Peritoneal dialysis in Brazil: twenty-five years of experience in a single center.

OBJECTIVES: To evaluate patient and technique survival and to provide an analysis of peritoneal dialysis (PD)-related peritonitis in 25 years of experience in a single center. STUDY DESIGN: Retrospective study of incident patients on PD from July 1980 to July 2005. SETTING: Single, university based, Brazilian dialysis program. PATIENTS: 680 patients were analyzed in our study from July 1980 to July 2005, with a cumulative experience of 15 303 patient-months. All patients over 15 years of age entering the dialysis program were included in the study. Patients with less than 30 days of follow-up were excluded. Biochemical and demographic variables, peritonitis episodes, and patient and technique survival were analyzed. RESULTS: Mean age at start of PD was 53 +/- 16 years; diabetic nephropathy was the main cause of chronic kidney disease. Cardiovascular disease was the main cause of death (44%); peritonitis was responsible for 16% of fatal events. The predictors of death in our study were diabetes [relative risk (RR) 1.23, p < 0.01], advanced age (RR 1.58, p < 0.001), low serum albumin level (RR 1.25, p < 0.01), and low serum phosphate level (RR 1.39, p < 0.001) upon starting PD. There were 1048 cases of peritonitis over the 25-year period, with a significant reduction in incidence after the introduction of the double-bag system. The number of incident PD patients originating from hemodialysis increased threefold over the observation period (p < 0.001), with a similar increase in comorbidities over time. CONCLUSION: In the largest single-center report of PD experience in Latin America, we describe the overall rate and trends over time of peritonitis as well as patient and technique survival, which are similar to previous reports. Significant changes in peritonitis rates and causative organisms as well as a significant time-dependent increase in high-risk patients starting PD were observed.

Insulin resistance is associated with circulating fibrinogen levels in nondiabetic patients receiving peritoneal dialysis.

BACKGROUND: Insulin resistance (IR) and inflammation are associated with increased risk of cardiovascular disease in the general population. Continuous glucose absorption in peritoneal dialysis (PD) may induce hyperglycemia and hyperinsulinemia. METHODS: We evaluated IR in nondiabetic patients receiving PD, and analyzed the association between IR and systemic inflammation biomarkers by performing a cross-sectional study on ambulatory dialysis. A total of 25 nondiabetic patients receiving PD and 25 healthy individuals, matched for gender, age, and body mass index (BMI), were included. The PD group was composed of 11 men and 14 women, with a mean age of 47 +/- 14 years and mean BMI of 25.5 +/- 4.7 kg/m(2). The control group was composed of 10 men and 15 women, with a mean age of 45 +/- 12 years and BMI of 24.0 +/- 2.8 kg/m(2). RESULTS: IR was evaluated by the homeostasis model assessment method (HOMA-IR). Inflammation was assessed through high-sensitivity C-reactive protein (CRP) and fibrinogen. Body composition and truncal fat were evaluated by dual energy x-ray absorptiometry. HOMA-IR was significantly higher (P < .0001) in subjects receiving PD (4.9, range: 2.3-9.3 mmol/L x muU/mL) compared with healthy subjects (1.2, range: 0.4-4.8 mmol/L x muU/mL). As expected, compared with controls, patients receiving PD had significantly higher levels of insulin (26.5 +/- 7.5 muU/mL vs 6.3 +/- 3.4 muU/mL; P < .0001), CRP (6.3, range: 0.3-61.1 mg/L vs 2.4, range: 0.6-5.9 mg/L; P = .001), and fibrinogen (379 +/- 101 mg/dL vs 268 +/- 66 mg/dL; P < .0001). However, there were no significant differences in body and truncal fat mass between the groups. A significant correlation between HOMA-IR and fibrinogen (Rho = 0.48; P = .01) was observed. However, no correlation was found between HOMA-IR and CRP. Also, no significant correlations were found between HOMA-IR and body fat mass (Rho = 0.11), and between HOMA-IR and truncal fat mass (Rho = 0.19). CONCLUSIONS: Patients receiving PD demonstrate a state of IR that is associated with high circulating levels of fibrinogen. This suggests that hyperfibrinogenemia may be involved in the pathogenesis of IR in this setting.

Associations between renal function, volume status and endotoxaemia in chronic kidney disease patients.

Inflammation is an important predictor of increased cardiovascular morbidity and mortality in patients with chronic kidney disease (CKD), but the mechanisms behind the chronic activation of the immune system are not clearly understood. CKD patients develop fluid overload, which has been proposed to be a stimulus for inflammatory activation due to the translocation of macromolecules from the gut. We hypothesize that fluid overload is associated with signs of systemic inflammation and endotoxaemia in stages 1-5 CKD patients. The aim of this prospective study was to evaluate the associations between renal function, fluid status [evaluated by the inferior vena cava diameter (IVCD) and the collapsibility index (CI)], systemic inflammation [plasma levels of C-reactive protein (CRP), fibrinogen and albumin] and endotoxaemia (through the Limulus amebocyte lysate enzymatic assay) in a group of CKD patients in our out-patient clinic. The population consisted of 74 (mean of 57; range 23-83 years of age; 47% males) CKD patients with glomerular filtration rate (based on the mean of urea and creatinine clearances) of 34 ml/min. Both albumin (Rho = 0.25; P = 0.05) and fibrinogen (Rho= - 0.48; P < 0.0001) were significantly correlated to glomerular filtration rate (GFR). According to the IVCD, 84% of the patients were fluid overloaded, while 83% were considered overloaded by the CI. Signs of endotoxaemia were detected in all patients. Endotoxin levels were higher in patients with signs of fluid overload (0.85 +/- 0.11ng/l) when compared with patients with normal values of IVCD (0.61 +/- 0.05 ng/l; P < 0.05). Endotoxin levels correlated to both IVCD (Rho=0.33, P < 0.005) and CI (Rho = -0.25, P < 0.05). There was no correlation between endotoxin levels and GFR, CRP or fibrinogen. In summary, although most CKD patients presented signs of fluid overload that was associated with endotoxaemia, there was no association between endotoxaemia and systemic inflammation, suggesting the endotoxaemia may not be the main determinant of the inflammatory status in this group of patients.

The recommendations from the International Society for Peritoneal Dialysis for Peritonitis Treatment: a single-center historical comparison.

The antibiotic treatment currently recommended by the International Society for Peritoneal Dialysis (ISPD) for peritonitis consists of a combination of a first- and a third-generation cephalosporin. The schedule formerly recommended combined a first-generation cephalosporin and an aminoglycoside. No comparison between the treatment schedules has been performed until now. We compared the effectiveness of these two regimens in peritoneal dialysis-related peritonitis at our center. From January 1999 to April 2000, we followed 107 patients in our PD clinic (period 1: 47% men; 32% with diabetes; mean age: 52 +/- 13 years). We followed a similar number of patients from January 2002 to July 2003 (period 2: 109 patients; 54% men; 51% with diabetes; mean age: 56 +/- 18 years). In each period, diagnosis and treatment of peritonitis were based on the recommendations of the ISPD as earlier described. Negative culture rates were similar in period 1 and period 2 (32% vs. 30%). In both study groups, the bacteria that most commonly caused peritonitis were Staphylococcus epidermidis (period 1: 41%; period 2: 39%) and S. aureus (period 1: 27%; period 2: 18%). Gram-positive infections occurred in 59% of patients during period 1 and in 57% during period 2. Gram-negative infections occurred in 16% of patients during period 1 and in 18% during period 2. We observed no significant difference in the peritonitis cure rate from period 1 to period 2 (78% vs. 83%; chi-square: 0.98; p = 0.3), but changes in the primary antibiotic schedule were necessary in 4 patients in period 1 as compared with 1 patient in period 2. The rates of catheter removal were not significantly different during the two periods (period 1: 14%; period 2: 5%; chi-square: 2.5; p = 0.11). Mortality was also not significantly different during the two periods (period 1: 7%; period 2: 5%; chi-square: 0.23; p = 0.62). The two antibiotic schedules were equally effective in the treatment of peritonitis. Cost-effectiveness, impact on residual renal function, and potential development of bacterial resistance must be considered when selecting the antibiotic schedule for peritonitis treatment.