Continuous flow peritoneal dialysis (CFPD) improves ultrafiltration in children with acute kidney injury on conventional PD using a 4.25 % dextrose solution

Gravity-assisted continuous flow peritoneal dialysis technique use in acute kidney injury in children: a randomized, crossover clinical trial

BACKGROUND

Our previously demonstrated continuous flow peritoneal dialysis (CFPD) technique in children with acute kidney injury (AKI), although effective, was manpower heavy and expensive due to the high-volume pumps required. The aim of this study was to develop and test a novel gravity-driven CFPD technique in children using readily available, inexpensive equipment and to compare this technique to conventional PD.

METHODS

After development and initial in vitro testing, a randomised crossover clinical trial was conducted in 15 children with AKI requiring dialysis. Patients received both conventional PD and CFPD sequentially, in random order. Primary outcomes were measures of feasibility, clearance and ultrafiltration (UF). Secondary outcomes were complications and mass transfer coefficients (MTC). Paired t-tests were used to compare PD and CFPD outcomes.

RESULTS

Median (range) age and weight of participants were 6.0 (0.2-14) months and 5.8 (2.3-14.0) kg, respectively. The CFPD system was easily and rapidly assembled. There were no serious adverse events attributed to CFPD. Mean ± SD UF was significantly higher on CFPD compared to conventional PD (4.3 ± 3.15 ml/kg/h vs. 1.04 ± 1.72 ml/kg/h; p < 0.001). Clearances for urea, creatinine and phosphate for children on CFPD were 9.9 ± 3.10 ml/min/1.73 m², 7.9 ± 3.3 ml/min/1.73 m² and 5.5 ± 1.5 ml/min/1.73 m² compared to conventional PD with values of 4.3 ± 1.68 ml/min/1.73 m², 3.57 ± 1.3 ml/min/1.73 m² and 2.53 ± 0.85 ml/min/1.73 m², respectively (all p < 0.001).

CONCLUSION

Gravity-assisted CFPD appears to be a feasible and effective way to augment ultrafiltration and clearances in children with AKI. It can be assembled from readily available non-expensive equipment. A higher resolution version of the Graphical abstract is available as Supplementary information.

Perspectives: Neonatal acute kidney injury (AKI) in low and middle income countries (LMIC)

Neonatal AKI (NAKI) remains a challenge in low- and middle-income countries (LMICs). In this perspective, we address issues of diagnosis and risk factors particular to less well-resourced regions. The conservative management pre-kidney replacement therapy (pre-KRT) is prioritized and challenges of KRT are described with improvised dialysis techniques also included. Special emphasis is placed on ethical and palliation principles.

Peritoneal dialysis for term neonates in a neonatal intensive care unit

BACKGROUND

This study aimed to evaluate the indications, complications, and outcomes of peritoneal dialysis (PD) in term neonates from a state hospital.

METHODS

The demographic, clinical, and laboratory data of 67 newborn term infants who underwent PD within the first 4 weeks of life between June 2014 and June 2019 were retrospectively analyzed.

RESULTS

Twenty-five patients (37.3%) were male, 42 (63.7%) were female. The mean gestational age was 38.3 ± 0.8 (range: 37-40) weeks and mean birthweight 3,100 ± 504.9 g (range: 1,800-5,000 g). The mean age of patients at the start of dialysis was 7.97 ± 8.34 days (range:1-44 days) and the mean duration for dialysis was 3 ± 5.42 days (range 1-40 days). The majority of patients who underwent PD had inborn error of metabolism (59.7%). The most common complication was dialysate leakage. Thirty-three neonates (49.2%) died during PD process because of underlying disease, 17 patients (25.4%) were referred to other centers, and 17 patients (25.4%) were discharged. There were seven acute kidney injury patients associated with hypernatremic dehydration. There were statistically significant differences between non-survivors and survivors in terms of dialysis duration, birthweight, weight at admission, requirements for mechanical ventilation, and inotrop agent, and also the renal angina index.

CONCLUSIONS

In our region, hypernatremic dehydration is still a one of the major cause for acute kidney injury (AKI) in newborns. In state hospitals, pediatric specialists must be present in neonatal intensive care units in order not to refer unstable patients to other centers and to provide high-quality patient care.

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.

Computer Simulations of Continuous Flow Peritoneal Dialysis Using the 3-Pore Model-A First Experience

Background:Continuous flow peritoneal dialysis (CFPD) is performed using a continuous flux of dialysis fluid via double or dual-lumen PD catheters, allowing a higher dialysate flow rate (DFR) than conventional treatments. While small clinical studies have revealed greatly improved clearances using CFPD, the inability to predict ultrafiltration (UF) may confer a risk of potentially harmful overfill. Here we performed physiological studies of CFPD in silico using the extended 3-pore model.Method:A 9-h CFPD session was simulated for: slow (dialysate to plasma creatinine [D/P crea] < 0.6), fast (D/P crea > 0.8) and average (0.6 ≤ D/P crea ≤ 0.8) transporters using 1.36%, 2.27%, or 3.86% glucose solutions. To avoid overfill, we applied a practical equation, based on the principle of mass-balance, to predict the UF rate during CFPD treatment.Results:Increasing DFR > 100 mL/min evoked substantial increments in small- and middle-molecule clearances, being 2 - 5 times higher compared with a 4-h continuous ambulatory PD (CAPD) exchange, with improvements typically being smaller for average and slow transporters. Improved UF rates, exceeding 10 mL/min, were achieved for all transport types. The β₂-microglobulin clearance was strongly dependent on the UF rate and increased between 60% and 130% as a function of DFR. Lastly, we tested novel intermittent-continuous regimes as an alternative strategy to prevent overfill, being effective for 1.36% and 2.27%, but not for 3.86% glucose.Conclusion:While we find substantial increments in solute and water clearance with CFPD, previous studies have shown similar improvements using high-volume tidal automated PD (APD). Lastly, the current in silico results need confirmation by studies in vivo.