerns related to patient hemodynamic and thermodynamic instability. The choice of which RRT modality to use depends on numerous criteria that are both patient and treatment center specific. Surprisingly, despite decades of use, no randomized, controlled trial study involving RRT in pediatrics has been performed. Because of these factors, clear-cut consensus is lacking regarding key questions surrounding RRT delivery. In this paper, we will summarize existing data concerning RRT use in children. We discuss the major modalities and the data-driven specifics of each, followed by controversies in RRT. As no standard of care is in widespread use for RRT in AKI or in multiorgan disease, we conclude in this paper that prospective studies of RRT are needed to identify best practice guidelines.

Use of peritoneal dialysis after surgery for congenital heart disease in children

Acute kidney injury (AKI) is a common complication in children after surgery for congenital heart disease, and peritoneal dialysis (PD) is usually the renal replacement therapy (RRT) of choice, especially in very young children. The aim of the present study was to describe our experience of using PD to treat AKI after cardiac surgery. We retrospectively analyzed children 1 week to 16 years of age undergoing cardiac surgery during 2000-2008 and found the incidence of AKI treated with PD to be 2.3%. In the 23 patients treated with PD (13 male; average age: 29 ± 48.4 months; weight: 9.1 ± 8.1 kg), the indications for PD initiation were oliguria (n = 13), anuria (n = 9), and acidosis (n = 1). The average time between cardiac surgery and AKI was 4.8 ± 16.8 hours, and between AKI and PD initiation, it was 12 ± 16.8 hours. Patients were treated for a mean of 4.8 ± 3.8 days. Two patients developed peritonitis, and mechanical dysfunction of the PD catheter occurred in 1 patient. In-hospital mortality was 43.4%. Patients treated with PD weighed less (p = 0.004) and had longer bypass time (p = 0.004), inotrope use (p = 0.000), and mechanical ventilation (p = 0.000). However, in a regression analysis, only cardiopulmonary bypass time (odds ratio: 1.021; 95% confidence interval: 0.998 to 1.027; p = 0.032) remained predictive of a subsequent need for PD. We conclude that PD is an efficacious RRT for AKI in children undergoing cardiac surgery and that, in this setting, bypass time is the strongest predictor of a subsequent need for RRT.

Perioperative management of low birth weight infants for open-heart surgery

Infants of birth weight ≤2500 g are termed low birth weight (LBW). These children often have considerable morbidity from prematurity and intra-uterine growth restriction. Additionally, LBW infants have increased risk for cardiac and noncardiac congenital anomalies and may require surgery. Primary rather than palliative surgical repair of cardiac lesions has been preferred in recent years. However, LBW remains a risk factor for increased mortality and morbidity after open-heart surgery (OHS). There is a paucity of information about the anesthetic challenges presented by LBW infants undergoing OHS. This review summarizes the perioperative issues of relevance to anesthesiologists who manage these high-risk patients. Emphasis is placed on management concerns that are unique to LBW infants. Retrospective data from the authors' institution are provided for those aspects of anesthetic care that lack published studies. Successful outcome often requires substantial hospital resources and collaborative multi-disciplinary effort.

Continuous hemodiafiltration in children after cardiac surgery

Acute renal failure (ARF) after congenital cardiac surgery remains a serious complication and leading cause of morbidity and mortality. Continuous hemodiafiltration (CHDF) is presently accepted for pediatric applications. We retrospectively evaluated the effects of CHDF against ARF after congenital cardiac surgery at our hospital. We analyzed data from seven patients aged 23 days to 9 years and weighing 1.7-22.4 kg requiring dialysis therapy using CHDF after congenital cardiac surgery between April 2002 and January 2009. One patient who died could not be weaned from extracorporeal membrane oxygenation support and another died of multiple organ failure. Renal function recovered to normal in the other five (71%) patients. Treatment by CHDF lasted from 14 to 680 h and net ultrafiltration was 3.5 ± 1.4 mL/kg/h. Serum creatinine and urea concentrations were, respectively, 2.3 ± 1.6 and 43.7 ± 17.0 mg/dL before, and 0.5 ± 0.2 and 13.5 ± 8.1 mg/dL, after CHDF (P < 0.05). Thrombocytopenia developed in all patients, and platelet concentrates (0.76 ± 0.7 mL/kg/h) were infused during CHDF. Hypotension developed after changing the CHDF set in one patient. We suggest that CHDF is an effective alternative strategy for treating renal dysfunction after congenital cardiac surgery.