Fluid Management With Peritoneal Dialysis After Pediatric Cardiac Surgery

Recent Advances in Kidney Replacement Therapy in Infants: A Review

Kidney replacement therapy (KRT) is used to treat children and adults with acute kidney injury (AKI), fluid overload, kidney failure, inborn errors of metabolism, and severe electrolyte abnormalities. Peritoneal dialysis and extracorporeal hemodialysis/filtration can be performed for different durations (intermittent, prolonged intermittent, and continuous) through either adaptation of adult devices or use of infant-specific devices. Each of these modalities have advantages and disadvantages, and often multiple modalities are used depending on the scenario and patient-specific needs. Traditionally, these therapies have been challenging to deliver in infants due the lack of infant-specific devices, small patient size, required extracorporeal volumes, and the risk of hemodynamic stability during the initiation of KRT. In this review, we discuss challenges, recent advancements, and optimal approaches to provide KRT in hospitalized infants, including a discussion of peritoneal dialysis and extracorporeal therapies. We discuss each specific KRT modality, review newer infant-specific devices, and highlight the benefits and limitations of each modality. We also discuss the ethical implications for the care of infants who need KRT and areas for future research.

Cardiac Surgery Outcomes in Patients Receiving Hemodialysis Versus Peritoneal Dialysis

Rationale & Objective

We sought to compare outcomes of patients receiving dialysis after cardiothoracic surgery on the basis of dialysis modality (intermittent hemodialysis [HD] vs peritoneal dialysis [PD]).

Study Design

This was a retrospective analysis.

Setting & Participants

In total, 590 patients with kidney failure receiving intermittent HD or PD undergoing coronary artery bypass graft and/or valvular cardiac surgery at Cleveland Clinic were included.

Exposure

The patients received PD versus HD (intermittent or continuous).

Outcomes

Our primary outcomes were in-hospital and 30-day mortality. Secondary outcomes were length of stay, days in the intensive care unit, the number of intraoperative blood transfusions, postsurgical pericardial effusion, and sternal wound infection, and a composite of the following 4 in-hospital events: death, cardiac arrest, effusion, and sternal wound infection.

Analytical Approach

We used χ2, Fisher exact, Wilcoxon rank sum, and t tests, Kaplan-Meier survival, and plots for analysis.

Results

Among the 590 patients undergoing cardiac surgery, 62 (11%) were receiving PD, and 528 (89%) were receiving intermittent HD. Notably, 30-day Kaplan-Meier survival was 95.7% (95% CI: 93.9-97.5) for HD and 98.2% (95% CI: 94.7-100) for PD (P = 0.30). In total, 75 patients receiving HD (14.2%) and 1 patient receiving PD (1.6%) had a composite of 4 in-hospital events (death, cardiac arrest, effusion, and sternal wound infection) (P = 0.005). Out of 62 patients receiving PD, 16 (26%) were converted to HD.

Limitations

Retrospective analyses are prone to residual confounding. We lacked details about nutritional data. Intensive care unit length of stay was used as a surrogate for volume status control. Patients have been followed in a single health care system. The HD cohort outnumbered the PD cohort significantly.

Conclusions

When compared with PD, HD does not appear to improve outcomes of patients with kidney failure undergoing cardiothoracic surgery. Patients receiving PD had a lower incidence of a composite outcome of 4 in-hospital events (death, cardiac arrest, pericardial effusion, and sternal wound infections).

Programs and processes for advancing pediatric acute kidney support therapy in hospitalized and critically ill children: a report from the 26th Acute Disease Quality Initiative (ADQI) consensus conference

Pediatric acute kidney support therapy (paKST) programs aim to reliably provide safe, effective, and timely extracorporeal supportive care for acutely and critically ill pediatric patients with acute kidney injury (AKI), fluid and electrolyte derangements, and/or toxin accumulation with a goal of improving both hospital-based and lifelong outcomes. Little is known about optimal ways to configure paKST teams and programs, pediatric-specific aspects of delivering high-quality paKST, strategies for transitioning from acute continuous modes of paKST to facilitate rehabilitation, or providing effective short- and long-term follow-up. As part of the 26th Acute Disease Quality Initiative Conference, the first to focus on a pediatric population, we summarize here the current state of knowledge in paKST programs and technology, identify key knowledge gaps in the field, and propose a framework for current best practices and future research in paKST.

Early postoperative weight-based fluid overload is associated with worse outcomes after neonatal cardiac surgery

OBJECTIVES

Evaluate the association of postoperative day (POD) 2 weight-based fluid balance (FB-W) > 10% with outcomes after neonatal cardiac surgery.

METHODS

Retrospective cohort study of 22 hospitals in the NEonatal and Pediatric Heart and Renal Outcomes Network (NEPHRON) registry from September 2015 to January 2018. Of 2240 eligible patients, 997 neonates (cardiopulmonary bypass (CPB) n = 658, non-CPB n = 339) were weighed on POD2 and included.

RESULTS

Forty-five percent (n = 444) of patients had FB-W > 10%. Patients with POD2 FB-W > 10% had higher acuity of illness and worse outcomes. Hospital mortality was 2.8% (n = 28) and not independently associated with POD2 FB-W > 10% (OR 1.04; 95% CI 0.29-3.68). POD2 FB-W > 10% was associated with all utilization outcomes, including duration of mechanical ventilation (multiplicative rate of 1.19; 95% CI 1.04-1.36), respiratory support (1.28; 95% CI 1.07-1.54), inotropic support (1.38; 95% CI 1.10-1.73), and postoperative hospital length of stay (LOS 1.15; 95% CI 1.03-1.27). In secondary analyses, POD2 FB-W as a continuous variable demonstrated association with prolonged durations of mechanical ventilation (OR 1.04; 95% CI 1.02-1.06], respiratory support (1.03; 95% CI 1.01-1.05), inotropic support (1.03; 95% CI 1.00-1.05), and postoperative hospital LOS (1.02; 95% CI 1.00-1.04). POD2 intake-output based fluid balance (FB-IO) was not associated with any outcome.

CONCLUSIONS

POD2 weight-based fluid balance > 10% occurs frequently after neonatal cardiac surgery and is associated with longer cardiorespiratory support and postoperative hospital LOS. However, POD2 FB-IO was not associated with clinical outcomes. Mitigating early postoperative fluid accumulation may improve outcomes but requires safely weighing neonates in the early postoperative period. A higher resolution version of the Graphical abstract is available as Supplementary information.

Delivering optimal renal replacement therapy to critically ill patients with acute kidney injury

Critical illness is often complicated by acute kidney injury (AKI). In patients with severe AKI, renal replacement therapy (RRT) is deployed to address metabolic dysfunction and volume excess until kidney function recovers. This review is intended to provide a comprehensive update on key aspects of RRT prescription and delivery to critically ill patients. Recently completed trials have enhanced the evidence base regarding several RRT practices, most notably the timing of RRT initiation and anticoagulation for continuous therapies. Better evidence is still needed to clarify several aspects of care including optimal targets for ultrafiltration and effective strategies for RRT weaning and discontinuation.

Early Peritoneal Dialysis and Postoperative Outcomes in Infants After Pediatric Cardiac Surgery: A Systematic Review and Meta-Analysis

OBJECTIVE

Peritoneal dialysis (PD) is used in several cardiac surgical units after cardiac surgery, and early initiation of PD after surgery may have the potential to influence postoperative outcomes. This systematic review and meta-analysis aims to summarize the evidence for the association between early PD after cardiac surgery and postoperative outcomes.

DATA SOURCES

MEDLINE, Embase, and PubMed from 1981 to November 1, 2021.

STUDY SELECTION

Observational studies and randomized trials reporting on early PD after pediatric cardiac surgery.

DATA EXTRACTION

Random-effects meta-analysis was used to estimate the pooled odds ratios (ORs) and their 95% CIs for postoperative mortality and pooled mean difference (MD) (95% CI) for duration of mechanical ventilation and ICU length of stay.

DATA SYNTHESIS

We identified nine studies from the systematic review, and five were considered suitable for meta-analysis. Early initiation of PD after cardiac surgery was associated with a reduction in postoperative mortality (OR, 0.43 (95% CI, 0.23-0.80); number of estimates = 4). Early commencement of PD shortened duration of mechanical ventilation (MD [95% CI], -1.09 d [-1.86 to -0.33 d]; I2 = 56.1%; p = 0.06) and intensive care length of stay (MD [95% CI], -2.46 d [-3.57 to -1.35 d]; I2 = 18.7%; p = 0.30], respectively. All three estimates had broad 95% prediction intervals (crossing null) denoting major heterogeneity between studies and wide range of possible study estimates in similar future studies. Overall, studies reporting on the effects of early PD included only a subset of infants undergoing cardiac surgery (typically high-risk infants), so selection bias may be a major issue in published studies.

CONCLUSIONS

This review suggests that early initiation of PD may be associated with beneficial postoperative outcomes in infants after cardiac surgery. However, these results were based on studies of varying qualities and risk of bias. Early identification of high-risk infants after cardiac surgery is important so that prevention or early mitigation strategies can be applied to this cohort. Future prospective studies in high-risk populations are needed to study the role of early PD in influencing postoperative outcomes.

Factors affecting the clinical outcomes in pediatric post-cardiotomy patients requiring perioperative peritoneal dialysis

OBJECTIVE

Fluid overload is associated with increased mortality and morbidity in pediatric cardiac surgery. In the pediatric age group, peritoneal dialysis might improve postoperative outcome with avoiding fluid overload and electrolyte imbalance. It preserves hemodynamic status with the advantage of passive drainage. In this study, we are reporting our results of peritoneal dialysis after cardiac surgery.

METHODS

In this retrospective study, we evaluated the patients who underwent pediatric cardiac surgery in our hospital between December 2010 and January 2020. Patients who required peritoneal dialysis during hospitalization period were included in the study. Patients' clinical status and outcomes were evaluated.

RESULTS

Peritoneal dialysis was performed to 89 patients during the study period. The age varies from the newborn to 4 years old. The indication of peritoneal dialysis was prophylactic in 68.5% (n=61) and for the treatment in 31.5% (n=28). There were 31 mortalities. The risk factors for the mortality were preoperative lower age, longer cardiopulmonary bypass time, lengthened intubation, lengthened inotropic support, and requirement of extracorporeal membrane oxygenation (p<0.0001).

CONCLUSION

Earlier initiation of peritoneal dialysis in pediatric cardiac surgery helps maintain hemodynamic instability by avoiding fluid overload, considering the difficulty in the treatment of electrolyte imbalance and diuresis.

Prophylactic Peritoneal Catheter Placement in Congenital Cardiac Surgery

The use of a peritoneal catheter in selected patients, in relation to the congenital heart defect and surgical procedure, may improve postoperative fluid balance and recovery. The peritoneal catheter allows to either drain ascites passively out of the peritoneal cavity or utilize cycles of peritoneal dialysis. However, potential benefits contrast with risk. This article provides a step-by-step guide on how to implant a peritoneal catheter in the operating room after cardiac surgery, or insert it at the bedside in the ICU, to minimize the risk of complications such as bowel perforation, herniation or omental adhesions.

Case report and review of the literature: Successful transition from acute continuous veno-venous hemodiafiltration therapy to chronic peritoneal dialysis in a chronically ventilated child with hypoplastic left heart syndrome following fontan

Fontan palliation depends on low pulmonary vascular resistance in order to maintain pulmonary blood flow and adequate oxygenation. This physiology results in higher central venous pressures with limited renal perfusion pressure and cardiac output. Positive pressure ventilation with mechanical ventilation increases intrathoracic pressure and raises central venous pressure and can further limit pulmonary and renal perfusion. Fluid removal with intermittent hemodialysis can be challenging in Fontan patients and can cause intolerable hypotension, however the increased abdominal filling pressures during peritoneal dialysis dwells can exacerbate systemic venous hypertension seen in Fontan patients and threaten adequate pulmonary blood flow and cardiac output. Successful transition to peritoneal dialysis in a chronically ventilated patient with hypoplastic left heart syndrome, end-stage renal disease and Fontan physiology has not been described. We present details outlining the successful transition across multiple modalities of renal replacement therapy to assist other teams faced with similar challenges in chronically ventilated Fontan patients with end-stage renal disease.

ISPD guidelines for peritoneal dialysis in acute kidney injury: 2020 Update (paediatrics)

SUMMARY OF RECOMMENDATIONS

1.1 Peritoneal dialysis is a suitable renal replacement therapy modality for treatment of acute kidney injury in children. (1C)2. Access and fluid delivery for acute PD in children.2.1 We recommend a Tenckhoff catheter inserted by a surgeon in the operating theatre as the optimal choice for PD access. (1B) (optimal)2.2 Insertion of a PD catheter with an insertion kit and using Seldinger technique is an acceptable alternative. (1C) (optimal)2.3 Interventional radiological placement of PD catheters combining ultrasound and fluoroscopy is an acceptable alternative. (1D) (optimal)2.4 Rigid catheters placed using a stylet should only be used when soft Seldinger catheters are not available, with the duration of use limited to <3 days to minimize the risk of complications. (1C) (minimum standard)2.5 Improvised PD catheters should only be used when no standard PD access is available. (practice point) (minimum standard)2.6 We recommend the use of prophylactic antibiotics prior to PD catheter insertion. (1B) (optimal)2.7 A closed delivery system with a Y connection should be used. (1A) (optimal) A system utilizing buretrols to measure fill and drainage volumes should be used when performing manual PD in small children. (practice point) (optimal)2.8 In resource limited settings, an open system with spiking of bags may be used; however, this should be designed to limit the number of potential sites for contamination and ensure precise measurement of fill and drainage volumes. (practice point) (minimum standard)2.9 Automated peritoneal dialysis is suitable for the management of paediatric AKI, except in neonates for whom fill volumes are too small for currently available machines. (1D)3. Peritoneal dialysis solutions for acute PD in children3.1 The composition of the acute peritoneal dialysis solution should include dextrose in a concentration designed to achieve the target ultrafiltration. (practice point)3.2  Once potassium levels in the serum fall below 4 mmol/l, potassium should be added to dialysate using sterile technique. (practice point) (optimal) If no facilities exist to measure the serum potassium, consideration should be given for the empiric addition of potassium to the dialysis solution after 12 h of continuous PD to achieve a dialysate concentration of 3-4 mmol/l. (practice point) (minimum standard)3.3  Serum concentrations of electrolytes should be measured 12 hourly for the first 24 h and daily once stable. (practice point) (optimal) In resource poor settings, sodium and potassium should be measured daily, if practical. (practice point) (minimum standard)3.4  In the setting of hepatic dysfunction, hemodynamic instability and persistent/worsening metabolic acidosis, it is preferable to use bicarbonate containing solutions. (1D) (optimal) Where these solutions are not available, the use of lactate containing solutions is an alternative. (2D) (minimum standard)3.5  Commercially prepared dialysis solutions should be used. (1C) (optimal) However, where resources do not permit this, locally prepared fluids may be used with careful observation of sterile preparation procedures and patient outcomes (e.g. rate of peritonitis). (1C) (minimum standard)4. Prescription of acute PD in paediatric patients4.1 The initial fill volume should be limited to 10-20 ml/kg to minimize the risk of dialysate leakage; a gradual increase in the volume to approximately 30-40 ml/kg (800-1100 ml/m²) may occur as tolerated by the patient. (practice point)4.2 The initial exchange duration, including inflow, dwell and drain times, should generally be every 60-90 min; gradual prolongation of the dwell time can occur as fluid and solute removal targets are achieved. In neonates and small infants, the cycle duration may need to be reduced to achieve adequate ultrafiltration. (practice point)4.3 Close monitoring of total fluid intake and output is mandatory with a goal to achieve and maintain normotension and euvolemia. (1B)4.4 Acute PD should be continuous throughout the full 24-h period for the initial 1-3 days of therapy. (1C)4.5  Close monitoring of drug dosages and levels, where available, should be conducted when providing acute PD. (practice point)5. Continuous flow peritoneal dialysis (CFPD)5.1   Continuous flow peritoneal dialysis can be considered as a PD treatment option when an increase in solute clearance and ultrafiltration is desired but cannot be achieved with standard acute PD. Therapy with this technique should be considered experimental since experience with the therapy is limited. (practice point) 5.2  Continuous flow peritoneal dialysis can be considered for dialysis therapy in children with AKI when the use of only very small fill volumes is preferred (e.g. children with high ventilator pressures). (practice point).

Advances in Kidney Replacement Therapy in Infants

Acute kidney injury continues to be a highly occurring disease in the intensive care unit, specifically affecting up to a third of critically ill neonates as per various studies. Although first-line treatments of acute kidney injury are noninvasive, kidney replacement therapy (KRT) is indicated when conservative management modes fail. There are various modalities of KRT which can be used for neonatal populations, including peritoneal dialysis, hemodialysis, and continuous KRT. However, these KRT modalities present their own challenges in this specific patient population Thus, it is the aim of this review to introduce each of these KRT modalities in terms of their challenges, advances, and future directions, with specific emphasis on new technology including the Cardio-Renal Pediatric Emergency Dialysis Machine, Newcastle infant dialysis and ultrafiltration system, and the Aquadex system for ultrafiltration.

Dialysis modalities for the management of pediatric acute kidney injury

Acute kidney injury (AKI) is an increasingly frequent complication among hospitalized children. It is associated with high morbidity and mortality, especially in neonates and children requiring dialysis. The different renal replacement therapy (RRT) options for AKI have expanded from peritoneal dialysis (PD) and intermittent hemodialysis (HD) to continuous RRT (CRRT) and hybrid modalities. Recent advances in the provision of RRT in children allow a higher standard of care for increasingly ill and young patients. In the absence of evidence indicating better survival with any dialysis method, the most appropriate dialysis choice for children with AKI is based on the patient's characteristics, on dialytic modality performance, and on the institutional resources and local practice. In this review, the available dialysis modalities for pediatric AKI will be discussed, focusing on indications, advantages, and limitations of each of them.

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.

Prophylactic Peritoneal Drainage is Associated with Improved Fluid Output after Congenital Heart Surgery

Infants undergoing congenital heart surgery (CHS) with cardiopulmonary bypass (CPB) are at risk of acute kidney injury (AKI) and fluid overload. We hypothesized that placement of a passive peritoneal drain (PPD) can improve postoperative fluid output in such infants. We analyzed 115 consecutive patients, age birth to 60 days, admitted to the PICU after CHS with CPB between 2012 and 2018. Patients who needed postoperative ECMO were excluded. Linear and logistic regression models compared postoperative fluid balances, diuretics administration, AKI, vasoactive-inotropic scores (VIS), time intubated, and length of stay after adjusting for pre/operative predictors including STAT category, bypass time, age, weight, and open chest status. PPD patients had higher STAT category (p = 0.001), longer CPB times (p = 0.001), and higher VIS on POD 1-3 (p ≤ 0.005 daily). PPD patients also had higher AKI rates (p = 0.01) that did not reach significance in multivariable modeling. There were no postoperative deaths. Postoperative hours of intubation, hospital length of stay, and POD 1-5 fluid intake did not differ between groups. Over POD 1-5, PPD use accounted for 48.8 mL/kg increased fluid output (95% CI [2.2, 95.4], p = 0.043) and 3.41 mg/kg less furosemide administered (95% CI [1.69, 5.14], p < 0.001). No PPD complications were observed. Although PPD placement did not affect end-outcomes, it was used in higher acuity patients. PPD placement is associated with improved fluid output despite lower diuretic administration and may be a useful postoperative fluid management adjunct in some complex CHS patients.