Pre to post‐dialysis plasma sodium change better predicts clinical outcomes than dialysate to plasma sodium gradient in quotidian hemodialysis

Sodium balance across a hemodialysis treatment influences interdialytic weight gain (IDWG), pre‐dialysis blood pressure, and the occurrence of intradialytic hypotension, which associate with patient morbidity and mortality. In thrice weekly conventional hemodialysis patients, the dialysate sodium minus pre‐dialysis plasma sodium concentration (δDPNa+) and the post‐dialysis minus pre‐dialysis plasma sodium (δPNa+) are surrogates of sodium balance, and are associated with both cardiovascular and all‐cause mortality. However, whether δDPNa+ or δPNa+ better predicts clinical outcomes in quotidian dialysis is unknown. We performed a retrospective analysis of clinical and demographic data from the Southwestern Ontario Regional Home Hemodialysis program, of all patients since 1985. In frequent nocturnal hemodialysis, δPNa+ was superior to δDPNa+ in predicting IDWG (R² = 0.223 vs. 0.020, P = 0.002 vs. 0.76), intradialytic change in systolic (R² = 0.100 vs. 0.002, P = 0.02 vs. 0.16) and diastolic (R² = 0.066 vs. 0.019, P = 0.02 vs. 0.06) blood pressure, and ultrafiltration rate (R² = 0.296 vs. 0.036, P = 0.001 vs. 0.52). In short hours daily hemodialysis, δDPNa+ was better than δPNa+ in predicting intradialytic change in diastolic blood pressure (R² = 0.101 vs. 0.003, P = 0.02 vs. 0.13). However, δPNa+ was better than δDPNa+ in predicting IDWG (R² = 0.105 vs. 0.019, P = 0.04 vs. 0.68) and pre‐dialysis systolic blood pressure (R² = 0.103 vs. 0.007, P = 0.02 vs. 0.82). We also found that the intradialytic blood pressure fall was greater in frequent nocturnal hemodialysis patients than in short hours daily patients, when exposed to a dialysate to plasma sodium gradient. These results provide a basis for design of prospective trials in quotidian dialysis modalities, to determine the effect of sodium balance on cardiovascular outcome.     

Prevalence of hidradenitis suppurativa in Denmark

The morbidity of hidradenitis suppurativa can be considerable, but little is known about its epidemiology. Our purpose was to describe the one-year and point prevalences of hidradenitis suppurative and its potential precursor lesions. We obtained the histories and examined an unselected sample (599 persons) of the general population (one-year prevalence), and we performed physical examination for a consecutive sample of 507 persons undergoing screening for sexually transmitted diseases (point prevalence). The point prevalence was 4.1% (95% confidence interval [CI] = 3.0-6.0) on the basis of objective findings. The one-year prevalence of hidradenitis was 1.0% (CI = 0.4-2.2) on the basis of subject recollection only. The patients in the sample on which the point prevalence is based were younger than those in the unselected sample of the general population (p < 0.001). Hidradenitis was significantly more common in women (p = 0.037), which may result from a female preponderance of genitofemoral lesions (odds ratio [OR] = 5.4; CI = 1.5-19.3). No sex difference was found in the prevalence of axillary lesions. Hidradenitis suppurativa is significantly more common than hitherto estimated. A female preponderance of patients is confirmed, except for patients with axillary lesions. Additional longitudinal studies are necessary to assess the importance of potential precursor lesions such as non-inflamed nodules or comedones.     

The influence of between-needle cannulation distance on the efficacy of hemodialysis treatments

There is a belief that there should be a minimum of 5 cm between two cannulating needles of an arteriovenous fistula. This study examined the effect of reduction of space between needles from 5 cm to 2.5 cm on access recirculation, the measurement of access blood flow rate (by indicator dilution technology), and dialysis efficiency (by effective ionic dialysance). Twelve patients were studied, with half having their dialysis needles placed 2.5 cm apart for five consecutive dialysis treatments followed by placing needles 5 cm apart for a further five consecutive treatments. The other half initiated with 5 cm followed by 2.5 cm distance for a similar number of treatments. All 120 dialyses had successful cannulations with access recirculation excluded. Access blood flow (Qa mL/min) measurement was attempted for each patient twice, with each of the two needle positions. The Qa with needles 2.5 cm apart was 1310.95 ± 525.7 mL/min (M ± SD, n = 21) and was 1001.0 ± 240.4 mL/min when 5 cm apart (n = 22) (p = 0.014). There was a correlation between these two sets of Qa values (r = 0.554; p = 0.011). The effective ionic dialysance values obtained with needles 2.5 cm or 5 cm apart were similar and correlated strongly (r = 0.71; p = 0.000). Hemodialysis treatments using arteriovenous fistulae and two needles as close as 2.5 cm apart are possible without access recirculation and impairment of clearance. Indicator dilution access blood flow measurements are not recommended under these circumstances.     

The advanced practice nurse–nephrologist care model: Effect on patient outcomes and hemodialysis unit team satisfaction

The tertiary care nurse practitioner/clinical nurse specialist (NP/CNS) is an advanced practice nurse with a relatively new role within the health‐care system. It is stated that care provided by the NP/CNS is cost‐effective and of high quality but little research exists to document these outcomes in an acute‐care setting. The clinical coverage pattern by nephrologists and NP/CNS of a hemodialysis unit in a large academic center allowed such a study. Two NP/CNS plus a nephrologist followed two of three hemodialysis treatment shifts per day; only a nephrologist followed the third shift. The influence of this care pattern of patients was examined using a cross‐sectional review of outcomes such as adequacy of delivered dialysis, anemia management, phosphate control, hospitalizations, etc. In addition, the level of satisfaction of the dialysis team and perceptions of care delivered with the care models was assessed. The care model staff‐to‐patient‐number ratio was similar in both groups (1:27 for NP/CNS plus nephrologist; 1:29 for nephrologist alone). Patient demographics were similar in both groups but the NP/CNS–nephrologist group had patients with more comorbidities. No statistically significant (p < 0.05) differences existed between the groups in patient laboratory data, adherence to standards, medications, inter‐ and intradialytic blood pressure, achievement of target postdialysis weights, and hospitalizations or emergency room visits. Significantly more adjustments were made to target weights and medications and more investigations were ordered by the NP/CNS–nephrologist team. Team satisfaction and perceptions of care delivery were higher with the NP/CNS–nephrologist model. It is concluded that the NP/CNS–nephrologist care model may increase the efficiency of the care provided by nephrologists to chronic hemodialysis patients. The model may also be a solution to the problem of providing nephrologic care to an ever‐growing hemodialysis population.     

Optimal timing of initiation of chronic hemodialysis?

Despite the availability of clinical guidelines for the timing of dialysis initiation in both the United States and Canada, patients continue to start dialysis at very low levels of predicted glomerular filtration rate (GFR). A cross-sectional study was performed to determine the demographic and clinical characteristics of patients who started hemodialysis, their level of GFR, and mortality at 1 and 2 years following the initiation of dialysis. Retrospective data were collected on all eligible patients who commenced chronic hemodialysis in 1 tertiary care center in Canada from March 2001 to February 2005. Only those patients who had been followed by a nephrologist in the chronic kidney disease clinic before dialysis initiation were included (n=271). Seventeen percent of patients started hemodialysis late (GFR<5 mL/min/1.73 m(2)). Compared with the group of patients who started dialysis earlier, the late start group were significantly younger (p=0.008), had more females (p=0.013), more employed (p=0.051), less cardiac (p<0.001), and peripheral vascular disease (p=0.031), and were taking medication for hypertension (p=0.041). Serum albumin was lower in the late start group (p=0.023). At year 1, there was no difference in mortality rate while at year 2, the earlier the dialysis, the greater the mortality rate (p=0.022). After adjustment for demographic variables and comorbidities, only antihypertensive use had an independent but weak association with the 2 year mortality. Adjustment for all these variables eliminated the significant association noted for the 2 year mortality in the early versus late dialysis start. The survival benefit for late versus early dialysis start appears to be multifactorial and relates to a preponderance of clinical and demographic factors favoring a lengthened survival occurring in the late dialysis group. Our survival benefit findings suggest the premorbid health condition is a more important determinant of 2 year survival than the timing of dialysis initiation.     

Screening for depression in chronic hemodialysis patients: comparison of the Beck Depression Inventory, primary nurse, and nephrology team

Depression in patients with end-state renal disease (ESRD) is both underdiagnosed and treated, which may contribute to an increase in morbidity and mortality. Efforts aimed at screening, diagnosing, and treating depression could potentially modify outcomes in this population. The purpose of this study was to compare the prevalence of depression, as measured by the Beck Depression Inventory (BDI-II), the primary nurse, and nephrology team, among a cohort of patients receiving chronic hemodialysis (HD). A secondary objective was to identify patient variables associated with depression. Patients were screened for depression at the same time point, using the BDI-II, the primary nurse and the nephrology team. Depression was defined as a BDI-II score > or =14. Agreement between the BDI-II score, nurse, and nephrology team assessment of depression was compared using a kappa score and receiver-operating characteristic (ROC) curves were generated. One hundred and twenty-four of an eligible 154 patients completed the study. Depression as measured by a BDI-II> or =14, the nurse and the team was diagnosed in 38.7%, 41.9%, and 24.2% of patients, respectively. With the BDI-II as the gold standard, the nurses' diagnosis of depression had an agreement of 74.6% vs. only 24.2% agreement with the nephrology team. A previous history of malignancy was the only variable associated with the diagnosis of depression. Depression is common among patients on HD, supporting the need for a routine depression-screening program. The primary dialysis nurse is in a key position to identify patients with depression and should be considered as an integral part of the nephrology team.