Susan Lavoie

Complications and catheter survival with prolonged embedding of peritoneal dialysis catheters

BACKGROUND Our centre uses a modification of the Moncrief technique of embedding peritoneal dialysis (PD) catheters. We undertook this study to test the hypothesis that catheter survival on PD is a function of the time a catheter is left embedded prior to use. METHODS Data were retrospectively abstracted from review of patient records of those who received a first PD catheter over a 5-year period. Patients were divided into tertiles based on the number of days between insertion of the catheter and exteriorization to create three equal groups representing early (group 1, 11-47 days), mid (group 2, 48-133 days) and late (group 3, 134-2041 days) exteriorization strategies. RESULTS 435 embedded PD catheters were inserted, 349 were exteriorized and total observation period was 5624 patient-months. Time to catheter loss was shortest in group 1 and longest in group 2 (P = 0.04). The overall rate of primary catheter failure was 6% and was significantly different in the three groups (6.9% in group 1, 1.7% in group 2 and 9.4% in group 3, P = 0.04). The time to first episode of peritonitis was longest in group 3 and shortest in group 1 (group 1 versus group 3, P = 0.009; group 2 versus group 3, P = 0.03). Adjusted peritonitis rates, however, were not different between the three groups. CONCLUSIONS Mechanical complications and catheter loss are associated with the length of time a catheter is embedded. We recommend insertion 6 weeks to 5 months ahead of the need for PD to maximize catheter survival.

Fluoroscopic Manipulation of Peritoneal Dialysis Catheters: Outcomes and Factors Associated with Successful Manipulation

BACKGROUND AND OBJECTIVES Mechanical failure of the peritoneal dialysis (PD) catheter is an important cause of technique failure. Fluoroscopic guidewire manipulation may be undertaken in an attempt to correct the failure. The purpose of this study was to determine the efficacy of fluoroscopic manipulation of previously embedded PD catheters, the factors associated with successful manipulation, and the complication rate associated with manipulation. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS A single-center, retrospective review of 70 consecutive PD patients undergoing fluoroscopic manipulation for mechanical failure of their PD catheter from June 2006 to February 2011 was undertaken. Logistic regression models were developed to determine the variables associated with successful manipulation. RESULTS Of the 70 manipulations, 44 were successful (62.9%). In univariate analysis, catheters located in the pelvis compared with those in the upper abdomen (73.5% versus 42.9%, P=0.01) and catheters that were previously functional compared with those that failed at exteriorization (75.0% versus 46.7%, P=0.04) were more likely to be successfully manipulated. Time embedded, previous hemodialysis, and number of intra-abdominal surgeries were not correlated with likelihood of successful manipulation. In multivariate analysis, catheters located in the pelvis (P=0.01) and those with secondary failure (P=0.01) were more likely to successfully manipulated. Two of the patients developed peritonitis (2.9%), neither requiring cessation of PD. CONCLUSIONS Fluoroscopic manipulation is an effective and safe therapy for failed PD catheters that are unresponsive to conservative treatment. Properly positioned catheters and those that were previously functional are more likely to be successfully manipulated.

Hospitalization Rates for Patients on Assisted Peritoneal Dialysis Compared with In-Center Hemodialysis

BACKGROUND AND OBJECTIVES Assisted peritoneal dialysis is a treatment option for individuals with barriers to self-care who wish to receive home dialysis, but previous research suggests that this treatment modality is associated with a higher rate of hospitalization. The objective of our study was to determine whether assisted peritoneal dialysis has a different rate of hospital days compared to in-center hemodialysis. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS We conducted a multicenter, retrospective cohort study by linking a quality assurance dataset to administrative health data in Ontario, Canada. Subjects were accrued between January 1, 2004 and July 9, 2013. Individuals were grouped into assisted peritoneal dialysis (family or home care assisted) or in-center hemodialysis on the basis of their first outpatient dialysis modality. Inverse probability of treatment weighting using a propensity score was used to create a sample in which the baseline covariates were well balanced. RESULTS The study included 872 patients in the in-center hemodialysis group and 203 patients in the assisted peritoneal dialysis group. Using an intention to treat approach, patients on assisted peritoneal dialysis had a similar hospitalization rate of 11.1 d/yr (95% confidence interval, 9.4 to 13.0) compared with 12.9 d/yr (95% confidence interval, 10.3 to 16.1) in the hemodialysis group (P=0.19). Patients on assisted peritoneal dialysis were more likely to be hospitalized for dialysis-related reasons (admitted for 2.4 d/yr [95% confidence interval, 1.8 to 3.2] compared with 1.6 d/yr [95% confidence interval, 1.1 to 2.3] in the hemodialysis group; P=0.04). This difference was partly explained by more hospital days because of peritonitis. Modality switching was associated with high rates of hospital days per year. CONCLUSIONS Assisted peritoneal dialysis was associated with similar rates of all-cause hospitalization compared with in-center hemodialysis. Patients on assisted peritoneal dialysis who experienced peritonitis and technique failure had high rates of hospitalization.

METABOLIC EFFECTS OF INCREMENTAL DOSES OF INTRAPERITONEAL AMINO ACIDS ON AUTOMATED PERITONEAL DIALYSIS

♦ Background: The use of amino acid (AA) dialysate to ameliorate protein-energy malnutrition has been limited by adverse metabolic effects. ♦ Objective: We undertook this study to examine the acute metabolic effects of escalating doses of AAs delivered with lactate/bicarbonate dialysate on automated peritoneal dialysis (APD). ♦ Patients and Methods: 12 APD patients were treated with conventional lactate-buffered dialysate (week 1), followed by lactate/bicarbonate-buffered dialysate (week 2), then 2 – 2.5 L 1.1% AA solution were added (week 3), and then an additional 2 – 2.5 L 1.1% AA were added (week 4). The primary outcomes were change in serum bicarbonate and pH, change in protein catabolic rate (PCR), and change in normalized ultrafiltration (milliliters/gram of carbohydrate infused). ♦ Results: Serum bicarbonate rose from week 1 to week 2 (28.9 ± 3.2 vs 26.9 ± 4.1 mmol/L, p = 0.03). Addition of one bag of AAs led to a decline in plasma bicarbonate (26.9 ± 2.1 vs 28.9 ± 3.2 mmol/L, p < 0.01), which was further magnified by the addition of the second bag of AAs (23.8 ± 2.7 vs 26.9 ± 2.1 mmol/L, p < 0.01). Serum bicarbonate fell significantly by week 4 compared to week 1 (23.8 ± 2.7 vs 26.9 ± 3.2 mmol/L, p < 0.01) although there was no significant change in venous pH or PCR when week 4 was compared to week 1. Normalized ultrafiltration was stable for the first 3 weeks but rose significantly in week 4 compared to week 1 (5.32 ± 2.30 vs 4.14 ± 1.58 mL/g, p = 0.03). ♦ Conclusions: Higher doses of AAs mixed with newer bicarbonate/lactate dialysate on APD result in a small decrease in serum bicarbonate but improved normalized ultrafiltration. This merits further study as both a nutritional supplement and a glucose-sparing strategy.

A high serum vancomycin level is associated with lower relapse rates in coagulase-negative staphylococcal peritonitis.

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Asymptomatic peritoneal leukocytosis after exteriorization of buried peritoneal dialysis catheters: a case series.

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No Change in Small Molecule Transport with Prolonged Embedding of Peritoneal Dialysis Catheters

Editor: We read with interest the article by Flessner and colleagues and were intrigued by the findings in Wistar rats of a significant increase in peritoneal inflammation with a dormant silicone peritoneal catheter compared with a peritoneal catheter that was used to inject solution (1). Our program routinely uses embedded peritoneal catheters inserted months before the need for dialysis. Our mechanical and infectious outcomes have been published previously, but these results prompted us to look for any relationship between baseline peritoneal small molecule transport and duration of time the catheter was embedded prior to use (2,3). We chose to look at the dialysate-to-plasma creatinine (D/P Cr) ratio at 4 hours with a standard peritoneal equilibration test (PET) as some groups have shown a relationship between higher D/P Cr and increased levels of effluent inflammatory markers (4). Using our previously published cohort, we identif ied 314 patients with embedded catheters and a PET performed within 12 months of starting peritoneal dialysis. Median time embedded was 83 days and median time from exteriorization of the catheter to the PET was 27 days. There was no correlation between time embedded and baseline D/P Cr (r 2 = –0.05). Baseline D/P Cr broken down by tertile of time embedded is shown in Table 1. The mean baseline D/P Cr of 0.66 ± 0.13 is similar to that reported by other groups that do not routinely use embedded catheters (5). The absence of correlation between time embedded and baseline PET characteristics has multiple possible interpretations. One is that D/P Cr is not a sensitive marker for peritoneal inflammation and that it would not be expected to change despite the inflammation associated with a dormant catheter in a dry abdomen. This is supported by Flessner’s findings of a lack of correlation between histologic inflammatory changes and transport changes in their catheter and needle injection groups. Alternatively, one could postulate that the membrane transport characteristics of our patients may have been correlated to duration of catheter embedding at baseline but, by the time the PET was performed, these differences had resolved. A third interpretation is that a dormant catheter does not produce any significant inflammation in humans. Prospective collection of serum and peritoneal markers of inflammation may allow us to distinguish between these hypotheses.