Peritoneal dialysis in infants and children after open heart surgery

Murine models of renal ischemia reperfusion injury: An opportunity for refinement using noninvasive monitoring methods

BACKGROUND

Renal ischemia reperfusion injury (R-IRI) can cause acute kidney injury (AKI) and chronic kidney disease (CKD), resulting in significant morbidity and mortality. To understand the underlying mechanisms, reproducible small-animal models of AKI and CKD are needed. We describe how innovative technologies for measuring kidney function noninvasively in small rodents allow successful refinement of the R-IRI models, and offer the unique opportunity to monitor longitudinally in individual animals the transition from AKI to CKD.

METHODS

Male BALB/c mice underwent bilateral renal pedicle clamping (AKI) or unilateral renal pedicle clamping with delayed contralateral nephrectomy (CKD) under isoflurane anesthetic. Transdermal GFR monitoring and multispectral optoacoustic tomography (MSOT) in combination with statistical analysis were used to identify and standardize variables within these models.

RESULTS

Pre-clamping anesthetic time was one of the most important predictors of AKI severity after R-IRI. Standardizing pre-clamping time resulted in a more predictably severe AKI model. In the CKD model, MSOT demonstrated initial improvement in renal function, followed by significant progressive reduction in function between weeks 2 and 4. Performing contralateral nephrectomy on day 14 enabled the development of CKD with minimal mortality.

CONCLUSIONS

Noninvasive monitoring of global and individual renal function after R-IRI is feasible and reproducible. These techniques can facilitate refinement of kidney injury models and enable the degree of injury seen in preclinical models to be translated to those seen in the clinical setting. Thus, future therapies can be tested in a clinically relevant, noninvasive manner.

Acute Kidney Injury following Cardiopulmonary Bypass: A Challenging Picture

Recent studies have recognized several risk factors for cardiopulmonary bypass- (CPB-) associated acute kidney injury (AKI). However, the lack of early biomarkers for AKI prevents practitioners from intervening in a timely manner. We reviewed the literature with the aim of improving our understanding of the risk factors for CPB-associated AKI, which may increase our ability to prevent or improve this condition. Some novel early biomarkers for AKI have been introduced. In particular, a combinational use of these biomarkers would be helpful to improve clinical outcomes. Furthermore, we discuss several interventions that are aimed at managing CPB-associated AKI, may increase the effect of renal replacement therapy (RRT), and may contribute to preventing CPB-associated AKI. Collectively, the conclusions of this paper are limited by the availability of clinical trial evidence and conflicting definitions of AKI. A guideline is urgently needed for CPB-associated AKI.

The Epidemiology and Management of Pediatric AKI in Asia

Because of the lack of early recognition and referral, the incidence of pediatric acute kidney injury (AKI) in Asia still is underestimated. Although each diagnostic criteria has its own merits, the Kidney Disease Improving Global Outcomes classification now is widely accepted. In Asia, the spectrum of pediatric AKI is wide-ranging, from pediatric AKI in highly sophisticated tertiary-care pediatric intensive care units in resource-rich regions due to advanced procedures such as transplantation, cardiac surgery, and other hospital-acquired causes, to primary care preventable causes, such as infectious diseases, snakebite, and so forth in rural parts of the developing world. The development and application of novel biomarkers, concepts such as the Renal Angina Index and advanced renal replacement therapy have revolutionized the era of treating AKI, but the cost and feasibility are the key determinants, especially in rural areas. In view of availability and expenses, peritoneal dialysis should be the first choice in less-developed areas, however, because of various barriers, it still needs more effort. Effective educational steps to both medical carers and families are needed urgently.

Passive Peritoneal Drainage Impact on Fluid Balance and Inflammatory Mediators: A Randomized Pilot Study

BACKGROUND

Infants after cardiopulmonary bypass are exposed to increasing inflammatory mediator release and are at risk of developing fluid overload. The aim of this pilot study was to evaluate the impact of passive peritoneal drainage on achieving negative fluid balance and its ability to dispose of inflammatory cytokines.

METHODS

From September 2014 to November 2016, infants undergoing STAT category 3, 4, and 5 operations were randomized to receive or not receive intraoperative prophylactic peritoneal drain. We analyzed time to negative fluid balance and perioperative variables for each group. Pro- and anti-inflammatory cytokines were measured from serum and peritoneal fluid in the passive peritoneal drainage group and serum in the control group postoperatively.

RESULTS

Infants were randomized to prophylactic passive peritoneal drain group (n = 13) and control (n = 12). The groups were not significantly different in pre- and postoperative peak lactate levels, postoperative length of stay, and mortality. Peritoneal drain patients reached time to negative fluid balance at a median of 1.42 days (interquartile range [IQR]: 1.00-2.91), whereas the control at 3.08 (IQR: 1.67-3.88; P = .043). Peritoneal drain patients had lower diuretic index at 72 hours, median of 2.86 (IQR: 1.21-4.94) versus 6.27 (IQR: 4.75-11.11; P = .006). Consistently, tumor necrosis factor-α, interleukin (IL)-4, IL-6, IL-8, IL-10, and interferon-γ were present at higher levels in peritoneal fluid than serum at 24 and 72 hours. However, serum cytokine levels in peritoneal drain and control group, at 24 and 72 hours postoperatively, did not differ significantly.

CONCLUSIONS

The prophylactic passive peritoneal drain patients reached negative fluid balance earlier and used less diuretic in early postoperative period. The serum cytokine levels did not differ significantly between groups at 24 and 72 hours postoperatively. However, there was no significant difference in mortality and postoperative length of stay.

Acute Kidney Injury and Fluid Overload in Pediatric Cardiac Surgery

PURPOSE OF REVIEW

Acute kidney injury (AKI) and fluid overload affect a large number of children undergoing cardiac surgery, and confers an increased risk for adverse complications and outcomes including death. Survivors of AKI suffer long-term sequelae. The purpose of this narrative review is to discuss the short and long-term impact of cardiac surgery associated AKI and fluid overload, currently available tools for diagnosis and risk stratification, existing management strategies, and future management considerations.

RECENT FINDINGS

Improved risk stratification, diagnostic prediction tools and clinically available early markers of tubular injury have the ability to improve AKI-associated outcomes. One of the major challenges in diagnosing AKI is the diagnostic imprecision in serum creatinine, which is impacted by a variety of factors unrelated to renal disease. In addition, many of the pharmacologic interventions for either AKI prevention or treatment have failed to show any benefit, while peritoneal dialysis catheters, either for passive drainage or prophylactic dialysis may be able to mitigate the detrimental effects of fluid overload.

SUMMARY

Until novel risk stratification and diagnostics tools are integrated into routine practice, supportive care will continue to be the mainstay of therapy for those affected by AKI and fluid overload after pediatric cardiac surgery. A viable series of preventative measures can be taken to mitigate the risk and severity of AKI and fluid overload following cardiac surgery, and improve care.

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.

Acute Kidney Injury after Cardiac Surgery: Risk Factors and Novel Biomarkers

Acute kidney injury (AKI) is a common and severe complication after cardiac surgery. Currently, a series of novel biomarkers have favored the assessment of AKI after cardiac surgery in addition to the conventional indicators. The biomartkers, such as urinary liver fatty acid binding protein (L-FABP), urinary neutrophil gelatinase-associated lipocalin (NGAL), serum L-FABP, heart-type FABP, kidney injury molecule 1 (KIM-1), and interleukin-18 were found to be significantly higher in patients who developed AKI after cardiac surgery than those who did not. Apart from urinary interleukin-18, the novel biomarkers have been recognized as reliable indicators for predicting the diagnosis, adverse outcome, and even mortality of AKI after cardiac surgery. The timing of the renal replacement therapy is a significant predictor relating to patients’ prognoses. In patients with AKI after cardiac surgery, renal replacement therapy should be performed as early as possible in order to achieve promising outcomes. In children, AKI after cardiac surgery can be managed with peritoneal dialysis. AKI after cardiac surgery has received extensive attention as it may increase early mortality and impact long-term survival of patients as well. The purpose of this article was to analyze the changes of the pertinent biomarkers, to explore the related risk factors leading to the occurrence of AKI after cardiac surgery, and to provide a basis for the clinical prevention and reduction of AKI.

Fluid Management With Peritoneal Dialysis After Pediatric Cardiac Surgery

Children who undergo cardiac surgery with cardiopulmonary bypass are a unique population at high risk for postoperative acute kidney injury (AKI) and fluid overload. Fluid management is important in the postoperative care of these children as fluid overload is associated with increased morbidity and mortality. Peritoneal dialysis catheters are an important tool in the armamentarium of a cardiac intensivist and are used for passive drainage for fluid removal or dialysis for electrolyte and uremia control in AKI. Prophylactic placement of a peritoneal catheter is a safe method of fluid removal that is associated with few major complications. Early initiation of peritoneal dialysis has been associated with improved clinical markers and outcomes such as early achievement of a negative fluid balance, lower vasoactive medication needs, shorter duration of mechanical ventilation, and decreased mortality. In this review, we discuss the safety and potential benefits of peritoneal catheters for dialysis or passive drainage in children following cardiopulmonary bypass.

Comprehensive Management Considerations of Select Noncardiac Organ Systems in the Cardiac Intensive Care Unit

As the acuity and complexity of pediatric patients with congenital cardiac disease have increased, there are many noncardiac issues that may be present in these patients. These noncardiac problems may affect clinical outcomes in the cardiac intensive care unit and must be recognized and managed. The Pediatric Cardiac Intensive Care Society sought to provide an expert review of some of the most common challenges of the respiratory, gastrointestinal, hematological, renal, and endocrine systems in pediatric cardiac patients. This review provides a brief overview of literature available and common practices.

Peritoneal Drainage Versus Pleural Drainage After Pediatric Cardiac Surgery

BACKGROUND

We aimed to determine whether infants undergoing cardiac surgery would more efficiently attain negative fluid balance postoperatively with passive peritoneal drainage as compared to traditional pleural drainage.

METHODS

A prospective, randomized study including children undergoing repair of tetralogy of Fallot (TOF) or atrioventricular septal defect (AVSD) was completed between September 2011 and June 2013. Patients were randomized to intraoperative placement of peritoneal catheter or right pleural tube in addition to the requisite mediastinal tube. The primary outcome measure was fluid balance at 48 hours postoperatively. Variables were compared using t tests or Fisher exact tests as appropriate.

RESULTS

A total of 24 patients were enrolled (14 TOF and 10 AVSD), with 12 patients in each study group. Mean fluid balance at 48 hours was not significantly different between study groups, -41 ± 53 mL/kg in patients with periteonal drainage and -9 ± 40 mL/kg in patients with pleural drainage (P = .10). At 72 hours however, postoperative fluid balance was significantly more negative with peritoneal drainage, -52.4 ± 71.6 versus +2.0 ± 50.6 (P = .04). On subset analysis, fluid balance at 48 hours in patients with AVSD was more negative with peritoneal drainage as compared to pleural, -82 ± 51 versus -1 ± 38 mL/kg, respectively (P = .02). Fluid balance at 48 hours in patients with TOF was not significantly different between study groups.

CONCLUSION

Passive peritoneal drainage may more effectively facilitate negative fluid balance when compared to pleural drainage after pediatric cardiac surgery, although this benefit is not likely universal but rather dependent on the patient's underlying physiology.

Acute kidney injury and fluid overload in infants and children after cardiac surgery

Acute kidney injury is a common and serious complication after congenital heart surgery, particularly among infants. This comorbidity has been independently associated with adverse outcomes including an increase in mortality. Postoperative acute kidney injury has a complex pathophysiology with many risk factors, and therefore no single medication or therapy has been demonstrated to be effective for treatment or prevention. However, it has been established that the associated fluid overload is one of the major determinants of morbidity, particularly in infants after cardiac surgery. Therefore, in the absence of an intervention to prevent acute kidney injury, much of the effort to improve outcomes has focused on treating and preventing fluid overload. Early renal replacement therapy, often in the form of peritoneal dialysis, has been shown to be safe and beneficial in infants with oliguria after heart surgery. As understanding of the pathophysiology of acute kidney injury and the ability to confidently diagnose it earlier continues to evolve, it is likely that novel preventative and therapeutic interventions will be available in the future.

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.

Fluid Management: Pharmacologic and Renal Replacement Therapies

OBJECTIVES

Focusing on critically ill children with cardiac disease, we will review common causes of fluid perturbations, clinical recognition, and strategies to minimize and treat fluid-related complications.

DATA SOURCE

MEDLINE and PubMed.

CONCLUSIONS

Meticulous fluid management is vital in critically ill children with cardiac disease. Fluid therapy is important to maintain adequate blood volume and perfusion pressure in order to support cardiac output, tissue perfusion, and oxygen delivery. However, fluid overload and acute kidney injury are common and are associated with increased morbidity and mortality. Understanding the etiologies for disturbances in volume status and the pathophysiology surrounding those conditions is crucial for providing optimal care.

Extent, risk factors, and outcome of fluid overload after pediatric heart surgery*

OBJECTIVES

Fluid overload is associated with poor PICU outcomes in different populations. Little is known about fluid overload in children undergoing cardiac surgery. We described fluid overload after cardiac surgery, identified risk factors of worse fluid overload and also determined if fluid overload predicts longer length of PICU stay, prolonged mechanical ventilation (length of ventilation) and worse lung function as estimated by the oxygenation index.

DESIGN

Retrospective cohort study.

SETTING

Montreal Children's Hospital PICU, Montreal, Canada.

PATIENTS

Patients 18 years or younger undergoing cardiac surgery (2005-2007).

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Cumulative fluid overload % was calculated as [(total fluid in - out in L)/admission weight (kg) × 100] and expressed as PICU peak cumulative fluid overload % throughout admission and PICU day 2 cumulative fluid overload %. Primary outcomes were length of stay and length of ventilation. The secondary outcome was oxygenation index. Fluid overload risk factors were evaluated using stepwise linear regression. Fluid overload-outcome relations were evaluated using stepwise Cox regression (length of stay, length of ventilation) and generalized estimating equations (daily PICU cumulative fluid overload % and oxygenation index repeated measures). There were 193 eligible surgeries. Peak cumulative fluid overload % was 7.4% ± 11.2%. Fluid overload peaked on PICU day 2. Lack of past cardiac surgery (p = 0.04), cyanotic heart disease (p = 0.03), and early postoperative fluids (p = 0.0001) was independently associated with higher day 2 fluid overload %. Day 2 fluid overload % predicted longer length of stay (adjusted hazard ratio, 0.95; 95% CI, 0.92-0.99; p = 0.009) and length of ventilation (adjusted hazard ratio, 0.97; 95% CI, 0.94-0.99; p = 0.03). In patients without cyanotic heart disease, worse daily fluid overload % predicted worse daily oxygenation index.

CONCLUSION

Fluid overload occurs early after cardiac surgery and is associated with prolonged PICU length of stay and ventilation. Future fluid overload avoidance trials may confirm or refute a true fluid overload-outcome causative association.

Safety and utility of passive peritoneal drainage following Fontan palliation

OBJECTIVE

Placement of peritoneal drainage catheters intra-operatively has been shown to help prevent fluid overload in children recovering from surgery for two-ventricle heart disease. We aimed to determine whether this practice is also helpful in children recovering from Fontan palliation.

MATERIAL AND METHODS

A retrospective review was performed on children with single-ventricle anatomy undergoing Fontan palliation at our institution from 2007 to 2011. Variables in those with peritoneal drainage were compared with those without using t-tests, Mann-Whitney U-tests, chi-square tests, or analysis of variance for repeated measures as appropriate. Data were represented as mean with standard deviation unless otherwise noted.

RESULTS

A total of 43 children were reviewed, 21 (49%) with peritoneal drainage catheters. No complications from catheter placement occurred. The groups did not differ with regard to cardiopulmonary bypass duration, dominant ventricle, pre-operative haemodynamic data, fenestration use, and initial intensive care unit ventilation index. Central venous pressures, vasoactive medication use, and diuretic use during the first 48 hours were also not statistically different. At 48 hours, the median fluid balance was -9 (interquartile range : -50, +20) in those with peritoneal drainage and +77 cc/kg (interquartile range : +22, +96) in those without (p < 0.001), yet median duration of mechanical ventilation was 40 hours (range: 19-326) in those with peritoneal drainage and 23 hours (range: 9-92) in those without, p = 0.01.

CONCLUSION

Patients with peritoneal drainage recovering from Fontan palliation achieved negative fluid balance as compared with those without peritoneal drainage, although this difference was associated with a longer duration of mechanical ventilation.

Haemodialysing babies weighing <8 kg with the Newcastle infant dialysis and ultrafiltration system (Nidus): comparison with peritoneal and conventional haemodialysis

BACKGROUND

To compare the efficacy of the Newcastle infant dialysis and ultrafiltration system (Nidus) with peritoneal dialysis (PD) and conventional haemodialysis (HD) in infants weighing <8 kg.

METHODS

We compared the urea, creatinine and phosphate clearances, the ultrafiltration precision, and the safety of the Nidus machine with PD in 7 piglets weighing 1-8 kg, in a planned randomised cross-over trial in babies, and in babies for whom no other therapy existed, some of whom later graduated to conventional HD.

RESULTS

Two babies entered the randomised trial; 1 recovered rapidly on PD, the other remained on the Nidus as PD failed. Additionally, 9 babies were treated on the Nidus on humanitarian grounds: 3 because of failed PD, and 3 with permanent kidney failure later converted to conventional HD. We haemodialysed 10 babies weighing between 1.8 and 5.9 kg for 2,475 h during 354 Nidus sessions without any clinically important incidents, and without detectable haemolysis. Single-lumen vascular access was used with no blood priming of circuits. The urea, creatinine and phosphate clearances using the Nidus were around 1.5 to 2.0 ml/min in piglets and babies, and were consistently higher than PD clearances, which ranged from about 0.2 to 0.8 ml/min (p ≤ 0.0002 for each chemical). Ultrafiltration was achieved to microlitre precision by the Nidus, but varied widely with PD. Fluid removal using conventional HD was imprecise and resulted in some hypovolaemic episodes requiring correction.

CONCLUSION

The Nidus can provide HD in the Pediatric Intensive Care Unit (PICU) and outpatient intermittent HD without blood priming for babies weighing <8 kg, It generates higher dialysis clearances than PD, and delivers more precise ultrafiltration control than either PD or conventional HD.

[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.

Acute kidney injury according to pediatric RIFLE criteria is associated with negative outcomes after heart surgery in children

BACKGROUND

The aim of this study was to investigate the association between the occurrence of acute kidney injury (AKI) according to pediatric RIFLE (pRIFLE) criteria and adverse outcomes in children after heart surgery.

METHODS

Children undergoing heart surgery in a tertiary hospital in Southern Brazil were followed during their stay in the pediatric intensive care unit (PICU) or until death. The exposure variable was occurrence of AKI according to pRIFLE criteria which place AKI in three categories: R (risk), I (injury), and F (failure). The outcomes studied were death, length of mechanical ventilation (MV), and length of PICU stay.

RESULTS

Eighty-five children were enrolled in the study. Of these, 47 (55.3 %) did not have AKI, while 22 (25.9 %), seven (8.2 %), and nine (10.6 %) were classified into pRIFLE categories R, I, and F, respectively. The incidence of death was 18.4 and 4.2 % in patients with and without AKI, respectively. Compared to children who did not develop AKI, the adjusted odds ratio for death was 1.05 [95 % confidence interval (CI) 0.09-11.11], 8.36 (95 % CI 1.32-52.63), and 7.85 (95 % CI 1.53-40.29) in the R, I, and F groups, respectively (p = 0.022). Duration of MV and of PICU stay were significantly higher in those children with AKI.

CONCLUSIONS

The occurrence of AKI according to pRIFLE criteria is associated to adverse outcomes in children after heart surgery.

Acute kidney injury based on corrected serum creatinine is associated with increased morbidity in children following the arterial switch operation

BACKGROUND AND OBJECTIVES

Evaluate risk factors for and impact of acute kidney injury on children following the arterial switch operation.

DESIGN

Single-center retrospective chart review.

SETTING

A tertiary children's hospital.

PATIENTS

A total of 92 patients receiving the arterial switch operation from 1997 to 2008 at severe acute kidney injury was defined as a 100% serum creatinine rise over baseline.

RESULTS

Of 92 patients, 18 (20%) developed severe acute kidney injury. Neither patient age or weight nor cardiopulmonary bypass time correlated with the development of acute kidney injury. Acute kidney injury was associated with the following: higher postoperative day 1 (POD1) fluid balance, higher inotrope scores (POD1 and POD2), and longer: postoperative ICU length of stay (p = 0.005), overall ICU length of stay (p = 0.05), and postoperative hospital length of stay (p = 0.006). The time to peak creatinine for acute kidney injury patients was between POD1 and POD2. Correction of serum creatinine for fluid balance increased the population defined as severe acute kidney injury and strengthened the association of acute kidney injury with postoperative morbidity.

CONCLUSIONS

Acute kidney injury following the arterial switch operation is associated with increased morbidity. In this single center, single population, and homogenous cohort of patients, the development of acute kidney injury was not correlated with age, size, or cardiopulmonary bypass time, but was still associated with prolonged duration of ventilation and hospitalization. Notably, the failure to correct serum creatinine for fluid balance underestimates the prevalence and impact of acute kidney injury.

Factors associated with survival in patients who undergo peritoneal dialysis catheter placement following cardiac surgery

PURPOSE

Pediatric post-cardiac surgery patients are at risk for acute kidney injury and intraabdominal hypertension. The present study assesses indications and outcomes of postoperative peritoneal dialysis catheter (PDC) placement in this population.

METHODS

We retrospectively reviewed single-institution patients who underwent PDC placement post-cardiac surgery between 1999 and 2011 (n=55). Baseline, clinical course, and outcome data were recorded pre- and post-PDC. We used multivariable logistic and Cox analyses to assess factors associated with mortality.

RESULTS

In-hospital mortality of the study cohort was 67.3% (n=37). Peritoneal dialysis was performed in 21 patients (38.2%). Five patients (9.1%) experienced adverse events related to PDC placement. Greater post-PDC decreases in abdominal girth (adjusted odds ratio [OR]=2.43; P=0.02) and BUN (OR=1.06; P=0.04) were associated with survival. Additionally, preoperative ventilator independence (hazard ratio [HR]=1.18; P<0.01) and lower creatinine (HR=8.32; P<0.01), as well as greater post-PDC decrease in inotrope score (HR=1.33; P<0.02) were associated with survival.

CONCLUSIONS

In-hospital mortality of the study cohort was 67%. Less severe pre-PDC renal impairment, increased pre-PDC abdominal girth, and greater post-PDC improvement of abdominal girth, renal function, and inotrope requirements were associated with survival. Prospective trials are needed to assess appropriate indications and timing of PDC placement, with consideration of more aggressive treatment for intraabdominal hypertension.

Fluid overload in infants following congenital heart surgery

OBJECTIVE

To describe postoperative fluid overload patterns and correlate degree of fluid overload with intensive care morbidity and mortality in infants undergoing congenital heart surgery.

DESIGN

Prospective, observational study. Fluid overload (%) was calculated by two methods: 1) (Total fluid in - Total fluid out)/(Preoperative weight) × 100; and 2) (Current weight - Preoperative weight)/(Preoperative weight) × 100. Composite poor outcome included: need for renal replacement therapy, upper quartile time to extubation or intensive care length of stay (> 6.5 and 9.9 days, respectively), or death ≤ 30 days after surgery.

SETTING

University hospital pediatric cardiac ICU.

PATIENTS

Forty-nine infants < 6 months of age undergoing congenital heart surgery with cardiopulmonary bypass during the period of July 2009 to July 2010.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Patients had a median age of 53 days (21 neonates) and mean weight of 4.5 ± 1.3 kg. Forty-two patients (86%) developed acute kidney injury by meeting at least Acute Kidney Injury Network and Kidney Disease Improving Global Outcomes stage 1 criteria (serum creatinine rise of 50% or ≥ 0.3mg/dL). The patients with adverse outcomes (n = 17, 35%) were younger (7 [5 - 10] vs. 98 [33 - 150] days, p = 0.001), had lower preoperative weight (3.7 ± 0.7 vs. 4.9 ± 1.4 kg, p = 0.0002), higher postoperative mean peak serum creatinine (SCr) (0.9 ± 0.3 vs. 0.6 ± 0.3mg/dL, p = 0.005), and higher mean maximum fluid overload by both method 1 (12% ± 10% vs. 6% ± 4%, p = 0.03) and method 2 (24% ± 15% vs. 14% ± 8%, p = 0.02). Predictors of a poor outcome from multivariate analyses were cardiopulmonary bypass time, use of circulatory arrest, and increased vasoactive medication requirements postoperatively.

CONCLUSIONS

Early postoperative fluid overload is associated with suboptimal outcomes in infants following cardiac surgery. Because the majority of patients developed kidney injury without needing renal replacement therapy, fluid overload may be an important risk factor for adverse outcomes with all degrees of acute kidney injury.

Characterizing peritoneal dialysis catheter use in pediatric patients after cardiac surgery

OBJECTIVE

Children who undergo cardiac surgery are at high risk for renal insufficiency and abdominal compartment syndrome. Peritoneal dialysis catheter (PDC) implantation is used in this population for abdominal decompression and access for dialysis. However, there is no consensus regarding PDC use, and the practice varies widely. This study was undertaken to assess associated factors, outcomes, and variability in the use of PDC in patients who have undergone cardiac surgery.

METHODS

The cohort was obtained from the Kids' Inpatient Database, years 2006 and 2009. Patients who underwent cardiac surgery were included and the subset that underwent PDC implantation during the same hospitalization was identified. Univariable and multivariable analyses assessed factors associated with PDC and survival.

RESULTS

A cohort of 28,259 patients underwent cardiac surgery, of whom 558 (2%) had PDCs placed. In the PDC group, 39.1% (n = 218) had acute renal failure whereas 3.5% or patients (n = 974) in the non-PDC group had acute renal failure. Among patients receiving PDC, mortality was 20.3% (n = 113; vs 3.4% overall mortality, n = 955). Excluding patients with acute renal failure, mortality remained 12% (n = 41) for the PDC group. Factors associated significantly with PDC placement in the overall cohort were younger age, greater surgical complexity, nonelective admission, hospital region, use of cardiopulmonary bypass, and acute renal failure.

CONCLUSIONS

Patients receiving PDC after cardiac surgery had 20% mortality, which remained 12% after excluding patients with acute renal failure. Given the variability in PDC use and poor outcomes, further research is needed to assess the possible benefit of earlier intervention for peritoneal access in this high-risk cohort.

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 implementation of neonatal peritoneal dialysis in a clinical setting

OBJECTIVE

To investigate etiology, outcome and complications related to neonatal peritoneal dialysis (PD).

METHODS

Neonates treated with PD in our neonatal intensive care unit during 2007-2010 were analyzed retrospectively.

RESULTS

Among 4036 hospitalized neonates; 20 neonates (0.5%) who underwent 21 cycles of PD [7 preterm, 13 term; 13 female, 7 male] were included. The mean birth weight was 2930.2 ± 720.6 g (1120-4570), mean gestational age was 37.5 ± 3.5 weeks (27-41). The etiologic disorders included inborn errors of metabolism (propionic acidemia, methylmalonic acidemia, citrullinemia, glutaric aciduria type 2, maple syrup urine disease, 10), or acute renal failure secondary to perinatal asphyxia (4), sepsis (2), prematurity (2), hypoplastic left heart syndrome (1), kernicterus (1). The complications included peritonitis (2), early leakage (4), hemorrhage (1), catheter removal (3) and occlusion (2). The mortality rate was 50%. The gestational ages and birth weights of surviving neonates were higher (p < 0.05). Among surviving neonates, chronic renal failure (1), severe (4) and moderate neuromotor impairment (2) developed within 4-43 months.

CONCLUSION

PD, although invasive, is an effective therapy in neonates. The complexity and invasiveness of the procedure is probably responsible for high rate of complications and mortality. If appropriate catheter selection and technique in the placement should be done, PD might improve outcome.

Passive peritoneal drainage improves fluid balance after surgery for congenital heart disease

OBJECTIVE

In some centers, passive peritoneal drainage (PD) is implemented following surgery for congenital heart disease. The utility of this practice has yet to be studied. We hypothesized that passive PD can promote negative fluid balance without compromising intravascular volume.

METHODS

A retrospective review of infants who underwent repair of complete atrioventricular septal defect (AVSD) between 6/2006 and 8/2010 was completed. Data are represented as mean ± standard deviation.

RESULTS

Thirty-six infants underwent AVSD repair, 18 of whom had PD catheters placed without complication. Infants with passive PD had longer duration of cardiopulmonary bypass (211 ± 59 vs 137 ± 41 min, P < 0.001) and aortic cross-clamp (148 ± 29 vs 102 ± 21 min, P < 0.001); had higher Aristotle complexity score (12.6 ± 3 vs 10.7 ± 2, P = 0.03) and ventilatory support immediately after surgery (ventilation index score 19.5 ± 6.5 vs 14.3 ± 2.5, P = 0.004); and received greater fluid administration (225 ± 6 3 vs 168 ± 45 ml kg(-1), P = 0.002) in the first 48 postoperative hours. Despite these differences, infants with passive PD achieved negative fluid balance more rapidly (12 ± 10 vs 27.3 ± 13 h, P < 0.0001) and to a greater extent (-73 + 55 vs +2.6 + 39 mL kg(-1) at 48 h, P = 0.002). Moreover, postoperative hemodynamics, urine output, creatinine clearance, blood urea nitrogen, peak lactate, and duration of mechanical ventilation were similar between groups.

CONCLUSIONS

Passive PD is safe and promotes negative fluid balance after repair of complete AVSD without adversely affecting intravascular volume.

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.