Peritonitis Prevention in CAPD: To Mask or Not?

Objective

To assess the efficacy of wearing a face mask to prevent peritonitis during continuous ambulatory peritoneal dialysis (CAPD) bag exchange.

Setting

Renal unit at a university hospital.

Patients

Two groups of patients on CAPD were compared: those performing bag exchange with ( n = 24) and those without a face mask ( n = 40).

Outcomes

Occurrence of first episode of peritonitis and total number of episodes.

Results

No difference was found between groups with respect to probability of developing the first episode of peritonitis ( p = 0.757). Patients holding university degrees had evidence of protection, with borderline significance [relative risk (RR) 0.52; confidence interval (CI) 95%, 0.23 – 1.18; p = 0.109]. Cox's proportional hazard regression analysis also demonstrated a significant protective factor for patients with university level education (RR 0.42; CI 95%, 0.18 – 0.98; p = 0.04). Incidence of peritonitis was not significantly different between groups: with-mask group had 1.0 episode/year, and without-mask group had 0.94 episodes/year. Staphylococcus epidermidis was the most commonly identified agent. Staphylococcus aureus was found more frequently in the with-mask group ( p = 0.003). Peritonitis due to Streptococcus viridans and Enterococci were detected only in the without-mask group.

Conclusion

The current study suggests that routine use of face masks during CAPD bag exchanges may be unnecessary and could be discontinued.

Time to Positivity of Bacteria Cultures in Peritoneal Dialysis Fluid: Evaluation of Different Laboratory Techniques

Patients with chronic kidney disease on peritoneal dialysis (PD) are susceptible to infections, with peritonitis being the primary cause of dropout. Peritoneal fluid culture is one of the essential elements for proper diagnosis and peritonitis treatment. The aim of this study was to compare the time required to obtain a positive culture using different laboratory methods. An in vitro cross-sectional study was conducted comparing different techniques for preparation and culture of bacteria in peritoneal fluid. The research was carried out with 21 sterile dialysis bags and 21 PD bags containing peritoneal fluid drained from patients without peritonitis. Fluids from the 42 PD bags were contaminated by injecting a coagulase-negative Staphylococcus suspension and then prepared for culture using 4 distinct techniques: A - direct culture; B - post-centrifugation culture; C - direct culture after 4 h sedimentation; and D - culture after 4 h sedimentation and centrifugation. This was followed by seeding. In the 21 contaminated sterile bags, mean times to obtain a positive culture with techniques D (19.6 h ± 2.6) and C (19.1 h ± 2.3) were longer than with technique A (15.8 h ± 3.0; p < 0.01), but not statistically different from group B (19.0 h ± 3.2). The same occurred in the 21 bags drained from patients, with mean times for techniques D (14.0 h ± 1.9) and C (14.5 h ± 1.7) being longer than technique A (12.22 h ± 1.94; p < 0.05) but not statistically different from technique B (13.2 h ± 1.3). The sedimentation and centrifugation steps seem to be unnecessary and may delay antibiotic sensitivity test results by approximately 8 hours.

Study on the association of UGT1A9 gene c.98T>C polymorphism and mycophenolic acid plasma levels in renal transplant patients

Mycophenolate mofetil (MMF) is a prodrug active only after its hydrolysis to mycophenolic acid (MPA). The UGT1A9 enzyme is of special interest since it is the main enzyme involved in the glucuronidation of MPA. Single nucleotide polymorphisms (SNPs) in the UGT1A9 gene may be responsible for individual differences in the pharmacokinetics of MMF. Expression levels and the activity of UGT1A9 may depend on the presence of some SNPs located in the gene promoter region (-2152C>T and -275T>A), as well as changes in the coding region (c.98T>C). The objective of this study was to evaluate the effect of allelic variants of the UGT1A9 c.98T>C polymorphism (rs72551330; g. 87289T>C) on MMF metabolism in renal transplant patients. MPA and MPA 7-O glucuronide (MPAG) levels were determined on plasma samples of kidney transplant patients (N = 39) by high-performance liquid chromatography using ultraviolet detection. DNA was isolated from leukocytes and stored at -20°C. The presence of SNPs was investigated using polymerase chain reaction, followed by amplicon sequencing. The analysis of the UGT1A9 c.98T>C polymorphism revealed that all study patients presented the TT genotype. Diverse MPA and MPAG plasma concentrations were detected, including therapeutic, subtherapeutic, and toxic levels. A standardized molecular method permitted identification of UGT1A9 c.98T>C polymorphism genotypes in the examined renal transplant patients. All individuals of the study group presented the same genotype (c.98TT) for that polymorphism. Thereby, no association between the c.98T>C polymorphism and MPA and MPAG plasma levels could be evaluated, despite different levels of these compounds being observed.

Depression, quality of life, and body composition in patients with end-stage renal disease: a cohort study

Objective:

To prospectively evaluate depressive symptoms, nutritional status, and quality of life (QoL) and search for possible associations in patients with end-stage renal disease undergoing hemodialysis.

Methods:

A cohort study of 104 adult patients with end-stage renal disease undergoing hemodialysis was conducted. Anthropometric, clinical, and biochemical variables were evaluated after a midweek hemodialysis session. The participants’ body composition was assessed by direct segmental multi-frequency bioimpedance analysis. The WHOQOL-Bref questionnaire was used to evaluate QoL. Participants were separated into two groups - depressive symptoms and no depressive symptoms - at inclusion and evaluated annually for 2 years thereafter using the Beck Depression Inventory. Survival analysis used the Kaplan-Meier method and Cox regression analysis for the goodness of fit of associated factors. All-cause mortality was the outcome of interest.

Results:

Participants’ mean age was 55.3±15.6 years, 60% were male, and the median time on hemodialysis was 17.5 (8.0-36.8) months. Thirty-two patients had depressive symptoms and a significantly lower QoL compared with the 72 patients in the no depressive symptoms group. The fitted outcome model showed that lean body mass had a protective effect against all-cause mortality (hazard ratio [HR] = 0.89; 95%CI 0.80-0.99; p = 0.038).

Conclusion:

Depressive symptoms were highly prevalent in the cohort, and correlated with the physical and psychological components of the QoL life questionnaire, as well as with C-reactive protein and phosphorus levels. Lean body mass was protective for the assessed outcome.

Hand hygiene in peritoneal dialysis patients: a comparison of two techniques

INTRODUCTION AND OBJECTIVES

Hand hygiene is essential for preventing peritoneal dialysis (PD)-related infections. The present study compared the effectiveness of two hygiene techniques in reducing the number of colony-forming units (CFUs) on the hands of patients undergoing PD.

METHODS

In this controlled clinical trial, 22 participants enrolled in the same PD program underwent a two-hand evaluation for microbiologic flora. Participants participated in two treatments: a) simple hand hygiene plus antiseptic hand hygiene, in which the patients washed their hands with water and glycerin soap for 1 minute and then rubbed and dried their hands with 70% ethyl alcohol gel; and b) antiseptic hand hygiene, in which the patients rubbed their hands with 70% ethyl alcohol gel until fully dry. To sample distal finger surfaces, we asked the participants to touch sheep blood agar plates directly.

RESULTS

The CFU count for both hands was significantly higher in the regular hygiene group than in the gel-only group [69.0 (16.0 - 101.0) CFU vs 9.0 (2.2 - 55.5) CFU, p < 0.010]. Growth of coagulase-negative Staphylococcus colonies was significantly higher in right-hand cultures from the regular hygiene group than in those from the gel-only group [69.5 (26.25 - 101.0) CFU vs 9.5 (1.0 - 41.7) CFU; p < 0.050].

CONCLUSIONS

Among patients undergoing PD, using 70% ethyl alcohol gel to cleanse the hands may be more effective than following the regular hygiene recommendations in reducing bacterial populations.

Erythrocytes L-arginine y+ transporter inhibition by N-ethylmaleimide in ice-bath

Erythrocytes L: -arginine uptake is conveyed by y+ and y+L membrane transport systems. Pre-incubation with N-ethylmaleimide for 10 min at 37°C inhibits the y+ system. The aim of this study was to determine the ideal pre-incubation temperature in evaluating y+ and y+L systems. Cells were pre-incubated with or without N-ethylmaleimide for 10 min at 4°C and 37°C. L: -Arginine uptake was quantified by radioisotope and standard erythrocytes membrane flux methodology. Results demonstrate that erythrocytes L: -arginine content is depleted by pre-incubation at 37°C for 10 min, thus changing the V (max) measurement. The inhibitory effect of N-ethylmaleimide pre-incubation was temperature independent and already complete after 1 min of incubation. No significant difference in kinetic parameters was detected between cells pre-incubated at 37°C or 4°C, under zero-trans conditions. In conclusion, we suggest that measurement of erythrocytes L: -arginine uptake by y+ and y+L systems could be carried out without N-ethylmaleimide pre-incubation at 37°C.

Solutes transport characteristics in peritoneal dialysis: variations in glucose and insulin serum levels

BACKGROUND

Differences in small solutes transport rate (SSTR) during peritoneal dialysis (PD) may affect water and solutes removal. Patients with high SSTR must rely on shorter dwell times and increased dialysate glucose concentrations to keep fluid balance. Glucose absorption during peritoneal dialysis (PD), besides affecting glucose and insulin metabolism, may induce weight gain. The study aimed at examining acute glucose and insulin serum level changes and other potential relationships in PD patients with diverse SSTR.

METHODS

This cross-sectional study used a modified peritoneal equilibration test (PET) that enrolled 34 prevalent PD patients. Zero, 15, 30, 60, 120, 180, and 240-minute glucose and insulin serum levels were measured. Insulin resistance index was assessed by the homeostasis model assessment (HOMA-IR) formula. SSTR categories were classified by quartiles of the four-hour dialysate/serum creatinine ratio (D(4)/P(Cr)). Demographic and clinical variables were evaluated, and the body mass index (BMI) was estimated. Correlations among variables of interest and categories of SSTR were explored.

RESULTS

Glucose serum levels were significantly different at 15, 30, and 60 minutes between high and low SSTR categories (p = 0.014, 0.009, and 0.022). Increased BMI (25.5 +/- 5.1) and insulin resistance [HOMA-IR = 2.60 (1.40-4.23)] were evidenced overall. Very strong to moderate correlations between insulin levels along the PET and HOMA-IR (r = 0.973, 0.834, 0.766, 0.728, 0.843, 0.857, 0.882) and BMI (r = 0.562, 0.459, 0.417, 0.370, 0.508, 0.514, 0.483) were disclosed. CONCLUSIONS; Early glucose serum levels were associated with SSTR during a PET. Overweight or obesity and insulin resistance were prevalent. An association between insulin serum levels and BMI was demonstrated.

Erythrocyte L-arginine uptake in peritoneal dialysis patients changes over time

During long-term exposure to continuous ambulatory peritoneal dialysis (PD), the characteristics of the peritoneal membrane may be altered. The substrate for nitric oxide synthesis is L-arginine, which may enter cells via the y+ and y+L transport systems. Peritoneal membrane characteristics may depend on vascular function and the L-arginine-NO pathway. Maximal capacity for L-arginine transport is higher in patients with a lower dialysis adequacy index. Our aim was to evaluate erythrocyte L-arginine uptake in PD patients at the start and end of a 3-year interval. Our longitudinal study evaluated 8 stable patients on PD who were not using NO donors and who had been free of peritonitis for at least 1 month. Uptake of L-arginine was measured in 2003 and again in 2006. Maximal transport capacity (Vmax, in micromoles per liter-cells per hour) and half-saturation constant (km, in micromoles per liter) were measured in erythrocytes using 14C as a marker and N-ethylmaleimide as inhibitor of the y+ system. For the years 2003 and 2006 respectively, mean +/- standard deviation for total L-arginine uptake Vmax was 749 +/- 182 micromol/L-cells/h and 1146 +/- 365 micromol/L-cells/h (p = 0.016, paired t-test),for y+L Vmax was 180 +/- 58 micromol/L-cells/h and 515 +/- 142 micromol/L-cells/h (p = 0. 002), and for y+ Vmax was 556 +/- 177 micromol/L-cells/h and 662 +/- 267 micromol/ L-cells/h (nonsignificant). The total y+L and y+km were not significantly different. The L-arginine maximal uptake capacity in erythrocytes increased after 3 years of PD treatment. These findings agree with the suggestion of an association between y+L activity and dialysis adequacy or uremia toxicity. Peritoneal membrane characteristics may depend on vascular function and the L-arginine-NO pathway.

Quality of life and sexuality in chronic dialysis female patients

Patients in end-stage renal disease (ESRD) present reduced quality of life (QOL) and impaired sexual function. Previous studies have mostly addressed male sexual dysfunction. This was a cross-sectional controlled study that applied a general and the World Health Organization Quality of Life-bref questionnaires to assess demographic, marital, and sexual conditions, and QOL in 86 healthy women aged 18 or more years (Group 1), and 38 female ESRD patients on dialysis for at least 2 months (Group 2). The effect of several explanatory variables upon QOL components was estimated. Quality of life was lower in Group 2 -- overall, and on physical and environment domains. To undergo dialysis and to be poorly educated negatively affected the QOL. Yet age, a stable marital relationship or being sexually active had no effect. Female patients undergoing chronic dialysis had lower QOL and were significantly more sexually dysfunctional than comparable healthy women. Decline in sexual function had no effect on the QOL.

Incidence of delayed graft function in cadaveric kidney transplants in Brazil: a multicenter analysis

To evaluate the frequency of delayed graft function (DGF) in kidney transplant centers in Brazil, we sent a questionnaire requesting information on the number of cadaveric donor kidney transplants performed during the years 2000, 2001, and 2002, the number of early nonfunctioning grafts, and the number of patients on dialysis during the first posttransplant week with subsequent recovery. Among all centers performing more than 50 kidney transplants during the last year of evaluation, 6, performing 612 cadaveric kidney transplants during the study period, replied to the questionnaire. Sixty procedures (9.7%) resulted in nonfunctioning grafts, while 312 (55.6%) patients required dialysis during the first Ptx week: 216 (53.9%) in 2000, 189 (62.3%) in 2001, and 216 (51.6%) in 2002. The frequency of DGF during the study period was higher than that noted by several previous foreign studies. To better evaluate the possible causes of this finding, a more extensive and focused study is warranted.

Acute renal failure needing dialysis in the intensive care unit and prognostic scores

BACKGROUND

Generic prognostic scores used in acute renal failure (ARF) give imprecise results; disease-specific indices applied to distinct populations or intensive care practices becomes inaccurate. The current study evaluates the adequacy of prognostic scores, in patients with severe ARF needing dialysis.

METHODS

Known generic (APACHE II) and disease-specific (ATN-ISS) indices were applied to a cohort (n = 280) with ARF needing dialysis, under intensive care. Possible risk factors as causal factors, organ dysfunctions and clinical variables were examined, and a local index assembled by multivariate logistic regression analysis. Area under the receiver operating characteristics (ROC) curves evaluated the indices discriminating capacity. Goodness-of-fit testing and linear regression analysis appraised calibration. Validation was accomplished by the bootstrapping technique. The end-point was hospital mortality.

RESULTS

Overall mortality was 85%. Female gender < 44 years (OR: 0.29; 95% CI: 0.10-0.84), liver/obstructive biliary disease (OR: 6.03; 95% CI: 1.65-22.08), being conscious (OR: 0.49; 95% CI: 0.21-1.14), use of vasoactive drug (OR: 3.13; 95% CI: 1.25-7.83), respiratory dysfunction (OR: 5.20; 95% CI: 1.25-7.83) or sepsis (OR: 2.62; 95% CI: 1.14-6.02) were associated with outcome. Areas under the ROC curve of 0.815, 0.652 and 0.814; Goodness-of-fit test P = 0.593, P < 0.001 and P = 0.002; and linear regression R2 = 0.973, R2 = 0.526 and R2 = 0.919 for the local index, APACHE II and ATN-ISS, respectively, indicate better performance by the local index. The local index median area under the ROC curve, by bootstrapping, was 0.820 (95% CI: 0.741-0.907).

CONCLUSIONS

APACHE II score was inaccurate, and ATN-ISS poorly calibrated. When mortality or intensive care practices significantly deviate, local scores may better evaluate prognosis in severe ARF.

Bag exchange in continuous ambulatory peritoneal dialysis without use of a face mask: experience of five years

This article describes our five-year experience of continuous ambulatory peritoneal dialysis (CAPD) with bag exchanges performed without use of a face mask. The study took place in the renal unit at a university hospital. All patients admitted to the CAPD program from February 1995 to March 2000 were trained to perform bag exchanges without use of a face mask. Occurrence of peritonitis episodes was the outcome of interest. We evaluated 94 patients (52 women, 42 men) with a mean age of 48 +/- 21 years and a total follow-up of 50,502 patient-days. During that time, 79 episodes of peritonitis occurred in 46 patients, for a peritonitis rate of 0.57 episodes/year. The most frequently isolated micro-organisms were Staphylococcus epidermidis in 20 patients (25.3%) and S. aureus in 11 patients (13.9%). Renal transplantation was the major cause of drop-out [23 patients (43.4%)], followed by peritonitis [14 patients (26.4%)], death due to cardiovascular complications [9 patients (17.0%)], loss of ultrafiltration [2 patients (3.8%)], and other causes [5 patients (9.4%)]. The probability of being free of peritonitis at 12 months was 0.60, and at 60 months, 0.37. Peritonitis rates during the study period were not different from those reported by other centers, supporting the hypothesis that routine use of a face mask during CAPD bag exchange may be unnecessary.

Peritonitis prevention in CAPD: to mask or not?

OBJECTIVE

To assess the efficacy of wearing a face mask to prevent peritonitis during continuous ambulatory peritoneal dialysis (CAPD) bag exchange.

SETTING

Renal unit at a university hospital.

PATIENTS

Two groups of patients on CAPD were compared: those performing bag exchange with (n = 24) and those without a face mask (n = 40).

OUTCOMES

Occurrence of first episode of peritonitis and total number of episodes.

RESULTS

No difference was found between groups with respect to probability of developing the first episode of peritonitis (p = 0.757). Patients holding university degrees had evidence of protection, with borderline significance [relative risk (RR) 0.52; confidence interval (CI) 95%, 0.23 -1.18; p= 0.109]. Cox's proportional hazard regression analysis also demonstrated a significant protective factor for patients with university level education (RR 0.42; Cl 95%, 0.18 - 0.98; p = 0.04). Incidence of peritonitis was not significantly different between groups: with-mask group had 1.0 episode/year, and without-mask group had 0.94 episodes/year. Staphylococcus epidermidis was the most commonly identified agent. Staphylococcus aureus was found more frequently in the with-mask group (p = 0.003). Peritonitis due to Streptococcus viridans and Enterococci were detected only in the without-mask group.

CONCLUSION

The current study suggests that routine use of face masks during CAPD bag exchanges may be unnecessary and could be discontinued.