Increasing mupirocin resistance of Staphylococcus aureus in CAPD--should it continue to be used as prophylaxis?

This editorial summarizes the mechanisms of mupirocin resistance and the conditions that promote its development. While there is increasing evidence that high-level mupirocin resistance is developing during systematic use of mupirocin as prophylaxis against Staphylococcus aureus, the appearance of resistance does not preclude the beneficial effect of regular prophylaxis. Vigilance has to be exercised to notice larger-scale resistance that may require limiting the use of mupirocin.

Normal or low initial PTH levels are not a predictor of morbidity/mortality in patients undergoing chronic peritoneal dialysis.

OBJECTIVE: During the past few decades, the pattern of bone disease in uremic patients has changed significantly. There has been an increase in the number of patients with normal or low initial parathyroid hormone (PTH) levels, particularly in patients on chronic peritoneal dialysis (CPD). Previous authors have described a higher prevalence of bone pain, microfractures, and fractures, and higher mortality among these patients. The aim of this study was to determine the incidence, morbidity, and mortality of patients who had a low or normal intact PTH (iPTH) level when they started CPD. DESIGN: We reviewed the records of 251 patients in our program that started CPD during the past 5 years (January 1996-December 2000). Clinical data, laboratory variables, medication, and dialysis parameters/dose were available at every clinic visit (approximately every 4 weeks). Intact PTH was used to express parathyroid function; values 3 times higher than the upper limit of normal (ULN) were assumed to be optimal. Variables predictive of the development of parathyroid dysfunction were calculated by univariate and multivariate logistic regression analysis. RESULTS: Of the patients who started CPD, 15.5% had iPTH values below the ULN (7.6 pmol/L), and an additional 29.5% had an iPTH of less than 3 times the ULN (i.e., between 7.6 and 22.8 pmol/L). We call these two groups of patients the normal/low initial iPTH group. During the follow-up period (3-63 months), we found a trend toward increasing iPTH levels. By the end of the study period, 61.2% of those with normal/low initial iPTH remained in the normal/low iPTH range, and 38.8% had converted to a group with an iPTH range higher than 22.8 pmol/L. The patients who converted their iPTH grouping were younger, fewer of them were diabetics (p = not significant), and they were more frequently on low calcium dialysate (p < 0.05). Hyperphosphatemia was an independent risk factor for subsequent iPTH changes during the course of continuous ambulatory PD treatment. All patients in the normal/low iPTH groups had a low prevalence of bone fractures (3.5%). Also, patients who remained in the normal/low iPTH group at the end of the follow-up period did not have more fractures than those who converted to the hyperparathyroid group (3.8% vs 3.1%). We found no differences in bone fractures between patients with iPTH levels below 22.8 and those with levels above 22.8 pmol/L (3.5% vs 5.4%), nor were there differences in patient and technique survival between these two groups. CONCLUSION: Normal/low initial iPTH is a frequent finding among patients starting CPD. Serum phosphorus was an independent risk factor for subsequent iPTH changes during the course of CPD treatment. Use of low calcium dialysate was significantly higher in patients who converted their iPTH into the high iPTH range. Very few patients with low/normal iPTH had bone-related symptoms (pain and fractures), and their morbidity and mortality did not differ from those patients with a high initial iPTH level.

Chiropody may prevent amputations in diabetic patients on peritoneal dialysis.

BACKGROUND: A multidisciplinary approach has been shown to be of benefit in the prevention of lower limb ulceration and amputation in patients with diabetes, but there is less information on the role of such an approach in patients receiving dialysis treatment. OBJECTIVE: The purpose of the present study was to determine whether the institution of a chiropody program would result in fewer amputations in diabetic patients on peritoneal dialysis (PD). DESIGN: Retrospective chart review. SETTING: The PD program at a tertiary-care hospital. PATIENTS: Patients with diabetes that were enrolled in the PD program between January 1997 and December 1999, inclusive, that were offered the opportunity to see a chiropodist, and that agreed to be seen. A total of 132 patients were included. INTERVENTION: Education about foot care, assessment, and, in some instances, treatment by a chiropodist. RESULTS: Patients with an amputation were more likely to be male (p < 0.01) and have peripheral vascular disease (p < 0.001) compared to those without an amputation. They also had a lower average mean arterial pressure (p < 0.05), lower weekly creatinine clearance (p < 0.01), higher mean erythropoietin dose (p < 0.05), and longer duration of end-stage renal disease (p < 0.001). Factors that were predictive of shorter time to death or amputation were older age [hazard ratio (HR) = 1.03, p < 0.05], peripheral vascular disease (HR = 2.66, p< 0.01), and cerebrovascular disease (HR = 2.70, p< 0.01). Being seen by a chiropodist was protective (HR = 0.39, p < 0.01). CONCLUSION: The current study suggests that a chiropody program may help to prevent amputation in patients with diabetes on PD.

Predictors of outcome following bacterial peritonitis in peritoneal dialysis.

OBJECTIVE: No studies have been done to examine factors that predict the outcome of bacterial peritonitis during peritoneal dialysis (PD), beyond the contribution of the organism causing the peritonitis, concurrent exit-site or tunnel infection, and abdominal catastrophes. DESIGN: In this study we examined several clinical and laboratory parameters that might predict the outcome of an episode of bacterial peritonitis. Between March 1995 and July 2000, we identified 399 episodes of bacterial peritonitis in 191 patients on dialysis. RESULTS: There were 260 episodes of gram-positive peritonitis, 99 episodes of gram-negative peritonitis, and 40 episodes of polymicrobial peritonitis. Gram-positive peritonitis had a significantly higher resolution rate than either polymicrobial peritonitis or gram-negative peritonitis. Staphylococcus aureus episodes had poorer resolution than other gram-positive infections. Nonpseudomonal peritonitis had a better outcome than Pseudomonas aeruginosa episodes. Among all the gram-negative infections, Serratia marcescens had the worst outcome. Episodes associated with a purulent exit site had poor outcome only on univariate analysis. For those peritonitis episodes in which the PD fluid cell count was > 100/microL for more than 5 days, the nonresolution rate was 45.6%, compared to a 4.2% nonresolution rate when the cell count returned to 100/microL or less in less than 5 days. Those patients that had a successful outcome had been on continuous ambulatory PD for a significantly shorter period of time than those patients that had nonresolution. The nonresolution rate for those patients that had been on PD for more than 2.4 years was 24.4%, compared to 16.5% for those that had been on PD for less than 2.4 years (p = 0.05). CONCLUSION: The duration of PD and the number of days the PD effluent cell count remained > 100/microL were the only factors that independently predicted the outcome of an episode of peritonitis. Caucasians seem to have a higher nonresolution (failure) rate compared to Blacks. Other variables, such as the number of peritonitis episodes before the episode in question, vancomycin-based initial empiric treatment, serum albumin level, total lymphocyte count and initial dialysate white blood cell count, age, sex, diabetes, previous renal transplantation, and the use of steroids did not affect the outcome of peritonitis.

Hypotension in patients on chronic peritoneal dialysis: etiology, management, and outcome.

We retrospectively evaluated the phenomenon of arterial hypotension in peritoneal dialysis (PD) in a large cohort of 633 PD patients from two centers (Toronto Western Hospital, Toronto, Canada, and Division of Nephrology, Democritus University of Thrace, Greece), thus extending our previously reported experience for an additional 6 years (1995-2000). Together, the units had 81 hypotensive patients (12.8%), whose mean age was 63.8 +/- 14.2 years and whose mean duration of peritoneal dialysis was 49.3 +/- 30 months. Based on the underlying pathophysiology, the hypotensive PD patients were divided into four groups: (A) hypovolemia, 32 patients (39.5%); (B) congestive heart failure (CHF), 15 patients (18.5%); (C) receiving antihypertensive medications, 11 patients (13.6%); and (D) "unknown" etiology, 23 patients (28.4%). All patients in the hypovolemic and antihypertensive groups responded well to treatment (volume expansion and discontinuation of antihypertensive medication, respectively), but in the CHF and "unknown" groups, only 40% improved with the appropriate intervention. Patients in the latter two groups showed the poorest prognosis, with an approximate death rate of 65%. The hypovolemic group had better outcomes, which might reflect prompt response to fluid replacement in that group. We conclude that, in PD patients, careful use of antihypertensive medication, the right evaluation of target weight (especially in patients with cardiac failure), and judicious use of hypertonic exchanges may prevent the severe complication of arterial hypotension.

Differences in survival on peritoneal dialysis between oriental Asians and Caucasians: one center's experience.

BACKGROUND: Recently it has been suggested that the survival of dialysis patients may differ among different races. Both registry data and data from Asian countries indicates that Asians on peritoneal dialysis may survive longer than their Caucasian counterparts. In the present study, we performed a detailed analysis of survival differences between oriental Asians and Caucasians on peritoneal dialysis in our multiethnic, multicultural program. METHODS: Retrospectively we analyzed the survival data for patients who started peritoneal dialysis after January 1, 1996 and before December 31, 1999, in our hospital. They were followed for at least for two years. Excluded from the present analysis were those who survived for less than three months on peritoneal dialysis. The patient demographic characteristics, comorbidities, and residual renal function at the start of dialysis were collected. Indices for adequacy of dialysis were collected 1-3 months after the initiation of dialysis. Actuarial survival rates were determined by the Kaplan-Meier method. The Cox proportional hazards model was used to classify risk factors for a high mortality. RESULTS: There were 87 Caucasians and 29 Oriental Asian peritoneal dialysis patients. No differences were found in age, gender, primary renal disease, and residual renal function between the two groups. The Caucasians had significantly higher body surface area and urea volume and higher incidence of cardiovascular diseases. Even with slightly higher dialysis dose, the peritoneal creatinine clearance was significantly lower among the Caucasians than among Asians. There was no difference in the peritoneal D/P value between the two groups. However, compared to the Caucasians, the 24hr peritoneal fluid removal and total fluid removal volumes were significantly lower in the Asian patients. The one, two, three and four year survival rates were 95.8%, 91%, 86% and 80% for Asians and 91.3%, 78.1%, 64.7% and 54.1% for Caucasians. Significant predictors for a higher mortality were the presence of cardiovascular disease (42% increase in risk), Caucasians (39% increase in risk) and older age (37% increase in risk for age older than 65). CONCLUSIONS: Our study confirms that oriental Asians on peritoneal dialysis patients survive much longer than their Caucasian counterparts; this was partly due to the fact that Asian patients have less cardiovascular disease when they began peritoneal dialysis. Due to their smaller body size, the Asians tended to have a higher peritoneal small solute clearances despite their smaller dialysis doses, indicating that, to achieve the same solute clearance targets, Asians need a smaller dialysis dose compared to Caucasians.

Peritoneal dialysis in the nursing home.

BACKGROUND: During the past few decades, the demographics of end stage renal disease have been changed significantly with the emerging predominance of elderly patients. Elderly dialysis patients are usually more dependent and may need long-term placement in a long-term care facility. Failure to meet the needs of these patients may have a significant impact on the peritoneal dialysis program. We report our experience of starting peritoneal dialysis program in a community-based Long Term Care Facility (LTCF). METHODS: During the period of 2000-2001, after appropriate training of nursing home personnel, we admitted 8 peritoneal dialysis patients to one community-based nursing home. All information presented here has been collected through chart review. RESULTS: At the time of admission the average age of the 8 patients was 77.3 +/- 7.2 years (range 69 to 91 years). All patients had several comorbid diseases and six of the eight were bed-ridden. The patients stayed in the facility for a total of 29.57 patient months. One patient had three episodes of peritonitis within three months (all culture negative) and has been excluded from the analysis of the overall peritonitis rate. The peritonitis rate for the other seven patients was 1 per 7.54 patient month. Six patients were readmitted to hospital because of peritonitis, severe malnutrition and hip fracture. Four of them died in the hospital. One died in the nursing home. One patient remains in the nursing home at the present time. CONCLUSIONS: Our experience suggests that peritoneal dialysis can be achieved in a community-based nursing home. This requires a systematic training program for the LTCF personnel and the availability of a "dedicated" nephrology dialysis staff. This is crucial to the success of the program. It is important that patients, their families and ESRD care professionals are informed of the limited survival expectation particularly for very old and severely impaired patients.

Improvement in uremic symptoms after increasing daily dialysate volume in patients on chronic peritoneal dialysis with declining renal function.

OBJECTIVE: Patients on peritoneal dialysis (PD) can develop uremic symptoms as their residual renal function declines. In this retrospective study, we assessed the effect of increasing the dose of dialysis in patients who developed uremic symptoms. METHODS: Patients on PD who had an increase in their dialysis dose due to either the appearance of uremic symptoms or to worsening biochemical parameters were included in this study. These patients had to have been on PD for at least 6 months before and after the increase in their dialysis dose. Patients whose dialysis dose was increased after the initial Adequest (done within 2-3 months of starting PD) findings or for reasons other than underdialysis were excluded from this study. The symptoms studied in 104 patients included fatigue, anorexia, insomnia, pruritus and nausea. The presence or absence of theses symptoms was evaluated before and after the increase in the dialysis volume. Several clinical and laboratory data including the adequacy results were compared before and after the increase in dialysis dose. RESULTS: Patients were on PD for 24.6+/-16 months when dialysis dose was increased. Eighty-five (82%) of them were on continuous ambulatory peritoneal dialysis (CAPD) while the remaining were on continuous cycler peritoneal dialysis (CCPD). Fatigue was the most common symptom that led to an increase in the dialysis dose (64%). The prevalence of all the symptoms studied decreased significantly after the increase in dose of dialysis. The weekly peritoneal creatinine clearance increased from 47.35+/-0.88 to 57.34+/-1.401 (P < 0.0001) and the weekly Kt/V increased from 1.8+/-0.03 to 2.27+/-0.05 (P < 0.0001). The daily urine volume and the residual GFR decreased from 318.7+/-36.4 to 151.9+/-22.8 ml/day (P < 0.0001) and 2.05+/-0.2 to 0.82+/-0.12 ml/min (P < 0.0001) respectively during the study period. CONCLUSION: The prevalence of all uremic symptoms decreased significantly after the daily dialysate volume was increased. The improvement in symptoms despite the decline in residual function emphasizes the beneficial effect of increased dialysate volume, which produced a significantly higher peritoneal creatinine clearance and Kt/V after the change in the PD prescription.

Routine use of mupirocin at the peritoneal catheter exit site and mupirocin resistance: still low after 7 years.

OBJECTIVE: The purpose of this study (the third in a series of similar studies) is to evaluate the prevalence of Staphylococcus aureus (SA), methicillin-resistant SA (MRSA) and mupirocin-resistant SA (MuRSA) carriers in a peritoneal dialysis centre where patients have been instructed to use prophylactic mupirocin ointment at the catheter exit site over the last 7 years. METHODS: Swabs were taken from catheter exit site, nares, axillae and groin in 147 chronic peritoneal dialysis out-patients between November 2003 and January 2004. Axillae/groin and nasal samples were pooled and cultured in the same medium, whereas exit site swabs were cultured separately. All SA isolated were tested for methicillin and mupirocin resistance using oxacillin screening plates and E-test strips. RESULTS: Sixteen of 147 patients (10.9%) were found to be SA carriers: of these 13 (8.8%) had a positive nasal/axillae/groin culture; two (1.4%) had both nasal/axillae/groin- and exit site-positive culture; and one (0.7%) had only exit site-positive culture. In these 16 SA carriers, we found mupirocin-resistant strains (MuRSA) in four patients (25%) and MRSA in two patients (12.5%). Among the four MuRSA carriers, one had both nasal/axillae/groin- and exit site-positive culture and three had only nasal/axillae/groin-positive culture. Three high-level resistance and one low-level resistance MuRSA carriers were isolated. One MuRSA strain was also methicillin resistant. All MRSA strains were sensitive to vancomycin and rifampicin. CONCLUSION: After 7 years' routine use of prophylactic mupirocin ointment at the catheter exit site in non-selected chronic peritoneal dialysis patients, MuRSA was found in 25% of SA strains isolated or in 2.7% of the patients. Compared with our previous study, 3 years earlier, there is no significant increase in the MuRSA prevalence in peritoneal dialysis patients who routinely apply mupirocin ointment at the catheter exit site.