Sung Hee Chung

Poor outcomes for fast transporters on PD: the rise and fall of a clinical concern.

A rapid peritoneal solute transport rate (PSTR), generally termed a “high” PSTR, may in fact be associated with low small solute transport due to the low ultrafiltration rates with which it is associated; the term “fast” PSTR has, therefore, been proposed as a more accurate descriptive term. During the 1990s several studies showed that fast PSTR was associated with high mortality—presumably because it may lead to fluid overload, nutritional and metabolic alterations but also because it may be associated with other risk factors such as cardiovascular disease, other comorbid diseases, and inflammation. However, the consensus of today is that a fast PSTR is not as critical for patient survival as previously thought but that the prognosis depend on the type of fast PSTR: Type 1—an early inherent type which is associated with increased mortality mainly because it is associated with comorbidity and inflammation; these patients would have a poor prognosis also if they were treated by hemodialysis. Type 2—an early inherent type with a large peritoneal surface area; and Type 3—a late acquired type with peritoneal membrane changes which develop with time on peritoneal dialysis (PD); these two types have a good prognosis provided that fluid balance is controlled using automated peritoneal dialysis (APD) and icodextrin‐based PD solution. Thus, with the increased use of APD and icodextrin, the prognosis of fast transporters now looks less bleak. Perhaps, it will be possible in the future to even demonstrate improved survival in the Type 2 and Type 3 fast transporters using APD and icodextrin. In addition, there is hope that the new PD solutions may prevent the development of fast PSTR as well as have a favorable impact on its complications.

Effect of Prolonged Subcutaneous Implantation of Peritoneal Catheter on Peritonitis Rate during CAPD: A Prospective Randomized Study

We conducted a prospective randomized controlled study to confirm our earlier observation that prolonged subcutaneous implantation of peritoneal catheter reduced peritonitis rate when compared to retrospective data from patients with catheters placed by conventional access technique. A total of 60 patients were randomized into two groups: 30 patients had catheters left implanted subcutaneously for 6 weeks (I) and the other 30 patients had catheters inserted by conventional technique and had 6 weeks of break-in period (C). Subgroups of 15 patients each with new and conventional techniques used Y-connector (IY, CY) and remaining patients used standard spikes (IS, CS).Mean age was 47.7 years (range 16–71); 61.0% were male and 44.1% diabetics. Peritonitis, exit site infection, simultaneous peritonitis and exit site infection, and complication related to Staphylococcus or Pseudomonas infections were observed for up to 2 years in each patient after initiation of bag exchange or until termination of CAPD by transfer to hemodialysis or by death.Total duration of observation was 493.2 patient-months for new access technique and 409.6 patient-months for conventional technique. Patients in IY group had the lowest incidence of peritonitis (1/14.9 patient-months) and exit site infection (1/16.8 patient-months) among four subgroups. Peritonitis rate in IY was significantly lower compared to CY or CS. The total peritonitis-free period in those patients who did not experience peritonitis during the observation period was also significantly longer in IY (120 patient-months) than in CY (26 patient-months), IS (10.6 patient-months), or CS (10.4 patient-months). Simultaneous peritonitis and exit site infection was observed in none of IY group but 3 episodes in CY, 4 episodes in IS, and 3 episodes in CS. The rates of complications related to Staphylococcus aureus and Pseudomonas infections were also significantly lower in IY than in CY, IS, or CS. Technique survival did not differ between the two groups.The present results confirm our previous observation that the new access technique reduces the incidence of peritonitis probably by reducing infection via periluminal route. The Y-connector system further reduces peritonitis rate by reducing infection via intraluminal route.

Risk factors for mortality in diabetic peritoneal dialysis patients

BACKGROUND It is well established that the survival rate of diabetic end-stage renal disease patients remains the lowest among all primary diagnoses probably because of higher prevalence of cardiovascular diseases (CVD) associated with diabetes. This study was designed to evaluate the impact of CVD and other risk factors individually or in combination on mortality in diabetic peritoneal dialysis (PD) patients. METHODS In a retrospective study, 213 incident PD patients [118 had diabetes mellitus (DM), 94 were female, mean age 55 ± 13 years] underwent initial assessment of nutritional status, comorbid disease (CMD) survey, residual renal function (RRF), dialysis adequacy and peritoneal transport characteristics at a mean of 9 days (range, 3-24 days) after start of PD and were then followed for 30 ± 24 months (range, 3-115 months). Of 213 patients, 154 patients were reassessed after a mean of 11 months (range, 6-19 months). Nutritional status was assessed by subjective global assessment and other methods. CMD was graded by Davies index and included DM, CVD, liver disease and respiratory disease. RESULTS On Kaplan-Meier analysis, patient survival was significantly lower in female DM patients compared to other groups. The 3-year patient survival rate was 46, 70, 82 and 83% for female DM, male DM, male non-DM and female non-DM, respectively (P = 0.003). On Cox proportional hazards multivariate analysis including all patients, old age, presence of CVD or protein-energy wasting (PEW), low serum albumin concentration and low RRF were independent predictors of mortality but not DM per se or female gender. In DM patients, old age, female gender, presence of CVD or PEW and low RRF were independent predictors of mortality while old age was the only risk factor in non-DM patients. After adjustment for age, gender and RRF, DM patients with both CVD and PEW had a risk of mortality that was 3.3 times that of DM patients without CVD and PEW. In DM patients without CVD and PEW, patient survival was not different from that of non-DM patients without CVD and PEW. CONCLUSIONS DM per se was not a risk factor for mortality in this group of PD patients. Instead, the higher mortality rate in diabetic PD patients, in particular among female patients, was mainly attributable to concurrent morbidity such as CVD and PEW, together with low RRF.

Editorial: Poor Outcomes for Fast Transporters on PD: The Rise and Fall of a Clinical Concern

A rapid peritoneal solute transport rate (PSTR), generally termed a “high” PSTR, may in fact be associated with low small solute transport due to the low ultrafiltration rates with which it is associated; the term “fast” PSTR has, therefore, been proposed as a more accurate descriptive term. During the 1990s several studies showed that fast PSTR was associated with high mortality—presumably because it may lead to fluid overload, nutritional and metabolic alterations but also because it may be associated with other risk factors such as cardiovascular disease, other comorbid diseases, and inflammation. However, the consensus of today is that a fast PSTR is not as critical for patient survival as previously thought but that the prognosis depend on the type of fast PSTR: Type 1—an early inherent type which is associated with increased mortality mainly because it is associated with comorbidity and inflammation; these patients would have a poor prognosis also if they were treated by hemodialysis. Type 2—an early inherent type with a large peritoneal surface area; and Type 3—a late acquired type with peritoneal membrane changes which develop with time on peritoneal dialysis (PD); these two types have a good prognosis provided that fluid balance is controlled using automated peritoneal dialysis (APD) and icodextrin‐based PD solution. Thus, with the increased use of APD and icodextrin, the prognosis of fast transporters now looks less bleak. Perhaps, it will be possible in the future to even demonstrate improved survival in the Type 2 and Type 3 fast transporters using APD and icodextrin. In addition, there is hope that the new PD solutions may prevent the development of fast PSTR as well as have a favorable impact on its complications.

Causes of Poor Appetite in Patients on Peritoneal Dialysis

Anorexia is common in patients with chronic kidney disease and is a main contributor to the high prevalence of protein-energy wasting in them. The peritoneal dialysis (PD) procedure may further impair appetite by causing abdominal discomfort and also through the absorption of the osmotic agent and other factors. An increased peritoneal solute transport rate has been linked to protein-energy wasting and also to the malnutrition, inflammation, and atherosclerosis syndrome, which has been associated to poor appetite and plays a role in most premature deaths in these patients. The pathogenesis of these associations is unclear. In this review, we discuss the effect of PD, in particular, PD solutions, inflammation, and increased peritoneal solute transport rate, on appetite. We also describe strategies to increase appetite in PD patients.

Screening and study enrolment in the Randomized Evaluation of Normal vs. Augmented Level (RENAL) Replacement Therapy Trial

Background and Objectives: Aspects of trial design, screening and study efficiency can affect recruitment and the findings of the trial itself. A clear understanding of the screening and study inclusion process will assist clinicians in interpreting trial results. Design: Prospective observational data collection on all patients screened for possible inclusion in a randomized controlled trial of normal vs. augmented renal replacement therapy in critically ill patients (the RENAL Trial). Setting: 35 hospitals in Australia and New Zealand. Participants: All patients screened for the RENAL Trial. Results: We screened 4,551 patients. Of these patients, 767 were ineligible because of lack of inclusion criteria and 2,085 because of exclusion criteria. Of the remaining 1,699, 1,508 (88.7%) were enrolled. The three most common exclusion criteria which prevented recruitment of potentially eligible patients were that the patient had end-stage kidney failure and was already on chronic dialysis (484; 23.2%), the patient’s body weight was either <60 or >120 kg (456; 21.8%), and the fact that the patient had already received renal replacement therapy during the index admission. Important modifiable impediments to recruitment were inability to obtain consent in 191 cases, unavailability of research staff in 124 cases, physician objection in 89 cases, and inability to deliver the trial protocol in 78 cases. Conclusion: The RENAL Trial’s enrolment efficiency was high and compared favourably with previous large intensive care units trials and with that of trials in patients with acute renal failure. The high rate of enrolment suggests that the results can be applied with confidence to most patients with de novo acute renal failure. The loss of close to 1.5% of patients due to consent issues highlights a common problem in critical care trials. The low rate of physician objection suggests clinical equipoise.

Impact of incremental risk factors on peritoneal dialysis patient survival: proposal of a simplified clinical mortality risk score.

Background/Aim: Peritoneal dialysis (PD) patient survival is influenced by many factors and there is no consensus on the relative importance of these predictors, independently or combined. This study was designed to evaluate how these independent factors, alone or in various combinations, may influence PD patient survival. Methods: A peritoneal equilibration test, subjective global assessment (SGA), and comorbid diseases (CMD) were assessed. Results: On multivariate analysis, age (>60 years), CMD, malnutrition, and low RRF (≤2 ml/min) were independent predictors of mortality. Three-year patient survival was 100, 95, 75, 49, and 0%, and the risk ratio for mortality was 1.0, 6.6, 21.9, and 85.9 in patients with none, one, two, three, and four of these risk factors, respectively. Conclusions: The combination of independent predictors of mortality in PD patients leads to a markedly increasing risk for mortality. Evaluation of a single risk factor underestimates the true impact of risk factors.

Editorial: Poor Outcomes for Fast Transporters on PD: The Rise and Fall of a Clinical Concern: POOR OUTCOMES FOR FAST TRANSPORTERS ON PD

A rapid peritoneal solute transport rate (PSTR), generally termed a “high” PSTR, may in fact be associated with low small solute transport due to the low ultrafiltration rates with which it is associated; the term “fast” PSTR has, therefore, been proposed as a more accurate descriptive term. During the 1990s several studies showed that fast PSTR was associated with high mortality—presumably because it may lead to fluid overload, nutritional and metabolic alterations but also because it may be associated with other risk factors such as cardiovascular disease, other comorbid diseases, and inflammation. However, the consensus of today is that a fast PSTR is not as critical for patient survival as previously thought but that the prognosis depend on the type of fast PSTR: Type 1—an early inherent type which is associated with increased mortality mainly because it is associated with comorbidity and inflammation; these patients would have a poor prognosis also if they were treated by hemodialysis. Type 2—an early inherent type with a large peritoneal surface area; and Type 3—a late acquired type with peritoneal membrane changes which develop with time on peritoneal dialysis (PD); these two types have a good prognosis provided that fluid balance is controlled using automated peritoneal dialysis (APD) and icodextrin‐based PD solution. Thus, with the increased use of APD and icodextrin, the prognosis of fast transporters now looks less bleak. Perhaps, it will be possible in the future to even demonstrate improved survival in the Type 2 and Type 3 fast transporters using APD and icodextrin. In addition, there is hope that the new PD solutions may prevent the development of fast PSTR as well as have a favorable impact on its complications.