Frequency and risk factors for cognitive dysfunction in peritoneal dialysis patients.

OBJECTIVE: There is limited data on cognition in patients undergoing peritoneal dialysis (PD). We assessed prevalence and associated risk factors of neurocognitive impairment (NCI) in PD patients. DESIGN AND METHODS: A cross-sectional cohort study of 149 PD patients at a single centre between 2016 and 2020 who underwent neurocognitive screening at defined intervals by Addenbrooke's Cognitive Examination - Revised (ACE-R) with incorporated Mini-Mental State Examination (MMSE). Paired-sample t-test was used to compare cognitive performance to the general population and compare cohorts for dichotomous risk factors. Residual renal function (RRF) and clearance kinetics were evaluated using local regression models. Sub-analysis was performed in patients with cerebrovascular disease (CVD). RESULTS: Patients on PD performed poorly in ACE-R screening compared to population norms, with discrepancy in all cognitive domains. In patients without CVD, attention and language domains were comparable to norms. The MMSE detected cognitive impairment in 2% of studied patients, significantly fewer than when the ACE-R was applied (32%). Age, gender, diabetic status and depression were associated with lower neurocognitive screening performance (p < .05). Dialysis vintage beyond 12 months conferred poorer cognitive performance. RRF correlated with cognitive performance. CONCLUSION: Patients on PD have higher prevalence of NCI than the general population, primarily with impairments in memory, fluency and visuospatial reasoning. CVD confers poorer performance in attention and language domains. The MMSE is ineffective in detecting subtle NCI in this population compared with ACE-R. Risk factors for NCI include age, gender, diabetic status, depression and vintage beyond 12 months. Protective factors include RRF.

Known unknowns: Examining the burden of neurocognitive impairment in the end-stage renal failure population.

The burden of neurocognitive impairment (NCI) in patients receiving maintenance dialysis represents a spectrum of deficits across multiple cognitive domains that are associated with hospitalization, reduced quality-of-life, mortality and forced decision-making around dialysis withdrawal. Point prevalence data suggest that dialysis patients manifest NCI at rates 3- to 5-fold higher than the general population, with executive function the most commonly affected cognitive domain. The unique physiology of the renal failure state and maintenance dialysis appears to drive an excess of vascular dementia subtype compared to the general population where classical Alzheimer's disease predominates. Despite the absence of evidence-based cost-effective therapies for NCI, detecting it in this population creates opportunity to proactively personalize care through education, supported decision making and targeted communication strategies to cover specific areas of deficit and help define goals of care. This review discusses NCI in the dialysis setting, including developments in the definition of neurocognitive impairment, dialysis-specific epidemiology across modalities, screening strategies and opportunities for dialysis providers in this space.

The longitudinal effects of peritonitis on peritoneal membrane function
.

BACKGROUND: The longitudinal effects of peritoneal dialysis (PD) peritonitis on small solute clearance and ultrafiltration are controversial. MATERIALS AND METHODS: We identified 27 patients with PD peritonitis over a 4-year period at a tertiary hospital. Adequacy tests at an "early" (1 - 3 months), "intermediate" (6 ± 2 months), and a "late" (12 ± 2 months) time period after the episode were compared with a pre-peritonitis baseline. The effect of time on serum albumin, weekly creatinine clearance, Kt/V, and net fluid volume removal was assessed. RESULTS: At 12 months, 16/27 (59.3%) patients were no longer on PD. Ten were transferred to hemodialysis, predominantly due to peritonitis (60%). Five patients died, and 1 received a renal allograft. Total daily fluid volume removal significantly decreased over time with an aggregated mean reduction of 523 mL/day between the baseline and 12-month test (1,624 ± 139 mL vs. 1,101 ± 160 mL; p = 0.02). This was due to an equivalent loss of both ultrafiltration and residual urine output, although the separate decline in these individual parameters was not statistically significant. There was no significant change in Kt/V, creatinine clearance, or serum albumin indicating preserved solute transport in those patients with sustained technique survival post peritonitis. CONCLUSION: Peritonitis is a common cause for transfer to hemodialysis. Fluid volume removal is the most significantly affected parameter at 12 months post peritonitis, driven by the combination of both ultrafiltration reduction and loss of residual diuresis. Clinicians should be aware that peritonitis identifies patients at high risk for technique failure. These findings should prompt clinicians to closely surveil volume status and consider backup dialytic strategies as early as 12 months post peritonitis.
.

Percutaneous insertion of peritoneal dialysis catheters using ultrasound and fluoroscopic guidance: A single centre experience and review of literature.

Various methods of peritoneal dialysis (PD) catheter insertion are available. The purpose of this study was to evaluate a percutaneous insertion technique using ultrasound (US) and fluoroscopy performed under conscious sedation and as day case procedure. Data of 87 percutaneous inserted dialysis catheters were prospectively collected, including patients' age, gender, body mass index, history of previous abdominal surgery and cause of end stage renal failure. Length of hospital stay, early complications and time to first use were also recorded. Institutional review board approval was obtained. A 100% technical success rate was observed. Early complications included bleeding (n = 3), catheter dysfunction (n = 6), exit site infection (n = 1) and exit site leakage (n = 1). All cases of catheter dysfunction and one case of bleeding required surgical revision. Median time of follow-up was 18 months (range 3-35), and median time from insertion to first use was days 14 (1-47). Of the 82 patients who started dialysis, 20 (23%) ceased PD at some stage during follow-up. Most frequently encountered reasons include deteriorating patient cognitive or functional status (n = 5), successful transplant kidney (n = 4) and pleuro-peritoneal fistula (n = 4). Sixty-two (71%) PD catheter insertions were performed as day case. The remaining insertions were performed on patients already admitted to the hospital. Percutaneous insertion of dialysis catheter using US and fluoroscopy is not only safe but can be performed as day case procedure in most patients, even with a medical history of abdominal surgery and/or obesity.

Radiological insertion of Tenckhoff catheters for peritoneal dialysis: a 1-year single-centre experience.

BACKGROUND: Peritoneal dialysis (PD) is an important home-based dialysis modality for patients with end-stage kidney disease (ESKD). The initiation of PD requires timely and skilled insertion of a Tenckhoff catheter (TC). At most centres, TCs are inserted laparoscopically by surgeons under general anaesthetic. This requires access to increasingly scarce surgical, anaesthetic and hospital inpatient resources. Radiological insertion of TCs performed as a day procedure under local anaesthetic allows for easier access to the TC insertion with reduced resource requirements. We report our 1-year experience following the introduction of this technique to our PD programme. METHODS: This is a retrospective review of the outcomes for all patients who had TCs inserted radiologically (percutaneously with the assistance of ultrasound and fluoroscopy) over the 12-month period from December 2011 to December 2012. Relevant patient demographics collected included age, gender, body mass index (BMI), previous abdominal surgery and cause of ESKD. Extended details of the insertion procedure were also obtained including length of stay, early complications and time to first use of the catheter for PD. RESULTS: Thirty Argyle(™) Swan Neck TCs were inserted under radiological guidance during the study period. The mean age of patients was 56 (SD ± 14). The male-to-female ratio was 2:1. The mean BMI was 25.7 (SD ± 4.8). PD was the initial dialysis modality in 22 (73%) patients. Of the 30 patients, 14 (46.7%) had previously undergone extraperitoneal abdominal surgery. All catheters were inserted successfully as day cases except four patients (13.3%) who had catheters inserted during an inpatient hospital admission. Most catheters were not accessed for a minimum of 10 days to reduce the chance of exit site leakage, in two cases the catheters were used within 5 days without complication. There were no cases of peritonitis or exit site infection during the observation period. Catheter migration occurred in four patients (13.3%) but only one required surgical intervention. Minor pain issues were noted in six patients (20%) and bleeding around the exit site requiring suturing in two patients (6.7%). The introduction of this technique at our institution saw a 67% increase in the number of patients performing PD. CONCLUSIONS: Radiological insertion of TCs for PD provided improved access to catheter insertion in a timely manner with reduced resource requirements. Over the 12-month observation period we noted a high technical success rate with very few complications. Our study supports radiological insertion of TCs under local anaesthetic as a viable alternative to catheter insertion in theatre under general anaesthetic. The relative ease of radiological TC insertion has resulted in a significant increase in patient uptake of PD at our centre.