Longitudinal evaluation of transport kinetics in children receiving peritoneal dialysis

Peritoneal Dialysis Guidelines 2019 Part 1 (Position paper of the Japanese Society for Dialysis Therapy)

Approximately 10 years have passed since the Peritoneal Dialysis Guidelines were formulated in 2009. Much evidence has been reported during the succeeding years, which were not taken into consideration in the previous guidelines, e.g., the next peritoneal dialysis PD trial of encapsulating peritoneal sclerosis (EPS) in Japan, the significance of angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs), the effects of icodextrin solution, new developments in peritoneal pathology, and a new international recommendation on a proposal for exit-site management. It is essential to incorporate these new developments into the new clinical practice guidelines. Meanwhile, the process of creating such guidelines has changed dramatically worldwide and differs from the process of creating what were “clinical practice guides.” For this revision, we not only conducted systematic reviews using global standard methods but also decided to adopt a two-part structure to create a reference tool, which could be used widely by the society’s members attending a variety of patients. Through a working group consensus, it was decided that Part 1 would present conventional descriptions and Part 2 would pose clinical questions (CQs) in a systematic review format. Thus, Part 1 vastly covers PD that would satisfy the requirements of the members of the Japanese Society for Dialysis Therapy (JSDT). This article is the duplicated publication from the Japanese version of the guidelines and has been reproduced with permission from the JSDT.

The short peritoneal equilibration test in pediatric peritoneal dialysis

The peritoneal equilibration test (PET) is the gold standard method for defining peritoneal membrane permeability and for prescribing peritoneal dialysis (PD) therapy on an individual basis. However, it is laborious, consumes nursing time, and requires many hours to be performed. Therefore, several authors have attempted to validate a short PET protocol, with controversial results. To evaluate the concordance between the 2-h (short) and 4-h (classical) peritoneal equilibrium test, a prospective observational protocol was applied in three PD centers (Mexico, Chile, and Uruguay) between July 1, 2008 and July 31 2009. PET protocol: the night prior to the test, each patient received five exchanges, 1 h each, at the same glucose concentration as previously used. Afterwards, a 2.5% glucose dialysis solution was used for a dwell time of 4 h. Exchange fill volume was 1,100 ml/m2 body surface area. The next morning, the 4-h dwell was drained, and Dianeal 2.5% was infused. Three dialysate samples at 0, 2, and 4 h were obtained. A single blood sample was obtained at 120 min. Creatinine D/P and glucose D/D0 ratios were calculated at hours 0, 2, and 4. Patients were categorized as low, low average, high average, or high transporters according creat D/P and gluc D/D0 results. Pearson and Kappa test were used for numerical and categorical correlations, respectively, and p<0.05 was considered significant. Eighty-seven PET studies were evaluated in 74 patients, 33 males, age 11.1+/-5.05 years old. A positive linear correlation of 92% between 2 and 4-h creat D/P and 80% between 2 and 4-h gluc D/D0 (p<0.001) was founded. The Kappa test showed a significant concordance between creat D/P and gluc D/D0 categories at 2 and 4 h (p<0.001). When analyzing cut-off-value categories, creat D/P was founded to be lower and gluc D/D0 higher than other experiences. This multicentric prospective study strongly suggests that PET obtained at 2 h and 4 h, based on either creatinine or glucose transport, provides identical characterization of peritoneal membrane transport capacity in PD children.

Dialysis-associated peritonitis in children

Peritonitis remains a frequent complication of peritoneal dialysis in children and is the most common reason for technique failure. The microbiology is characterized by a predominance of Gram-positive organisms, with fungi responsible for less than 5% of episodes. Data collected by the International Pediatric Peritonitis Registry have revealed a worldwide variation in the bacterial etiology of peritonitis, as well as in the rate of culture-negative peritonitis. Risk factors for infection include young age, the absence of prophylactic antibiotics at catheter placement, spiking of dialysis bags, and the presence of a catheter exit-site or tunnel infection. Clinical symptoms at presentation are somewhat organism specific and can be objectively assessed with a Disease Severity Score. Whereas recommendations for empiric antibiotic therapy in children have been published by the International Society of Peritoneal Dialysis, epidemiologic data and antibiotic susceptibility data suggest that it may be desirable to take the patient- and center-specific history of microorganisms and their sensitivity patterns into account when prescribing initial therapy. The vast majority of patients are treated successfully and continue peritoneal dialysis, with the poorest outcome noted in patients with peritonitis secondary to Gram-negative organisms or fungi and in those with a relapsing infection.

Short PET in pediatric peritoneal dialysis

Peritoneal equilibration test (PET) is a common technique used in children to evaluate peritoneal membrane transport capacity and adequate the dialysis regimen. Considering that this is a laborious test, a shortened version has been proposed. Our goal was to evaluate the concordance between the 2-h (short) and 4-h (classical) PET values to determine whether the short PET could be used in the clinical setting. Eighty-one PET corresponding to 81 peritoneal dialysis patients from two pediatric nephrology centers were retrospectively analyzed. Peritoneal transport capacity was evaluated using the dialysate to plasma ratio (D/P) of creatinine and the ratio of dialysate glucose to baseline dialysate glucose (D/D(0)) at 2 and 4 h. The mean [+/- standard deviation (SD)] creatinine D/P ratio at 2 and 4 h were 0.41 +/- 0.13 and 0.66 +/- 0.17, respectively, and the mean (+/- SD) D/D(0) glucose were 0.64 +/- 0.11 and 0.39 +/- 0.12 at the same times. Applying McNemar chi(2) test to evaluate the association between the categories obtained at 2 and 4 h, we found no relationship between the 2- and 4-h PET for both D/P and D/D(0) (p > 0.05). These results suggest that the use of this abbreviated test is probably not reliable for estimating the transport capacity of the peritoneal membrane in the pediatric population.

Pathogenesis and treatment of peritoneal membrane failure

Peritoneal dialysis (PD) is a viable treatment option for end stage renal disease (ESRD) patients worldwide. PD may provide a survival advantages over hemodialysis (HD) in the early years of treatment. However, the benefits of PD are short-lived, as peritoneal membrane failure ensues in many patients, owing mainly to structural and functional changes in the peritoneal membrane from the use of conventional bio-incompatible PD solutions, which are hyperosmolar, acidic, have lactate buffer and contain high concentrations of glucose and glucose degradation products (GDPs). Current data suggest that chronic exposure of the peritoneum to contemporary PD fluids provokes activation of various inflammatory, fibrogenic and angiogenic cytokines, interplay of which leads to progressive peritoneal fibrosis, vasculopathy and neoangiogenesis. There is emerging evidence that peritoneal vascular changes are mainly responsible for increased solute transport and ultrafiltration failure in long-term PD. However, the precise pathophysiologic mechanisms initiating and propagating peritoneal fibrosis and angiogenesis remain elusive. The protection of the peritoneal membrane from long-term toxic and metabolic effects of high GDP-containing, conventional, glucose-based solutions is a prime objective to improve PD outcome. Recent development of new, more biocompatible, PD solutions should help to preserve peritoneal membrane function, promote ultrafiltration, improve nutritional status and, hopefully, preserve peritoneal membrane and improve overall PD outcomes. Elucidation of molecular mechanisms involved in the cellular responses leading to peritoneal fibrosis and angiogenesis spurs new therapeutic strategies that might protect the peritoneal membrane against the consequences of longstanding PD.

Dialysis for end-stage renal disease

Peritoneal dialysis is the major renal replacement therapy for children with end-stage renal disease, with hemodialysis used for a substantial number of pediatric patients. Reduction of morbidity and mortality is a major goal with the use of these modalities. Adequacy of dialysis and maintenance of peritoneal membrane function are important considerations for children on long term dialysis. Both adequacy and function are important to ensure optimal growth and nutrition and improve morbidity in this population. Use of supplemental gastrostomy tube feeds has improved calorie-protein malnutrition. Therapy advancements, such as growth hormone and erythropoietin, have improved the quality of life for dialysis patients. As the survival of the pediatric patient with end-stage renal disease improves, issues regarding cardiovascular disease and other factors that increase mortality in the adult population will need to be addressed.