Current concepts. Continuous ambulatory peritoneal dialysis

30 Years of Peritoneal Dialysis Development: The past and the Future

A review is given of 30 years of development in peritoneal dialysis (PD). After a short description of the first 20 years, the main emphasis is put on the last 10 years. Subjects discussed are the increasing use of PD in high-risk populations, peritonitis and other catheter-related problems, adequacy of dialysis and nutrition, patient outcomes in comparison with hemodialysis, and peritoneal membrane changes with time on PD. Topics that have emerged during the last decade and the challenges for the next decennium are discussed. The great importance of quality assurance in fast-growing PD populations and of prevention of long-term membrane alterations are emphasized.

Initial Treatment of Dialysis Associated Peritonitis: A Controlled Trial of Vancomycin versus Cefazolin

Objective

To determine if intraperitoneal administration of vancomycin (a slowly absorbed antibiotic) im proves the management of dialysis-associated peritonitis over that obtained by using cefazolin, an equally potent, rapidly absorbed antibiotic.

Setting

A university operated teaching hospital, with patient treatment initiated at home.

Patients

One hundred thirty-one patients trained to perform peritoneal dialysis (CAPD and CCPD) and followed at the University of Iowa Hospitals and Clinics Home Dialysis Treatment Center.

Design

Patients were prospectively allocated into groups adding either vancomycin 25 mgm/L, orcefazolin 50 mgm/L to their dialysate when signs or symptoms of peritonitis developed. Treatment results were analysed using chi-square testing.

Findings

Compared to cefazolin, initial peritonitis therapy with vancomycin improved the peritonitis resolution rate [67% vs 81 %; p=0.008], reduced the incidence of hospital admissions [68% vs 48%; p=0.001], and decreased the risk of superinfection [4% vs 0%; p=0.039].

Conclusion

Vancomycin appeared to be superior to cefazolin in the treatment of peritoneal dialysis associated peritonitis.

Reviews and Original Articles

The recommendations provided in this document represent a distillation of various experiences, as well as data obtained from published studies in the setting of substantial changes in antibiotic sensitivity. It is hoped that this revised compilation will provide a basis upon which future developments and advances can be made in the therapeutic approach to infectious complications of peritoneal dialysis.

Continuous Ambulatory Peritoneal Dialysis: An Option in the Developing World?

Objective

To evaluate specified biomedical, socio-economic, and psychosocial criteria as predictors of therapeutic success to optimize patient selection for continuous ambulatory peritoneal dialysis (CAPD) in a developing country.

Design

A restrospective cohort study investigating the relationship between episodes of peritonitis and exitsite infection, and predetermined biomedical, socioeconomic, and psychosocial data.

Setting

A CAPD unit in a large tertiary care teaching hospital.

Patients

AI1132 patients entering the CAPD program between 1987 and 1991.

Results

Overall mean survival time on CAPD was 17.3 months. Peritonitis rates were high, especially among blacks. Multivariate analysis demonstrated that increased peritonitis rates were associated with age, black race, diabetes, and strongly so with several psychosocial factors. Because being black was strongly linked to poor socioeconomic conditions, repeat analysis excluding blacks showed the same associations with the above variables, but, additionally, several socioeconomic factors were associated with high peritonitis rates. No significant explanatory variables were shown for exit-site infections.

Conclusions

The association of biomedical, socio-economic, and psychosocial variables with high peritonitis rates has important implications for the selection of patients for CAPD in this setting.

Abdominal Cocoon: An Animal Model for a Complication of Peritoneal Dialysis

Objective

The purpose of this work was to develop an animal model of sclerosing encapsulating peritonitis, a complication of continuous ambulatory peritoneal dialysis in which the intestines are conglomerated into an ovoid cocoonlike structure.

Design

Toward this end, rats were injected with a chemical irritant (household bleach) intraperitoneally. One week later, before the resultant peritonitis could cause adhesions, 10 or 25 mL of fresh whole rat blood was injected into the peritoneal cavity. Two weeks later, the effect of the treatments was evaluated by macroscopic and microscopic study.

Results

The irritant caused a chemical peritonitis. The subsequently injected blood clotted on the surfaces of the inflamed intestines, and contraction of the clot (syneresis) was responsible for bringing the intestinal loops together. This conglomeration was made permanent by the fibrosis evoked by the chemical peritonitis. The end result was an ovoid encapsulated mass of intestines and other viscera.

Conclusion

An animal model for an abdominal cocoon has been produced. It can be used for studies of the pathogenesis and prevention of this complication of peritoneal dialysis.

Phagocytosis and Killing of Suspended and Adhered Bacteria by Peritoneal Cells after Dialysis

Objective

To determine the effect of dialysis fluid containing various glucose concentrations on the phagocytosis and killing of Staphylococcus aureus by rat peritoneal cells under conditions mimicking the in vivo situation.

Design

Phagocytosis and killing were evaluated by quantitation of the killing capacity of macrophages after in vivo phagocytosis of the bacteria as well as by an in vitro flow cytometric assay of the phagocytosis and killing of adhered bacteria by peritoneal cells.

Animals

Male Wistar rats.

Main Outcome Measure

It was expected that the intraperitoneal administration of dialysis fluid would im pair the capacity of peritoneal cells to eliminate bacteria.

Results

The first test revealed no effects of glucose concentration or dwell time on the killing of phagocytosed bacteria by macrophages, median percentages ranging between 29% and 64%. In the second series of experiments no effect of glucose concentration on the phagocytosis and killing of adhered bacteria was found either; however, longer dwell times significantly enhanced both the phagocytosis (at a dwell time of 1 hour, under 20%; at dwell times of 4 or 18 hours, above 20%, p < 0.02) and the killing (at a dwell time of 1 hour, under 53%; at dwell times of 4 and 18 hours, above 70%, p < 0.01).

Conclusions

Glucose concentration has no effect on the phagocytosis and killing of Staphylococcus aureus, whereas the dwell time significantly enhances both of these functional capacities of peritoneal cells if the bacteria are adhered to surfaces.

Establishing an Experimental Infection Model for Peritoneal Dialysis: Effect of Inoculum and Volume

The effect of the number of bacteria and the volume of the inoculum was studied in an experimental infection model to establish a peritoneal dialysis model in the rat. Staphylococcus aureus was used in all experiments, and Staphylococcus epidermidis only in the volume experiments. A bacterial number between 108 and 109 colony forming units (cfu) resulted in a time-dependent decrease of bacteria collected from the peritoneal cavity. Higher concentrations resulted in the death of animals, while lower concentrations were rapidly cleared. There was a positive correlation between the volume in which 3 x 108 cfu were dissolved and the number of bacteria isolated from the peritoneal cavity 24 hours after infection. The results of this study led to an experimental dialysis model using 10 mL of dialysis fluid and 0.5 mL of a suspension containing 3 x 108 cfu of Staphylococcus aureus.

Multiple-Dose-Kinetics of Ofloxacin after Intraperitoneal Application in CAPD Patients

Pharmacokinetics of ofloxacin in plasma and peritoneal fluid were studied in 11 patients on continuous ambulatory peritoneal dialysis (CAPD). Seven patients without peritonitis received 20 mg ofloxacin added to 2L dialysate i.p. every 6 h for one day only, while 4 patients with acute peritonitis were treated with this same dosage every 4 h for 3 days, then every 6 h for the next 7 days. Ofloxacin concentrations in plasma and dialysate were determined by HPLC.

After i.p. drug application there was a rapid elimination of ofloxacin from dialysate, this being significantly faster in patients with peritonitis as compared to those without. Likewise, the total amount lost from the first bag after a 3 h dwell was higher in the peritonitis group (84.7±1.5%; mean±SEM) than in the non-peritonitis group (75.6±2.1 %). Twenty-four h after start of ofloxacin treatment, the mean peritoneal fluid concentrations at the end of each exchange studied were all above 3 mg/L. In patients with peritonitis, plasma concentrations of ofloxacin rose to 0.94±0.05 mg/L after 24 h reaching a Cmax of 1.8±0.2 mg/L after a tmax of 84±23 h.lntraperitoneal administration of ofloxacin was well tolerated, and no local or systemic adverse events were observed. Peritonitis episodes that were caused by Staphylococcus epidermidis (3) and by E. coli (1) were cured in all patients.

Comparisons of Y-Set Disconnect System (Ultraset) versus Conventional Spike System in Uremic Patients on Capd: Outcome and Cost Analysis

We conducted a single-blind, prospective randomized study on the use of the V -set disconnect system (Uttraset) (U) versus the conventional (C) spike system to assess the peritonitis rate, exit-site infection (ESt), clinical outcome, the resulting hospitalization rate, and recurrent costs. Forty new end-stage renal failure patients admitted to the dialysis program were recruited into the study and 20 each were randomly allocated to the U and C systems. They were studied for a period of 12 months. The mean number of days required to train patients for the U and C systems were 8.6 and 9.8 days, respectively. The peritonitis rates for the U and C systems were one episode every 17 and 11.4 patient-months, respectively. The ESI rates for the U and C systems were one episode every 26.4 and 21.6 patient-months, respectively. Four catheters were removed due to fungal peritonitis (three with the C system and one with the U system). As related to peritonitis, patients on the C system required 57 hospital-days while those on the U system required 28 days per year. On cost analysis, the extra cost required for the U system can be offset by the other expenses incurred for events related to more infections on the C system.

It is concluded that for the similar cumulative costs required for the patients on the two systems, the Y-set disconnect has a better morbidity profile than the conventional spike system.

Treatment of Peritonitis in Continuous Ambulatory Peritoneal Dialysis (CAPD) with Intraperitoneal Cefazolin and Gentamicin

Between 1983 and 1988 57 peritonitis episodes in an unselected patient population were initially treated with intraperitoneal cefazolin and gentamicin. The loading dose consisted of 500 mg cefazolin/L dialysate and 40 mg gentamicin/L dialysate. The maintenance dosage was 125 mg cefazolin and 8 mg gentamicin per liter dialysate. Forty-five (78.9%) patients were primarily cured with this regimen (responder group = RG). Twelve patients (21.1 %) did not respond to the initial therapy (nonresponder group = NG). Eight peritonitis episodes in the NG (14.0% of all patients) were caused by tunnel infections and 2 by diverticulitis (3.5%). The cure rate in patients without tunnel infection or bowel disease was 95.7%. A relapse occurred in 2 patients (3.5%). Duration of therapy was assessed by daily white blood cell count (WBC) in the effluent and treatment was discontinued when the WBC was <100/μ1 for 3 days. The mean duration of therapy with cefazolin and gentamicin was 8.1 days in the RG and 6.0 days in the NG. Nonresponders were subsequently treated with a modified antibiotic regimen on an average 11.9 days.

Treatment Recommendations 1993 Update

In conclusion, the recommendations provided in this document represent a distillation of various experiences, as well as data obtained from published studies. It is hoped that this compilation will provide a basis upon which future developments and advances can be made in the therapeutic approach to infectious complications of peritoneal dialysis.

Comparison of Large Volume Culture to Other Methods for Isolation of Microorganisms from Dialysate

Patients on continuous ambulatory peritoneal dialysis (CAPD) who reside long distances from a CAPD center often use community medical laboratories to document and manage episodes of peritonitis. We examined the feasibility of using large volume cultures as an alternative to more costly and labor intensive methods and to enhance earlier recovery of microorganisms from these patients.

Three methods of processing dialysate from patients on CAPD were compared: (a) inoculation of 400 mL dialysate into a transfer bag (Baxter Healthcare, Inc., Round Lake, IL) containing 100 mL of 5-fold concentrate of trypticase-soy broth: (b) inoculation of 5 mL into each of two Bactec bottles (Johnston Laboratories, Towson, MD): and (c) centrifugation of 50 mL and culture of the sediment without white cell lysis on plated media and two Bactec bottles.

Of the 58 specimens cultured, 34 (59%) were positive by one or more methods. Antimicrobial activity was detected in 20158 (34%) dialysates, which represent 54% of all no-growth cultures. Of the 34 culture-positive specimens, microorganisms were recovered on plated media in 22 (65%); by the centrifugation system in 32 (94%); by the routine Bactec system in 28 (82%); and by large volume culture in 30 (88%).

The large volume culture system is an acceptable alternative to the more costly Bactec System and the labor intensive centrifugation method but does not significantly improve recovery of microorganisms.

Prolonged Stability of Antimicrobial Activity in Peritoneal Dialysis Solutions

← Objective

To evaluate the stability of the antimicrobial chemical and bioactivity of gentamicin, vancomycin, and gentamicin and vancomycin in combination, and the stability of the bioactivity of ceftazidime, admixed in standard peritoneal dialysis solutions and then maintained over a 14-day period at room temperature or under refrigeration.

← Setting

Peritoneal dialysis center and microbiology laboratory at a military, teaching medical center.

← Measurements

Standard peritoneal dialysate bags admixed with gentamicin, vancomycin, gentamicin and vancomycin in combination, or ceftazidime were stored at either 4°C or 20°C for 14 days. Sequential aliquots were withdrawn and assayed for antibiotic activity by bioassay and, except for ceftazidime, immunoassay for chemical activity. The bioassay was performed using a standardized Kirby–Bauer disc method. Significance was determined by ANOVA and, where the effect size was significant at the p < 0.05 level, the application of the paired t-test or the Wilcoxon signed rank test to the difference in activity between the first and last samples.

← Results

Antibiotic concentration by immunoassay did not significantly deteriorate over 14 days for vancomycin or gentamicin when either room temperature or refrigerated samples were studied. By bioassay, gentamicin and ceftazidime, but not vancomycin, lost moderate but significant activity over 14 days when refrigerated bags were assayed (except for an insignificant decrement in gentamicin in the combined vancomycin and gentamicin bags). Bags stored at room temperature, in general, lost significant bioactivity over 14 days, but to levels where clinical efficacy would still be expected. The vancomycin bioassay performed on the combination bags demonstrated a remarkably enhanced bioactivity, presumably reflecting synergy with gentamicin.

← Conclusion

These data indicate that the study antibiotics admixed with peritoneal dialysis fluids retain stable chemical activity, whether refrigerated or kept at room temperature, for at least 14 days. A moderate decrement in bioactivity occurred for study antibiotics when stored either refrigerated or at room temperature over 14 days, although clinically significant levels were maintained. The clinical significance of a possible synergy between vancomycin and gentamicin is yet to be determined.

Continuous ambulatory peritoneal dialysis catheter placement: Is omentectomy necessary?

Context:

There are different methods of continuous ambulatory peritoneal dialysis (CAPD) catheter placement. Open surgical technique is a widely followed method. The complication rate following catheter placement varies and catheter blockage due to omental plugging is one of the main reasons.

Aim:

To analyze the need for routine omentectomy during CAPD catheter placement.

Materials and Methods:

This was a retrospective analysis of 58 CAPD catheter placements performed between July 2002 and June 2007. Tenckhoff double cuffed catheter was used in all. The postoperative complications were analyzed.

Results:

There were 44 males and 14 females. The mean age was 51 years ranging from 15 to 76 years. Of these, 40 (69%) patients underwent omentectomy (group A) and 18 (31%) did not (group B). Laparoscopic and open techniques were performed in 5 and 53 patients, respectively. Omentectomy was not performed in 13 patients with open technique and all the five in the laparoscopic group. One patient in group A developed hemoperitoneum which was treated conservatively. None from group A developed catheter blockage, whereas five (27.8%) from group B developed catheter blockage postoperatively. The median time interval between the primary procedure and development of catheter blockage was 45 days (ranged from 14 to 150 days).

Conclusions:

Omentectomy during CAPD catheter placement prevents catheter blockage and secondary interventions.

Ego mechanisms of defense are associated with patients' preference of treatment modality independent of psychological distress in end-stage renal disease

Several parameters mediate the selection of treatment modality in end-stage renal disease (ESRD). The nephrology community suggests that patient preference should be the prime determinant of modality choice. We aimed to test whether ego mechanisms of defense are associated with patients' treatment modality preferences, independent of psychological distress. In 58 eligible ESRD patients who had themselves chosen their treatment modality, we administered the Symptom Distress Checklist-90-R and the Defense Style Questionnaire. Thirty-seven patients (53.4%) had chosen hemodialysis and 21 (46.6%) peritoneal dialysis. Patients who preferred peritoneal dialysis were younger (odds ratio [OR], 0.89; 95% confidence interval [CI]: 0.804-0.988), had received more education (OR, 8.84; 95% CI: 1.301-60.161), and were twice as likely to adopt an adaptive defense style as compared to patients who preferred hemodialysis (57.1% vs 27.0%, respectively; P < 0.033). On the contrary, the latter were more likely to adopt an image-distorting defense style (35.1% vs 14.3%; P = 0.038) and passive-aggressive defenses (OR, 0.73: 95% CI: 0.504-1.006). These results were independent of psychological distress. Our findings indicate that the patient's personality should be taken into account, if we are to better define which modalities are best suited to which patients. Also, physicians should bear in mind passive-aggressive behaviors that warrant attention and intervention in patients who preferred hemodialysis.

An African community-based chronic ambulatory peritoneal dialysis programme

BACKGROUND

The reasons for failure of continuous ambulatory peritoneal dialysis (CAPD) are varied. Against a background of mass poverty, poor resources, and the cheaper cost of CAPD it is the primary choice of dialysis. The aims of this study were to determine infection rates and document factors responsible for CAPD failure.

METHODS

We report a prospective study in a large African tertiary hospital and its community based satellite clinics. Infection rates as well as factors that may influence them were studied. Sites of infections were documented and causes of CAPD failure recorded. All patients qualifying for dialysis from January 1998 to July 1999 were included.

RESULTS

Eighty-four patients were enrolled. There were 55 males and 29 females. The mean age was 39+/-10 (range 16-71) years and mean duration on dialysis at the end of the trial period was 17 months. The peritonitis rate was one episode every 27.9 patient months. Attrition to haemodialysis occurred in 16.6% of patients (n=14) and loss to follow-up in 29.8% (n=25). Fourteen patients regained renal function or were transplanted. Peritonitis appeared to be related to a poor BAD-C score (Bara Adapted Dialysis Compliance), i.e. combination of clinical status and clinic visits (P=0.07). The odds ratio for failure of CAPD with peritonitis was 5.3 times higher (confidence interval (CI) 1.7-17.1; P=0.0085). A low BAD-C score was a significant indicator of CAPD 'failure' (P=0.0001). The natural turnover rate of patients was 46%. Home conditions, employment, and education levels did not correlate with CAPD 'failure'.

CONCLUSION

The peritonitis rate and aetiology are similar to the developed world. Socioeconomic factors did not appear to play a role in peritonitis rates or CAPD failure.

Renal function and renal disease in the elderly: Part I

In all industrialized countries, life expectancy has risen in the past 100 years. The incidence of elderly patients reaching end-stage renal disease (ESRD) and requiring renal replacement therapy has also increased. During the past few decades, the pattern of ESRD has changed significantly with the emerging predominance of elderly patients. The causes of this phenomenon are manifold and include an increasing number of chronic diseases typical of the 'third age', such as type 2 diabetes mellitus and vascular disease. In many species, a consequence of aging includes deterioration of renal function, partly due to structural alterations, and partly as the result of a diminishing blood flow. In humans, the aging kidney is characterized by modifications resulting from organic and functional disturbances. In particular, type 2 diabetes mellitus has emerged as an important condition, the microvascular and macrovascular complications of which are a common cause of morbidity and mortality in older patients. In part I of this review, the morphological and functional changes of the aging kidney will be reviewed, as well as the pathological conditions leading to the loss of renal function in the elderly.

Thoracic complications of peritoneal dialysis

Approximately 20% of the 100,000 patients in the United States currently undergoing dialysis therapy for end-stage renal disease use the technique of peritoneal dialysis. We present a patient on peritoneal dialysis who developed a large posterior mediastinal mass, which on surgical exploration was found to be a paraesophageal hernia sac filled with omentum and dialysis fluid. We use this case as an introduction to review the thoracic complications of peritoneal dialysis.

Comparison of double-bag and Y-set disconnect systems in continuous ambulatory peritoneal dialysis: a randomized prospective multicenter study

We performed a multicenter, single-blinded, prospective randomized study on the use of a double-bag disconnect system (B) versus a Y-set disconnect system (Y). The peritonitis rate, exit site infection, clinical outcome, and patients' acceptance to the procedure were assessed. A total of 120 new end-stage renal failure patients of three regional hospitals were randomized: 60 each to the B and the Y systems. The results of 60 patients on the B system and 51 on the Y system were analyzable. They were followed up for a median of 16 months. Peritonitis rates for the B and the Y systems were 33.5 and 29.4 patient-months per episode, respectively. Exit site infection rates for the B and Y systems were 17.4 and 16.0 patient-months per episode, respectively. Four catheters were removed in each group. Patients on the B system were hospitalized for 2.1 days per patient per year related to peritonitis and exit site infection, and those on the Y system were hospitalized for 1.2 days. There was no significant difference between the B and Y systems in the incidences of peritonitis (all causes and those due to coagulase-negative staphylococci), exit site infection, and in hospitalization days. However, there was a higher percentage of gram-positive infections in the Y system (52%) than in the B system (32%) and a lower percentage of gram-negative infections in the Y system (16%) than in the B system (32%). Patients on the B system had a better acceptance of the procedure than patients on the Y system, as assessed by a six-item, 10-point questionnaire (total score, 43.1 +/- 10.2 v 37.6 +/- 9.4; P < 0.005 at 1 month; 44.6 +/- 9.1 v 39.8 +/- 8.6; P < 0.01 at 6 months). From this study, it is concluded that the B and Y systems are similar in the incidences of peritonitis and exit site infection, although the B system is better accepted by patients. This is probably the first multicenter randomized study comparing the double-bag and Y-set disconnect system using only new patients who had never used other systems of continuous ambulatory peritoneal dialysis.

Male fertility of kidney transplant patients with one to ten years of evolution using a conventional immunosuppressive regimen

The reproductive functions and hormone serum levels of 55 male kidney transplant recipients were assessed. Patients underwent peritoneal dialysis before transplantation and were given immunosuppressive therapy afterward for 1 to 10 years. Spermatobioscopies were performed, and serum urea, creatinine, luteinizing hormone (LH), follicle-stimulating hormone (FSH), prolactin (PRL), and testosterone (T) levels were determined. Average serum urea and creatinine levels were 54.6+/-1.4 and 3+/-1.3 mg/dL, respectively. The average serum hormone levels were 3.2+/-2 mIU/mL (LH), 6.3+/-1.7 mIU/mL (FSH), 11.7+/-1.5 ng/mL (PRL), and 23+/-1.4 pg/mL (T). Libido reduction was reported in 88% of patients within 8 months following transplantation. Normozoospermia was seen in 47.3% of the patients, asthenozoospermia in 18.2% oligozoospermia in 14.5%, while oligoteratozoospermia, asthenoteratozoospermia, oligoasthenozoospermia, oligoasthenoteratozoospermia, and azoospermia were seen in the rest. Twenty-six patients procreated one or more children after transplantation; 36.6% of those children were premature but nonetheless healthy. No association existed between the post-transplant period and urea or creatinine levels. Significant differences were found when LH levels and sperm motility were assessed. Also, statistically significant differences were found when duration of dialysis, FSH levels, sperm counts, morphology, and motility between posttransplant fertile and infertile patients were correlated. In conclusion, there was an adequate recovery of sexual and reproductive functions in most patients subjected to kidney transplantation and conventional immunosuppressants.

[Cost-effectiveness of interventions for end-stage renal disease]

OBJECTIVE

The study reports the cost-effectiveness results of end-stage renal disease (ESDR) patients in Mexico in terms of years of life gained and quality of life and the economic cost with regards to three treatment alternatives that could be considered mutually exclusive: continuous peritoneal ambulatory dialysis (CAPD), hemodialysis (HD) and renal transplant (RT).

METHOD

The economic costs were calculated by using the average cost case-management methodology and further, the probable of life expectancy and the quality of life were cross-sectionally assessed by means of the Quality Adjusted Life Years (QALY) measured by the Rosser Index.

RESULTS

The results show that economic costs in US$ of the three treatment alternatives were: CAPD $5,643.07, HD $9,631.60, and RT $3,021.63. The probability of life expectancy for CAPD and RT for the first and third year were: 86.2% and 66.9%, and 89.9% and 79.6%, respectively. The QALY scores for patients were: CAPD 0.8794, HD 0.8640, and RT 0.9783.

CONCLUSION

The intervention with the highest cost-effectiveness coefficient was the renal transplant (3,088.69), followed by the CAPD (6,416.95) and HD (11,147.68). A significant difference was found between the transplanted patients and patients undergoing dialysis. Finally, this study concluded that the RT offers the least expensive alternative and the greatest number of years of life gained as well as providing significant changes in the quality of life of ESRD patients.

[Costs of interventions for patients with chronic renal disease]

INTRODUCTION

The results of a study which identified the cost of health interventions in the management of patients with chronic renal disease are presented.

MATERIAL AND METHOD

The costing method was based on a consensus technique and the instrumentation of case management through the identification of the materials used and functions of production for the demand of each service solicited. The interventions included: peritoneal dialysis, hemodialysis, and renal transplant.

RESULTS

The cost per event in U.S. dollars was $3.71, $57.95, and $8,778.32, respectively. The annual cost of case management was: Peritoneal Dialysis $5,643.07, Hemodialysis $9,631.60 and renal transplant $3,021.67.

CONCLUSIONS

The information generated from the costs of the events differed considerably from the information that was generated by the annual cost of case management. These differences are significant for the design and evaluation of patterns for allocating resources.

Automated peritoneal dialysis: new implications for pharmacists

OBJECTIVE

To review the new automated peritoneal dialysis (APD) modalities that are available to patients with end-stage renal disease (ESRD), and to examine their potential pharmacokinetic and drug dosing consequences.

DATA SOURCES

A MEDLINE search (from January 1966 to June 1996) of English-language literature pertaining to peritoneal dialysis was performed. Additional references were obtained by reviewing the references of pertinent articles identified through the search. Tertiary sources were also used.

DATA EXTRACTION

Data regarding peritoneal dialysis techniques and pharmacokinetics were extracted from the literature. Data were evaluated according to the study design, population, results, and conclusions.

DATA SYNTHESIS

ESRD is the result of progressive chronic renal insufficiency and requires renal replacement therapy. APD is the fastest growing renal replacement therapy by percentage in the US and provides dialysis exchanges via a machine while the patient sleeps, thereby improving patient convenience, peritoneal dialysis compliance rates, and decreasing peritonitis rates. Well-designed pharmacokinetic studies involving APD have not been conducted. Consequently, no formal drug dosing recommendations are available for APD, and pharmacists must rely on established dosing guidelines for continuous ambulatory peritoneal dialysis (CAPD) when recommending dosing regimens. This article describes the new APD treatment modalities available and the potential pharmacokinetic differences between CAPD and APD.

CONCLUSIONS

Well-designed studies are needed to fully characterize the pharmacokinetic parameters of drugs in APD. Until then, pharmacists should recommend that intraperitoneally administered drugs be given during the longest peritoneal dialysate dwell of the day and that serum concentrations of drugs with narrow therapeutic indices be monitored closely.

Lipids, lipoproteins and apolipoproteins abnormalities in patients undergoing dialysis

Twenty hemodialysis (HD) patients and 20 patients on continuous ambulatory peritoneal dialysis (CAPD) were investigated for lipids, lipoproteins and apolipoproteins abnormalities. HD patients had elevated serum triglyceride, decreased high-density lipoprotein cholesterol (HDL-C) and apolipoprotein A-I (Apo A-I), while CAPD patients had elevated total cholesterol, triglyceride, low-density lipoprotein cholesterol (LDL-C), Apolipoprotein B (Apo B), Apo B/Apo A-I ratio, and decreased HDL-C, Apo A-I. Because of the molecular sieving effects of peritoneum, CAPD have a negative effect on these abnormalities. CAPD patients might be at greater risk of developing coronary artery disease than HD patients who are also at increased risk as compared with normals.

Renal syndromes in diabetes

Renal disorders attributed to diabetes mellitus are increasingly recognized as the dominant feature of long-term management. Renal failure in diabetic patients is the most commonly recognized cause of irreversible uremia in the United States, Europe, and Japan. Treating hypertension and normalizing hyperglycemia slows the previously thought inexorable progress of renal insufficiency in diabetes. Once end-stage renal disease has developed, either dialytic therapy or a renal transplant affords life extension, often with excellent rehabilitation.

Use of home automated intermittent peritoneal dialysis in the treatment of end stage renal failure

We report our retrospective analysis of 16 uraemic patients who were treated with home automated intermittent peritoneal dialysis (IPD) from 1988 to 1993. Six patients were diabetic. The mean age was 58.5 years. The reasons for home automated IPD were: old age, poor eyesight, low intelligence or poor dexterity, family or patient request and old stroke. It took an average of 8.8 sessions to train the helper. The mean frequency of the home IPD was once every 5.8 days with a mean volume of 48 litres of dialysate used during each dialysis. There were 3 peritonitis episodes making the peritonitis rate once every 93 patient months. Four patients were still on home IPD and two were transplanted. Ten patients died of stroke, myocardial infarction, tuberculosis, chronic obstructive lung disease or suicide. A low plasma albumin is the only significant parameter in the early mortality group. Such high mortality can be accounted for by the fact that patients were older and forty per cent were diabetic. We conclude that home automated IPD can be an alternative for some patients in whom other modes of dialysis are difficult.

Nutrition aspects of continuous ambulatory peritoneal dialysis: a review

Continuous ambulatory peritoneal dialysis (CAPD) is an increasingly popular alternative to hemodialysis. Nutrition practitioners in the in- and outpatient setting must be knowledgeable about specific nutritional considerations in these patients. In this paper, we briefly review factors which play a role in the malnutrition often encountered in end-stage renal disease, and focus on metabolic abnormalities, nutritional requirements, and nutritional assessment of patients undergoing CAPD. Urea kinetic modeling as an adjunct to nutritional assessment is explained in detail.

Effect of lovastatin on serum lipid profile in the treatment of dyslipoproteinaemia in uraemic patients on continuous ambulatory peritoneal dialysis

BACKGROUND

Dyslipoproteinaemia is an important risk factor for cardiovascular disease in uraemic patients on continuous ambulatory peritoneal dialysis (CAPD). Lovastatin is an HMG Coenzyme A reductase inhibitor which is useful in treating non-uraemic patients with hypercholesterolaemia.

AIMS

We conducted a single blind cross-over study versus placebo in 10 CAPD patients to examine the effect of lovastatin (20-40 mg) on the serum lipid profile and its safety in uraemic patients.

METHODS

Treatment phases were of eight weeks' duration. Each four weeks' measurements were made of serum total cholesterol (TC), triglyceride (TG), HDL-cholesterol (HDL-C), LDL-cholesterol (LDL-C), VLDL-cholesterol (VLDL-C), Apolipoprotein A1 & B (Apo A1 & Apo B) and Lipoprotein (a). After eight weeks, lovastatin significantly reduced TC by 29% from 6.7 +/- 0.3 (mean +/- S.E.M.) to 4.8 +/- 0.1 mmol/L, LDL-C by 41% from 4.6 +/- 0.3 to 2.7 +/- 0.1 mmol/L and Apo B by 32% from 116 +/- 7 to 78 +/- 3 mg/dl (p < 0.01). HDL-C increased by 8% from 1.2 +/- 0.1 to 1.3 +/- 0.2 mmol/L after eight weeks' therapy (p < 0.05). TG decreased by 18% from 1.9 +/- 0.4 to 1.6 +/- 0.3 mmol/L (p < 0.05). There was no significant difference in changes of other lipid profiles between placebo and drug. No adverse effects of the drug were noted during treatment and the liver function and muscle enzymes were not significantly altered by either drug therapy or placebo.

RESULTS

Lovastatin appears to be a safe and useful drug in effectively treating dyslipoproteinaemia in CAPD patients.

Posthysteroscopy fungal peritonitis in a patient on continuous ambulatory peritoneal dialysis

We report the first case of posthysteroscopy fungal peritonitis, which developed in a woman 11 days after she had a hysteroscopy for menorrhagia. A high vaginal swab grew Candida albicans and the same organism was cultured from the peritoneal dialysate effluent. A vaginoperitoneal communication was suspected to allow the distension medium to carry the fungus into the peritoneum. The potential use of a prophylactic local antifungal agent before hysteroscopy is discussed.

Peritoneal macrophages from patients on continuous ambulatory peritoneal dialysis show a differential secretion of prostanoids and interleukin-1 beta

In vitro secretion of the prostanoids PGE2 and PGI2 and of the cytokine IL-1 beta by peritoneal macrophages obtained from CAPD patients during episodes of peritonitis and infection free periods, was determined, after culturing with or without 5 micrograms/ml of LPS. The release of PGE2 and PGI2 as measured by its stable metabolite 6-keto-PGF alpha was determined in 10 episodes of peritonitis and 10 infection free periods. IL-1 beta release was determined in 14 episodes of peritonitis and 20 infection free periods. PGI2 release from macrophages declined sharply during peritonitis both in the absence and presence of LPS in the culture medium (p less than 0.005). A tendency to decreased PGE2 release was found during peritonitis, when macrophages were cultured in the absence of LPS. In the presence of LPS, the same amounts of PGE2 were released during peritonitis and during an infection free period. On the other hand, peritoneal macrophages released significantly more IL-1 beta during peritonitis as compared to an infection free period, provided that the cells were in vitro stimulated with LPS. In view of the interregulatory effects between prostanoids and macrophage cytokines in their production, these findings may indicate that the impaired release of PGI2 during peritonitis has allowed the macrophages to secrete more IL-1 beta after in vitro stimulation with LPS. This implies that PGI2 and PGE2 may play a distinct role in the regulation of cytokine secretion by these cells.

Prostaglandin E2 inhibits the release of tumor necrosis factor-alpha, rather than interleukin 1 beta, from human macrophages

We have reported previously that macrophages obtained from renal patients on continuous ambulatory peritoneal dialysis (CAPD) during an episode of infectious peritonitis display a decrease in intracellular cAMP levels and in spontaneous in vitro release of PGE2 and PGI2. Such macrophages also release large quantities of IL-1 beta and TNF alpha when stimulated in vitro by LPS. In view of the interregulatory effects between PGE2 and macrophage cytokines (IL-1 beta and TNF alpha) in their production, we examined in the present work to what extent the LPS-induced release of either IL-1 beta or TNF alpha in vitro from CAPD-originated peritoneal macrophages is affected by graded doses of exogenous PGE2 (range 0-1000 ng/ml) and by the cyclooxygenase inhibitor indomethacin (INDO) (10(-6) M). IL-1 beta and TNF alpha were determined using an enzyme-linked immunoabsorbent assay and an immunoradiometric assay, respectively. We found that PGE2 invariably induced a dose-dependent decrease in TNF alpha release. In peritoneal macrophages collected during an infection-free period, TNF alpha release decreased from 3225 pg/ml (controls) to 353 pg/ml at 1000 ng/ml of PGE2, and in peritoneal macrophages collected during an episode of infectious peritonitis, it decreased from 4100 pg/ml (controls) to 545 pg/ml at 100 ng/ml of PGE2. However, PGE2 failed to influence the secretion of IL-1 beta. INDO induced an approx. two-fold increase in TNF alpha release, but had no effect on IL-1 beta release. These findings indicate that exogenous and endogenous PGE2 controls the release of TNF alpha rather than IL-1 beta from LPS-stimulated peritoneal macrophages.

Ten years' experience with continuous ambulatory peritoneal dialysis

Up to January 1989, 171 patients were trained at our center on continuous ambulatory peritoneal dialysis (CAPD), and 17 on continuous cyclic peritoneal dialysis (CCPD). Over 10 years, we have gained 5,068 patient-months experience. Patient survival was 60% and 31% at 5 and 10 years, respectively. In contrast, diabetics had a survival of 32% at 5 years. Major complications included 499 new episodes of peritonitis, 304 exit-site infections, 22 hernias, five bowel perforations, one hydrothorax, and three episodes of sclerosing encapsulating peritonitis. Our technique survival has been 62% and 40% at 5 and 10 years, respectively. We believe that CAPD is a viable dialysis technique for long-term treatment of chronic renal failure and it should be offered as an option to intermittent hemodialysis.

Pharmacokinetics of quinapril and its active metabolite quinaprilat during continuous ambulatory peritoneal dialysis

The pharmacokinetics of quinapril, a novel angiotensin converting enzyme (ACE) inhibitor, and its active metabolite, quinaprilat, were determined following a single 20-mg oral dose of quinapril in six patients with chronic renal failure maintained on continuous ambulatory peritoneal dialysis (CAPD). Overall, quinapril was well tolerated by these CAPD patients, with mild and transient side effects, not unexpected in this clinical setting, which included pruritus, headache, nausea, and cough. Blood pressure reduction was observed in four of six patients, with onset reliably two to four hours after dosing and duration up to 48 hours, associated with quinaprilat concentrations in plasma above 90 ng/mL for at least 33 hours postdose. Two patients experienced significant hypotension, systolic blood pressure below 90 mm Hg, which responded promptly to oral fluid administration and/or reduction in dialysate tonicity. The pharmacokinetic profile of quinapril in these CAPD patients was not significantly different from that previously observed in healthy subjects with normal renal function and in patients with moderate to severe renal dysfunction not yet requiring dialysis (RDND). The apparent elimination half-life of quinapril was approximately one hour, with negligible dialysate excretion. The pharmacokinetic profile of quinaprilat in these CAPD patients was similar to that previously observed in patients with RDND. The elimination half-life of quinaprilat was markedly prolonged when compared to that in healthy subjects and averaged 20 hours, with only a small amount of quinaprilat excreted in dialysate (mean = 2.6% of total dose).(ABSTRACT TRUNCATED AT 250 WORDS)

Surgical complications of continuous ambulatory peritoneal dialysis

Surgical experience with 260 consecutive patients with chronic renal failure receiving continuous ambulatory peritoneal dialysis (CAPD) at one medical center from 1980 to 1989 is reviewed. Patients received CAPD for a mean of 24.2 months (range: 3 days to 91 months). Catheter longevity consistently improved in all but 1 year from 1984 to 1989, as did exit-site and tunnel infections. Of 311 catheters inserted, 151 (49%) required removal, of which 111 (74%) were attributed to peritonitis. Cumulative patient survival was 80%, 60%, and 53% at 1, 2, and 3 years, respectively. Diabetic patients had statistically significant lower survival rates. Additional complications including catheter leakage, catheter malposition, catheter obstruction, and abdominal wall hernias were negligible. Although CAPD is not free from serious complications, our data show remarkable improvement since 1980 in catheter longevity, hospital stay, and infection rates.

Outcome of renal replacement treatment in patients with diabetes mellitus

OBJECTIVE

To compare the outcome of renal replacement treatment in patients with diabetes mellitus and in non-diabetic patients with end stage renal failure.

DESIGN

Retrospective comparison of cases and matched controls.

SETTING

Renal unit, Western Infirmary, Glasgow, providing both dialysis and renal transplantation.

PATIENTS

82 Diabetic patients starting renal replacement treatment between 1979 and 1988, compared with 82 matched non-diabetic controls with renal failure and 39 different matched controls undergoing renal transplantation.

MAIN OUTCOME MEASURES

Patient characteristics, history of smoking, prevalence of left ventricular hypertrophy and myocardial ischaemia at start of renal replacement treatment; survival of patients with renal replacement treatment and of patients and allografts with renal transplantation.

RESULTS

The overall survival of the diabetic patients during the treatment was 83%, 59%, and 50% at one, three, and five years. Survival was significantly poorer in the diabetic patients than the controls (p less than 0.001). Particularly adverse features for outcome at the start of treatment were increasing age (p less than 0.01) and current cigarette smoking (relative risk (95% confidence interval) 2.28 (0.93 to 4.84), p less than 0.05). Deaths were mainly from cardiac and vascular causes. The incidence of peritonitis in patients on continuous ambulatory peritoneal dialysis was the same in diabetic patients and controls (49% in each group remained free of peritonitis after one year), and the survival of renal allografts was not significantly worse in diabetic patients (p less than 0.5).

CONCLUSIONS

Renal replacement treatment may give good results in diabetic patients, although the outlook remains less favourable than for non-diabetic patients because of coexistent, progressive vascular disease, which is more severe in older patients.

Methicillin-resistant staphylococcal infections in an outpatient peritoneal dialysis program

In view of the increasing concern about hospital-acquired methicillin resistance, we examined the sensitivities and outcome of staphylococcal infections related to outpatient peritoneal dialysis over a 5-year period. Data on all episodes of peritonitis (n = 360) and catheter infections (n = 507) were gathered prospectively from January 1984 to December 1988. The numbers of patients on peritoneal dialysis each year ranged from 136 in 1984 to 109 in 1987. Fifteen methicillin-resistant staphylococcal infections (MRSI) related to outpatient peritoneal dialysis occurred. Three were due to methicillin-resistant Staphylococcus aureus found in infected exit sites (2.3% of all S aureus catheter infections). Two of these infections occurred in a continuous ambulatory peritoneal dialysis (CAPD) patient who carried methicillin-resistant S aureus in his nares. The other 12 methicillin-resistant organisms were coagulase-negative staphylococci that caused peritonitis. There was a significant increase in the percentage of episodes of coagulase-negative staphylococci peritonitis caused by methicillin-resistant organisms; from 5% (3/57) in 1984 through 1986 to 28% (9/32) in 1987 through 1988 (P less than 0.005). In view of the high percentage of coagulase-negative staphylococci peritonitis that is methicillin-resistant, vancomycin rather than cephalosporins should be used for initial treatment.

Endotoxin-stimulated peritoneal macrophages obtained from continuous ambulatory peritoneal dialysis patients show an increased capacity to release interleukin-1 beta in vitro during infectious peritonitis

Interleukin-1 (IL-1) release by peritoneal macrophages obtained from patients on continuous ambulatory peritoneal dialysis (CAPD) was studied in nine patients during an infection-free period and eight patients during an infectious peritonitis, using an ELISA for IL-1 beta. Without exogenous stimulation with LPS, peritoneal macrophages from infected and uninfected patients released the same amounts of IL-1 beta, 183 +/- 40 pg ml-1 24 h-1) per 10(6) cells (means +/- SEM) and 251 +/- 96 pg ml-1, respectively. However, in response to a dose of 5 micrograms ml-1 of LPS, peritoneal macrophages released significantly more (P less than 0.005) IL-1 beta during peritonitis (6579 +/- 2793 pg ml-1 24 h-1 per 10(6) cells) compared with the infection-free period (1040 +/- 182 pg ml-1). These findings show that after microbial invasion of the peritoneal cavity, peritoneal macrophages are primed in vivo to release an increased amount of IL-1 beta in vitro after subsequent exogenous stimulation with LPS, indicating that peritoneal macrophage activation for IL-1 beta secretion occurs in steps.

Isolation, identification, and analysis of 4-acetylaminophenol-glucuronide in body fluids of dialyzed renal patients; a molecular mass marker for peritoneal diffusive transport

A noncharacteristic solute, appearing in gradient elution liquid chromatography (HPLC) profiles of body fluids of dialyzed renal patients, was isolated and identified by preparative HPLC, beta-glucuronidase induced enzymatic peak shift, and mass spectrometry. The compound was shown to be p-acetylaminophenol ('paracetamol')-glucuronide (PG). Serum and peritoneal dialysate PG concentrations were determined in a number of patients. Cuprophan in vivo dialyzer clearances were calculated. Peritoneal membrane mass transfer coefficients (MTC) of PG were calculated and compared with those of molecular mass markers for peritoneal diffusive mass transport studies (urea, creatinine, uric acid, and inulin). By extrapolation of an MTC versus molecular mass calibration line for urea, creatinine, and uric acid it is shown that PG behaves as expected from its molecular mass. We suggest that PG (Mr = 327) is suitable as a molecular mass marker for the molecular mass range between Mr 200 and 500. It may also be used as a marker for diffusive solute transport in hemodialysis treatment. The HPLC gradient elution technique used here appears to be suitable for the simultaneous analysis of the molecular mass markers creatinine, uric acid, and paracetamolglucuronide.