Outcomes after transfer from hemodialysis to peritoneal dialysis vs peritoneal dialysis as initial therapy: A systematic review and meta-analysis

Outcomes of patients who are transferred to peritoneal dialysis (PD) after an initial phase of hemodialysis (HD) compared to patients initiating dialysis with PD is controversial. We performed a systematic literature to assess evidence. Primary outcome was overall survival (OS), while secondary outcomes were technique failure, mortality and peritonitis. Meta-analysis indicated that PD initial group had significantly better OS as compared to HD to PD group. Pooled analysis demonstrated a significantly higher probability of technique failure in the HD to PD group as compared to PD initial group. Mortality rate in HD to PD group was significantly higher but there was no statistically significant difference in peritonitis rates between the two groups. On meta-regression analysis, transfer from HD to PD due to vascular access problems was associated with significantly reduced probability of OS. Our study indicates that patients transferred from HD to PD after at least 3 months of HD therapy may have reduced OS as compared to patients initiating dialysis with PD. Our findings lend some support to PD first policy and the need for heightened vigilance among the switched patients to monitor for adverse events.

Randomized, Open Label, Controlled Clinical Trial of Oral Administration of an Egg Albumin-Based Protein Supplement to Patients on Continuous Ambulatory Peritoneal Dialysis

Background/Aim

Malnutrition is highly prevalent in patients on continuous ambulatory peritoneal dialysis (CAPD) and is a strong predictor of increased morbidity and mortality. Therefore, the aim of this study was to evaluate the effect of oral administration of an egg albumin-based protein supplement on the nutritional status of CAPD patients.

Methods

In this randomized, open label, controlled clinical trial, 28 CAPD patients were allocated to a study ( n = 13) or a control ( n = 15) group. Both groups received conventional nutritional counseling; the study group received, additionally, an oral egg albumin-based supplement. During a 6-month follow-up, all patients had monthly clinical and biochemical evaluations and quarterly assessments of adequacy of dialysis and nutrition.

Results

Serum albumin levels were not different between groups; however, a significant increase (baseline vs final) was observed in the study group (2.64 ± 0.35 vs 3.05 ± 0.72 g/dL) but not in the control group (2.66 ± 0.56 vs 2.80 ± 0.54 mg/dL). Calorie and protein intake increased more in the study group (calories 1331 ± 432 vs 1872 ± 698 kcal; proteins 1.0 ± 0.3 vs 1.7 ± 0.7 g/kg) than in the control group (calories 1423 ± 410 vs 1567 ± 381 kcal; proteins 1.0 ± 0.4 vs 1.0 ± 0.3 g/kg). Similarly, non-protein nitrogen appearance rate (nPNA) increased significantly more in the study (1.00 ± 0.23 vs 1.18 ± 0.35 g/kg/day) than in the control group (0.91 ± 0.11 vs 0.97 ± 0.14 g/kg/day). Triceps skinfold thickness (TSF) and midarm muscle area (MAMA) displayed a nonsignificant trend to a greater increase in the study group (TSF 16.7 ± 8.7 vs 18.3 ± 10.7 mm; MAMA 23.8 ± 6.2 vs 25.8 ± 5.9 cm2) than in controls (TSF 16.4 ± 5.7 vs 16.9 ± 7.0 mm; MAMA 28.7 ± 7.8 vs 30.0 ± 7.9 cm2). At the end of follow-up, the frequency of patients with moderate or severe malnutrition decreased 6% in the control group and decreased 28% in the study group. At the final evaluation, the most important predictors of serum albumin were the oral egg albumin-based supplement administration and protein intake ( p < 0.05); secondary predictors ( p = 0.06) were peritoneal transport rate and MAMA.

Conclusions

In the study group, oral administration of the egg albumin-based supplement significantly improved serum albumin, calorie and protein intake, and nPNA, and, compared to controls, this maneuver was associated with a trend to increased anthropometric parameters and improved Subjective Global Assessment evaluation. Oral administration of the albumin supplement and protein intake were the most significant predictors of serum albumin at the end of follow-up. This oral supplement may be a safe, effective, and cheap method to improve nutritional status in peritoneal dialysis patients.

The Role of Peritoneal Dialysis as the First-Line Renal Replacement Modality

Twenty years after its introduction, peritoneal dialysis (PD) is a well-established alternative to hemodialysis (HD) as a modality of renal replacement therapy. Much debate and research is apparent in the literature, comparing hemodialysis and PD as “opposite” modalities and trying to ascertain which modality should be more optimal.

In our opinion, HD and PD are two distinct modalities, each with its own advantages and disadvantages. In addition, it is clear that for both HD and PD, rates of technique failure are high, causing patients to transfer between modalities. The question is thus not which modality is best, but rather, which flow-chart of modalities makes best use of the advantages of each modality, while avoiding its disadvantages. In this respect, HD and PD appear to be complementary modalities.

The better preservation of residual renal function, lower risk of infection with hepatitis B and C, better outcome after transplantation, preservation of vascular access, and lower costs are arguments to promote PD as a good initial treatment. When PD-related problems arise (adequacy, ultrafiltration, peritonitis, patient burnout), a timely transfer to HD has to be planned.

This editorial tries to review arguments supporting the complementary nature of both modalities, and especially the role of PD as the first-line renal replacement therapy.

Rate of Decline of Residual Renal Function in Patients on Continuous Peritoneal Dialysis and Factors Affecting It

Objective

We analyzed residual renal function (RRF) in a large number of new peritoneal dialysis (PD) patients to prospectively define the time course of decline of RRF and to evaluate the risk factors assumed to be associated with faster decline.

Study Design

Single-center, prospective cohort study.

Setting

Home PD unit of a tertiary care University Hospital.

Patients

The study included 242 patients starting continuous PD between January 1994 and December 1997, with a minimum follow-up of 6 months and at least three measurements of RRF.

Measurement

All patients had data on demographic and laboratory variables, episodes of peritonitis and the use of aminoglycoside (AG) antibiotics, temporary hemodialysis, and number of radiocontrast studies. Adequacy of PD was measured from 24-hour urine and dialysate collection and peritoneal equilibration test using standard methodology. Further data on RRF was collected every 3 to 4 months until the patient became anuric (urine volume < 100 mL/day or creatinine clearance < 1.0 mL/min) or until the end of study in December 1998.

Outcome Measure

The slope of the decline of residual glomerular filtration rate (GFR) (an average of renal urea and creatinine clearance) was the main outcome measure. Risk factors associated with faster decline were evaluated by a comparative analysis between patients in the highest and the lowest quartiles of the slopes of GFR, and a multivariate analysis using a stepwise option within linear regression and general linear models.

Results

There was a gradual deterioration of residual GFR with time on PD, with 40% of patients developing anuria at a mean of 20 months after the initiation of PD. On multivariate analysis, use of a larger volume of dialysate ( p = 0.0001), higher rate of peritonitis ( p = 0.0005), higher use of AG ( p = 0.0006), presence of diabetes mellitus ( p = 0.005), larger body mass index (BMI) ( p = 0.01), and no use of antihypertensive medications ( p = 0.04) independently predicted the steep slope of residual GFR. Male gender, higher grades of left ventricular dysfunction, and higher 24-hour proteinuria were associated with faster decline on univariate analysis only.

Conclusion

Faster decline of residual GFR corresponds with male gender, large BMI, presence of diabetes mellitus, higher grades of congestive heart failure, and higher 24-hour proteinuria. Higher rate of peritonitis and use of AG for the treatment of peritonitis is also associated independently with faster decline of residual GFR. Whether the type of PD (CAPD vs CCPD/NIPD) is associated with faster decline of residual GFR remains speculative.

Enhanced Ultrafiltration using 7.5% Icodextrin / 1.36% Glucose Combination Dialysate: A Pilot Study

Objective

A pilot study to compare the use of a combination dialysate (7.5% icodextrin / 1.36% glucose) versus icodextrin 7.5% alone for the long dwell in patients on peritoneal dialysis (PD).

Design

A 4-week, prospective, randomized crossover study.

Setting

A large regional renal unit providing treatment for a population of 1.7 million.

Patients

Five patients on continuous ambulatory PD (CAPD) and 3 patients on automated PD.

Main Outcome Measurements

Long-dwell and 24-hour ultrafiltration volumes, body weight, 24-hour ambulatory blood pressure, and antihypertensive / diuretic tablet count.

Results

The use of the combination dialysate resulted in an increase in the median (interquartile range) long-dwell ultrafiltration, from 750 (650 – 828) mL to 1000 (889 – 1100) mL ( p < 0.001), and 24-hour ultrafiltration, from 739 (400 – 1623) mL to 956 (700 – 1750) mL ( p < 0.001). Weight, blood pressure, and tablet count remained unchanged.

Conclusions

The use of the novel combination dialysate resulted in a 33% increase in long-dwell ultrafiltration and a 29% increase in 24-hour ultrafiltration.

Comparison of peritoneal dialysis with hemodialysis on survival of diabetic patients with end-stage kidney disease: a meta-analysis of cohort studies

Aim: Renal replacement therapy was primary treatment for end stage kidney (ESRD) patients. Numbers of studies comparing peritoneal dialysis (PD) and hemodialysis (HD) yielded inconsistent results. The aim of this study was to assess the mortality risk between diabetic PD patients and those in HD.

Methods: We included cohort studies comparing the risk of death among diabetic ESRD patients who receiving peritoneal dialysis or hemodialysis by searching Medline and Embase. Overall estimates were calculated using the random-effects model.

Results: Seventeen studies were included in the meta-analyses. Mortality comparison between PD and HD in the diabetic ESRD patients showed PD significantly increased mortality rate (hazard ratio (HR) 1.20; 95% confidence interval (CI) 1.10–1.30; I² = 89.1%). The overall HR using an intention-to-treat analysis was 1.23 with 95% CI (1.13 to 1.34). Meta-regression demonstrated PD patients from Asian country were associated with increase in mortality risk (coefficient = 0.270, SE = 0.112, p = .033).

Limitation: The high heterogeneity in our meta-analyses undermined the robustness of the findings.

Conclusion: ESRD patients with diabetes may benefit more from HD than PD.

The Impact of Fluid Overload and Variation on Residual Renal Function in Peritoneal Dialysis Patient

BACKGROUND

The effect of fluid overload and variation on residual renal function (RRF) in peritoneal dialysis (PD) patients is controversial.

METHODS

Retrospective cohort study was designed. One-hundred and ninety PD patients with measured glomerular filtration rate (mGFR) ≧ 3 ml/min/1.73 m2 were recruit. Fluid status of every participant was assessed by bioelectrical impedance analysis (BIA) every 3 months for 1 year. The cohort was divided into three hydration groups, namely persistent overhydration (PO) group, intermittent overhydration (IO) group and normal hydration (NH) group. Additionally, participants were also divided into high or low fluid variation groups. The decline rate of RRF and the event of anuria were followed up for 1 year. The association of fluid overload with RRF loss was evaluated by Cox proportional hazard models adjusted for confounders.

RESULTS

Thirty-six (18.9%) patients developed anuria. The decline rate of mGFR in both PO and IO groups were significantly faster than that of NH group (PO vs NH: -0.2 vs -0.1 ml/min/1.73 m2/month, p < 0.01; IO vs NH: -0.2 vs -0.1 ml/min/1.73 m2/month, p < 0.01). Kaplan-Meier analysis showed poorer RRF outcome in both PO and IO groups compared with that of NH group (PO vs NH: p < 0.001; IO vs NH: p = 0.006). Patients with high fluid variation had worse RRF survival than those with low fluid variation (p = 0.04). Adjusted Cox regression models indicated the hazard ratio of RRF loss in PO group was 8.90-folds higher (95% confidence interval 3.07-31.89) than that in NH group.

CONCLUSIONS

These findings suggested fluid overload was independently associated with the decline of RRF in PD patients.

Peritoneal Dialysis Access: Open versus Laparoscopic Surgical Techniques

Aim

To outline pros and cons with the open and laparoscopic techniques when placing peritoneal dialysis (PD) catheters.

Background

Controversy exists regarding which technique, the open and laparoscopic, if any, is superior to the other. In addition, there is the question of which approach is best in rescuing malfunctioning PD catheters.

Results

Rather than promoting one doctrine fits all, philosophically, doing the right thing for the patient by specific criteria is ethically the better model. These specific selection criteria include patient characteristics, the team's skills and knowledge and institutional resources and commitment. Also, the sophistication of a PD unit for training and monitoring of patients is crucial for successful outcomes. Open paramedian and two laparoscopic approaches are described in detail, outlining advantages and disadvantages of each, with suggestions when one method is preferred.

Conclusions

In general, the laparoscopic technique is associated with longer operative times, higher costs and the need to utilize general anesthesia. It is, however, the preferred method when rescuing malfunctioning catheters and may increase the PD patient population in patients with previous abdominal surgeries. The dialysis access surgeon should be familiar with both open and laparoscopic techniques and appropriately choose the ideal method based upon the individual patient and institutional resources.

Clinical outcomes of peritoneal dialysis patients transferred from hemodialysis: a matched case-control study

OBJECTIVE

Our study aimed to evaluate clinical outcomes of patients transferred to peritoneal dialysis (PD) because of complications related to hemodialysis (HD). ♢

METHODS

In a 1:2 matched case-control study, we compared patient and technique survival between patients initially treated with HD for at least 3 months and then transferred to PD (transfer group) and patients started on and continuing with PD (no-transfer group). ♢

RESULTS

All baseline characteristics except for initial residual urinary output were comparable between the groups. Compared with patients in the transfer group, patients in the no-transfer group had a higher initial daily residual urinary output [850 mL (range: 600 - 1250 mL) vs 0 mL (range: 0 - 775 mL/d), p = 0.000]. The main reasons for transfer to PD were vascular access problems and cardiovascular disease. Patient survival and technique failure rates did not significantly differ between the groups (p > 0.05). The 1-, 3-, and 5-year patient survival rates were 80.0%, 53.7%, and 27.6% in the transfer group and 89.7%, 60.2%, and 43.1% in the no-transfer group. Age (per 10 years) and serum albumin were independent risk factors for long-term survival in PD patients. Relative risk of either death or technique failure was not significantly increased in patients transferred from HD. ♢

CONCLUSIONS

Patients who transferred to PD after failing HD had outcomes on PD similar to those for patients who started with and were maintained on PD. Age (per 10 years) and serum albumin were independent risk factors for long-term survival in PD patients.

Should the Preservation of Residual Renal Function Cost Volume Overload and Its Consequence Left Ventricular Hypertrophy in New Hemodialysis Patients?

BACKGROUND

Left ventricular hypertrophy (LVH) is an important predictor of mortality in dialysis patients. The loss of residual renal function (RRF) appears to occur more rapidly in hemodialysis than continuous ambulatory peritoneal dialysis (CAPD). It is more likely that volume expansion in patients on CAPD may preserve RRF. The aim of this study was to investigate whether there is a cause-effect relationship between volume overload and preserving RRF in new hemodialysis patients.

METHODS

Nineteen patients with end-stage renal disease (ESRD) starting hemodialysis therapy were included in the study. At the beginning, their elevated blood pressures (BP) were treated with antihypertensive drugs. Thereafter, until normovolemia and normal BP were obtained, strict volume control was applied. The effects of both treatment modalities on the loss of RRF and LVH were evaluated prospectively.

RESULTS

At the initial examination, all of the patients were hypertensive and had markedly increased left ventricular mass index (LVMI). The daily urine production was 1575+/-281 mL. At the end of drug treatment period lasting three months, although BP significantly decreased, daily urine production and LVMI only decreased by 12% and 6%, respectively. At the end of the period in which strict volume control was applied, the body weight significantly decreased (from 60+/-5 to 55+/-8 kg, p<0.0001). This decrease in body weight was accompanied by marked decreases in dilated cardiac chamber size and more importantly daily urine production. At the end of this period, while 7 of 19 patients had no residual urine production, residual urine production was below 200 mL/d in the remaining 12 patients. Although the period of volume control was short, there was significant reduction in the LVMI (decreased from 251+/-59 to 161+/-25 gr/m2, p<0.0001).

CONCLUSION

The results of our prospective study have clearly shown that the persistence of residual renal function in patients with ESRD starting hemodialysis therapy may largely depend on volume overload. Equally interesting was the finding that despite significantly reduced BP level with hypotensive drugs, there was no marked regression in LVMI. In the contrary, after the volume control period, LVMI was significantly decreased. Our results support the hypotheses that decrease in volume may be more important than pressure reduction in regressing the left ventricular hypertrophy.

Residual Renal Function and Volume Control in Peritoneal Dialysis Patients

BACKGROUND

Fluid overload is not uncommon in patients on continuous ambulatory peritoneal dialysis (CAPD). Previous studies suggested that residual renal function (RRF) played an important role in maintaining fluid balance. However, good fluid status should be a balance between fluid intake and removal. Therefore, in the present study, we investigated the effect of RRF on patients' fluid status after focusing on the balance between fluid intake and removal in CAPD patients.

METHODS

In this cross-sectional study, 195 stable CAPD patients in a single center were included. Patients were divided into three groups according to their urine output: anuric group with urine < or =100 ml/day, oliguric group with urine < or =400 ml/day and UO >400 ml group with urine >400 ml/day. Fluid status was evaluated by bioimpedance analysis and mean arterial pressure (MAP). The sodium removal and plasma sodium concentration were also measured. All the patients were educated to try to achieve good volume control by focusing on salt and fluid intake and their removals.

RESULTS

There were 51, 31 and 113 patients in anuric, oliguric and UO >400 ml group, respectively. Anuric patients were older and had been on CAPD longer than that of the oliguric and UO >400 ml patients (p < 0.05). The urine output in the three groups were 9.28 +/- 22.68, 236.13 +/- 75.43 and 1,013.34 +/- 541.54 ml/day, respectively (p < 0.001). Bioimpedance analysis showed that the differences of extracellular water, intracellular water and total body water were not statistically significant among the three groups. However, there was significant difference in MAP among the three groups (MAP in anuric, oliguric and UO >400 ml groups were 93.27 +/- 13.35, 96.63 +/- 9.94 and 102.36 +/- 13.70 mm Hg, p < 0.01), and UO >400 ml group had higher MAP than anuric and oliguric groups (p < 0.05). The total sodium removal (renal + peritoneal) in anuric, oliguric and UO >400 ml groups were 96.44 +/- 60.18, 98.95 +/- 73.82 and 134.64 +/- 72.44 mmol/day, respectively (p < 0.01). The UO >400 ml group also had higher plasma sodium concentration than anuric and oliguric groups (plasma sodium in the three groups were 137.49 +/- 3.43, 137.82 +/- 2.63 and 139.15 +/- 3.30 mmol/l, respectively; p < 0.01).

CONCLUSIONS

This study showed that extracellular water among anuric, oliguric and UO >400 ml groups was not significantly different, which suggested that RRF may be not so important as expected in maintaining good volume status. The higher blood pressure in patients with higher RRF and higher sodium and fluid removal in the present study suggested restricting salt and fluid intake might be more important for better blood pressure control in CAPD patients.

Peritoneal Dialysis: A Viable Renal Replacement Therapy Option

The number of patients with end-stage renal disease requiring dialysis has increased markedly over the last decade and continues to grow at an alarming rate in the United States. Of the currently available dialysis options for end-stage renal disease (hemodialysis and peritoneal dialysis), peritoneal dialysis (PD) is underutilized in the United States for nonmedical reasons. In fact, PD is the less expensive dialysis modality and may provide a survival advantage over hemodialysis in first 2 to 4 years of treatment, but that advantage is not as robust with increasing age and with the presence of diabetes. Moreover, the initial survival advantage is lost in long-term PD, mainly owing to changes in the peritoneal membrane from the use of conventional bio-incompatible PD solutions. Current data suggest that not many patients continue on PD beyond 10 years. The recent development of a more biocompatible PD solution should help to preserve membrane function, promote ultrafiltration, improve nutritional status, and, it is hoped, prolong the survival advantage of PD. Identification of molecular mechanisms involved in cellular responses leading to peritoneal fibrosis and angiogenesis evokes new therapeutic strategies that might protect the peritoneal membrane against the consequences of long-term PD.

Nutritional status in peritoneal dialysis: studies in body composition, lipoprotein metabolism and peritoneal function

This thesis is based on clinical studies including virtually all patients treated with peritoneal dialysis in Gothenburg during the 1990s. The patients had a fundamentally altered body composition compared to healthy subjects, characterised by a reduction in body cell mass and body fat already at start of dialysis. During PD treatment. a further decrease in body cell mass was observed. Energy stores tended to normalise during the first years of treatment and remained constant thereafter, or declined subsequently. Extracellular water, calculated from the four-compartment model, was increased when patients started PD treatment and increased further, in parallel to the reduction in body cell mass. These alterations were seen in combination with a normal. or slightly reduced, body weight. Standard methods of assessing nutritional status may therefore not be valid in the dialysis population. Prediction equations to estimate total body water, used in measurements of dialysis adequacy, give erroneous results in PD patients, as shown in a study on our PD population. This may have important clinical consequences, especially in wasted patients. Reduced muscle mass is a marker of protein-energy malnutrition, and therefore simple and reliable methods to measure muscle mass are warranted. When lean body mass was calculated from creatinine generation rate and compared to lean body mass estimated from measurements of total body potassium. the agreement between the two methods was low. Furthermore, when repeated measurements of creatinine generation rate were performed, the variation coefficient was unacceptably high. Thus. creatinine generation rate cannot be recommended as a method to evaluate somatic protein status in PD patients. The lipoprotein metabolic derangements are pronounced in PD patients. in which a further increase in cholesterol and cholesterol-rich apoB-containing lipoproteins are added to the already pre-existing renal dyslipidemia. characterised by increased concentration of triglycerides and triglyceride-rich complex lipoproteins. There are indications that dialytic variables may influence this development. When peritoneal function was assessed by the Peritoneal Dialysis Capacity test at start of dialysis, it was observed that peritoneal function reflected patient characteristics and co-morbidity. Patients with systemic disease had enhanced diffusion capacity compared to patients with primary renal disorders. Furthermore, in patients with more severe co-morbidity. peritoneal protein losses were increased. Finally, elderly patients had ultrafiltration conditions that were different from those of younger patients. Peritoneal function remained essentially stable during medium-long term follow up. Body composition features in dialysis patients are similar to those seen in severe disease in general. Thus, it is difficult to separate the effects of malnutrition from the effects of the underlying disease. Specific standards for nutritional status adapted for patients with renal failure are required.

Peritoneal dialysis in anuric patients: concerns and cautions

Most recent studies have found an equivalent survival for patients on peritoneal dialysis (PD) and hemodialysis (HD); evidence even suggests that PD might be the preferred modality during the first 3-4 years of renal replacement therapy. This is probably related to the continuous and minimally invasive character of PD as compared to HD, resulting in better preservation of residual renal function (RRF) and less cardiovascular strain. On the other hand, blood pressure control, fluid balance, and adequacy targets may be difficult to obtain in long-term PD patients. The question arises whether PD is a feasible option in anuric patients. It is clear that the answer depends on the body size and the peritoneal membrane transport characteristics of the patient, so that PD will be feasible in some anuric patients, whereas in others it will not be. Evaluation of the peritoneal transport characteristics and adaptation of the PD prescription is warranted. A constant evaluation of the fluid balance, nutritional, and cardiovascular status is needed. This article reviews the physiologic insights and clinical evidence necessary for a good PD prescription in anuric patients.

Iodine-131 ablation therapy for a patient receiving peritoneal dialysis

The authors describe a patient with follicular thyroid carcinoma who was receiving continuous ambulatory peritoneal dialysis to manage end-stage renal disease. To deliver radioiodine therapy to ablate thyroid remnants safely and under optimal conditions, the behavior of 37 MBq (1 mCi) I-131 was followed daily for 3 days. Blood activity and total body count decreased with a half-life of 100 hours (4.17 days). The daily iodide removal rate, estimated as a percentage of the total administrated activity, was low: 5.3% to 8.6% in peritoneal dialysate and 1.3% to 2.2% in urine. The thyroid uptake, measured using a probe, was 2.4% to 2.1% from day 1 to day 3 and 1.9% later at day 8. The volume of thyroid remnants was determined by ultrasonography to be 0.6 g. The patient received a reduced ablative I-131 dose of 814 MBq (22 mCi). Radiation emitted from the patient after I-131 therapy, monitored using a radiation monitor probe located at a distance of 1 meter, decreased with an effective half-life of 70 hours (2.9 days). The integration of the curve from t = 0 showed a level always less than 25 microSv/hour as early as 24 hours after treatment. Because the iodine removal rate is continuous but low in a case of peritoneal dialysis, smaller therapeutic doses must be administered to deliver maximal radiation to residual thyroid tissue while minimizing excessive radiation exposure to patients, their families, and medical staff.

Role of diuretics in the preservation of residual renal function in patients on continuous ambulatory peritoneal dialysis

BACKGROUND

Patients on continuous ambulatory peritoneal dialysis (CAPD) are dependent on residual renal function for solute and water clearances, and this declines with time on dialysis. Loop diuretics have been postulated to slow this decline.

METHODS

Sixty-one patients new to dialysis were randomly assigned to either furosemide 250 mg every day or no furosemide at the time of CAPD training and were followed prospectively. Urine volume (UV), urea clearance (C(Urea)), and creatinine clearance on cimetidine (C(Cr)) were measured at randomization at six months and at one year. Patients underwent a standard four-hour peritoneum equilibrium test, and total body water was measured by bioelectrical impedance. Results were expressed on an intention-to-treat basis.

RESULTS

UV, C(Cr), and C(Urea) were similar at randomization (1020 +/- 104 vs. 1040 +/- 130 mL/24 hours, 4.95 +/- 0.51 vs. 4.07 +/- 0.40 mL/min/1.73 m2, 0.91 +/- 0.09 vs. 0.84 +/- 0.08, diuretic vs. control). UV in the diuretic-treated group increased, whereas in the control group, it declined (+176 vs. -200 mL/24 hours at 6 months and +48.8 vs. -305 mL/24 hours at 1 year, P < 0.05). C(Cr) and C(Urea) declined at a constant rate and were unaffected by diuretic administration (0.12 +/- 0.05 vs. 0.071 +/- 0.04 mL/min/1.73 m2/month, 0.020 +/- 0.01 vs. 0.019 +/- 0.01 per month). Urinary sodium excretion increased in the diuretic group and declined in the control group (+0.72 +/- 0.85 vs. -2.56 +/- 1.31 mmol/24 hours/month, P = 0.04). Body weight rose in both groups (4.3 vs. 3.0 kg), but the percentage of total body weight rose in the control group and remained constant in the diuretic group (52 +/- 2.4 vs. 64 +/- 6.6%, P = 0.10).

CONCLUSIONS

Long-term furosemide produces a significant increase in UV over 12 months when on CAPD and may result in clinically significant improvement in fluid balance. However, furosemide has no effect on preserving residual renal function.

Preservation of glomerular filtration rate on dialysis when adjusted for patient dropout

BACKGROUND

Residual renal function (RRF) plays an important role in dialysis patients. Studies in patients on maintenance dialysis suggest that RRF is better preserved in patients receiving peritoneal dialysis (PD) vis-à-vis those receiving hemodialysis (HD). We speculated that regardless of the patient's type of therapy, the estimate obtained for the rate of decline in glomerular filtration rate (GFR) may be biased because of informative censoring associated with patient dropout. Informative censoring occurs when patients who die or transfer to another modality very early have associated with them a lower starting GFR or a higher rate of decline of GFR than patients who either complete the study or who die or transfer much later. If patient dropout is indeed related to the rate of decline in GFR and if this relationship is ignored in the analysis, then the estimate obtained of the rate of decline in GFR may be biased.

METHODS

In an attempt to determine if there is a relationship between patient dropout and the decline in GFR, we reanalyzed the CANUSA data by modeling GFR as a nonlinear function of time with the rate of decline being exponential.

RESULTS

This article highlights the significance of "informative censoring" when studying the decline of RRF on dialysis. The results show that for the CANUSA cohort, the mean initial GFR was significantly lower, and the rate of decline was significantly higher for patients who died or transferred to HD than for patients who were randomly censored or received a transplant. It is important to emphasize that the impact of informative censoring on previous analyses of the decline of RRF between PD versus HD is presently unclear. If bias caused by informative censoring is the same regardless of what therapy a patient is on, then conclusions from previous studies comparing the decline in GFR between PD and HD would still be valid. However, if the magnitude of the bias differs according to therapy, then additional adjustments would be needed to fairly compare the decline in GFR between PD and HD. Because this analysis is restricted to patients on PD, it would be scientifically incorrect to interpret previous studies solely on the basis of the results from this analysis.

CONCLUSION

In any longitudinal study designed to estimate trends in an outcome measured over time, it is important that the analysis of the data takes into account any effect patient dropout may have on the estimated trend. This analysis demonstrates that among PD patients, both the starting GFR and the rate of decline in GFR are associated with patient dropout. Consequently, future studies aimed at estimating the rate of decline in GFR among PD patients should also account for any dependencies between dropout and GFR. Similarly, data analyzing for apparent differences in the rate of decline of GFR between PD and HD should also adjust for possible informative censoring.

An evaluation of an integrative care approach for end-stage renal disease patients

Studies analyzing the outcome of integrative care of end-stage renal disease (ESRD) patients, whereby patients are transferred from one renal replacement modality to another according to individual needs, are scant. In this study, we analyzed 417 files of 223 hemodialysis (HD) and 194 peritoneal dialysis (PD) patients starting renal replacement therapy between 1979 and 1996, to evaluate the effect of such an approach. Analysis was done for survival of patients on their first modality, for intention-to-treat survival (counting total time on renal replacement therapy, but with exclusion of time on transplantation), and for total survival. Log rank analysis was used and correction for risk factors was performed by Cox proportional hazards regression. Intention-to-treat survival and total survival were not different between PD and HD patients (log rank, P > 0.05). Technique success was higher in HD patients compared to PD patients (log rank, P = 0.01), with a success rate after 3 yr of 61 and 48%, respectively. Thirty-five patients were transferred from HD to PD and 32 from PD to HD. Transfer of PD patients to HD was accompanied by an increase in survival compared to those remaining on PD (log rank, P = 0.001), whereas, in contrast, transfer of patients from HD to PD was not (log rank, P = 0.17). Survival of patients remaining more than 48 mo on their initial modality was lower for PD patients (log rank, P < 0.01). A matched-pair analysis between patients who started on PD and who were transferred to HD later (by definition called integrative care patients), and patients who started and remained on HD, showed a survival advantage for the integrative care patients. These results indicate that patient outcome is not jeopardized by starting patients on PD, at least if patients are transferred in a timely manner to HD when PD-related problems arise.