Extravascular lung water and peripheral volume status in hemodialysis patients with and without a history of heart failure.

Determining volume status in hemodialysis patients with a history of congestive heart failure (CHF) is difficult. Extravascular lung water (EVLW) may be derived from blood ultrasound velocity changes following injections of 0.9% and 5% saline. Bioimpedance spectroscopy can measure total body water (TBW) and its intracellular fluid (ICF) and extracellular fluid (ECF) compartments. We studied 29 clinically euvolemic hemodialysis patients, 12 of whom had a history of CHF. The ECF and ICF were measured before dialysis, and EVLW was measured during dialysis. Values of EVLW were similar between patients without CHF and those with CHF (3.55 ml/kg +/- 0.94 SD versus 3.88 ml/kg +/- 0.82 SD, respectively; p = NS). The ECF/ICF ratio was higher among patients with a history of CHF (1.27 +/- 0.29) than among those without such a history (1.04 +/- 0.04; p < 0.05), indicating that ECF volume overload was present in both groups, but was higher in those with a CHF history. There was a positive correlation between EVLW and ECF/ICF ratios (r = 0.54, p < 0.01). Measurements of EVLW were higher in two pulmonary edema patients ((7.95 ml/kg and 5.95 ml/kg; p < 0.05). The results of this study suggest that 1) hemodialysis patients with a history of CHF have more ECF volume overloaded than those without such a history; 2) the degree of ECF expansion is associated with increasing EVLW volume, even in patients without pulmonary edema; and 3) ECF volume expansion eventually exceeds limits and pulmonary edema occurs. These developing technologies of volume measurement may be of value in this challenging clinical area.

Determining lung water volume in stable hemodialysis patients.

Lung water (LW) reflects the water content of the lung interstitium. Because hemodialysis patients have expanded total body water (TBW) they may also have increased LW. Hypertonic saline promotes a flux of water from lung to blood, which is measured by ultrasound flow probes on hemodialysis tubing. The volume of flux is an indirect measure of LW. Our purpose was to determine the feasibility and reproducibility of LW derived with ultrasound velocity dilution, to determine the effect of ultrafiltration on LW in stable hemodialysis patients, and to compare changes in LW with fluid compartment shifts using bioimpedance. Lung water, cardiac output, total body water, and extracellular and intracellular fluid volumes were measured in 24 stable hemodialysis patients at the beginning of hemodialysis and after ultrafiltration. The LW values at the beginning of hemodialysis (298.8 +/- 90.2 ml or 3.67 +/- 1.47 ml/kg) fell during hemodialysis (250.8 +/- 55.8 ml or 3.12 +/- 0.96 ml/kg; p < 0.05), as did TBW and extracellular fluid volumes (p < 0.001). Cardiac output, cardiac index, and central blood volume also decreased significantly with ultrafiltration (p < 0.005, p < 0.005, and p < 0.01, respectively). Results showed that stable hemodialysis patients have higher specific LW values (3.67 ml/kg) than the normal population (2 ml/kg) and ultrafiltration produces a significant decline in LW values.

Erythropoietin dose requirements when converting from subcutaneous to intravenous administration among patients on hemodialysis.

BACKGROUND: The optimal route for administration of exogenous erythropoietin remains controversial, particularly after the increased incidence in pure red cell aplasia. In Canada, the majority of hemodialysis units have converted to the intravenous route for administration of erythropoietin to potentially decrease the risk of pure red cell aplasia. OBJECTIVE: To compare the difference in the weight-adjusted, weekly erythropoietin dose (units/kg/wk) administered by the subcutaneous compared with the intravenous route in a chronic hemodialysis population followed for 12 months. METHODS: This prospective cohort study recruited patients receiving subcutaneous erythropoietin for at least 3 months while undergoing dialysis in a tertiary care hemodialysis program. Participants were switched to intravenous erythropoietin, and the average weekly dose was recorded at 1, 2, 3, 6, and 12 months. Anemia management and hemoglobin, iron, and delivered dialysis dose targets remained constant throughout the study. RESULTS: The erythropoietin dose increased by 24.5 units/kg/wk (95% CI 12.7 to 36.3; p < 0.001), representing a 20.2% increase (95% CI 10.5% to 29.9%; p < 0.001) 12 months after conversion from the subcutaneous to intravenous route of administration. Both patients with and without residual renal function at baseline required a significant increase in the intravenous dose. CONCLUSIONS: A 20.2% increase in erythropoietin dose was required to maintain hemoglobin targets between 11 and 12 g/dL after conversion from a subcutaneous to intravenous formulation. Healthcare funding agencies need to reexamine the cost benefit of using intravenous erythropoietin in the hemodialysis population with a low incidence of pure red cell aplasia.

Plasma exchange when myeloma presents as acute renal failure: a randomized, controlled trial.

BACKGROUND: Two small, randomized trials provide conflicting evidence about the benefits of plasma exchange for patients with acute renal failure at the onset of multiple myeloma. OBJECTIVE: To assess the effect of 5 to 7 plasma exchanges on a composite outcome in patients with acute renal failure at the onset of multiple myeloma. DESIGN: Randomized, open, controlled trial, stratified by chemotherapy and dialysis dependence, conducted from 1998 to 2004. SETTING: Hospital plasma exchange units in 14 Canadian medical centers. PARTICIPANTS: 104 patients between 18 and 81 years of age with acute renal failure at the onset of myeloma. INTERVENTION: Study participants were randomly assigned to conventional therapy plus 5 to 7 plasma exchanges of 50 mL per kg of body weight of 5% human serum albumin for 10 days or conventional therapy alone. Ninety-seven participants completed the 6-month follow-up. MEASUREMENTS: The primary outcome was a composite measure of death, dialysis dependence, or glomerular filtration rate less than 0.29 mL x s(-2) x m(-2) (<30 mL/min per 1.73 m2). RESULTS: At enrollment, the plasma exchange and control groups were similar for dialysis dependence, chemotherapy, sex, age, hypercalcemia, serum albumin level, 24-hour urine protein level, serum creatinine level, and Durie-Salmon staging. The primary composite end point occurred in 33 of 57 (57.9%) patients in the plasma exchange group and in 27 of 39 (69.2%) patients in the control group (difference between groups, 11.3% [95% CI, -8.3% to 29.1%]; P = 0.36). One third of patients in each group died. LIMITATIONS: The study was small, used a composite outcome, and did not use renal biopsy as an inclusion criterion. Recruiting physicians were blinded to treatment allocation but not to treatment thereafter. CONCLUSIONS: In patients with acute renal failure at the onset of multiple myeloma, there is no conclusive evidence that 5 to 7 plasma exchanges substantially reduce a composite outcome of death, dialysis dependence, or glomerular filtration rate less than 0.29 mL.s(-2).m(-2) (<30 mL/min per 1.73 m2) at 6 months.

Perioperative N-acetylcysteine to prevent renal dysfunction in high-risk patients undergoing cabg surgery: a randomized controlled trial.

CONTEXT: Renal dysfunction is a complication of coronary artery bypass graft (CABG) surgery performed with cardiopulmonary bypass (CPB) that is associated with increased morbidity and mortality. N-acetylcysteine, an antioxidant and vasodilator, counteracts renal ischemia and hypoxia. OBJECTIVE: To determine whether perioperative intravenous (IV) N-acetylcysteine preserves renal function in high-risk patients undergoing CABG surgery with CPB compared with placebo. DESIGN, SETTING, AND PATIENTS: Randomized, quadruple blind, placebo-controlled trial (October 2003-September 2004) in operating rooms and general intensive care units (ICUs) of 2 Ontario tertiary care centers. The 295 patients required elective or urgent CABG and had at least 1 of the following: preexisting renal dysfunction, at least 70 years old, diabetes mellitus, impaired left ventricular function, or undergoing concomitant valve or redo surgery. INTERVENTIONS: Patients received 4 (2 intraoperative and 2 postoperative) doses of IV N-acetylcysteine (600 mg) (n = 148) or placebo (n = 147) over 24 hours. MAIN OUTCOME MEASURES: The primary outcome was the proportion of patients developing postoperative renal dysfunction, defined by an increase in serum creatinine level greater than 0.5 mg/dL (44 micromol/L) or a 25% increase from baseline within the first 5 postoperative days. Secondary outcomes included postoperative interventions and complications, the requirement for renal replacement therapy (RRT), adverse events, hospital mortality, and ICU and hospital length of stay. RESULTS: There was no difference in the proportion of patients with postoperative renal dysfunction (29.7% vs 29.0%, P = .89; relative risk [RR], 1.03 [95% confidence interval {CI}, 0.72-1.46]) in the N-acetylcysteine and placebo groups, respectively. We noted nonsignificant differences in postoperative interventions and complications, the need for RRT (0.7% vs 2.1%; P = .37), total (6.1% vs 9.6%; P = .26) and serious adverse events, hospital mortality (3.4% vs 2.7%; P>.99), and ICU and hospital length of stay between the N-acetylcysteine and placebo groups. A post hoc subgroup analysis of patients (baseline creatinine level >1.4 mg/dL [120 micromol/L]) showed a nonsignificant trend toward fewer patients experiencing postoperative renal dysfunction in the N-acetylcysteine group compared with the placebo group (25.0% vs 37.1%; P = .29). CONCLUSIONS: N-acetylcysteine did not prevent postoperative renal dysfunction, interventions, complications, or mortality in high-risk patients undergoing CABG surgery with CPB. Further research is required to identify CABG patients at risk for postoperative renal events, valid markers of renal dysfunction, and to establish renal thresholds associated with important clinical outcomes.

Midodrine appears to be safe and effective for dialysis-induced hypotension: a systematic review.

BACKGROUND: Dialysis-induced hypotension is an important complication of haemodialysis. Midodrine is an oral alpha-1 agonist that has been used in several small studies to prevent intradialytic hypotension (IDH). METHODS: The authors searched MEDLINE, EMBASE, ASN conference proceedings, and references of potentially relevant articles, and contacted industry (Shire Pharmaceuticals) for unpublished data. Observational studies, randomized controlled trials, crossover studies and pre- and post-intervention design studies with >/=5 haemodialysis patients were included. Study outcomes assessed were: hypotensive symptoms, changes in systolic and/or diastolic blood pressure, dry weight and length of stay after treatment. Data were abstracted on: study design, patient characteristics, intradialytic changes in blood pressure, nadir blood pressure and symptom improvement with midodrine. Thirty-seven full text articles were retrieved and nine met the selection criteria, in addition to one unpublished study. Midodrine dosing regimens ranged from 2.5 to 10 mg of midodrine given 15-30 min before dialysis. RESULTS: Post-dialysis systolic blood pressure was higher by 12.4 mmHg [95% confidence interval (CI) 7.5-17.7] and diastolic pressure was higher by 7.3 mmHg (95% CI 3.7-10.9) during midodrine treatment vs control. Likewise, the nadir systolic blood pressure was higher by 13.3 mmHg (95% CI 8.6-18.0), with a difference in nadir diastolic pressure of 5.9 mmHg (95% CI 2.7-9.1). Six of 10 studies report improvement in symptoms of IDH, and there were no reported serious adverse events ascribed to midodrine. CONCLUSIONS: This systematic review would suggest that midodrine has a role in the therapy of haemodialysis patients experiencing IDH. This conclusion must be viewed with caution, however, given the quality and sample size of the studies included in this review.

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.

Effect of awareness of a randomized controlled trial on use of experimental therapy.

CONTEXT: Use of experimental therapies during but outside of randomized controlled trials (RCTs) has not been studied. OBJECTIVE: To determine whether initiation of an RCT leads to increased use of the experimental therapy outside the trial. DESIGN AND SETTING: Data on national apheresis use during 3 Canadian RCTs for multiple sclerosis (1986-1988), thrombotic thrombocytopenic purpura (1982-1988), and myeloma cast nephropathy (1998-2000) were obtained from 19 major medical centers in Canada. The multiple sclerosis and myeloma cast nephropathy trials had data on apheresis use for 3 years prior to and during the trials, which permitted a time-series analysis to determine the impact of the RCTs on the use of apheresis. The ongoing myeloma cast nephropathy trial provided data on the number of patients inside and outside of the RCTs in trial and nontrial centers. Initial and follow-up questionnaires were sent to 24 Canadian physicians in trial and nontrial centers to determine if they had noted an increase in apheresis activity during the trials and, if so, their explanation for it. MAIN OUTCOME MEASURE: Change in number of patients undergoing apheresis for thrombotic thrombocytopenic purpura, multiple sclerosis, and myeloma cast nephropathy prior to and during the respective RCTs compared with all patients undergoing apheresis during the same periods. RESULTS: During all 3 RCTs, there were large increases in use of apheresis. The majority of the increased use of apheresis was outside of the trials: for multiple sclerosis, 30 of 49 patients per year (61% of increase); thrombotic thrombocytopenic purpura, 49 of 56 patients per year (72% of increase); and myeloma cast nephropathy, 60 of 72 patients per year (57% of increase). The myeloma cast nephropathy study noted that this increase occurred in both nontrial and trial centers. Among questionnaire respondents (n = 22; 92% response rate), most physicians noted an increase in apheresis activity during the trials and attributed it to a "jumping-the-gun" phenomenon. CONCLUSIONS: During 3 Canadian RCTs, apheresis increased, but most of the increase occurred outside the trials. This behavior during an RCT, in the absence of clear efficacy, can be termed jumping the gun.

Nocturnal but not short hours quotidian hemodialysis requires an elevated dialysate calcium concentration.

Interest in quotidian (daily) hemodialysis (HD) is growing. Some advocate short-hours high-efficiency daily HD (SDH) and others long-hours slow-flow nocturnal HD (NH) while the patient is asleep, both being used 5 to 7 d/week. The London Daily/Nocturnal Hemodialysis Study was the first attempt to obtain data of SDH and NH that may be compared with conventional thrice weekly HD (CH). This was a 4-yr observational study designed to enter and follow 40 patients: 10 receiving SDH, 10 receiving NH, and 20 receiving CH. The CH patients were cohort control subjects matched for each SDH and NH patient by age, gender, comorbidity, and original dialysis modality (in-center, home, self-care, or satellite HD). All SDH and NH treatments were at home. Data collection to December 2001 was analyzed. Then enrollment had been completed and all patients had been followed for 15 mo, eight SDH plus six NH for 18 mo, seven SDH plus six NH for 21 mo, and seven SDH and five NH for 24 mo. This report gives data on calcium and phosphorus metabolism in these patients. All patients were initially dialyzed against a 1.25-mmol/L calcium bath. Predialysis serum calcium levels became lower in NH versus SDH patients by the first month and at 9 mo were 2.67 +/- 0.25 mmol/L (M +/- SD) in SDH, 2.40 +/- 0.16 mmol/L in NH, and 2.52 +/- 0.21 mmol/L in CH (SDH versus NH, P = 0.038; SDH versus CH versus NH, NS). Predialysis phosphorus levels were better controlled by NH than by SDH or CH, and with NH, all phosphate binders were discontinued. By 12 mo, a rise in bone alkaline phosphatase was seen in NH patients (but not in SDH or CH patients), which peaked at 15 to 18 mo (NH 191 IU/L +/- 70; SDH 82 +/- 34; CH 80 +/- 36; P < 0.002) and similarly with intact parathyroid hormone (iPTH) levels (NH 159 pmol/L +/- 75; SDH 13.1 +/- 10; CH 18 +/- 18; P < 0.00001). Because of these changes, the dialysate calcium concentration was increased to 1.75 mmol/L for the NH patients. Postdialysis calcium then rose to 2.57 +/- 0.21, and alkaline phosphatase and iPTH normalized completely by 21 mo. These observations prompted mass balance studies that showed that a 1.25-mmol/L calcium dialysate was associated with a mean net calcium loss of 2.1 mmol/h of dialysis time, whereas 1.75-mmol/L calcium dialysate provides a net gain of 3.7 mmol/h. In addition, the mass balance studies showed that phosphate removal by NH (43.5 +/- 20.7 mmol) was significantly (P < 0.05) higher than by SHD (24.2 +/- 13.9 mmol) but not by CH (34.0 +/- 8.7 mmol) on a per-treatment basis. With the increased frequency of treatments provided by quotidian dialysis, the weekly phosphorus removal (261.2 +/- 124.2 mmol) by NH was significantly higher than by SDH (P = 0.014) and CH (P = 0.03). This allowed the discontinuation of P binders in the NH group, which in turn eliminated approximately 8 g elemental Ca/wk oral intake. This, together with a 4 g elemental Ca/wk dialysate loss induced by a 1.25-mmol/L Ca bath, explains the changes in Ca, alkaline phosphatase, and iPTH seen in the NH patients. The SDH patients have weekly dialysis times similar to CH and still require P binders and do not become Ca deficient using 1.25-mmol/L Ca dialysate. With NH but not SDH, an elevated dialysate Ca concentration is required.

The London Daily/Nocturnal Hemodialysis Study--study design, morbidity, and mortality results.

BACKGROUND: Despite the growing interest in more frequent hemodialysis (HD), to date, there have been no randomized prospective studies comparing outcomes in patients dialyzed using conventional thrice-weekly therapy with either the short hours daily or long slow nocturnal HD modalities. METHODS: The London Daily/Nocturnal Hemodialysis Study, a prospective, comparative, nonrandomized study, directly compared outcomes of quotidian HD patients with conventional thrice-weekly HD patients. Patients were assigned to either daily HD (n = 11) or nocturnal HD (n = 12) and followed up for 5 to 36 months; all data were directly compared with matched control patients receiving conventional HD. This report describes the study design, morbidity and mortality results, and vascular access results. RESULTS: There were no significant differences between patient groups in total numbers of hospital admissions or hospital days. Likewise, there was no significant difference in number of emergency visits per patient-year. There were 3 patient deaths in each of the nocturnal HD and control groups, although none of the deaths was deemed related to HD treatment. No deaths occurred in the daily HD group. Vascular access differences between study groups were not statistically significant. Among patients with arteriovenous (AV) fistulae, more than 80% of daily HD and nocturnal HD patients elected to use the buttonhole technique and successfully performed quotidian HD through their buttonhole at the 18-month follow-up. Patients with AV fistulae had the lowest annual rates of access complications and interventions. The annual access infection rate for quotidian HD patients using catheters decreased significantly after patients switched from in-center conventional HD to more frequent HD treatments at home. CONCLUSION: Results from this comprehensive and pioneering study support the hypothesis that quotidian HD is more physiological than conventional HD and results in better patient outcomes.

Calcium and phosphate balance with quotidian hemodialysis.

BACKGROUND: Conventional hemodialysis (HD) is associated with profound disturbances in calcium and phosphate metabolism and abnormal parathyroid hormone (PTH) levels. Effects of more frequent HD on calcium and phosphate balance have not been fully elucidated. METHODS: The London Daily/Nocturnal Hemodialysis Study examined effects of quotidian HD, either daily HD (n = 11) or nocturnal HD (n = 12), on calcium and phosphate metabolism, bone alkaline phosphatase levels, and intact PTH (iPTH) levels. RESULTS: Daily HD patients showed a slight decrease in predialysis serum phosphate levels, no changes in phosphate-binder requirements or serum calcium levels, and slight increases in serum bone alkaline phosphatase and iPTH levels. Nocturnal HD patients showed a trend for decreased predialysis phosphate levels, with significantly lower values than daily HD and matched control patients on conventional HD therapy at several times. Phosphate-binder use by nocturnal HD patients was significantly reduced. Both quotidian HD groups showed decreases in calcium x phosphate product, with significantly lower values for nocturnal HD patients (38.11 mg(2)/dL(2)) compared with daily HD and control patients (53.99 and 52.51 mg(2)/dL(2), respectively) at 18 months. Bone alkaline phosphatase levels increased slightly and attained statistical significance compared with baseline values for both quotidian HD groups. A trend for increases in serum iPTH levels, coupled with increasing levels of bone alkaline phosphatase in nocturnal HD patients, led to the decision to increase the dialysate calcium concentration from 5.0 to 7.0 mg/dL. This 1-time adjustment resulted in a reversal of the trend and a return to baseline values. CONCLUSION: This study shows the superior control of serum phosphate levels in nocturnal HD patients compared with daily HD or conventional HD patients and the benefits of dialysate with a greater calcium concentration in slow nocturnal HD.

The impact of quotidian hemodialysis on nutrition.

BACKGROUND: Malnutrition is a common problem in hemodialysis (HD) patients and one of the most important factors influencing morbidity and mortality. More frequent HD has been shown to improve nutritional status in HD patients. METHODS: The London Daily/Nocturnal Hemodialysis Study compared the nutritional status of patients receiving quotidian HD, either short daily HD (n = 11) or long nocturnal HD (n = 12), with that of 22 matched control patients receiving conventional thrice-weekly HD. A number of biochemical parameters indicative of nutritional status were measured, including protein equivalent of total nitrogen appearance (nPNA), serum albumin, serum prealbumin, dietary calcium, serum lipids, and water-soluble vitamin levels. RESULTS: nPNA tended to increase throughout the study for both quotidian HD groups and remained unchanged in the control group, which had the lowest values (1 to 1.1 g/kg/d). Daily HD patients showed a significant increase in mean serum albumin levels at 3, 12, and 18 months. The nocturnal HD group showed a significant decrease in albumin levels at month 9, and control patients maintained relatively stable albumin levels throughout the study. Serum prealbumin levels averaged 0.04 g/dL for daily HD patients, whereas serum prealbumin levels decreased in nocturnal HD patients during the study period. Half the nocturnal HD patients had vitamin C levels lower than the reference range. Body composition data showed increased arm muscle area and maintenance of 100% to 110% of relative body weight (RBW) after several months of daily HD, whereas patients on nocturnal HD therapy showed a significant decline in RBW. There were no significant differences in lean body mass, percentage of body fat, or body mass index among the 3 study groups. CONCLUSION: Increased nPNA, serum albumin levels, and arm muscle area suggest that daily HD patients experienced improved nutritional status.

Patient quality of life on quotidian hemodialysis.

BACKGROUND: Studies have shown improved quality of life for hemodialysis (HD) patients after changing from conventional thrice-weekly HD treatment to more frequent HD. METHODS: In the London Daily/Nocturnal Hemodialysis Study, 23 patients (11 patients, short daily HD; 12 patients, long nocturnal HD) were compared with 22 conventional thrice-weekly HD patients serving as controls. All patients completed 3 sets of quality-of-life assessment tools: (1) a locally developed renal disease-specific questionnaire that assessed dialysis symptoms, uremic symptoms, psychosocial stress, and social-leisure activity; (2) the generic Medical Outcomes Survey 36-Item Short Form (SF-36); and (3) the global Health Utilities Index (HUI). As a supplement to the HUI, a subset of patients was asked to complete the Time Trade-Off assessment. RESULTS: Overall, the reduction in symptoms shows better fluid management because quotidian HD patients reported experiencing fewer and less severe cramping during dialysis, fewer headaches, less hypotension, fewer episodes of dizziness, decreased fluid restrictions, fewer blood pressure problems, decreased interdialytic weight gains, fewer episodes of shortness of breath, and a reduction in the sensation of easily feeling cold. HUI results showed that quotidian HD patients maintained functionality throughout the study period, whereas control patients showed a significant loss. Given the choice, all patients chose to remain on quotidian HD therapy after switching from conventional HD therapy. The Time Trade-Off analysis indicated that study patients were willing to trade far less time on quotidian HD therapy and much more time on conventional HD therapy in exchange for "perfect" health. CONCLUSION: As more studies focus on improved patient outcomes and appropriate funding mechanisms are established, more frequent home HD treatment should become a standard treatment option for patients with end-stage renal disease.

Adequacy of quotidian hemodialysis.

BACKGROUND: Several methods exist to quantitate small-solute clearance by daily hemodialysis (HD) regimens, but these have not been empirically applied or compared. METHODS: In the London Daily/Nocturnal Hemodialysis Study, dosing and adequacy of quotidian HD regimens, both short daily HD (n = 11) and long nocturnal HD (n = 12), were compared with conventional thrice-weekly HD (n = 22) using several models. Urea clearance was computed by percentage of reduction in urea, kinetic modeling (single-pool Kt/V [spKt/V]), Daugirdas rate equation (equilibrated Kt/V [eKt/V]), and Gotch standardized Kt/V (stdKt/V). RESULTS: Nocturnal HD patients maintained a mean single-session spKt/V of 1.64 throughout the study, similar to that of conventional HD patients (1.73), whereas daily HD patients showed a significant decrease in mean single-session spKt/V (0.93) compared with baseline (t(0)) values. Mean weekly spKt/V values increased from t(0) for both quotidian HD groups (9.08 for nocturnal HD, 5.55 for daily HD) and were higher in both quotidian HD groups compared with conventional HD patients. Weekly eKt/V, stdKt/V, and normalized protein equivalent of nitrogen appearance values showed similar trends. Comparison of the 3 different adequacy models showed an increase in weekly HD doses for both quotidian HD regimens compared with conventional HD; however, percentages of increases from t(0) to follow-up differed according to the model used. The calculated efficiency of dose delivery at the 10-month follow-up comparing daily HD with conventional HD was 257 +/- 26 minutes versus 306 +/- 17 stdKt/V unit delivered, respectively, amounting to almost 1 dialysis-hour saved per stdKt/V unit delivered for daily HD. CONCLUSION: These results show that both quotidian HD regimens are more effective than conventional HD in improving weekly urea clearance measured by spKt/V, stdKt/V, and eKt/V.

An operating cost comparison between conventional and home quotidian hemodialysis.

BACKGROUND: Although several studies have shown that simulated annual direct health care costs are substantially lower for patients undergoing more frequent hemodialysis (HD), there is limited information about the economics of daily HD and nocturnal HD. METHODS: The London Daily/Nocturnal Hemodialysis Study compared the economics of short daily HD (n = 10), long nocturnal HD (n = 12), and conventional thrice-weekly HD (n = 22) in patients over 18 months. A retrospective analysis of patients' conventional HD costs during the 12 months before study entry was conducted to measure the change in cost after switching to quotidian HD. RESULTS: As the data show, annual costs (in Canadian dollars) for daily HD are substantially lower than for both nocturnal HD and conventional HD: approximately 67,300 Can dollars, 74,400 Can dollars, and 72,700 Can dollars per patient, respectively. Moreover, marginal changes in operating cost per patient year were - 9,800 Can dollars, -17,400 Can dollars, and +3,100 Can dollars for the daily HD, nocturnal HD, and conventional HD groups. Because of the increase in number of treatments, treatment supply costs per patient for the daily HD and nocturnal HD study groups were approximately twice those for conventional HD patients. However, average costs for consults, hospitalization days, emergency room visits, and laboratory tests for quotidian HD patients tended to decline after study entry. The major cost saving in home quotidian HD derived from the reduction in direct nursing time, excluding patient training. Total annualized cost per quality-adjusted life-year for the daily HD and nocturnal HD groups were 85,442 Can dollars and 120,903 Can dollars, which represented a marginal change of - 15,090 Can dollars and - 21,651 Can dollars, respectively, reflecting both improved quality of life and reduced costs for quotidian HD patients. CONCLUSION: Substantial clinical benefits of home quotidian HD, combined with the economic advantage shown by this study, clearly justify its expansion.

Nursing issues related to patient selection, vascular access, and education in quotidian hemodialysis.

BACKGROUND: Increased interest in quotidian hemodialysis (HD) programs requires that nephrology nurses have a larger role in transitioning patients to more frequent HD. Nursing issues include the selection, training, and education of patients before they begin more frequent HD therapy. METHODS: The London Daily/Nocturnal Hemodialysis Study directly compared data from patients undergoing either short daily HD (n = 11) or long nocturnal HD (n = 12) with those undergoing conventional thrice-weekly HD (n = 22). Patient training, education, safety, and vascular access data were collected. RESULTS: The patient training period varied from 10 to 25 days, with an average length of 16.64 days. Patients used 1 of 3 types of vascular access: native arteriovenous (AV) fistulae, grafts, or central catheters. No statistically significant differences in access flow rates between the study and control groups were noted or when comparing different types of access. A significant decrease in catheter infection rate was seen when patients switched to daily HD therapy. Patient cannulation surveys showed that patients with AV fistulae or grafts showed improvements with ease and comfort as the study progressed, and patients widely preferred the buttonhole technique to the rotating-needle method for cannulation. CONCLUSION: With growing interest in the development of quotidian HD programs, HD nursing personnel face the exciting challenge of improving on existing training programs and treatment modalities.

Patient monitoring in the London Daily/Nocturnal Hemodialysis Study.

BACKGROUND: Patient monitoring involves real-time surveillance of patients while they dialyze at home by a staff member ("monitor") at a centralized location. Monitoring is designed to ensure patient safety, patient compliance with treatment, and automatic collection of treatment data. METHODS: In the London Daily/Nocturnal Hemodialysis Study, 14 nocturnal hemodialysis (HD) patients were monitored from 13 to 602 sessions for a total of 4,096 patient-nights. Alarm data were collected and analyzed. RESULTS: The number of alarms per night ranged from 0 to 54, with an average of 1.31 +/- 2.81, resulting in a total of 5,351 registered alarms. Three hundred twenty-two calls because of nonresponse or slow response to alarms were made to patients' homes, but no calls to designated contact persons or emergency medical services were required. Arterial and venous pressure alarms were the most common type of alarm and were caused primarily by the patient obstructing blood tubing. The average number of alarms per night decreased significantly over time as patients gained experience with nocturnal HD, from a maximum of 1.98 +/- 3.31 alarms/night during the first month at home to a low of 0.74 +/- 1.63 alarms/night by the final month of follow-up. Each progressive decrease from month 3 through month 18 was statistically significantly lower than the value at month 1. CONCLUSION: Monitoring is essential for the initial 3 months of nocturnal HD therapy until the HD team is convinced the patient is stable and compliant. Thereafter, monitoring is necessary only if medically indicated.

Central, peripheral, and other blood volume changes during hemodialysis.

Volume overload is a factor in development of hypertension in hemodialysis patients. Fluid removal by hemodialysis (HD), however, may cause intradialytic hypotension and associated symptoms. A better understanding of the relationships between blood pressure volume status and the pathophysiology of fluid removal during HD are, therefore, necessary to control blood pressure and to eliminate intradialytic hypotension. The objectives of the study were to determine the amount and direction of change of body fluid compartments after ultrafiltration (UF) and to determine whether any correlations exist between mean arterial pressure (MAP), change in circulating blood volume (deltaBV), total body water (TBW), central blood volume (which constitutes the volume of blood in the lungs, heart, and great vessels [CBV]), and intracellular and extracellular fluid volumes (ICF, ECF). The study population included 20 patients on regular HD. Each individual had their CBV, cardiac output, and peripheral vascular resistance (PVR) measured by means of saline dilution technique and deltaBV monitored by an online hematocrit sensor (Crit Line). MAP was calculated from measured blood pressure and ICF and ECF were measured using bioelectric impedance analysis techniques. Measurements were obtained before and after maximum UF measured by deltaBV (reduction of 6-10% by Crit Line). Ten healthy controls also had ECF and ICF values measured by bioelectric impedance analysis. Before HD, MAP correlated with TBW (r = 0.473, p = 0.035) and CBV (r = 0.419, p = 0.066), suggesting that hypertension here may be due to volume overload. Patients were ECF expanded before HD with an ECF:ICF ratio of 0.96, which was significantly higher than the control ratio of 0.74 (p < 0.0001). During UF, fluid was removed from both ECF and ICF, but more from the ECF volume ratio 0.92 post UF, a significant reduction (p < 0.0001). After UF, MAP no longer correlated with TBW or CBV but correlated with peripheral vascular resistance (r = 0.4575, p = 0.043). After UF, deltaBV correlated inversely with PVR (r = -0.50, p = 0.024). Despite the fall in deltaBV (7.11+/-2.49%) with UF, CBV was maintained. CBV were 0.899 L and 0.967 L pre and post UF, respectively. These data suggest that in hemodialysis patients, predialysis volume status influences predialysis blood pressure. UF causes BV to fall, but CBV is preferentially conserved by increasing PVR, which also maintains blood pressure. Failure of a PVR response likely leads to intradialytic hypotension.

Reduced requirement for erythropoietin with quotidian hemodialysis therapy.

Quotidian (daily) hemodialysis has many potential advantages over conventional three times weekly hemodialysis, including improved control of anemia. However, previous reports do not consistently describe beneficial effects regarding anemia and erythropoietin requirements. We sought to determine whether erythropoietin dose is altered in this form of therapy, and elucidate the potential contributing factors. An analysis of an ongoing, nonrandomized, prospective trial of daily nocturnal, daily short, and their cohort of conventional hemodialysis controls was performed. Those patients who had completed 15 months of the trial were analyzed, which include nine patients in the quotidian dialysis group and nine cohort controls receiving conventional three times weekly dialysis. At 15 months, the weekly Kt/V in the quotidian group was 6.8 (+/-0.6) and 4.5 (+/-0.4) in the conventional group (p = 0.001). Mean erythropoietin dose fell in the quotidian group from 87 (+/-66) to 53 (+/-50) U/week per kg (p = 0.020). The mean hemoglobin rose from 115 (+/- 18) to 129 (+/- 14) g/L (p = 0.008). There was no significant change in erythropoietin dose or hemoglobin in the conventional hemodialysis group. Serum ferritin and the transferrin-saturation did not change significantly and remained above 100 microg/L and 20%, respectively, throughout. Serum albumin and C-reactive protein were similar between the quotidian and conventional dialysis groups and did not change over time. In patients who were receiving conventional thrice weekly hemodialysis, initiation of quotidian hemodialysis led to a 39% reduction in erythropoietin dose at 15 months, most likely due to the increased dose of delivered dialysis.