The Infant KIdney Dialysis and Utrafiltration (I-KID) Study: A Stepped-Wedge Cluster-Randomized Study in Infants, Comparing Peritoneal Dialysis, Continuous Venovenous Hemofiltration, and Newcastle Infant Dialysis Ultrafiltration System, a Novel Infant Hemodialysis Device.

OBJECTIVES: Renal replacement therapy (RRT) options are limited for small babies because of lack of available technology. We investigated the precision of ultrafiltration, biochemical clearances, clinical efficacy, outcomes, and safety profile for a novel non-Conformité Européenne-marked hemodialysis device for babies under 8 kg, the Newcastle Infant Dialysis Ultrafiltration System (NIDUS), compared with the current options of peritoneal dialysis (PD) or continuous venovenous hemofiltration (CVVH). DESIGN: Nonblinded cluster-randomized cross-sectional stepped-wedge design with four periods, three sequences, and two clusters per sequence. SETTING: Clusters were six U.K. PICUs. PATIENTS: Babies less than 8 kg requiring RRT for fluid overload or biochemical disturbance. INTERVENTIONS: In controls, RRT was delivered by PD or CVVH, and in interventions, NIDUS was used. The primary outcome was precision of ultrafiltration compared with prescription; secondary outcomes included biochemical clearances. MEASUREMENTS AND MAIN RESULTS: At closure, 97 participants were recruited from the six PICUs (62 control and 35 intervention). The primary outcome, obtained from 62 control and 21 intervention patients, showed that ultrafiltration with NIDUS was closer to that prescribed than with control: sd controls, 18.75, intervention, 2.95 (mL/hr); adjusted ratio, 0.13; 95% CI, 0.03-0.71; p = 0.018. Creatinine clearance was smallest and least variable for PD (mean, sd ) = (0.08, 0.03) mL/min/kg, larger for NIDUS (0.46, 0.30), and largest for CVVH (1.20, 0.72). Adverse events were reported in all groups. In this critically ill population with multiple organ failure, mortality was lowest for PD and highest for CVVH, with NIDUS in between. CONCLUSIONS: NIDUS delivers accurate, controllable fluid removal and adequate clearances, indicating that it has important potential alongside other modalities for infant RRT.

In vitro measurements of ultrafiltration precision in hemofiltration and hemodialysis devices used in infants.

BACKGROUND: To determine in vitro whether infant hemofiltration and hemodialysis devices can reliably deliver precise ultrafiltration (UF) control. METHODS: We tested the Prismaflex, Aquarius and NIDUS devices which have different circuit types, by in vitro testing with a bag of saline set up as a dummy patient, and monitoring fluid shifts by precise weighing. We looked for differences between the UF rates set and achieved and between the UF result the device displays to the clinician and the true volumes removed, which may lead to clinical errors. We performed short studies at UF settings of zero and 40 ml/h, and with and without simulating poor withdrawal and return lines, and simulated a 4-h treatment session. RESULTS: The Prismaflex setting vs actual errors and display vs actual errors had wide variances, with SDs of 4.1 and 14.0 ml by 15 min, respectively, at both zero and 40 ml/h UF settings. The Aquarius values were wider at 17.3 and 30.3 ml, respectively. For the NIDUS, the mean UF errors were close to zero, and the variances were 0.17 ml. Stop-alarms induced by an obstructed line produced extra UF errors of up to 0.2 ml. A limitation was that we used crystalloid and not colloid for these tests. CONCLUSIONS: Hemotherapy devices with conventional circuits available in the UK do not regulate UF control sufficiently well to recommend for use in small infants, but the NIDUS volumetrically controlled circuit does. All hemotherapy devices intended for small infants should be tested for UF precision. We were unable to test the CARPEDIEM or Aquadex devices. A higher resolution version of the Graphical abstract is available as Supplementary information.

Domiciliary administration of intravenous albumin in congenital nephrotic syndrome.

BACKGROUND: Early management of congenital nephrotic syndrome invariably includes the frequent administration of intravenous human albumin solution. The safety and feasibility of intravenous administration of albumin in the patients' home setting has not previously been reported. CASE-DIAGNOSIS/TREATMENT: We report a series of seven paediatric patients whose parents were trained in the administration of albumin via a central venous catheter at home, with the aim of minimising hospital admission or attendances. We describe the clinical course of these patients and complication rates ascribed to this strategy. CONCLUSIONS: Our results demonstrate that home albumin infusion can be performed safely.

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.

Pan-Britain, mixed-methods study of multidisciplinary teams teaching parents to manage children's long-term kidney conditions at home: study protocol.

BACKGROUND: Care of children and young people (children) with long-term kidney conditions is usually managed by multidisciplinary teams. Published guidance recommends that whenever possible children with long-term conditions remain at home, meaning parents may be responsible for performing the majority of clinical care-giving. Multidisciplinary team members, therefore, spend considerable time promoting parents' learning about care-delivery and monitoring care-giving. However, this parent-educative aspect of clinicians' role is rarely articulated in the literature so little evidence exists to inform professionals' parent-teaching interventions. METHODS/DESIGN: This ongoing study addresses this issue using a combination of quantitative and qualitative methods involving the twelve children's kidney units in England, Scotland and Wales. Phase I involves a survey of multidisciplinary team members' parent-teaching interventions using:i) A telephone-administered questionnaire to determine: the numbers of professionals from different disciplines in each team, the information/skills individual professionals relay to parents and the teaching strategies/interventions they use. Data will be managed using SPSS to produce descriptive statisticsii) Digitally-recorded, qualitative group or individual interviews with multidisciplinary team members to explore their accounts of the parent-teaching component of their role. Interviews will be transcribed anonymously and analysed using Framework Technique. Sampling criteria will be derived from analysis to identify one/two unit(s) for subsequent in-depth studyPhase II involves six prospective, ethnographic case-studies of professional-parent interactions during parent-teaching encounters. Parents of six children with a long-term kidney condition will be purposively sampled according to their child's age, diagnosis, ethnicity and the clinical care-giving required; snowball sampling will identify the professionals involved in each case-study. Participants will provide signed consent; data gathering will involve a combination of: minimally-obtrusive observations in the clinical setting and families' homes; de-briefing interviews with participants to obtain views on selected interactions; focussed 'verbatim' field-notes, and case-note reviews. Data gathering will focus on communication between parents and professionals as parents learn care-giving skills and knowledge. Interviews will be digitally recorded and transcribed anonymously. DISCUSSION: This study involves an iterative-inductive approach and will provide a unique, detailed insight into the social context in which professionals teach and parents learn; it will inform professionals' parent-educative roles, educational curricula, and health care policy.

Acute hydrothorax complicating peritoneal dialysis.

AIM: To determine whether gradually increasing the peritoneal dialysate fill volume from 10 to 40 mL/kg over 6 days, rather than commencing at 40 mL/kg, prevents hydrothorax in children and reverses it if present. METHODS: A review of children peritoneally dialyzed in a single center. RESULTS: During the 20 years beginning June 1985, 416 children were peritoneally dialyzed, of which 327 (79%) had acute and 89 had end-stage renal failure. Among 253 children who had gradually increasing fill volumes, none developed acute hydrothoraces, but 13/163 (8%) who began with 40 mL/kg cycles did (p < 0.000, Fisher's exact test). These were diagnosed after a median (range) of 48 (6-72) hours and were predominantly right sided. Initially, we readily abandoned peritoneal dialysis; 2 were changed to hemodialysis. Subsequently, we found that peritoneal dialysis could be continued by using small volumes with the patients sitting up; cycle volumes were then gradually increased again. One pre-term baby died soon after developing an acute hydrothorax. One patient on chronic peritoneal dialysis developed an acute hydrothorax after forceful vomiting, but recovered after being dialyzed sitting up with low fills. CONCLUSION: Acute hydrothorax can be prevented and treated using graduated cycle volumes, and is not a contraindication for peritoneal dialysis.

A machine for haemodialysing very small infants.

Babies weighing under 6 kg are difficult to dialyse, especially those as small as 1 kg. Peritoneal dialysis is easier than haemodialysis, but is not always possible, and clears molecules less efficiently. Two factors complicate haemodialysis. First, extracorporeal circuits are large relative to a baby's blood volume, necessitating priming with fresh or modified blood. Second, blood flow from infants' access vessels is disproportionately low (Poiseuille's law), causing inadequate dialysis, or clotting within the circuit. These problems are minimised by using single lumen access, a very small circuit, and a reservoir syringe to separate the sampling and dialyser blood flow rates. Its manual operation is tedious, so we developed a computer-controlled, pressure-monitored machine to run it, including adjusting the blood withdrawal rate from poorly sampling lines. We have dialysed four babies weighing 0.8-3.4 kg, with renal failure or metabolic disorders. The circuits did not require priming. Clearances of creatinine, urea, potassium, phosphate and ammonia were mean (SD) 0.54 (0.22) ml/min using one dialyser, and 0.98 (0.22) ml/min using two in parallel. Ammonia clearance in a 2.4 kg baby had a 9 h half-life. Ultrafiltration up to 45 ml/h was achieved easily. This device provided infants with immediate, effective and convenient haemodialysis, typically delivered for prolonged periods.