ABC de la diálisis peritoneal en pediatría / ABC of the peritoneal dialysis in pediatrics

Resumen: La enfermedad renal crónica terminal (ERCT) tiene una incidencia de 5,5 a 9 ppm, y una prevalencia de 23 a 65 ppm en menores de 15 años. La diálisis peritoneal (DP) crónica representa en pediatría la terapia de reemplazo renal más usada, previo al trasplante renal. Existen 2 tipos de DP crónicas, manual (DPCA) y automatizada (DPA), cuya elección se basa en las características del peritoneo eva luado mediante el test de equilibrio peritoneal (PET), que divide a los pacientes en transportadores altos (intercambio rápido), promedio alto, promedio bajo, y bajos (intercambio lento). Este test eva lúa básicamente el transporte de solutos, al cual se ha sumado el MiniPET, que evalúa el transporte peritoneal de agua libre. Se debe igualmente determinar la cuantía de diálisis (Kt/V), que representa la dosis de diálisis aplicada, con un valor mínimo sugerido de 1,7, relacionado a la morbimortalidad. Estos parámetros deben ser evaluados periódicamente para ajustar la DP, y cada vez que se sospeche una depuración o ultrafiltración inadecuadas. El objetivo de esta revisión es entregar conceptos bási cos sobre fisiología del transporte peritoneal, modalidades de DP, evaluación del transporte de agua y solutos peritoneal, y el cálculo de la dosis de diálisis para una diálisis ajustada a las necesidades de cada paciente, como también revisar los mecanismos de corrección y ajuste del procedimiento cada vez que se requiera.

Abstract: End-stage renal disease (ESRD) has an incidence of 5.5 to 9 pmp, and a prevalence of 23 to 65 pmp in children under 15 years of age. Chronic peritoneal dialysis (PD) represents the most widely used renal replacement therapy in children before kidney transplantation. There are two PD modalities, the manual one (CAPD) and the automated one (APD). The choice is based on the peritoneum characteristics, evaluated through the peritoneal equilibrium test (PET), which divides patients into high transporters (rapid exchange membrane), high average, low average, and low transporters (slow exchange membrane). This test basically evaluates the solutes transport rate, and the MiniPET has been added which evaluates peritoneal free water transport. The amount of dialysis (Kt/V), which represents the dose of dialysis administered also must be evaluated to assure a minimal value of 1.7 related to morbidity and mortality. These parameters should be evaluated periodically to ad just the PD and whenever suspected an inadequate clearance or ultrafiltration. The objective of this review is to provide basic concepts on peritoneal transport physiology, PD modalities, free water transport and peritoneal solute transport evaluation, and the dialysis dose to be applied according to the patient's needs, as well as reviewing the correction mechanisms and procedure adjustment whenever required.

Comparison of three PET methods to assess peritoneal membrane transport

The peritoneal equilibration test (PET) is the most widespread method for assessing water and solute transport across the peritoneal membrane. This study compared three methods: traditional PET (t-PET), mini-PET, and modified PET (mod-PET). Non-diabetic adults (n=21) who had been on peritoneal dialysis (PD) for at least three months underwent t-PET (glucose 2.5%-4 h), mini-PET (glucose 3.86%-1 h), and mod-PET (glucose 3.86%-4 h) to determine dialysate-to-plasma concentration ratio (D/P) for creatinine and dialysate-to-baseline dialysate concentration ratio (D/D0) for glucose. Agreement between methods regarding D/P creatinine and D/D0 glucose was assessed using analysis of variance (ANOVA), Pearson's correlation coefficient, and Bland-Altman analysis. D/P creatinine differed between t-PET and mini-PET (P<0.001) and between mod-PET and mini-PET (P<0.01) but not between t-PET and mod-PET (P=0.746). The correlation of D/P creatinine with t-PET vs mod-PET was significant (r=0.387, P=0.009) but not that of t-PET vs mini-PET (r=0.088, P=0.241). Estimated bias was −0.029 (P=0.201) between t-PET and mod-PET, and 0.206 (P<0.001) between t-PET and mini-PET. D/D0 glucose differed between t-PET and mod-PET (P=0.003) and between mod-PET and mini-PET (P=0.002) but not between t-PET and mini-PET (P=0.885). The correlations of D/D0 glucose in t-PET vs mod-PET (r=−0.017, P=0.421) or t-PET vs mini-PET (r=0.152, P=0.609) were not significant. Estimated bias was 0.122 (P=0.026) between t-PET and mod-PET, and 0.122 (P=0.026) between t-PET and mini-PET. The significant correlation of D/P creatinine between t-PET and mod-PET suggested that the latter is a good alternative to t-PET. There was no such correlation between t-PET and mini-PET.

Proliferación de trypanosoma cruzi en la membrana peritoneal y líquido ascítico de ratones con infección aguda / Proliferation of trypanosoma cruzi in the peritoneal membrane and ascitic liquid of mice with acute infection

En este estudio fue analizada la parasitemia y el parasitismo en el líquido ascítico (LA), membrana peritoneal (MP) y en otros tejidos de 40 ratones machos NMRI durante la infección aguda. Los ratones (20 ratones por grupo) fueron inoculados por vía intradérmica con tripomastigotos metacíclicos linaje T.cr I de las cepas P6 y P11 obtenidos de Rhodnius prolixus. Formas delgadas y gruesas de tripomastigotos fueron encontradas en la sangre de todos los ratones. En los ratones infectados con la cepa P6 los tripomastigotos aparecieron primero en él LA a los 13 días pi y en la sangre a los 18 días pi, en los ratones infectados con la cepa P11 los parásitos se observaron primero en la sangre a los 15 días pi y en él LA a los 22 días pi. Los ratones desarrollaron emaciación, disnea, hirsutismo, pérdida de la actividad motora de las patas posteriores y hepatoesplenomegalia. Los ratones fueron sacrificados a los 39 días pi. El estudio histológico mostró que T. cruzi prolifera formando nidos de amastigotos y tripomastigotos en la MP. Los parásitos también fueron encontrados en el músculo esquelético y en el corazón de los ratones infectados con la cepa P6. La inmunotinción con PAP reveló antígeno de T. cruzi en las secciones de esófago, estómago, intestino delgado y grueso, bazo, riñón, hígado, próstata y pene de los ratones. Estos resultados confirmaron que las cepas P6 y P11 desarrollaron anormalidades histopatológicas en el tracto gastrointestinal, renal y órgano reproductivo. La localización intra-peritoneal de los parásitos y la acumulación de fluido peritoneal, reveló ascitis y peritonitis causada por el incremento de líquido en la cavidad peritoneal y destrucción del tejido peritoneal de los ratones. El presente estudio reporta por primera vez la proliferación de tripomastigotos en la cavidad peritoneal cinco días antes de encontrarse en la sangre periférica para la cepa P6 causando daño intraperitoneal y muerte del modelo murino utilizado.

In this study we analyzed the parasitemia and parasitism in the ascitic fluid (AF), peritoneal membrane (PM) and in other tissues of 40 NMRI male mice during acute infection. Mice (20 mice per group) were inoculated by intradermal route with metacyclic trypomastigotes T.cI lineage of P6 or P11 strains obtained from Rhodnius prolixus. Slender and stout forms were observed in the blood of all mice. In infected mice with P6 strain the trypomastigotes were observed first in the AF at day 13 pi and in blood at day 18 pi. Meanwhile in infected mice with P11 strain trypomastigotes were observed first in the blood at day 15 pi and in the AF at day 22 pi. Infected mice showed emaciation, dyspnea, bristled hair, loss of motor activities in the rear limbs and hepatosplenomegaly. Mice were sacrificed at day 39 pi. Histological finding indicated that T. cruzi proliferates forming amastigotes and trypomastigotes nests in the PM. Parasites were also observed in skeletal muscle of the mice and in the heart of infected mice with P6 strain. Imunostaining with PAP revealed T. cruzi antigen in esophagus, stomach, thin and thick intestine, spleen, and kidney, liver, prostate and penis. The results show that P6 and P11 colonized and produced abnormalities in the gastrointestinal tract, renal and reproductive organs. Intra-peritoneal localization of parasites and accumulation of peritoneal fluid, revealed ascites and peritonitis caused by increase of fluid in the peritoneal cavity and destruction of the membrane peritoneal of the mice. This study reports for the first time the proliferation of trypomastigotes in the peritoneal cavity five days earlier than in peripheral blood for the P6 strain causing intra-peritoneal damage and death in the murine model used.

Protective measures against ultrafiltration failure in peritoneal dialysis patients

Ultrafiltration failure in patients undergoing peritoneal dialysis is a condition with an incidence that increases over time. It is related to increased cardiovascular morbidity and mortality and is a major cause of the abandonment of the treatment technique. Because the number of patients undergoing renal replacement therapy is increasing with society aging and because approximately 10 percent of this population is treated with peritoneal dialysis, this matter is becoming more common in everyday practice for clinicians involved in the care of patients with chronic renal failure. In this review, we summarize the available measures used to prevent and treat ultrafiltration failure and the current state of research in the field, both in the experimental and clinical settings, focusing on the possible clinical applications of recent findings.

Changes of peritoneal membrane transport characteristics in continuous ambulatory peritoneal dialysis patients

Background: In recent years, Continuous Ambulatory Peritoneal Dialysis (CAPD) has been applied extensively in treating end-stage chronic renal failure. The peritoneal membrane transport characteristics were varied in each patient, dependent on peritoneal anatomical structures. Objective: To determine the peritoneal membrane transport characteristics in continuous ambulatory peritoneal dialysis patients and its changes after 6-month treatment. Subjects and method: The descriptive prospective study was performed on 44 CAPD patients using the Peritoneal Equilibration Test (PET) to evaluate the peritoneal membrane transport characteristics. Results: 44 patients (19 men and 25 women), age 42.8 +/- 13.5 years, mean body mass index 19.5 +/- 2.1. PET at the 1st month (M1) and 6th month (M6) showed that the high-moderate level of peritoneal membrane transport characteristics are prevalent (50% of patients), high: 27.3%, low-moderate: 18.2% and low: 5%. After 6 months of CAPD, the peritoneal membrane transport characteristics, mean values of PET, ultrafiltration, lost of protein \u2026 were unchanged. Conclusions: The high-moderate levels of peritoneal membrane transport characteristics are prevalent; this is a good type for CAPD about urea, creatinine clearance and ultrafiltration. The peritoneal membrane transport characteristics directly affected some of the clinical indexes: ultrafiltration, processing lost prorein through filtrated fluid, blood protein and albumin levels\u2026

The Factors Influencing Peritoneal Membrane Transport Characteristics Within 4 Weeks in CAPD Patients / 대한신장학회잡지

BACKGROUND: To get stability and reproducibility of peritoneal membrane transport characteristics of peritoneal dialysis patients, peritoneal equilibration test (PET) is usually recommended at least 1 month after initiation of peritoneal dialysis. But there has been controversy about the exact mechanism. The aim of this study was to compare peritoneal membrane transport characteristics at 2nd and 4th week after initiation of peritoneal dialysis and analyze associated factors. METHODS: From May 2001 to March 2002, 60 new CAPD patients in our hospital were enrolled (male: 31, mean age: 52.6 years old, DM: 23). PET, body weight, body surface area (BSA), blood hemoglobin, serum albumin, hs-CRP(high sensitivity C reactive protein), 24 hours dialysate volume and 24 hours dialysate albumin amount, weekly Kt/Vurea, weekly CCr, residual renal function (RRF) were checked at 2nd and 4th week. Paired t-test, independent t-test, Pearson correlation and multiple regression analysis (GEE by STATA, version 7.0) were used. RESULTS: We can summarize the RESULTS: D/P4Cr and hemoglobin level were significantly increased with time (0.66+/-0.13 g/dL vs. 0.69+/-0.11 g/dL and 9.38+/-1.12 g/dL vs. 9.82+/-1.09 g/dL, p<0.05, respectively) and body weight was significantly decreased with time (63.1+/-11.7 kg vs. 62.4+/-11.2 kg, p<0.05). Factors influencing D/P4Cr change were 24 hours dialysate volume, serum albumin and 24 hours dialysate albumin amount (Beta coefficients: -0.044/L, -0.062/g/dL and 0.028/g/day, p<0.01, respectively). Factors influencing serum albumin (g/dL) were D/ P4Cr, 24 hours dialysate volume and hemoglobin level (Beta coefficients: -0.129/0.1, -0.117/L and 0.133/g/ dL, p<0.01, respectively). There was positive correlation between delta changes of D/P4Cr and delta changes of hs CRP (r=0.297, p=0.02) CONCLUSION: The change of D/P4Cr within 1 month was reciprocally correlated with the change of serum albumin (negatively) and hs CRP (positively). The change of serum albumin, 24 hours dialysate volume and 24 hours albumin loss via dialysate influenced the change of D/P4Cr within 1 month after initiation of peritoneal dialysis.

Clinical Factors Affecting Peritoneal Membrane Function in Long-Term Continuous Ambulatory Peritoneal Dialysis Patients / 대한신장학회잡지

BACKGROUND: According to previous studies on peritoneal membrane function, solute transport significantly increased 3 years after the begining of peritoneal dialysis. However, there were only few reports regarding the change of peritoneal membrane function in long-term CAPD patients in Korea. METHODS: Clinical factors affecting peritoneal membrane function were analyzed, in patients who maintained CAPD more than 5 years. 124 patients performed peritoneal equilibration test(PET) 5 years after CAPD were included. Cross sectional study was performed to know the differences of clinical characteristics among 4 types of peritoneal membrane transport characteristics based on PET. Also, clinical factors affecting peritoneal memebrane function were analyzed in 31 patients who had undertaken PET initially and 5 years after the beginning of CAPD. RESULTS: D/P Cr was the highest(p<0.001) and ultrafiltration was the lowest(p=0.011) in high transport group. Also, the number of hypertonic glucose exchanges(more than 2.5%) per day was the highest (p=0.02), and serum albumin was the lowest(p<0.001) in this group. 17 patients were included in ultrafiltraion failure group. D/P Cr and the number of hypertonic glucose exchanges was significantly higher (p<0.001, p<0.001, respectively) and the duration of peritoneal dialysis was significantly longer(p=0.033) in ultrafiltration failure group compared with the others. D/P Cr of 124 patients was well correlated with the number of peritonitis(gamma=0.246, p=0.006), and the number of hypertonic glucose exchanges(gamma=0.33, p<0.001), but inversely correlated with serum albumin(gamma=-0.452, p<0.001) with the statistical significance. In 31 patients who undertook PET within 1 year after the begining of CAPD, although not significant, D/P Cr increased and ultrafiltration decreased after 5 years. A significant increase in D/P Cr(p=0.014) was seen in patients who experienced more than 2 episodes of peritonitis(n=14), compared with patients who experienced either peritonitis free or single episode of peritonitis(n=17). The linear regression analysis showed that the number of peritonitis and the number of hypertonic glucose exchanges per day were significantly correlated with the increased D/P Cr after 5 years(p=0.001, p=0.003, respectively). CONCLUSION: Clinical factors affecting peritoneal membrane function were the number of peritonitis, the use of hypertonic glucose exchanges and the duration of peritoneal dialysis. To preserve peritoneal membrane function, it is recommended to avoid hypertonic glucose exchanges and to reduce the number of peritonitis.

Factors Affecting Serum Albumin Level in Continuous Ambulatory Peritoneal Dialysis Patients / 대한내과학회지

OBJECTIVES: Protein-calorie malnutrition is a common problem in patients undergoing continuous ambulatory peritoneal dialysis (CAPD). Serum albumin(SA) concentration has been used as a marker for assessing nutritional status. Hypoalbuminemia has been linked to an increased risk of morbidity and mortality and more numerous, prolonged hospitalization for peritoneal dialysis patients. The aim of this study was to determine factors affecting SA value in CAPD patients. METHODS: We performed a cross-sectional study which included patients' demographics, anthropometric data, biochemical parameters, urea kinetic data and comorbidity in 106 stable CAPD patients. RESULTS: 1) There were 50 men and 56 women with a mean CAPD duration of 43 months and mean age of 49 years. The mean concentration of SA was 3.9+/-0.5 (range 2.5-5.3) g/dl and weekly Kt/Vurea 2.0+/-0.4 (range 1.32-3.79) 2) Twenty-one patients(20%) were classified as group I(SA<3.5g/dl)and the remaining patients(80%) as group II(SA 3.5g/dl) 3) Group I patients were significantly older(55+/-11 vs 47+/-11 years, p<0.05) and had significantly higher comorbidity score(1.5+/-0.8 vs 0.7+/-0.9, p<0.05), C-reactive protein (4.5+/-0.9 vs 0.5+/-0.1 mg/dl, p<0.05), 24-hr dialysate-toplasma creatinine(D/PCr) ratio(0.84+/-0.1 vs 0.76+/-0.1, p<0.05), 24-hr dialysate protein (7167+/-2031 vs 5471+/-1515 mg, p<0.05) and had significantly lower residual renal function(RRF)(0.2+/-0.3 vs 0.7+/-1.2 ml/min, p<0.05), BUN(48+/-14.8 vs 55.6+/-14.9 mg/dl, p<0.05), serum creatinine(10.4+/-2.8 vs 12.6+/-3.5 mg/dl, p<0.05), IGF-1(186+/-99 vs 260+/-131 ng/ml, p<0.05), serum phosphorus(4.1+/-1.2 vs 5.0+/-1.3 mg /dl, p<0.05) than group II.4) SA showed positive correlation with anion gap (r=0.43, p value=0.001), transferrin(r=0.41, p value= 0.001) phosphorus(r=0.31, p value=0.001) and negative correlation with 24-hr dialysate protein loss(r=-0.51, p value=0.001), 24-hr D/PCr ratio(r=-0.49, p value=0.001), comorbidity score(r=-0.36, p vluue=0.001). NPCR(r=0.22, p value=0.023), IGF-1(r=0.30, p value=0.002), BUN(r=0.23, p value=0.016) weakly correlated with SA.5) By stepwise multiple logistic regression analysis, age, CRP, 24-hr D/PCr ratio and RRF independently influenced SA level. CONCLUSION: SA level seems to be affected by non-nutritional factors such as age, peritoneal membrane transport characteristics, residual renal function and presence of acute phase protein response manifested by CRP elevation, in addition to nutritional factors.