Analysis of Ultrafiltration Failure Diagnosed at the Initiation of Peritoneal Dialysis with the Help of Peritoneal Equilibration Tests with Complete Drainage at Sixty Minutes. A Longitudinal Study.

UNLABELLED: ♦ BACKGROUND: Ultrafiltration failure (UFF) diagnosed at the initiation of peritoneal dialysis (PD) has been insufficiently characterized. In particular, few longitudinal studies have analyzed the time course of water transport in patients with this complication. ♦ OBJECTIVE: To investigate the time course of peritoneal water transport during the first year on PD in patients presenting UFF since the initiation of this therapy (study group). ♦ METHOD: Prospective, observational, single-center design. We analyzed, at baseline and after 1 year of follow-up, peritoneal water transport in 19 patients incident on PD with UFF. We used incident patients without UFF as a control group. Water transport was characterized with the help of 3.86/4.25% dextrose-based peritoneal equilibration tests (PETs) with complete drainage at 60 minutes. ♦ RESULTS: The study group revealed a disorder of water transport affecting both small-pore ultrafiltration (SPUF) (p = 0.054 vs incident without UFF) and free water transport (FWT) (p = 0.001). After 1 year of follow-up, FWT displayed a general increasing trend in the study group (mean variation 48.9 mL, 95% confidence interval [CI] 15.5, 82.2, p = 0.012), while the behavior of SPUF was less predictable (-4.8 mL, 95% CI -61.4, 71.1, p = 0.85). These changes were not observed in incident patients without UFF. Neither initial clinical characteristics, baseline PET-derived parameters, or suffering peritoneal infections during the first year predicted the time course of the capacity of UF in the study group. Recovery from incident UFF was apparently linked to improvement of SPUF. ♦ CONCLUSIONS: Patients with UFF at the start of PD suffer a disorder of peritoneal water transport affecting both FWT and SPUF. Free water transport increases systematically in these patients after 1 year of follow-up. The evolution of SPUF is less predictable, and improvement of this parameter marks reversibility of this complication.

Categorization of sodium sieving by 2.27% and 3.86% peritoneal equilibration tests--a comparative analysis in the clinical setting.

BACKGROUND: Analysis of the dialysate sodium concentration during a peritoneal equilibration test (PET) provides information on the rates of water and solute transport through different membrane pathways. A hypertonic (3.86%) glucose-based dialysate may enhance the accuracy of analysis. There are still gaps in our knowledge regarding this question, in the clinical setting. Objective. The aim of this study was to compare the categorization of the sodium sieving effect in peritoneal dialysis (PD) patients by 2.27% and 3.86% PETs, and to disclose clinical correlates of this phenomenon. Method. Ninety PD patients underwent prospectively 2.27% and 3.86% modified (dialysate samples at 0, 60, 90, 120 and 240 min) PETs, in a random order. We searched for differences in the time profiles of sodium sieving and its categorization. We correlated sodium sieving with ultrafiltration (UF) and solute transport capacity, as also with selected clinical and demographic variables, using a multivariate approach. RESULTS: The maximum dip in the dialysate sodium concentration (11.1 mM/L, 3.86% versus 7.1 mM/L, 2.27%, P < 0.001) was most common after 90 min in the 3.86% PET, with the 2.27% test somewhere between 60 and 90 min. Low sodium sieving (defined by a dip <5 mM/L at 60 min) was observed in 8.9% of the patients in the 3.86% test. The same limit categorized 34.4% of the patients as low sieving in the 2.27% test (100.0% sensitivity and 72.0% specificity, using 3.86% as a reference). UF and D/P(240 min) creatinine were independent predictors of the sodium sieving effect in both tests. Moreover, multivariate analysis disclosed a consistent inverse correlation between GFR and sodium sieving in both the 2.27% (B = -0.23, 95% CI -0.40, -0.07, P = 0.006) and 3.86% PET (B = -0.46, 95% CI -0.65, -0.26, P < 0.0005). CONCLUSIONS: The standard 2.27% PET permits some categorization of sodium sieving in PD patients. However, the information provided by this test lacks the discriminatory capacity of the 3.86% PET, which should be considered the one for reference for this purpose. GFR keeps a consistent inverse correlation with the intensity of sodium sieving in both the 2.27% and 3.86% PET.

Treatment of peritoneal dialysis-related peritonitis with ciprofloxacin monotherapy: clinical outcomes and bacterial susceptibility over two decades.

BACKGROUND: There is controversy about the preferred initial antibiotic therapy for peritoneal dialysis (PD)-related peritonitis. Quinolones have been used extensively in this setting, yet their long-term effectiveness is unknown. AIM: To analyze the results of a protocol of treatment of PD-related peritonitis with ciprofloxacin, maintained over two decades. METHOD: We analyzed the clinical outcome of 682 episodes of bacterial peritonitis treated with intraperitoneal ciprofloxacin monotherapy, and the time course of bacterial susceptibility to this antimicrobial, in a historical cohort of 641 PD patients (1988-2007). Main outcome variables included changes to initial therapy and rates of hospital admission, catheter removal, relapse, reinfection, PD dropout, and mortality. For comparisons we divided the study period into phases A (1988-1994), B (1995-2000), and C (2001-2007). RESULTS: The incidence of Staphylococcus aureus peritonitis decreased, while the incidences of polymicrobial and negative-culture peritonitis increased after phase A. In vitro susceptibility to ciprofloxacin decreased significantly only among coagulase-negative staphylococci (87.0% susceptible strains in phase A vs 70.0% in B and 70.1% in C, p = 0.006). Overall success rates (catheter not removed and ongoing PD after the episode) remained stable, at over 85%. However, the proportion of patients treated solely with ciprofloxacin declined from 75.7% (A) to 47.3% (B) to 32.4% (C) (p < 0.0005) and admission rates increased from 12.7% to 16.8% to 24.9% respectively (p = 0.001). These changes affected all the etiologic groups except culture-negative peritonitis. In vitro resistance to ciprofloxacin was a marker of multiresistance and correlated strongly with clinical outcome of peritonitis. Among isolates susceptible to ciprofloxacin, changing initial therapy for any reason also predicted a poor outcome. CONCLUSIONS: Following satisfactory early results, the effectiveness of ciprofloxacin as monotherapy for PD-related peritonitis has declined markedly in the long term. This decline cannot be explained solely by a decrease of in vitro susceptibility to this antimicrobial, which was significant only among coagulase-negative staphylococci. Resistance to ciprofloxacin is a strong marker of in vitro multiresistance and poor clinical outcome of peritonitis.

Mupirocin resistance after long-term use for Staphylococcus aureus colonization in patients undergoing chronic peritoneal dialysis.

Mupirocin (Mup) has been used extensively to prevent Staphylococcus aureus (SAu) infections in patients undergoing peritoneal dialysis (PD). Resistance to Mup has been reported, but its relevance after long-term use of this drug in PD is unknown. Colonization by SAu was treated with topic Mup in our unit between September 1990 and December 2000. Sensitivity to Mup was tested in 437 strains of SAu isolated from 155 PD patients and 62 dialysis partners. Resistance to Mup was classified as low (minimal inhibitory concentration [MIC] > or = 8 microg/mL) or high (MIC > or = 512 microg/mL) degree. MIC90 was 0.125 microg/mL in 1990 to 1996 (5% low, 0% high-degree resistance), 64 microg/mL in 1997 to 1998 (6.6% low, 8.3% high-degree resistance), and 1,024 microg/mL in 1999 to 2000 (2.3% low, 12.4% high-degree resistance). Mup-resistant SAu were isolated from 25 patients and 13 partners a median of 15 months after starting PD. Resistance was associated frequently with repeated treatments of SAu recolonization, but was detected in 3 cases at the start of PD therapy. The accumulated incidence of SAu exit-site infection in the period 1997 to 2000 was 32.3% in patients colonized by Mup-resistant SAu as compared with 14.5% in those colonized by Mup-sensitive SAu (P = 0.03). Mup-resistant SAu have emerged in a significant proportion of our PD patients and dialysis partners. This emergence has resulted in a moderate, but significant, increase in the risk of SAu exit-site infection and raises concerns about the future of Mup as the therapy of choice for SAu colonization in patients undergoing chronic PD.