Electronegative LDL and lipid abnormalities in patients undergoing hemodialysis and peritoneal dialysis

Background: Oxidative modification of low-density lipoprotein (LDL) has been demonstrated in patients with end-stage renal disease, where it is associated with oxidative stress and plays a key role in the pathogenesis of atherosclerosis. In this context, the generation of minimally oxidized LDL, also called electronegative LDL [ LDL(-)], has been associated with active disease, and is a detectable sign of atherogenic tendencies. The purpose of this study was to evaluate serum LDL(-) levels and anti-LDL(-)IgG autoantibodies in end-stage renal disease patients on dialysis, comparing patients on hemodialysis (HD), peritoneal dialysis (PD) and a control group. In addition, the serum lipid profile, nutritional status, biochemical data and parameters of mineral metabolism were also evaluated. Methods: The serum levels of LDL(-) and anti-LDL(-) IgG autoantibodies were measured in 25 patients undergoing HD and 11 patients undergoing PD at the Centro Integradode Nefrologia, Rio de Janeiro, Brazil. Ten healthy subjects served as a control group. Serum levels of albumin, total cholesterol, triglycerides and lipoproteins were measured. Calculations of subjects` body mass index and measurements of waist circumference, triceps skin fold and arm muscle area were performed. Measurements of hematocrit, serum blood urea nitrogen, creatinine, parathyroid hormone, phosphorus and calcium were taken. Results: Levels of LDL(-) were higher in HD patients (575.6 +/- 233.1 mu g/ml) as compared to PD patients (223.4 +/- 117.5 mu g/ml, p < 0.05), which in turn were higher than in the control group (54.9 +/- 33.3 mu g/ml, p < 0.01). The anti-LDL(-) IgG autoantibodies were increased in controls (0.36 +/- 0.09 mu g/ ml) as compared to PD (0.28 +/- 0.12 mu g/ml, p < 0.001) and HD patients (0.2 +/- 0.1 mu g/ml, p < 0.001). The mean values of total cholesterol and LDL were considered high in the PD group, whereas the mean triceps skin fold was significantly lower in the HD group. Conclusion: Levels of LDL(-) are higher in renal patients on dialysis than in normal individuals, and are reciprocally related to IgG autoantibodies. LDL(-) may be a useful marker of oxidative stress, and this study suggests that HD patients are more susceptible to cardiovascular risk due to this condition. Moreover, autoantibodies reactive to LDL(-) may have protective effects in chronic kidney disease. Copyright (C) 2008 S. Karger AG, Basel.

Peritoneal Dialysis in Acute Kidney Injury: Lessons Learned and Applied

Peritoneal dialysis (PD) is a simple, safe, gentle, and efficient renal replacement therapy (RRT) method. It is able to correct acute kidney injury (AKI)-induced metabolic, electrolytic, and acid-base disorders and volume overload both in and out the intensive care unit setting. Some PD modalities, such as high-volume PD and continuous flow PD, can provide RRT doses and efficiency comparable to extracorporeal blood purification methods. PD is particularly suitable for children, patients with refractory heart failure or hemodynamically instable, conditions where systemic anticoagulation should be avoided, patients with difficulty for vascular access and hypo- and hyperthermia conditions. In the following manuscript, PD technical aspects and the possible advantages and limitations of this RRT method will be discussed, and the more recent literature on clinical experience with PD for treatment of AKI will be reviewed.

Flow-through peritoneal dialysis in neonatal enema-induced hyperphosphatemia

Fleet enemas are hypertonic solutions with an osmotic action and a high concentration of phosphate. When retained in the human body they have a great toxic potential, causing severe hydro-electrolyte disorders in children, especially in newborns. We report the case of a previously healthy 8-day-old newborn who needed neonatal intensive care treatment after the inadvertent administration of an osmotically active hypertonic phosphate enema. Taking into account that phosphate removal by peritoneal dialysis (PD) strongly depends on total dialysate turnover, we chose continuous flow PD (CFPD) as the treatment option, with a successful outcome. Clinical experience with this dialytic modality is limited to a few case reports in pediatric and adult patients. To the best of our knowledge, we report here the first description of CFPD in the setting of acute phosphate nephropathy in the neonatal period. The modality of PD described here has potential as an alternative management option as it is a highly efficient, methodologically simple, and low-cost method without any need for sophisticated equipment. Physicians and parents should be aware of the adverse effects of a hypertonic phosphate enema and should never use these medications in infants and newborns.

Systemic and Local Inflammation in Peritoneal Dialysis: Mechanisms, Biomarkers and Effects on Outcome

Thanks to the technological development in peritoneal dialysis (PD) during the last three decades, the most important problem nowadays for the nephrologists is the maintenance of the long-term function of the peritoneal membrane. Although PD may exert an early survival benefit as compared with hemodialysis (HD), long-term PD is often associated with histopathological alterations in the peritoneal membrane that are linked to peritoneal ultrafiltration deficit and increased mortality risk. These alterations are closely related to the presence of a chronic activated (local and systemic) inflammatory response. PD itself may have other factors associated that could further modulate the inflammatory response, such as the bioincompatibility of dialysis solutions, fluid overload and changes in the body composition. Understanding the pathophysiology of inflammation in PD is essential for the adoption of adequate strategies to improve both membrane and patient survival. Copyright (C) 2009 S. Karger AG, Basel

Maintaining clearance in peritoneal dialysis

Numerous studies have now established that there is a strong association between small solute clearance and improved outcomes in peritoneal dialysis (PD) patients. Preservation of both renal and peritoneal clearances is therefore of paramount importance, although very few trials have satisfactorily addressed this critical issue. Observational studies have suggested that the groups most at risk of loss of residual renal function are women, non-whites, diabetic patients, patients with congestive cardiac failure, patients who experience frequent episodes of peritonitis and, possibly, patients treated with automated PD (APD). There have been no controlled trials of renoprotective therapies in PD patients, but reasonable strategies for preventing renal functional decline include avoidance of nephrotoxins and infection, maintenance of adequate blood pressure, abstinence from smoking and possibly administration of angiotensin-converting enzyme inhibitors and/or calcium channel blockers. In contrast, peritoneal small solute removal can be maximized by augmenting fill volume, increasing exchange frequency and using either long-dwell continuous ambulatory PD (CAPD) or short-dwell (APD) therapies to suit individual patients' transport characteristics. Tidal PD may additionally increase solute clearance, although studies have reported conflicting findings. Preservation of membrane function may be achieved by minimizing episodes of peritonitis and avoiding hypertonic glucose exchanges. Newer peritoneal dialysates, such as icodextrin, amino acids, bicarbonate-buffered solutions and aldehyde-poor fluids, are more biocompatible in experimental models of PD, but their long-term clinical safety and efficacy have not yet been established by clinical trials. Moreover, no trials have demonstrated an independent effect of peritoneal clearance on patient outcomes. Further studies determining the relative value of renal and peritoneal clearances are therefore urgently required in order to optimize dialytic adequacy for PD patients.

Icodextrin as salvage therapy in peritoneal dialysis patients with refractory fluid overload

Background Icodextrin is a high molecular weight, starch-derived glucose polymer, which is capable of inducing sustained ultrafiltration over prolonged (12–16 hour) peritoneal dialysis (PD) dwells. The aim of this study was to evaluate the ability of icodextrin to alleviate refractory, symptomatic fluid overload and prolong technique survival in PD patients. Methods A prospective, open-label, pre-test/post-test study was conducted in 17 PD patients (8 females/9 males, mean age 56.8 ± 2.9 years) who were on the verge of being transferred to haemodialysis because of symptomatic fluid retention that was refractory to fluid restriction, loop diuretic therapy, hypertonic glucose exchanges and dwell time optimisation. One icodextrin exchange (2.5 L 7.5%, 12-hour dwell) was substituted for a long-dwell glucose exchange each day. Results Icodextrin significantly increased peritoneal ultrafiltration (885 ± 210 ml to 1454 ± 215 ml, p < 0.05) and reduced mean arterial pressure (106 ± 4 to 96 ± 4 mmHg, p < 0.05), but did not affect weight, plasma albumin concentration, haemoglobin levels or dialysate:plasma creatinine ratio. Diabetic patients (n = 12) also experienced improved glycaemic control (haemoglobin Alc decreased from 8.9 ± 0.7% to 7.9 ± 0.7%, p < 0.05). Overall PD technique survival was prolonged by a mean of 11.6 months (95% CI 6.0–17.3 months). On multivariate Cox proportional hazards analysis, extension of technique survival by icodextrin was only significantly predicted by baseline net daily peritoneal ultrafiltration (adjusted HR 2.52, 95% CI 1.13–5.62, p < 0.05). Conclusions Icodextrin significantly improved peritoneal ultrafiltration and extended technique survival in PD patients with symptomatic fluid overload, especially those who had substantially impaired peritoneal ultrafiltration.

Obesity is associated with worse peritoneal dialysis outcomes in the Australia and New Zealand patient populations

Although obesity is associated with increased risks of morbidity and death in the general population, a number of studies of patients undergoing hemodialysis have demonstrated that increasing body mass index (BMI) is correlated with decreased mortality risk. Whether this association holds true among patients treated with peritoneal dialysis (PD) has been less well studied. The aim of this investigation was to examine the association between BMI and outcomes among new PD patients in a large cohort, with long-term follow-up monitoring. Using data from the Australia and New Zealand Dialysis and Transplant Registry, an analysis of all new adult patients (n = 9679) who underwent an episode of PD treatment in Australia or New Zealand between April 1, 1991, and March 31, 2002, was performed. Patients were classified as obese (BMI of greater than or equal to30 kg/m(2)), overweight (BMI of 25.0 to 29.9 kg/m(2)), normal weight (BMI of 20 to 24.9 kg/m(2)), or underweight (BMI of

High volume peritoneal dialysis vs daily hemodialysis: A randomized, controlled trial in patients with acute kidney injury

There is no consensus in the literature on the best renal replacement therapy (RRT) in acute kidney injury (AKI), with both hemodialysis (HD) and peritoneal dialysis (PD) being used as AKI therapy. However, there are concerns about the inadequacy of PD as well as about the intermittency of HD complicated by hemodynamic instability. Recently, continuous replacement renal therapy (CRRT) have become the most commonly used dialysis method for AKI around the world. A prospective randomized controlled trial was performed to compare the effect of high volume peritoneal dialysis (HVPD) with daily hemodialysis (DHD) on AKI patient survival. A total of 120 patients with acute tubular necrosis (ATN) were assigned to HVPD or DHD in a tertiary-care university hospital. The primary end points were hospital survival rate and renal function recovery, with metabolic control as the secondary end point. Sixty patients were treated with HVPD and 60 with DHD. The HVPD and DHD groups were similar for age ( 64.2 +/- 19.8 and 62.5 +/- 21.2 years), gender ( male: 72 and 66%), sepsis ( 42 and 47%), hemodynamic instability ( 61 and 63%), severity of AKI ( Acute Tubular Necrosis-Index Specific Score (ATN-ISS): 0.68 +/- 0.2 and 0.66 +/- 0.2), Acute Physiology, Age, and Chronic Health Evaluation Score (APACHE II) (26.9 +/- 8.9 and 24.1 +/- 8.2), pre-dialysis BUN (116.4 +/- 33.6 and 112.6 +/- 36.8mg per 100 ml), and creatinine ( 5.8 +/- 1.9 and 5.9 +/- 1.4 mg per 100 ml). Weekly delivered Kt/V was 3.6 +/- 0.6 in HVPD and 4.7 +/- 0.6 in DHD ( P<0.01). Metabolic control, mortality rate ( 58 and 53%), and renal function recovery ( 28 and 26%) were similar in both groups, whereas HVPD was associated with a significantly shorter time to the recovery of renal function. In conclusion, HVPD and DHD can be considered as alternative forms of RRT in AKI.

Advances in Peritoneal Dialysis in Acute Kidney Injury

Peritoneal dialysis (PD) is a simple, safe, cheap, and efficient renal replacement therapy method. It can correct metabolic disorders and fluid overload in acute kidney injury (AKI) patients both in and out of the intensive care unit. Use of PD in AKI is enhanced by placement of a Tenckhoff catheter, which can be safely accomplished at the bedside. Some PD modalities, such as high-volume PD and continuous-flow PD, can provide dialysis doses and efficiency comparable to extracorporeal blood purification methods. PD is particularly suitable for neonates, children, and patients with refractory heart failure or who are otherwise hemodynamically unstable. PD should be considered in situations where systemic anticoagulation and/or vascular access are problematic. PD is limited by a lower efficiency that may produce inadequate renal replacement in larger and/or severely hypercatabolic patients. Fluid removal can be unpredictable, there is a risk of infection, and possible issues with mechanical ventilation. In this article, we discuss the use of PD in AKI, with emphasis on recent advances. Copyright (c) 2012 S. Karger AG, Basel

Geographic and Educational Factors and Risk of the First Peritonitis Episode in Brazilian Peritoneal Dialysis Study (BRAZPD) Patients

Background and objectives Peritonitis remains as the most frequent cause of peritoneal dialysis (PD) failure, impairing patient's outcome. No large multicenter study has addressed socioeconomic, educational, and geographic issues as peritonitis risk factors in countries with a large geographic area and diverse socioeconomic conditions, such as Brazil.Design, setting, participants, & measurements Incident PD patients recruited from 114 dialysis centers and reporting to BRAZPD, a multicenter observational study, from December 2004 through October 2007 were included. Clinical, dialysis-related, demographic, and socioeconomic variables were analyzed. Patients were followed up until their first peritonitis. Cox proportional model was used to determine independent factors associated with peritonitis.Results In a cumulative follow-up of 2032 patients during 22.026 patient-months, 474 (23.3%) presented a first peritonitis episode. In contrast to earlier findings, PD modality, previous hemodialysis, diabetes, gender, age, and family income were not risk predictors. Factors independently associated with increased hazard risk were lower educational level, non-white race, region where patients live, shorter distance from dialysis center, and lower number of patients per center.Conclusions Educational level and geographic factors as well as race and center size are associated with risk for the first peritonitis, independent of socioeconomic status, PD modality, and comorbidities. Clin J Am Soc Nephrol 6: 1944-1951, 2011. doi: 10.2215/CJN.11431210

Peritoneal Dialysis-Related Peritonitis Due to Staphylococcus aureus: A Single-Center Experience over 15 Years

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Identification and antimicrobial susceptibility of Staphylococcus from home-treated peritoneal dialysis patients

Staphylococcus aureus is the main agent of infections during peritoneal dialysis (PD). The presence of S. aureus in the nasal cavity has been extensively studied and suggested as a risk factor of dialysis-related infections, whereas coagulase-negative Staphylococcus (CNS) species are frequently considered part of the normal human microbiota. The aim of this study was to identify Staphylococcus in the nasal cavity, pericatheter skin and peritoneal effluent from PD patients, as well as to evaluate the antimicrobial activity evolution in vitro. Thirty-two chronic PD patients were observed during 12 months and had nasal and pericatheter skin samples collected for culture. When peritonitis was detected, samples were also collected from the peritoneal effluent for culture. The activity of several antimicrobial drugs (penicillin G, oxacillin, cephalothin, ofloxacin, netilmicin and vancomycin) against different Staphylococcus species was measured by using the agar drug diffusion assay (Kirby-Bauer method). Staphylococcus was separated into S. aureus, S. epidermidis and other CNS species in order to determine the in vitro resistance level. S. epidermidis resistance to oxacillin progressively increased during the study period (p < 0.05). Resistance to ofloxacin was inexpressive, whereas resistance to netilmicin and vancomycin was not detected. of the oxacillin-resistant species (n = 74), 83% were S. epidermidis, 13% other CNS and 4% S. aureus (p < 0.05). Regarding multidrug resistant strains (n = 45), 82% were S. epidermidis, 13% other CNS, and 5% S. aureus (p < 0.05). This study shows the relevance of resistance to oxacillin and CNS multi-drug resistance, particularly concerning S. epidermidis, in PD patients.

High volume peritoneal dialysis for acute renal failure

Background. Peritoneal dialysis (PD) is still widely used for acute renal failure (ARF) in developing countries despite concerns about its inadequacy. Continuous PD has been evaluated in ARF by analyzing the resolution of metabolic abnormality and normalization of plasma pH, bicarbonate, and potassium.Methodology: A prospective study was performed on 30 ARF patients who were assigned to high-dose continuous PD (Kt/V = 0.65 per session) via a flexible catheter (Tenckhoff) and automated PD with a cycler. Fluid removal, pH and metabolic control, protein Loss, and patient outcome were evaluated.Results: Patients received 236 continuous PD sessions; 76% were admitted to ICUs. APACHE II score was 32.2 +/- 8.65. BUN concentrations stabilized after 3 sessions, creatinine after 4, and bicarbonate and pH after 2. Fluid removal was 2.1 +/- 0.62 L/day. Creatinine and urea clearances were 15.8 +/- 4.16 and 17.3 +/- 5.01 mL/minute respectively. Normalized creatinine clearance and urea Kt/V values were 110.6 +/- 22.5 L/week/1.73 m(2) body surface area and 3.8 +/- 0.6 respectively. Solute reduction index was 41% +/- 6.5% per session. Serum albumin values remained stable in spite of considerable protein tosses (median 21.7 g/day, interquartile range 9.1 - 29.8 g/day). Regarding ARF outcome, 23% of patients presented renal function recovery, 13% remained on dialysis after 30 days of follow-up, and 57% died.Conclusion: High-dose continuous PD by flexible catheter and cycler was an effective treatment for ARF. It provided high solute removal, allowing appropriate metabolic and pH control, and adequate dialysis dose and fluid removal. Continuous PD can therefore be considered an alternative to other forms of renal replacement therapy in ARF.

Utilization of peritoneal dialysis in the acute setting

Peritoneal dialysis (PD), although classically described and utilized in the treatment of patients with end-stage renal disease, can also be utilized in the acute setting in different clinical situations. Recent studies showed that, in patients with acute renal failure, it is possible to obtain reasonable dialysis doses with adequate metabolic and etectrolytic control and tow incidence of complications by utilizing continuous PD through a cycler at high volume. In patients with congestive heart failure without end-stage renal disease, PD is capable of promoting clinical improvement with slow removal of liquids, becoming an attractive alternative for situations of rapidly or slowly worsening cardiac function. In patients submitted to chronic hemodialysis but who have vascular access difficulties, PD can also be utilized as a bridge, thereby avoiding the use of central venous catheters, which can be associated with infectious complications such as bacterial endocarditis. New studies must be realized showing other indications for PD.