Update on Hemodialysis-Induced Multiorgan Ischemia: Brains and Beyond

Hemodialysis is a life-saving treatment for patients with kidney failure. However, patients requiring hemodialysis have a 10-20 times higher risk of cardiovascular morbidity and mortality than that of the general population. Patients encounter complications such as episodic intradialytic hypotension, abnormal perfusion to critical organs (heart, brain, liver, and kidney), and damage to vulnerable vascular beds. Recurrent conventional hemodialysis exposes patients to multiple episodes of circulatory stress, exacerbating and being aggravated by microvascular endothelial dysfunction. This promulgates progressive injury that leads to irreversible multiorgan injury and the well-documented higher incidence of cardiovascular disease and premature death. This review aims to examine the underlying pathophysiology of hemodialysis-related vascular injury and consider a range of therapeutic approaches to improving outcomes set within this evolved rubric.‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬.

Effects of Steady Glucose Concentration Peritoneal Dialysis on Ultrafiltration Volume and Sodium Removal: A Pilot Crossover Trial

BACKGROUND

Volume overload is common in patients treated with peritoneal dialysis (PD) and is associated with poor clinical outcome. Steady concentration PD is where a continuous glucose infusion maintains the intraperitoneal glucose concentration and as a result provides continuous ultrafiltration throughout the dwell. The primary objective of this study was to investigate the ultrafiltration rate and glucose ultrafiltration efficiency for steady concentration PD in comparison with a standard continuous ambulatory PD (CAPD) dwell, using the novel Carry Life UF device.

METHODS

Eight stable patients treated with PD (six fast and two fast average transporters) were investigated four times: a standard 4-hour CAPD dwell with 2 L of 2.5% dextrose solution as control and three 5-hour steady concentration PD treatments (glucose dose 11, 14, 20 g/h, initial fill 1.5 L of 1.5% dextrose solution). All investigations were preceded by an overnight 2 L 7.5% icodextrin dwell.

RESULTS

Intraperitoneal glucose concentration increased during the first 1-2 hours of the steady concentration PD treatments and remained stable thereafter. Ultrafiltration rates were significantly higher with steady concentration PD treatments (124±49, 146±63, and 168±78 mL/h with 11, 14, and 20 g/h, respectively, versus 40±60 mL/h with the control dwell). Sodium removal and glucose ultrafiltration efficiency (ultrafiltration volume/gram glucose uptake) were significantly higher with steady concentration PD treatments versus the control dwell, where the 11 g/h glucose dose was most efficient.

CONCLUSIONS

Steady concentration PD performed with the Carry Life UF device resulted in higher ultrafiltration rates, more efficient use of glucose (increased ultrafiltration volume/gram glucose absorbed), and greater sodium removal compared with a standard 2.5% dextrose CAPD dwell.

CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER

A Performance Analysis of the Peritoneal Ultrafiltration (PUF) Achieved With the Carry Life ® UF, NCT03724682 .

Encapsulating peritoneal sclerosis: what have we learned?

Encapsulating peritoneal sclerosis (EPS) is a rare complication of peritoneal dialysis (PD), but carries significant morbidity and mortality. We review the clinical features and radiologic and histologic changes found at diagnosis of EPS. Although EPS is strongly associated with the duration of PD, the pathogenesis remains only partly understood. We discuss the mechanisms thought to underlie the abnormally thickened, sclerotic peritoneal membrane seen in long-term PD patients including epithelial to mesenchymal transition and the molecular mediators of fibrosis and angiogenesis. We review how exposure to high-glucose, nonphysiological dialysis fluids, peritonitis, and uremia may be responsible for these changes. Much remains to be learned about optimal management of EPS, both medical and surgical, because the literature lacks controlled studies. Future research challenges include defining the role of surgery, immunosuppression, and antifibrotic agents in the management of EPS. We also need to understand why some patients progress from asymptomatic peritoneal sclerosis to the extreme levels of fibrin deposition and bowel encapsulation seen in EPS. Screening PD patients for potential future EPS remains difficult, and we need strategies for monitoring patients on longer-term PD that enable us to better quantify the risk of EPS for the individual patient.

Risk factors for high dialysate glucose use in PD patients--a retrospective 5-year cohort study

BACKGROUND

Use of high concentrations of glucose for peritoneal dialysis (PD) may produce unfavorable results. Our previous study showed that high initial glucose load is associated with poor PD technique survival.

OBJECTIVE

This retrospective cohort study at a medical center in Taiwan aimed to understand the factors associated with high glucose load in long-term PD patients.

PATIENTS AND METHODS

We reviewed 90 newly started PD patients over 5 years. We determined glucose load by calculating annual glucose weight and dialysate volume administered. Multiple linear regression analyses with time-dependent covariates were used to determine factors that influence the annual average dialysate glucose concentration.

RESULTS

The study group included 47 men and 43 women with a mean age of 53.4 +/- 13.9 years. Technique survival rates were 91.0%, 84.1%, and 77.6% at the beginning of the second, third, and fourth year of PD therapy respectively. The presence of diabetes mellitus (DM), high body mass index (BMI), and low weekly renal Kt/V were significantly correlated with high average dialysate glucose concentration during the first, second, and third years. For patients undergoing PD for more than 3 years, residual renal function (RRF) deteriorated, and only DM significantly affected higher dialysate glucose concentration in the fourth year.

CONCLUSIONS

Patients with DM, high BMI, and low RRF were more likely to require a high glucose load for PD therapy, especially during the first 3 years. After those 3 years of PD, DM was the only significant factor in the need for higher glucose load. To reduce the glucose load in chronic PD patients, alternative osmotic agents such as icodextrin or amino acids should be considered in the daily PD regimen.

Association of Kt/V and creatinine clearance with outcomes in anuric peritoneal dialysis patients

BACKGROUND

The 2006 Kidney Disease Outcomes Quality Initiative recommended a minimum total Kt/V of 1.7, eliminated creatinine clearance (Ccr) as a target, and recommended the use of ideal body weight to calculate Kt/V. We assessed these recommendations as predictors of outcomes in anuric peritoneal dialysis patients.

STUDY DESIGN

Retrospective observational study using administrative data.

SETTING & PARTICIPANTS

1,432 peritoneal dialysis patients with anuria from January 1, 1994, to January 31, 2005, in a national sample (1,428 with Kt/V, 1,416 with Ccr).

PREDICTORS

Kt/V and Ccr at anuria; Kt/V based on actual body weight and ideal body weight.

OUTCOMES & MEASUREMENTS

Association of dialysis adequacy with mortality and time to first hospitalization after anuria assessed by using accelerated failure time models.

RESULTS

293 anuric patients had Kt/V less than 1.7, 366 had Kt/V of 1.7 to 2.0, and 769 had Kt/V greater than 2.0, using actual body weight for calculation. In unadjusted analyses, Kt/V calculated using actual body weight both less than 1.7 (-41.3%; 95% confidence interval [CI], -55.5 to -22.6) and 1.7 to 2.0 (-26.1%; 95% CI, -42.6 to -4.6) were associated with shorter time to mortality. Kt/V calculated using actual body weight less than 1.7 was associated with shorter time to hospitalization (-38.1%; 95% CI, -50.0 to -23.4), but Kt/V calculated using actual body weight of 1.7 to 2.0 was not a significant predictor (-3.3%; 95% CI, -21.1 to 18.6). After adjustment, Kt/V calculated using actual body weight less than 1.7 remained associated with mortality (-25.3%; 95% CI, -41.1 to -4.8) and hospitalization (-33.4%; 95% CI, -47.1 to -16.0). Ccr did not predict mortality. In unadjusted analysis, Ccr was not associated with hospitalization, but after adjustment, Ccr less than 50 L/wk/1.73 m(2) was significantly associated with shorter time to hospitalization (-19.9%; 95% CI, -35.0 to -1.3). Kt/V using ideal body weight was not a significant predictor in adjusted models.

LIMITATIONS

This study was nonrandomized, with few malnourished patients. In addition, there is a potential for informative censoring for transfer to hemodialysis therapy before anuria.

CONCLUSIONS

Kt/V calculated using actual body weight less than 1.7 in anuric peritoneal dialysis patients is associated with increased mortality and hospitalization. Use of ideal body weight to calculate Kt/V weakened the associations with outcomes and therefore cannot be recommended.