Kerri Gallo

Patient attitudes towards the arteriovenous fistula: a qualitative study on vascular access decision making

BACKGROUND The use of arteriovenous fistulas (AVFs) among hemodialysis (HD) patients has been consistently associated with lower rates of morbidity and mortality; however, up to 30% of eligible patients refuse the creation or cannulation of an AVF. We aimed to understand the attitudes, beliefs, preferences and values of patients who refused creation or use of an AVF. METHODS With qualitative methodology, we conducted semi-structured interviews with 13 HD patients (Canada, 2009), who previously refused creation or use of an AVF. Three independent analysts reviewed interview transcripts. RESULTS We discovered three main themes that impacted the decision to refuse a fistula: (i) poor previous personal or vicarious experiences with the fistula, including cannulation, bleeding, time commitment and appearance; (ii) knowledge transfer and informed decision making. Patients identified information from other patients to be as important as information from health care workers, that information on vascular access (VA) was presented but not understood and that timing of information was crucial with information overload at the start of dialysis and (iii) maintenance of status quo and outlook on life. Some patients stated they live day-to-day without being influenced by the mortality risks with a catheter. CONCLUSIONS AVF refusal is multifactorial and depends on individual patients. Although nephrologists consider the fistula to be the optimal VA, patients do not think in the same terms of reducing infection rates but focus on the practical day-to-day use of their VA and its influence on their quality of life and future outlook.

Lowering postdialysis plasma sodium (conductivity) to increase sodium removal in volume-expanded hemodialysis patients: a pilot study using a biofeedback software system.

BACKGROUND Extracellular fluid expansion is common in hemodialysis patients. Aggressive fluid removal may lead to intradialytic complications. High dialysate sodium concentrations may lessen complications, but may increase extracellular volume. We hypothesized that decreasing plasma sodium concentration during dialysis will increase sodium removal and decrease extracellular volume. STUDY DESIGN Pilot clinical trial. SETTING & PARTICIPANTS 16 patients with end-stage kidney disease treated using thrice-weekly hemodialysis at a university teaching hospital hemodialysis unit. INTERVENTION Stepwise decrease in postdialysis plasma sodium level (calculated as end-of-session plasma conductivity) over 4 phases effected by dialysate conductivity measurement cells and a biofeedback software system (Diacontrol; Hospal, www.hospal.it) that allowed alteration of dialysate inlet conductivity and calculation of plasma conductivity. OUTCOMES Decrease in postdialysis plasma sodium (conductivity) levels, sodium removal, redistribution of body water, and effect of these on interdialytic weight gain and blood pressure. MEASUREMENTS Plasma sodium and conductivity values (the latter measured in millisiemens per centimeter); ionic mass balance (sodium removal); bioelectrical impedance analysis measurements of body-water compartments and phase angle; interdialytic weight gain; and blood pressure. RESULTS Plasma sodium concentrations at the end of dialysis were decreased from 137.8 (phase 1) to 135.6 mmol/L (phase 4) and end-of-session plasma conductivity values were decreased from 14.0 (phase 1) to 13.5 mS/cm (phase 4; all mean values). Ionic mass balance increased from 383 to 480 mmol. Extracellular water was significantly decreased, phase angle was increased, and blood pressure and interdialytic weight gain were decreased. Plasma sodium levels correlated significantly with plasma conductivity; thus, changes in postdialysis plasma sodium levels can be inferred from changes in end-of-session plasma conductivity values. LIMITATIONS Small number of patients. No information for dietary sodium intake. CONCLUSION To decrease extracellular volume, it may be necessary to add diffusive to convective sodium losses.

The chronic kidney disease Water Intake Trial (WIT): results from the pilot randomised controlled trial

Background and objectives Increased water intake may benefit kidney function. Prior to initiating a larger randomised controlled trial (RCT), we examined the safety and feasibility of asking adults with chronic kidney disease (CKD) to increase their water intake. Design, setting, participants and measurements Beginning in October 2012, we randomly assigned 29 adults with stage 3 CKD (estimated glomerular filtration rate (eGFR) 30–60 mL/min/1.73 m2 and albuminuria) to one of the two groups of water intake: hydration (n=18) or standard (n=11). We asked the hydration group to increase their water intake by 1.0–1.5 L/day (in addition to usual intake, depending on sex and weight) for 6 weeks, while the control group carried on with their usual intake. Participants collected a 24 h urine sample at baseline and at 2 and 6 weeks after randomisation. Our primary outcome was the between-group difference in change in 24 h urine volume from baseline to 6 weeks. Results (63%)of participants were men, 81% were Caucasians and the average age was 61 years (SD 14 years). The average baseline eGFR was 40 mL/min/1.73 m2 (SD 11 mL/min/1.73 m2); the median albumin to creatinine ratio was 19 mg/mmol (IQR 6–74 mg/mmol). Between baseline and 6-week follow-up, the hydration groups average 24 h urine volume increased by 0.7 L/day (from 2.3 to 3.0 L/day) and the control groups 24 h urine decreased by 0.3 L/day (from 2.0 to 1.7 L/day; between-group difference in change: 0.9 L/day (95% CI 0.4 to 1.5; p=0.002)). We found no significant changes in urine, serum osmolality or electrolyte concentrations, or eGFR. No serious adverse events or changes in quality of life were reported. Conclusions A pilot RCT indicates adults with stage 3 CKD can successfully and safely increase water intake by up to 0.7 L/day in addition to usual fluid intake. Trial registration Registered with Clinical Trials—government identifier NCT01753466.

Effect of N-Acetylcysteine on Serum Creatinine and Kidney Function: Results of a Randomized Controlled Trial

BACKGROUND Evidence for a protective effect of N-acetylcysteine (NAC) on acute and chronic kidney disease is equivocal, and controversy persists about whether NAC affects creatinine level independently of actual kidney function. Study objectives are to investigate whether NAC affects serum creatinine level independently of alterations in other measures of kidney function. STUDY DESIGN Double-blind randomized controlled trial. SETTING & PARTICIPANTS Patients with stage 3 chronic kidney disease (n = 60), Canada, 2007-2008. INTERVENTION Participants were randomly allocated to receive 4 doses of oral NAC (each 1,200 mg) or placebo, administered at 12-hour intervals. OUTCOME The primary outcome was change in serum creatinine level between baseline and 4 hours after the last treatment dose. In addition, changes in other parameters of kidney function were measured between baseline and 4, 24, or 48 hours after the last treatment dose. MEASUREMENTS Serum creatinine, cystatin C, 24-hour urine protein and creatinine excretion, and creatinine clearance. RESULTS 60 patients, mean age of 70 years, 75% men, 50% had diabetes, with mean creatinine clearance of 43.7 ± 18.8 (SD) mL/min were enrolled. Between baseline and 4 hours posttreatment, serum creatinine level decreased by 0.044 ± 0.15 mg/dL in the NAC group and 0.040 ± 0.18 mg/dL in the placebo group (95% CI for difference, -0.09 to 0.08; P = 0.9). No significant differences between groups were observed for change in serum creatinine, cystatin C, urine protein, urine creatinine, or creatinine clearance values at any time. LIMITATIONS Blinding patients to orally administered liquid NAC is difficult and it is possible that patients receiving NAC were not sufficiently blinded. Effects of NAC beyond 48 hours of treatment were not evaluated. CONCLUSIONS In this randomized controlled trial, NAC had no short-term effect on creatinine level and did not decrease urine protein excretion within 48 hours of treatment.

Effect of N-acetylcysteine on renal function in patients with chronic kidney disease.

Background:  N‐acetylcysteine (NAC) is commonly administered to high‐risk individuals to attenuate the risk of contrast‐induced nephropathy in spite of the debate regarding its efficacy. In several studies serum creatinine decreased after exposure to NAC and contrast dye. The mechanism by which NAC attenuates the decline in renal function is not known. Studies in subjects with normal renal function suggest NAC may have an effect on tubular secretion.

Hemodialysis in a Satellite Unit: Clinical Performance Target Attainment and Health-Related Quality of Life

BACKGROUND AND OBJECTIVES In Canada, patients are increasingly receiving hemodialysis (HD) in satellite units, which are closer to their community but further from tertiary care hospitals and their nephrologists. The process of care is different in the satellites with fewer visits from nephrologists and reliance on remote communication. The objective of this study is to compare clinical performance target attainment and health-related quality of life (HRQOL) in patients receiving HD in satellite versus in-center units. DESIGN, SETTING, PARTICIPANTS, AND MEASUREMENTS The London Health Sciences Centre in London, Ontario, Canada, has both tertiary care center and satellite HD units. All eligible patients who received dialysis treatment at one of these units as of July 24, 2008, were enrolled into a cross-sectional study (n = 522). Patient attainment of hemoglobin, albumin, calcium-phosphate (Ca-P) product, Kt/V, and vascular access targets were compared. Participants were also administered the Kidney Disease Quality of Life Short-Form questionnaire. RESULTS Satellite patients were more likely to attain clinical performance targets for albumin (adjusted odds ratio [OR] = 4.87 [95% confidence interval [CI]: 2.13 to 11.14]), hemoglobin (OR = 1.59 [95% CI: 1.08 to 2.35]), and Ca-P product (OR = 2.02 [95% CI: 1.14 to 3.60]), as well as for multiple targets (P < 0.05). HRQOL scores were largely similar between groups. CONCLUSIONS Patients receiving HD in a satellite unit were just as likely, or more likely, to demonstrate attainment of clinical performance targets as those dialyzing in-center, while maintaining a similar HRQOL. This supports the increased use of satellite units to provide care closer to the patients community.

The Chronic Kidney Disease Water Intake Trial: Protocol of a Randomized Controlled Trial:

Background: In observational studies, drinking more water associates with a slower rate of kidney function decline; whether the same is true in a randomized controlled trial is unknown. Objective: To examine the 1-year effect of a higher vs usual water intake on estimated glomerular filtration rate (eGFR) in patients with chronic kidney disease. Design: Parallel-group randomized controlled trial. Setting: Nine centers in Ontario, Canada. Enrollment and randomization occurred between May 2013 and May 2016; follow-up for the primary outcome will continue until June 2017. Participants: Adults (n = 631) with stage 3 chronic kidney disease (eGFR 30-60 mL/min/1.73 m2) and microalbuminuria. Intervention: The high water intake group was coached to increase their oral water intake by 1.0 to 1.5 L/day (depending on sex and weight), over and above usual consumed beverages, for a period of 1 year. The control group was coached to maintain their usual water intake during this time. Measures: Participants provided 24-hour urine samples at baseline and at 6 and 12 months after randomization; urine samples were analyzed for volume, creatinine, osmolality, and the albumin-to-creatinine ratio. Blood samples were obtained at baseline and at 3- to 6-month intervals after randomization, and analyzed for creatinine, copeptin, osmolality, and electrolytes. Other measures collected included health-related quality of life, blood pressure, body mass index, and diet. Primary outcome: The between-group change in eGFR from baseline (prerandomization) to 12 months after randomization. Secondary outcomes: Change in plasma copeptin concentration, 24-hour urine albumin-to-creatinine ratio, measured creatinine clearance, estimated 5-year risk of kidney failure (using the 4-variable Kidney Failure Risk Equation), and health-related quality of life. Planned analysis: The primary analysis will follow an intention-to-treat approach. The between-group change in eGFR will be compared using linear regression. Supplementary analyses will examine alternative definitions of eGFR change, including annual percentage change, rate of decline, and rapid decline (a P value <0.05 will be interpreted as statistically significant if there is concordance with the primary outcome). Trial Registration: This randomized controlled trial has been registered at www.clinicaltrials.gov; government identifier: NCT01766687.