Effect of duration of chronic peritoneal dialysis therapy on the development of peritonitis.

OBJECTIVE: Long-term chronic peritoneal dialysis (CPD) therapy has been associated with alterations in peritoneal membrane structure and peritoneal macrophage function. We thus reviewed our experience with the development of peritonitis among patients maintained on CPD therapy for various time periods to determine if the spectrum of organisms, rates of peritonitis, and outcome changed with the duration of CPD therapy. SETTING AND PATIENTS: Patients maintained on CPD therapy in our out-patient unit in New Haven, Connecticut. DESIGN: Retrospective review of the charts of patients maintained on CPD therapy (HomeChoice Cycler or Ultrabag, Baxter, McGaw Park, IL, U.S.A.) between 1 January 1997 and 31 March 1998. These patients were divided into three groups: group 1, patients maintained on CPD therapy < or = 12 months; group 2, patients maintained on CPD therapy for 13-36 months; and group 3, patients maintained on CPD therapy for > or = 37 months. RESULTS: The study included 256 patients: 101 patients in group 1, 110 patients in group 2, and 45 patients in group 3. All groups of patients were similar in age. There were significantly fewer Caucasians and fewer males in group 3 in comparison to groups 1 and 2. The incidence of diabetes mellitus, coronary artery disease, and peripheral vascular disease was significantly lower among patients in group 3 in comparison to groups 1 and 2. There were 155 episodes of peritonitis during the study period for an overall rate of 1 episode in 18.7 patient-months. The overall, gram-positive, and gram-negative rates of peritonitis were not significantly different among the patients in groups 1, 2, and 3. There were more episodes of Staphylococcus aureus peritonitis among patients in group 3 in comparison to group 2 (1 episode in 59.6 vs 1 episode in 280.2 patient-months, respectively). Two weeks after the development of peritonitis, 94.6% of the patients in group 3 continued CPD therapy, while 79.4% of the patients in group 1 continued CPD therapy (p < 0.05). No patient in group 3 transferred to hemodialysis, while 10.3% and 8.2% of the patients in groups 1 and 2 transferred to hemodialysis (p < 0.05). The death rate 2 weeks after the onset of peritonitis was 10.3%, 9.8%, and 5.4% in groups 1, 2, and 3, respectively (p = NS). CONCLUSIONS: Despite the immunological and morphological changes that occur in the peritoneal cavity with increased time on CPD therapy, there was no difference in the overall, gram-positive, or gram-negative rates of peritonitis for patients maintained on CPD therapy for various time periods. Patients in group 3 continued CPD therapy more often than did patients in group 1. Patients in group 3 transferred to hemodialysis less often than did the remaining patients in the study period. The incidence of death was not significantly different for the three groups of patients.

Once-daily intraperitoneal cefazolin and oral ciprofloxacin as empiric therapy for the treatment of peritonitis.

The Ad Hoc Advisory Committee on Peritonitis Management has recommended intraperitoneal (i.p.) cefazolin and an aminoglycoside as empiric therapy for the treatment of peritonitis. Because most of our patients are on continuous cycler therapy, we developed a strategy of once-daily i.p. cefazolin and oral ciprofloxacin as empiric therapy. All patients in our unit that developed peritonitis were given a once-daily 2 g load of i.p. cefazolin, plus 500 mg ciprofloxacin orally, twice daily. Ciprofloxacin was given two hours after any phosphate binder or iron supplement. The i.p. cefazolin was allowed to dwell for at least six hours. The dialysate was then drained and chronic peritoneal dialysis (CPD) resumed. Organisms sensitive to cefazolin were treated for 14 days with once-daily cefazolin alone; resistant organisms were treated with alternative antibiotics. A total of 40 patients were treated with this empiric regimen. Of these, 35 (88%) successfully continued CPD therapy, 1 (2%) transferred to hemodialysis, and 4 (10%) expired two weeks after the onset of peritonitis. A total of 22 patients (55%) were treated successfully with once-daily i.p. cefazolin. Although once-daily i.p. cefazolin and oral ciprofloxacin permitted continuation of CPD therapy in most patients in this study, the therapy was not optimal. While vancomycin may have provided better coverage, recent reports of vancomycin-resistant enterococci and Staphylococcus aureus present a major concern.

Differing outcomes of gram-positive and gram-negative peritonitis.

Peritonitis remains the leading cause of patient dropout from continuous peritoneal dialysis (CPD) therapy. Few studies have compared patient morbidity, mortality, and outcome for patients undergoing CPD who develop gram-positive and gram-negative peritonitis. We retrospectively reviewed the charts of patients who developed either gram-positive or gram-negative peritonitis between January 1, 1993, and December 31, 1995. Three hundred seventy-five patients who developed 415 episodes of gram-positive and gram-negative peritonitis were maintained on CPD therapy during this time period. There was no difference in age, race, and sex between patients who developed gram-positive or gram-negative peritonitis. More patients with diabetes developed gram-negative peritonitis than gram-positive peritonitis (53% v 40%, respectively; P < 0.05). Coagulase-negative staphylococcal species accounted for 47% of all gram-positive episodes, whereas Klebsiella organisms, Escherichia coli, and Enterobacter organisms accounted for 63% of all gram-negative episodes. Significantly more patients who developed gram-positive peritonitis continued CPD therapy 2 weeks and 6 months after the onset of peritonitis than patients who developed gram-negative peritonitis (97% v 73%; P < 0.05 at 2 weeks and 81% v 58% at 6 months; P < 0.05, respectively). Nine percent of the patients who developed gram-positive peritonitis died within 6 months after the onset of peritonitis, whereas 21% of the patients who developed gram-negative peritonitis died (P < 0.05). Patients who developed gram-negative peritonitis were significantly more likely to require hospitalization than patients who developed gram-positive peritonitis (74% v 24%; P < 0.001). More patients with gram-negative peritonitis required peritoneal catheter removal than patients with gram-positive peritonitis (18% v 4%; P < 0.001). Thirty-two percent of the patients who developed gram-positive peritonitis re-developed an episode of peritonitis with the same organism compared with only 9% of the patients who developed gram-negative peritonitis. Furthermore, peritonitis recurrence with the same organism within 6 months after the initial episode was noted in 60% of the patients with peritonitis caused by Staphylococcus aureus compared with 24% of patients with peritonitis caused by other gram-positive organisms (P < 0.05). We conclude that the outcomes of gram-positive and gram-negative peritonitis are different. When rates of peritonitis are used to predict outcome, it appears that gram-positive and gram-negative peritonitis rates need to be examined separately.

Peritonitis in the extended-care facility.

Many patients with end-stage renal disease (ESRD) require admission to an extended-care facility (ECF). Few data are available concerning the development of peritonitis among continuous peritoneal dialysis (CPD) patients residing in an ECF. We retrospectively reviewed the charts of 77 CPD patients admitted to an ECF between November 1993 and 31 August 1997. A total of 25 episodes of peritonitis developed among CPD patients in the ECF during this period for an overall peritonitis rate of 1 episode in 19.8 patient-months. The CPD patients developing peritonitis in the ECF were similar in age and gender to the CPD patients residing in the ECF not developing peritonitis. There were more African-Americans among the group of CPD patients residing in the ECF who developed peritonitis than among the ECF residents who did not develop peritonitis (41% vs. 23%, respectively; P < 0.05). Patients developing peritonitis in the ECF resided in the ECF significantly longer than the remaining CPD patients not developing peritonitis in the ECF (106 vs. 77 days, respectively; P < 0.05). The overall rate of peritonitis in the ECF was lower than that seen in the community (1 episode in 19.8 patient-months vs. 1 episode in 10.0 patient-months, respectively). The rate of gram-positive peritonitis was lower than the rate of gram-positive peritonitis seen in the community setting (1 episode in 54.9 patient-months vs. 1 episode in 14.9 patient-months, respectively). The rate of culture-negative peritonitis was higher among the ECF patients than among patients developing community-acquired peritonitis (1 episode in 61.9 patient-months vs. 1 episode in 106.2 patient-months, respectively). The spectrum of organisms in the ECF was different than the spectrum noted among patients developing hospital-acquired peritonitis. Eleven of the 25 episodes of peritonitis were treated successfully at the ECF while the remaining 14 episodes of peritonitis were treated at an acute-care hospital. Continuous PD therapy was continued following 19 of the 25 episodes (76%), 1 patient transferred to hemodialysis, and 5 patients expired. We conclude that patients develop peritonitis in the ECF less frequently than in the community setting, with the spectrum of organisms different than the spectrum seen in the community and hospital settings. Seventy-six percent of the patients continue CPD therapy following an episode of peritonitis.

Continuous cycler therapy, manual peritoneal dialysis therapy, and peritonitis.

An increasing number of patients are prescribed a continuous-cycling regimen because standard manual peritoneal-dialysis exchanges alone are not sufficient in achieving adequate dialysis as defined by the Dialysis Outcome Quality Initiative. Consequently, the number of patients on continuous-cycler therapy is increasing. There is controversy as to whether there are differences in the development of peritonitis between patients maintained on manual therapy and those on continuous cycling therapy. As a result, we retrospectively reviewed the charts of all cycler peritoneal dialysis (CPD) patients maintained on either manual peritoneal dialysis (Baxter UltraBag; Group I) or continuous cycler peritoneal dialysis (Baxter HomeChoice Cycler; Group II) between 1 June 1994 and 31 December 1996. A total of 239 patients were in Group I and 106 in Group II. Both groups were similar in age, race, gender, and presence of diabetes mellitus, coronary artery disease, peripheral vascular disease, and gastrointestinal disease. There was no difference in the overall rate of peritonitis between the two groups of patients [1 episode in 10.4 patient-months (Group I) vs. 1 in 10.0 patient-months (Group II); -0.01843 to 0.02619]. The rates of Staphylococcus aureus peritonitis [1 episode in 48.5 patient-months (Group I) vs. 1 in 141.8 patient months (Group II); -0.06152 to -1.1689]; polymicrobial peritonitis [1 episode in 278.8 patient-months (Group I) vs. 1 in 1134 patient months (Group II): -0.0079 to -0.0478], and fungal peritonitis (1 episode in 202.7 patient-months (Group I) vs. no episodes (Group II); 0.00202 to 0.00785] were significantly lower among patients maintained on the Baxter HomeChoice Cycler. The rate of gram-negative peritonitis was higher among patients maintained on the Baxter HomeChoice Cycler, but this difference was not statistically significant [1 episode in 82.6 patient-months (Group I) vs. 1 episode in 45.4 patient months (Group II); 0.4723 to -0.0248]. We conclude that individual rates of peritonitis were different for patients maintained on either manual or continuous CPD therapy, while the overall rate of peritonitis was found to be similar for both groups of patients. The finding that there may be a difference with the gram-negative peritonitis rate is important since gram-negative peritonitis has been shown to have a more severe outcome in terms of morbidity, mortality, and patient dropout from CPD therapy. A larger, randomized, multicenter study comparing the rates of gram-positive, gram-negative, fungal, and polymicrobial peritonitis is warranted.

Nine episodes of CPD-associated peritonitis with vancomycin resistant enterococci.

Nine episodes of chronic peritoneal dialysis (CPD)-associated peritonitis with vancomycin resistant enterococci (VRE) were described between November 1993 and February 1996 in our dialysis unit. During the time period, 216 patients were treated for 227 episodes of peritonitis. Of the patients developing peritonitis with VRE the mean age +/- SD was 56.3 +/- 9.7 years. There were 5 females, 4 males, 5 Caucasians and 4 African-Americans. Diabetes mellitus, cardiovascular disease and gastrointestinal disease were present in 7, 8 and 7 of the 9 patients with VRE peritonitis, respectively. Patients were maintained on CPD therapy for an average of 29.9 +/- 19.2 patient months before developing VRE peritonitis. The prior rate of CPD associated peritonitis in the patients developing VRE peritonitis was significantly higher than the rate noted in the CPD patients not developing peritonitis with VRE (1 episode in 6.3 patient months vs. 1 episode in 12.5 patient months, P < 0.05). All 9 patients had used vancomycin in the six months prior to the development of VRE peritonitis and 78% had used a cephalosporin. The antimicrobial therapy used to eradicate peritonitis with VRE varied among the 9 patients with chloramphenicol used in 4 patients. The Tenckhoff catheter was removed in 6 of the 9 patients and was successfully reinserted in one patient. The catheter was not removed in 3 patients and 2 of these patients expired. Five of the 9 patients expired while being treated for VRE, 2 transferred to hemodialysis and 2 continued CPD therapy. VRE peritonitis is a major concern for patients maintained on CPD therapy. Future studies are needed with case controls to determine the significance of prior vancomycin and cephalosporin therapy, fecal VRE carriage and certain demographic data on the acquisition of VRE peritonitis. Furthermore, the optimal therapy and outcome may be better clarified through such a review.

Continuous peritoneal dialysis-associated peritonitis of nosocomial origin.

OBJECTIVE: To describe our experience with nosocomial continuous peritoneal dialysis (CPD)-associated peritonitis focusing on the incidence, possible risk factors, spectrum of organisms, and outcome. DESIGN: Retrospective review of the medical records of our CPD patients admitted to an acute-care hospital between November, 1993 and December, 1994. SETTING: University-associated acute-care hospitals in New Haven, Connecticut. PATIENTS: One hundred and eighty-eight patients maintained on CPD therapy and admitted to an acute-care hospital. RESULTS: Nineteen patients (5%) developing nosocomial peritonitis (NP) were identified from the 408 admissions occurring during the study period. Patients developing NP were older than the hospitalized CPD patients not developing NP (65.5 +/- 14.6 vs 58.4 +/- 14.7 years, p < 0.05). Comorbid diseases including diabetes, peripheral vascular disease, gastrointestinal disease, cardiovascular disease, and human immunodeficiency virus seropositivity were not more common in the patients developing NP. Patients developing NP were hospitalized significantly longer than the CPD patients not developing NP (39.5 +/- 46.5 days vs 12.7 +/- 12.4 days, p < 0.001). The mean serum albumin was lower in the NP patients than in the CPD patients not developing NP (2.35 +/- 0.52 g/dL vs 3.02 +/- 0.60 g/L, p < 0.001). Antecedent antibiotic use and performance of invasive procedures were noted in 89% and 68% of the patients developing NP, respectively. Staphylococcal species, enterococcal species, and gram-negative organisms accounted for 26%, 21%, and 53% of the episodes of NP, respectively. Furthermore, two strains of Enterococcus resistant to vancomycin were cultured. Eight patients developing NP expired, 8 patients continued CPD therapy, 2 patients transferred to hemodialysis, and one patient recovered renal function. CONCLUSION: We conclude that NP is uncommon. Increased age, increased length of hospital stay, and hypoalbuminemia may predispose patients to the development of NP. Further studies with case controls should help to clarify whether antecedent antibiotics or prior performance of invasive procedures predispose patients to the development of nosocomial peritonitis. The spectrum of organisms accounting for NP is different than the spectrum of organisms causing community-acquired CPD-associated peritonitis. Some of these organisms may be resistant to standard antibiotic therapies. Patients developing NP do poorly, with 42% expiring while being treated for NP.

Fungal peritonitis in a large chronic peritoneal dialysis population: a report of 55 episodes.

Fungal peritonitis (FP) is a rare but serious complication of chronic peritoneal dialysis (CPD) therapy and is associated with high morbidity and CPD drop-out. Risk factors and management of FP remain controversial. We reviewed our experience with FP in an attempt to identify risk factors and to examine outcome in relation to treatment strategies. Between March 1984 and August 1994, 704 patients were maintained on CPD therapy in our unit. A total of 1,712 episodes of peritonitis were identified among these patients. Fungal peritonitis accounted for 55 (3.2%) of these episodes. The patients on CPD therapy who developed FP were similar to those who did not develop FP with regard to age, gender, underlying etiology for end-stage renal disease, and comorbid disease. Prior antibiotic use was noted in 87.3% of episodes of FP. The peritonitis rate in the patients who developed FP was one episode every 5.1 months compared with one episode every 9.9 patient-months in the CPD patients who did not develop this infection. Candida sp caused 74.5% of the episodes of FP. All patients were treated with antifungal drugs. In 85.5% of infections the Tenckhoff catheter was removed within 1 week of the diagnosis of FP; 31.9% of the patients who had the Tenckhoff catheter removed did not have the catheter replaced because of death or transfer to hemodialysis. In the patients who developed FP, 68.1% had the Tenckhoff catheter replaced; of these patients, 90.6% and 59.4% were on CPD therapy 1 and 6 months after catheter replacement, respectively. We conclude that risk factors identified in our population include peritonitis rate and prior antibiotic use. Fungal peritonitis is rare in our CPD population, and although it leads to significant CPD drop-out, it can be managed in many patients with antifungal therapy, early catheter removal, and temporary hemodialysis. Of the catheters replaced between 2 and 8 weeks after the diagnosis of FP, 91% functioned successfully, allowing continuation of CPD.

Comparison of continuous ambulatory peritoneal dialysis-related infections with different "Y-tubing" exchange systems.

Despite several modifications of the continuous ambulatory peritoneal dialysis (CAPD) technique over the last decade, peritonitis remains a major source of morbidity and is the leading cause of dropout for patients maintained on CAPD therapy. Recently, Baxter Healthcare introduced the Ultra Twin bag system, which uses drainage and infusion bags both secured to Y connecting tubing. Previous nonrandomized studies comparing the Ultra Twin bag system with other systems have indicated an improvement in the peritonitis rate with the Ultra Twin bag system. In this study, 82 patients were randomized to use the Ultra Twin bag system or the Ultra Y-set system, which uses only the drainage bag already attached to the Y connecting tubing. Peritonitis rates were significantly lower with the Ultra Twin bag system, one episode per 33.9 patient months, compared with the Ultra Y-set system, one episode per 11.7 patient months (P < 0.05). Furthermore, the 1-yr infection-free survival rates with the Ultra Twin bag system and the Ultra Y-set system were 71 and 40%, respectively. Exit-site infections were lower with the Ultra Twin bag system, one episode per 12.5 patient months, compared with the Ultra Y-set system, one episode per 28.3 patient months, although this difference was not statistically significant (P = 0.084). The effect of the reduction in the infection rate on patient dropout with the Ultra Twin bag system remains to be addressed.

Outcome of polymicrobial peritonitis in continuous ambulatory peritoneal dialysis patients.

Polymicrobial peritonitis is a relatively uncommon, but potentially serious complication that develops in continuous ambulatory peritoneal dialysis (CAPD) patients. Its cause and optimal management remain controversial. The authors reviewed the frequency and natural history of polymicrobial peritonitis in 432 CAPD patients. Of 1,405 episodes of peritonitis, 80 were polymicrobial (6%). Patients with polymicrobial peritonitis were similar to all CAPD patients in age, gender, race, and underlying renal disease. Diabetes mellitus, human immunodeficiency virus (HIV) status, and clinically apparent gastrointestinal disease did not predisposes patients to polymicrobial peritonitis. Thirty days after the polymicrobial peritonitis, 64 patients remained on CAPD (80%), and at 180 days 48 patients continued CAPD. Prior exit-site infections were present in 12 patients (14%) with polymicrobial peritonitis. Only 22% of patients required catheter removal to treat the infection. We conclude that polymicrobial peritonitis accounts for 6% of the total episodes of peritonitis; diabetes, HIV infection, and underlying gastrointestinal disease are not more prevalent in patients with multiorganism infections. Most patients continue CAPD therapy at 30 and 180 days after the episode of polymicrobial peritonitis.

Infection rates in end-stage renal disease patients treated with CCPD and CAPD using the UltraBag system.

Previous studies have shown the incidence of peritonitis to be generally lower for patients performing continuous cycling peritoneal dialysis (CCPD) than patients maintained on continuous ambulatory peritoneal dialysis (CAPD). Recent changes in CAPD techniques, particularly the introduction of the UltraBag system, have resulted in a marked decrease in peritonitis rates in CAPD patients. The purpose of the present study was to compare peritoneal dialysis-related infections in 73 patients treated with CCPD and 57 patients treated with CAPD using the UltraBag system for a 12-month period. Demographic data of the two groups were comparable. Peritonitis rates were significantly lower in the patients treated with CAPD on the UltraBag (one infection/23 patient-months) than in patients treated with CCPD (one infection/14.4 patient-months, p < 0.05). Exit-site infections were also significantly lower in patients treated with CAPD (one episode/35 patient-months) compared to patients treated with CCPD (one episode/11.5 patient-months, p < 0.05). The spectrum of organisms causing infection was similar in both groups of patients. The study suggests that peritonitis and exit-site infections are significantly less common in patients treated with CAPD with the UltraBag system than in patients treated with CCPD.

Selected outcome criteria and adequacy of dialysis in diabetic and elderly patients on CAPD therapy.

There has been a gradual increase in the number of diabetic and elderly patients maintained on continuous ambulatory peritoneal dialysis (CAPD) replacement therapy. Eighty randomly selected patients were studied over two years. Weekly normalized urea clearance (KT/Vurea), weekly creatinine clearance/1.73 m2 body surface area (BSA) (Ccr), and protein catabolic rate (PCR) were measured. Selected clinical outcome criteria were assessed. Weekly KT/Vurea was correlated with weekly Ccr (r = 0.538, p < 0.001), and weekly KT/Vurea was correlated with PCR (r = 0.393, p < 0.001). Patients were then stratified according to presence or absence of diabetes mellitus and age > 60 or < or = 60 years. Diabetic and nondiabetic patients had similar weekly KT/Vurea, weekly Ccr, PCR, serum albumin levels, weekly erythropoietin (EPO) requirements, peritonitis rates, and CAPD-related hospitalization rates. The total hospitalization rates, however, were higher in diabetic patients. Elderly and younger patients had similar weekly KT/Vurea, weekly Ccr, PCR, serum albumin levels, and weekly EPO requirements. Elderly patients, however, had higher peritonitis rates and higher total and CAPD-related hospitalization rates.

CAPD therapy for patients over 80 years of age.

OBJECTIVE: The purpose of the study is to review our experience with patients over 80 years of age with end-stage renal disease (ESRD) treated with continuous ambulatory peritoneal dialysis (CAPD). DESIGN: The records of all patients over 80 years of age treated in our unit with CAPD since 1979 were reviewed. SETTING: Out-patient CAPD facility. PATIENTS: Eighteen patients over 80 years of age were identified and studied. MAIN OUTCOME MEASURES: The duration of CAPD therapy, duration of CAPD training, mortality rate, hospitalization rate, peritonitis rate, and family assessment were reviewed and analyzed. RESULTS: The mean +/- SD duration of therapy was 20 +/- 17 months. Nine patients expired, 3 transferred to hemodialysis, 1 recovered renal function, and 5 remained on CAPD therapy. Peritonitis rates were 1.7 episodes/patient year. Of the organisms causing peritonitis, 56% were gram-positive bacteria. The average hospitalization rate was 13.9 days/patient year. The most frequent causes of hospitalization were peritonitis and cardiovascular disease. CONCLUSION: CAPD therapy is a reasonable therapeutic option for patients with end-stage renal disease over 80 years of age.

Weekly KT/V urea and selected outcome criteria in 56 randomly selected CAPD patients.

The optimal way to objectively measure the adequacy of continuous ambulatory peritoneal dialysis (CAPD) therapy remains controversial. It has been suggested that one-third or more of all CAPD patients are presently receiving "inadequate dialysis" when dialysis prescriptions are not carefully calculated. To better define the therapy being delivered in a large, freestanding CAPD center, weekly KT/V urea and creatinine clearance per 1.73 m2 body surface area were measured in 56 of 180 patients randomly selected from our unit in whom dialysis prescriptions were arbitrarily determined by nurses and physicians. In addition, protein catabolic rates and selected clinical outcome criteria were assessed. Weekly KT/V urea correlated with weekly creatinine clearance (r = 0.50) as well as with the protein catabolic rate (r = 0.45). Patients were arbitrarily divided into three groups based on KT/V urea measurements. Thirty percent of the patients had weekly KT/Vs < or = 1.4, 41% had KT/Vs between 1.5 and 1.8, and 29% had weekly KT/Vs > or = 1.9. Significant differences were not noted in hospitalization rates, erythropoietin doses, or serum albumin concentrations in patients with KT/Vs < or = 1.4 and in patients with KT/Vs > or = 1.9. Peritonitis rates were highest in the patients with KT/V > or = 1.9. Therefore, in patients randomly selected from our large CAPD center, 30% of the patients had weekly KT/V urea measurements < or = 1.4. The clinical significance of this finding remains uncertain.