Influencia del volumen peritoneal residual en los resultados de la prueba de equilibrio peritoneal. Estudio prospectivo / Influence of peritoneal residual volume on the results of the peritoneal equilibration test. Prospective study

Introducción y objetivos: La categorización de la capacidad de ultrafiltración durante la prueba de equilibrio peritoneal (PEP) es parte habitual de la monitorización del funcionalismo peritoneal en pacientes tratados con diálisis peritoneal (DP). La estimación del volumen residual (Vr) tras el cambio previo (Vrpre) y el de la propia PEP (Vrpost) podría ayudar a mejorar la precisión de la prueba. Método: Siguiendo un diseño prospectivo, estimamos el Vrpre y Vrpost en 116 pacientes incidentes o prevalentes en DP que fueron sometidos a una o dos (n=27) PEP con solución de glucosa al 3,86/4,25% y drenaje completo a los 60 minutos. Valoramos la consistencia del Vr comparando Vrpre y Vrpost y también estos parámetros en PEP sucesivas. Analizamos la posible influencia de factores demográficos y clínicos en la cuantía del Vr, así como el impacto de la corrección para Vr de la ultrafiltración durante la PEP sobre la categorización de la capacidad de ultrafiltración. Resultados: El Vrpost fue mayor que el Vrpre, por lo que la ultrafiltración corregida para Vr fue signficativamente mayor que la calculada por procedimiento estándar (494 vs. 449mL, p<0,0005). Resultó notable la escasa concordancia de estimaciones sucesivas (Vrpre vs Vrpost y PEP sucesivas) del Vr. Asimismo, ningún parámetro demográfico o clínico escrutado mostró asociación con la magnitud del Vr. Tan solo un 12,9% de los pacientes presentó una desviación clínicamente significativa (>200mL) de la ultrafiltración corregida para Vr frente al valor estándar. Sin embargo, un 21,1% de los pacientes que cumplían criterio de fallo de ultrafiltración por método estándar, no lo hacían si se aplicaba la corrección para Vr. (AU)

Background: Categorization of the capacity of ultrafiltration during a peritoneal equilibration test (PET) is a usual step during the monitoring of peritoneal transport characteristics of peritoneal dialysis (PD) patients. Quantifying the peritoneal residual volume (Vr) after the dwell preceding the PET (Vrpre) and at the end of the test (Vrpost) could help to improve the accuracy of the estimation of this variable. Method: Following a prospective design, we calculated Vrpre and Vrpost in 116 patients, incident or prevalent on DP, who underwent one or two (n=27) PET with 3.86/4.25% glucose-based PD solutions and complete drainage at 60min. We evaluated the consistency of Vr by comparing Vrpre and Vrpost, as also these two parameters in repeated tests. We scrutinized potential associations between demographic and clinical factors, on one side, and the amount of Vr on the other, as also the impact of correcting ultrafiltration during PET for Vr on the categorization of the capacity of ultrafiltration. Results: As a mean, Vrpost was larger than Vrpre. Consequently, correction of ultrafiltration for Vr resulted in significantly higher values than those obtained according to the standard procedure (494 vs 449mL, p<0.0005). We disclosed marked inconsistencies for different estimations of Vr in the same patients (Vrpre vs Vrpost and repeated PET studies). Moreover, no demographic or clinical variable was able to predict the amount of Vr. We observed a significant deviation (>200mL) between both methods of estimation of the capacity of utrafiltration in only 12.9% of the patients. However, 21.1% of the patients categorized as cases of ultrafiltration failure according to the standard procedure did not maintain this condition after correction for Vr. (AU)

Low Incidence of Acute Antibody-Mediated Rejection after HLA Desensitization in Living Donor Kidney Transplant Recipients.

Desensitization allows the performance of human leukocyte antigen (HLA)-incompatible transplants. However, the incidence of acute rejection (AR) is high. This study aims to analyze the incidence of AR after transplantation with HLA-incompatible living donors in patients who underwent desensitization. Patients were immunosuppressed with tacrolimus, mycophenolic acid derivatives, and steroids after being desensitized with rituximab, plasma exchange, and/or immunoadsorption with specific cytomegalovirus immunoglobulins. A negative complement-dependent cytotoxicity or flow cytometry crossmatch and a donor-specific antibody titer < 1000 mean fluorescence intensity (MFI) were used to determine desensitization efficacy. A total of 36 patients underwent desensitization, and 27 (75%) were transplanted. After a follow-up of 58 ± 58 months (Min−Max: 0.13−169.5), five episodes of AR occurred: two antibody-mediated and three T-cell-mediated. No differences were found in baseline calculated panel-reactive antibodies (cPRA), class I or II MFI, number of antibodies, or Relative Intensity Scale (RIS) between AR and non-AR patients. Patients with antibody-mediated AR had higher cPRA (NS), MFI class I (p = 0.07) and class II (p = 0.006), and RIS (p = 0.01). The two patients with antibody-mediated AR and one patient with T-cell-mediated AR lost their grafts. In conclusion, the incidence of acute antibody-mediated rejection after desensitization was 7.4%, which occurred early post-transplantation in patients with high MFI and was associated with early graft loss.

Does Prior Abdominal Surgery Influence Peritoneal Transport Characteristics or Technique Survival of Peritoneal Dialysis Patients?

INTRODUCTION: Prior abdominal surgery may result in peritoneal membrane adhesions and fibrosis, compromising the success of peritoneal dialysis (PD). The impact of this factor on peritoneal membrane function and PD technique survival has not been adequately investigated. METHODS: Following an observational, retrospective design, we studied 171 incident PD patients, with the main objective of analyzing the influence of prior abdominal surgical procedures (main study variable) on baseline and evolutionary peritoneal transport characteristics (main outcome) and PD patient and technique survival (secondary outcomes). Abdominal surgeries were categorized according to the degree of presumed injury to the peritoneal membrane. We also considered the additive effect of aggressions to the membrane during the first year on PD therapy. RESULTS: All patients had a baseline peritoneal equilibration test with complete drainage at 60', and 113 patients had a second study at the end of the first year. Sixty-one patients (35.7%) had a record of prior abdominal surgery, including 29 patients with at least one major intraperitoneal surgery, 22 having undergone minor intraperitoneal procedures, and 21 with a background of major abdominopelvic extraperitoneal surgery. We did not observe differences, at baseline or after 1 year, among patients with or without previous abdominal procedures regarding small solute transport, overall capacity of ultrafiltration, free water transport, small pore ultrafiltration, or peritoneal protein excretion. Stratified analysis, considering prior and first-year-on-PD peritoneal aggressions, did not reveal any differences, although in this case our analysis was hampered by a limited statistical power. Abdominal surgical events did not influence patient or PD technique survival. CONCLUSION: Prior abdominal surgical procedures do not appear to compromise peritoneal membrane function or technique survival in patients successfully started on PD.

Long-term trends in the incidence of peritoneal dialysis-related peritonitis disclose an increasing relevance of streptococcal infections: A longitudinal study.

BACKGROUND: The selective impact of strategies for prevention of PD-related peritonitis (PDrP) may have modified, in the long term, the causal spectrum, clinical presentation and outcomes of these infections. OBJECTIVES: To compare trends in the incidence of PDrP by different microorganisms during a 30-year period, with a particular focus on streptococcal infections. To analyze the clinical presentation and outcomes of these infections. Secondarily, to investigate how the isolation of different species of streptococci can influence the clinical course of PDrP by this genus of bacteria. METHOD: Following a retrospective, observational design we investigated 1061 PDrP (1990-2019). We used joinpoint regression analysis to explore trends in the incidence of PDrP by different microorganisms, and compared the risk profile (Cox), clinical presentation and outcomes (logistic regression) of these infections. MAIN RESULTS: Our data showed a progressive decline in the incidence of PDrP by staphylococci and Gram negative bacteria, while the absolute rates of streptococcal (average annual percent change +1.6%, 95% CI -0.1/+3.2) and polymicrobial (+1.8%, +0.1/+3.5) infections tended to increase, during the same period. Remarkably, streptococci were isolated in 58.6% of polymicrobial infections, and patients who suffered a streptococcal PDrP had a 35.8% chance of presenting at least one other infection by the same genus. The risk profile for streptococcal infections was comparable to that observed for PDrP overall. Streptococcal PDrP were associated with a severe initial inflammatory response, but their clinical course was generally nonaggressive thereafter. We did not observe a differential effect of different groups of streptococci on the clinical presentation or outcome of PDrP. CONCLUSIONS: Time trends in the incidence of PDrP by different microorganisms have granted streptococci an increasing relevance as causative agents of these infections, during the last three decades. This behaviour suggests that current measures of prevention of PDrP may not be sufficiently effective, in the case of this genus of microorganisms.

Analysis of Factors Influencing the Prognostic Significance of Hyponatremia in Peritoneal Dialysis Patients.

BACKGROUND: The evidence linking low serum sodium levels with the risk of mortality in peritoneal dialysis (PD) patients is controversial. Considering the different mechanisms contributing to hyponatremia in these patients, it is conceivable that the prognostic significance of this factor may vary, according to the clinical setting. METHODS: Following a retrospective, observational design, we analyzed the association between hyponatremia and mortality in 748 patients incident on PD. We applied multivariate strategies of analysis, with the main objective of identifying subgroups of patients in whom hyponatremia could sustain different degrees of association with mortality (main outcome variable). For this purpose, we performed preliminary analyses to: (1) disclose predictors of serum sodium levels before and after (mean of first 3 months) initiation of PD (main study variable) and (2) investigate the overall prognostic significance of hyponatremia, in our patients. RESULTS: Comorbidity, hypoalbuminemia, and lower glomerular filtration rate (GFR) were main predictors of hyponatremia. Use of icodextrin was another inverse correlate of serum sodium, and the only consistent predictor of a decline of natremia, once PD was started. Multivariate analysis confirmed early hyponatremia as an independent marker of survival. However, stratified analyses showed that this association was most apparent in specific subsets, namely, hypoalbuminemic, more anemic patients with higher baseline levels of GFR and C-reactive protein and faster peritoneal solute transport rates. Other factors potentially reinforcing the prognostic significance of hyponatremia included lower lean body mass levels, nonprescription of renin-angiotensin-aldosterone system antagonists, and use of icodextrin-based PD solution. On the contrary, baseline overhydration or categorization by classic predictors of mortality (age, comorbidity, diabetes) did not appear to influence the risk pattern associated with lower serum sodium levels. CONCLUSIONS: Our results suggest that hyponatremia performs as a consistent correlate of the risk of mortality mainly in PD patients manifesting direct or indirect signs of inflammation and wasting, while this association is not apparently linked to the presence of overhydration or nominal, preexisting comorbid conditions.

La sobrehidratación persistente asocia un riesgo significativo de infección peritoneal por gérmenes entéricos en pacientes tratados con diálisis peritoneal / Persistent overhydration is associated with a significant risk of peritoneal infection by enteric pathogens in patients treated with peritoneal dialysis

ANTECEDENTES Y OBJETIVOS: La sobrehidratación (SH) es frecuente, y a menudo persistente, en pacientes tratados con diálisis peritoneal (DP), y mantiene una asociación controvertida con el riesgo de infección peritoneal. El objetivo principal de este estudio fue desvelar una posible asociación entre la presencia de SH y el riesgo subsiguiente de infección peritoneal por gérmenes entéricos, en una población relativamente amplia de pacientes tratados con DP. MÉTODO: Según diseño prospectivo, monitorizamos de manera sistemática la composición corporal de pacientes tratados con DP en nuestra unidad (2011-2016), buscando una posible correlación con el riesgo de peritonitis durante el seguimiento, con un interés particular en la asociación entre SH persistente (variable de estudio principal) y el riesgo de infección peritoneal por patógenos entéricos (variable resultado principal). Para el análisis tuvimos en cuenta variables demográficas, clínicas y de laboratorio con influencia potencial en el riesgo de infección peritoneal. Utilizamos técnicas de análisis multivariante para clarificar el efecto específico de diferentes parámetros de composición corporal sobre la variable resultado principal. RESULTADOS PRINCIPALES: Incluimos 139 pacientes, con seguimiento medio de 24 meses. Sesenta y tres pacientes sufrieron al menos una peritonitis, y 17 al menos una infección por gérmenes entéricos. El análisis univariante mostró una tendencia general a mayor riesgo de infección peritoneal entérica en pacientes sobrehidratados, que se hacía evidente cuando se usaba el cociente agua extracelular/agua intracelular (AEC/AIC) (p = 0,007), el cociente SH/AEC (SH/AEG) (p = 0,033), o el cociente AEC/agua corporal total (AEC/ACT) (p = 0,004), pero no cuando se usaba la SH absoluta, como variable de estudio. El análisis multivariante confirmó estas asociaciones o tendencias (RR: 3,48; IC 95%: 1,03-14,59; p = 0,046, tercil mayor versus menor para AEC/AIC, RR: 2,31; IC 95%: 0,98-6,56; p = 0,061, tercil mayor versus menor para SH/AEC, y RR: 6,33; IC 95%: 1,37-19,37; p = 0,011, tercil mayor versus menor para AEC/ACT). Por el contrario, no observamos asociación consistente entre SH y riesgo general de infección peritoneal. CONCLUSIÓN: La SH persistente asocia un riesgo significativo de infección peritoneal por patógenos entéricos, en pacientes tratados con DP

BACKGROUND: Overhydration (OH) complicates frequently the clinical course of Peritoneal Dialysis (PD) patients, and keeps a controversial association with the risk of peritoneal infection. The main objective of this study was to disclose an association between persistent OH and the risk of enteric peritonitis in a relatively large sample of patients undergoing PD. METHOD: Following a prospective design, we monitorized systematically body composition of patients treated with PD in our unit (2011-2016), searching for a correlation with the ensuing risk of peritonitis, with an emphasis on the association between persistent OH (main study variable) and the risk of infection by enteric pathogens (main outcome). Essential demographic, clinical and laboratory variables with a potential influence on the risk of peritonitis were recorded. We used multivariate survival analysis to clarify the specific effect of different body composition parameters on the main outcome. MAIN RESULTS: We included 139 patients for analysis (mean follow-up 24 months). Sixty-three patients suffered at least one peritonitis, and 17 had at least one diagnosis of enteric peritonitis. Univariate analysis disclosed a general trend to an increased risk of enteric peritonitis in overhydrated patients, as evidenced by associations of this outcome with mean extracellular water/intracellular water (ECW/ICW) (p = .007), OH/ECW (p = .033) and ECW/total body water (ECW/TBW) (p = .004) ratios, but not with absolute OH values. Multivariate analysis confirmed similar associations or trends (RR: 3.48, 95% CI: 1.03-14.59; p = .046, highest versus lowest tertile of ECW/ICW, RR: 2.31, 95% CI: 0.98-6.56; p = .061, highest versus lowest tertile of OH/ECW, and RR: 6.33, 95% CI: 1.37-19.37; p = .011, highest versus lowest tertile of ECW/TBW). On the contrary, no apparent association was detected between OH and the overall risk of peritoneal infection. CONCLUSION: Persistent overhydration portends a significant risk of peritoneal infection by enteric pathogens, among patients undergoing chronic PD

Persistent overhydration is associated with a significant risk of peritoneal infection by enteric pathogens in patients treated with peritoneal dialysis. / La sobrehidratación persistente asocia un riesgo significativo de infección peritoneal por gérmenes entéricos en pacientes tratados con diálisis peritoneal.

BACKGROUND: Overhydration (OH) complicates frequently the clinical course of Peritoneal Dialysis (PD) patients, and keeps a controversial association with the risk of peritoneal infection. The main objective of this study was to disclose an association between persistent OH and the risk of enteric peritonitis in a relatively large sample of patients undergoing PD. METHOD: Following a prospective design, we monitorized systematically body composition of patients treated with PD in our unit (2011-2016), searching for a correlation with the ensuing risk of peritonitis, with an emphasis on the association between persistent OH (main study variable) and the risk of infection by enteric pathogens (main outcome). Essential demographic, clinical and laboratory variables with a potential influence on the risk of peritonitis were recorded. We used multivariate survival analysis to clarify the specific effect of different body composition parameters on the main outcome. MAIN RESULTS: We included 139 patients for analysis (mean follow-up 24 months). Sixty-three patients suffered at least one peritonitis, and 17 had at least one diagnosis of enteric peritonitis. Univariate analysis disclosed a general trend to an increased risk of enteric peritonitis in overhydrated patients, as evidenced by associations of this outcome with mean extracellular water/intracellular water (ECW/ICW) (p=.007), OH/ECW (p=.033) and ECW/total body water (ECW/TBW) (p=.004) ratios, but not with absolute OH values. Multivariate analysis confirmed similar associations or trends (RR: 3.48, 95% CI: 1.03-14.59; p=.046, highest versus lowest tertile of ECW/ICW, RR: 2.31, 95% CI: 0.98-6.56; p=.061, highest versus lowest tertile of OH/ECW, and RR: 6.33, 95% CI: 1.37-19.37; p=.011, highest versus lowest tertile of ECW/TBW). On the contrary, no apparent association was detected between OH and the overall risk of peritoneal infection. CONCLUSION: Persistent overhydration portends a significant risk of peritoneal infection by enteric pathogens, among patients undergoing chronic PD.