Outcomes associated with nocturnal hemodialysis

INTRODUCTION — The mortality rate of patients undergoing maintenance hemodialysis is unacceptably high [1]. An extremely high morbidity, relatively low quality of life (due in part to a high level of dependence and unemployment), and high cost have also been observed.

The Hemodialysis (HEMO) and Adequacy of Peritoneal Dialysis in Mexico (ADEMEX) trials found that increasing the dialysis dose within the general restrictions of a three-times-weekly regimen or of peritoneal dialysis, respectively, failed to decrease patient mortality [2-5] (see "Patient survival and maintenance dialysis" and "Prescribing and assessing adequate hemodialysis"). The institution of more intensive dialysis regimens provided evidence of improvement in morbidity and possible mortality in this patient population. Compared with conventional three-times-per-week regimens, for example, dialysis associated with longer duration and/or higher frequency correlated with enhanced outcomes [6-9].

Nocturnal hemodialysis was introduced as a (possibly) more desirable alternative to conventional dialysis since it provides superior dialysis based upon dose, duration, and, for home nocturnal dialysis, frequency. This can be accomplished because it is performed during sleep. Nocturnal dialysis regimens consist of either long (eg, six to eight hours) thrice-weekly dialysis sessions administered in-center, or long and frequent (eg, four to six days per week) dialysis sessions administered at home. Because of this variability, caution must be applied when interpreting outcomes data comparing nocturnal with conventional hemodialysis.

This topic will review the outcomes associated with nocturnal hemodialysis. Technical aspects of nocturnal hemodialysis and an overview of short daily hemodialysis are presented separately:

●(See "Technical aspects of nocturnal hemodialysis".)

●(See "Short daily hemodialysis".)

OVERVIEW — Several observational and cohort studies have shown that nocturnal hemodialysis is associated with marked benefits compared with conventional hemodialysis regimens. These include improved solute clearance, possibly improved quality of life, better blood pressure control and other cardiovascular benefits, reduced medication requirements, and decreased hospitalization and mortality rates. Some of these benefits have not been confirmed in randomized controlled trials and should be interpreted with caution, since patients receiving nocturnal hemodialysis tend to be younger, healthier [10], and have a higher functional status [11] than patients receiving conventional thrice-weekly hemodialysis. It should also be noted that while the majority of studies were performed using conventional hemodialysis machines with high dialysate flows, most of the home hemodialysis patients in the United States use low dialysate flow machines (eg, NxStage) [12].

Multiple observational studies and two randomized trials have shown that more frequent dialysis improves selected outcomes. A benefit on survival has not been convincingly shown. These data are discussed elsewhere. (See "Short daily hemodialysis", section on 'Outcomes'.)

SOLUTE CLEARANCE — Clearance of different solutes is markedly enhanced with nocturnal hemodialysis.

Urea — Even at low dialysate flow rates (100 mL/min), nocturnal hemodialysis can provide a nightly equilibrated Kt/V for urea of approximately 1 [13,14]. Higher dialysate flows in combination with large surface area dialyzers provide a single-pool Kt/V of 1.7 to 2 [15,16]. The weekly standard Kt/V, which allows for comparison of the dialysis dose across dissimilar regimens [17], is approximately 5 for a dialysis prescription of eight hours six nights per week [16,18]. Such values are substantially higher than the minimum thresholds of Kt/V suggested by the Kidney Disease Outcomes Quality Initiative (KDOKQI) guidelines [19].

Phosphate — Weekly removal of phosphate with nocturnal hemodialysis is higher compared with conventional hemodialysis, thereby obviating the need for phosphate binders in many patients [13,20-26]. As examples:

●In the Frequent Hemodialysis Network (FHN) Nocturnal trial, 87 patients were randomly assigned to either three-times-weekly conventional hemodialysis or six-times-weekly nocturnal hemodialysis [27]. At 12 months of follow-up, patients receiving frequent nocturnal hemodialysis, compared with those receiving conventional hemodialysis, had a lower serum phosphate (4.72 versus 5.91 mg/dL, respectively), and many more patients did not require phosphate binders (73 percent versus 8 percent in the conventional hemodialysis group) [25].

●In a crossover study, the serum phosphate levels of eight patients on chronic dialysis were measured during five months of conventional hemodialysis and then after the switch to five months of therapy with nocturnal hemodialysis [20]. Serum phosphate levels were significantly lower with nocturnal hemodialysis (4.0 versus 6.5 mg/dL [1.3 versus 2.1 mmol/L]) than with conventional hemodialysis. In addition, patients undergoing nightly dialysis increased their dietary phosphate intake by 50 percent and did not require phosphate binders after the fourth month. Furthermore, to maintain normal serum phosphate concentrations, more than 50 percent of all patients required the addition of phosphate to the dialysate.

●In a study of 26 patients who were converted from home hemodialysis (three to five hours, 3.5 to 4 sessions weekly) to every-other-night home hemodialysis (six to nine hours, 3.5 to 4 sessions weekly), the number of patients requiring phosphate binders decreased from 92.3 percent at baseline to 22.8 percent [28].

As phosphate removal is dialysis time dependent, the NxStage machine, despite its low dialysate flow, increases phosphate removal during nocturnal hemodialysis [29].

Beta2-microglobulin — Since large molecule removal by hemodialysis is time dependent, the removal of beta2-microglobulin is markedly higher with nocturnal hemodialysis than with conventional hemodialysis. In one study, nocturnal hemodialysis administered six nights per week was associated with a four-times-higher solute removal of beta2-microglobulin (585 versus 127 mg/week) and a greater reduction in plasma beta2-microglobulin concentrations (39 versus 21 percent) compared with conventional hemodialysis (performed for four hours, three times per week) [30]. Although unproven, this finding may be associated with a delay in the development of dialysis-related amyloidosis.

SURVIVAL — Studies evaluating patient survival on nocturnal hemodialysis have yielded conflicting results [10,31-37]. While several observational studies have shown a possible survival benefit compared with conventional hemodialysis, other studies including one randomized trial have not confirmed these findings. The following studies illustrate the range of findings:

●Among 746 patients initiated for the first time on in-center, three-times-weekly nocturnal hemodialysis performed at 77 outpatient centers in the United States, the two-year adjusted mortality risk was lower compared with 2062 matched control patients on conventional hemodialysis (19 versus 27 percent, respectively, hazard ratio [HR] 0.75, 95% CI 0.61-0.91) [10]. The mortality of the matched cohort was lower than the reported mortality rate for hemodialysis patients in the United States, however, suggesting that patients selected for in-center nocturnal hemodialysis may be healthier than the average hemodialysis patient in the United States [38].

●In one retrospective study, 338 patients who were receiving intensive home hemodialysis (either day or overnight with a mean of 4.8 sessions per week and a mean treatment time of 7.4 hours per session) were compared with 1338 propensity-matched patients on conventional hemodialysis (mean of three sessions per week with a mean treatment time of 7.4 hours per session) [34]. Mortality was lower among patients on intensive hemodialysis (13 versus 21 percent for control patients on conventional hemodialysis).

●A matched cohort study reported that mortality was significantly lower among 94 patients undergoing nocturnal hemodialysis compared with 43 patients undergoing thrice-weekly conventional hemodialysis (HR 0.38, 95% CI 0.22-0.61) [32].

●A retrospective, matched cohort study found similar survival rates in a Canadian cohort of patients undergoing nocturnal hemodialysis and an American deceased-donor transplantation cohort [31]. In a similar study that included a Canadian rather than an American patient transplantation cohort, the nocturnal hemodialysis patient survival rate was inferior to the diseased-donor cohort. This reflected the difference in mortality between the two transplant cohorts rather than the nocturnal hemodialysis groups [35].

●In the Frequent Hemodialysis Network (FHN) Nocturnal trial, which randomly assigned 87 patients to either three-times-weekly conventional hemodialysis or six-times-weekly nocturnal hemodialysis, there was no difference between the groups at 12 months in the two primary composite endpoints, which included death or change in left ventricular mass and death or change in quality of life as assessed by the RAND-36 survey [27].

A follow-up study of the patients after the completion of the FHN trial showed a higher mortality rate in the nocturnal hemodialysis group compared with controls dialyzed mainly on conventional home hemodialysis [33]. The deaths took place mainly during the year after the completion of the trial. The results were unexpected and contradict the data from the observational studies. It should be noted that the mortality rate of the control group was surprisingly low, the sample size was small, and there was a high rate of hemodialysis prescription change after the completion of the study [39].

QUALITY OF LIFE — Among those treated with and/or switched to nocturnal hemodialysis, there are improvements in some, but not all, parameters [27,40-46]. The improvement in the quality of life was not confirmed in two prospective, randomized, controlled trials [42,47], although some of the kidney-disease-specific quality-of-life domain parameters improved in one study [42]. Both trials may have been underpowered to show a possible benefit [27,48].

Using different methodologies to determine patient preference, patients appear to prefer nocturnal hemodialysis to conventional in-center hemodialysis [49].

CARDIOVASCULAR EFFECTS

Blood pressure — Excellent blood pressure control is achieved by nocturnal hemodialysis, with many patients no longer requiring antihypertensive medications. As an example, in the Frequent Hemodialysis Network (FHN) Nocturnal trial, systolic blood pressure was lower at 12 months among patients who received frequent nocturnal dialysis compared with those who received conventional three-times-weekly hemodialysis (137 versus 151 mmHg, respectively) [27,50]. A meta-analysis of 21 studies that included over 1000 patients on in-center nocturnal hemodialysis and over 15,000 patients on conventional three-times-weekly hemodialysis reported that nocturnal hemodialysis was associated with a 3.2 mmHg decrease in systolic blood pressure [26].

To achieve normotension without medications, the target weight is progressively decreased until all antihypertensive agents are discontinued [15,51].

Left ventricular hypertrophy — Some, but not all, studies suggest that nocturnal hemodialysis is associated with regression of left ventricular hypertrophy [15,22,27]. As an example, in a study of 44 patients undergoing maintenance hemodialysis who were randomly assigned to nocturnal hemodialysis (six times/week) or continued conventional hemodialysis (three times/week) [22], at six months, left ventricular mass had significantly decreased with nocturnal hemodialysis (177 to 164 g) compared with no change in the conventional hemodialysis group (182 to 183 g). The effect was related, in part, to a decrease in blood pressure; however, the effect of improved volume control was unclear since volume status was not assessed.

However, in the FHN Nocturnal trial, despite a positive trend, there was no difference at 12 months in one of the primary composite endpoints, which included death or change in left ventricular mass, among 87 patients who were randomly assigned to either three-times-weekly conventional hemodialysis or six-times-weekly nocturnal hemodialysis [27].

Left as well as right ventricular remodeling have been reported in patients on three-times-weekly nocturnal hemodialysis [52-54]. One small study suggested a potential mechanistic role for fibroblast growth factor 23 (FGF23), showing improvements in echocardiographic parameters, reduction in left ventricular hypertrophy, and lower levels of circulating FGF23 when patients were converted from conventional three-times-weekly hemodialysis to in-center nocturnal hemodialysis [55].

Cardiac function — Limited evidence suggests that the switch to nocturnal hemodialysis may improve myocardial function as assessed by ejection fraction. In one small study, for example, cardiac function improved upon conversion to frequent nocturnal hemodialysis in a group of six patients with end-stage kidney disease (ESKD) and diminished left ventricular ejection fraction [56]. Ejection fraction increased from 28 to 41 percent. In another study, intradialytic left ventricular regional wall motion abnormalities (myocardial stunning) decreased with increasing dialysis intensity, favoring daily and frequent nocturnal hemodialysis [57]. Myocardial stunning is associated with high ultrafiltration requirements, intradialytic hypotension, long-term loss of systolic function, increased likelihood of cardiovascular events, and death [57].

Vascular function — There are improvements in vascular responsiveness with nocturnal hemodialysis. In a prospective cohort study of 18 patients with ESKD before and after conversion to frequent nocturnal hemodialysis, an improvement in blood pressure control was associated with significant decreases in the total peripheral resistance (TPR) [58]. This suggests that the hypotensive effect of nocturnal hemodialysis is mediated through a reduction in an elevated TPR rather than exclusively by a fall in the intravascular volume [58]. Other studies have shown increased vascular compliance, improved endothelium-dependent vasodilatation, increased number and function of endothelial progenitor cells, improved angiogenesis, and restoration of perfusion associated with nocturnal hemodialysis [59-61].

Heart rate variability — Conversion from conventional to frequent nocturnal hemodialysis is associated with increased heart rate variability during sleep [62]. The FHN Nocturnal trial also detected beneficial effects of daily hemodialysis in the form of increased vagal modulation and increased beat-to-beat variation [63] (see "Short daily hemodialysis", section on 'Frequent Hemodialysis Network (FHN) daily trial'). A decrease in heart rate variability, a characteristic common in patients with ESKD, correlates with increased cardiovascular mortality in the general population [64]. How this affects clinical outcomes needs to be determined. Nocturnal hemodialysis has also been associated with improved baroreflex sensitivity and the baroreflex effectiveness index [65].

Coronary calcification — The natural history of coronary calcification and factors underlying progression were evaluated in an observational cohort study of 38 patients who converted to frequent nocturnal dialysis [66]. At follow-up at a mean of 16 months, there was no change in coronary calcification (as assessed by multislice computed tomography [CT]) in 24 patients with minimal coronary calcification (initial score of 0.7 to follow-up score of 6.0), while there was a nonsignificant increase in the remaining individuals with higher initial calcification (1874 to 2038). The calcium-phosphate product and use of oral calcium-based phosphate binders also significantly decreased after conversion.

This rate of coronary calcification progression is significantly lower than that observed in studies of patients undergoing conventional hemodialysis and peritoneal dialysis. Although further study with a randomized, controlled trial is required, these findings suggest that conversion to nocturnal hemodialysis may lower rates of progression of coronary calcification, perhaps due in part to favorable effects upon calcium/phosphate metabolism. (See "Vascular calcification in chronic kidney disease".)

ANEMIA — Several reports claiming improved anemia control on daily or nocturnal hemodialysis have been published [67,68]. However, negative results have also been reported [13,27,69].

In one study, 63 patients on frequent nocturnal hemodialysis and 32 self-care patients on dialysis were evaluated with respect to anemia control [70]. After conversion to nocturnal hemodialysis, there was a substantial increase in hemoglobin concentrations with a fall in recombinant human erythropoietin (rHuEPO) requirements, while the control cohort did not reflect such changes [70]. There were no differences in baseline iron indices between the two groups. In addition to these decreased requirements, approximately 24 percent of patients on nocturnal hemodialysis versus 9 percent of controls no longer required the administration of rHuEPO [18,70]. The effect of nocturnal hemodialysis on erythropoiesis needs further investigation.

There was no increase in hemoglobin or decrease in the rHuEPO dose associated with nocturnal hemodialysis in the Frequent Hemodialysis Network (FHN) Nocturnal trial [71].

A meta-analysis of 21 studies that included over 1000 patients on in-center nocturnal hemodialysis and over 15,000 patients on conventional three-times-weekly hemodialysis reported that nocturnal hemodialysis was associated with a 0.5 g/dL increase in hemoglobin level [26].

BONE MINERAL METABOLISM — The excellent phosphate control on nocturnal hemodialysis is useful in the prevention and treatment of secondary hyperparathyroidism. High dialysate calcium levels suppress parathyroid hormone (PTH) levels successfully and normalize alkaline phosphatase levels in most patients [72]. This is achieved by adjusting the dialysate calcium. Inadequate dialysate calcium can lead to negative calcium balance associated with increased PTH and alkaline phosphatase [73,74]. Conversely, an overzealous increase in dialysate calcium can lead to low bone turnover [72] or promote vascular calcifications.

Bone density studies can be useful in adjusting dialysate calcium concentrations and ensuring that negative calcium balance is avoided. The role of vitamin D analogs is unknown. In one patient, extensive preexisting extraosseous tumoral calcifications dissolved upon conversion to nocturnal hemodialysis [75].

There is also an increase in both 25-hydroxy and 1,25-dihydroxy vitamin D levels, which directly correlates with the enhanced dialysis dose in nocturnal hemodialysis [76]. The clinical significance of increased vitamin D levels is unclear.

DYSLIPIDEMIA — Chronic kidney disease, including end-stage kidney disease (ESKD), is associated with significant dyslipidemia. This commonly consists of increased levels of triglycerides, total cholesterol, low-density lipoproteins (LDL), non-high-density lipoproteins (HDL), and reduced HDL. (See "Lipid management in patients with nondialysis chronic kidney disease" and "Lipid abnormalities in nephrotic syndrome".)

Nocturnal hemodialysis may improve the lipid profile of patients with ESKD. This was reported in a study of 11 patients undergoing conventional hemodialysis in whom decreases in triglyceride levels (186 to 89 mg/dL [2.1 to 1.0 mmol/L]) and increases in HDL levels (45 to 64 mg/dL [1.17 to 1.65 mmol/L]) occurred after three months of frequent nocturnal hemodialysis [77]. Total cholesterol and LDL levels were unchanged.

SLEEP — Sleep disturbance is minimal during home nocturnal hemodialysis, and sleep architecture appears to improve [78]. In one study, for example, assessment of sleep performed before and after the conversion to nocturnal hemodialysis found that the new regimen significantly improved preexisting sleep apnea [79]. In seven patients, conversion was associated with a markedly decreased number of apnea and hypopnea episodes (46 to 9 per hour) and increased oxygen saturation (89.2 to 94.1 percent). However, periodic limb movements and daytime sleepiness do not improve on nocturnal hemodialysis [80]. (See "Sleep disorders in end-stage kidney disease", section on 'Sleep apnea'.)

NUTRITION — Nocturnal hemodialysis usually allows patients to liberalize their dietary intake. Most patients on nocturnal hemodialysis can be maintained on a free diet, including the unrestricted intake of salt, water, potassium, phosphate, and protein.

Although potassium intake is not restricted, the amount ingested needs to be relatively consistent. The potassium dialysate concentration is adjusted as necessary.

A high protein intake is encouraged as patients on nocturnal hemodialysis lose 10 to 15 g of amino acids daily in the dialysate [81].

Serum albumin did not change after a year on frequent nocturnal hemodialysis [13]. Conversely, one study detected a decrease in serum albumin on nocturnal hemodialysis not observed on short daily hemodialysis [82]. A secondary analysis of data from the Frequent Hemodialysis Network (FHN) trial cited above showed no difference between patients undergoing frequent nocturnal versus conventional hemodialysis in serum albumin, protein catabolic rate, or total body weight at 12 months [83]. Further studies are needed to delineate the effect of nocturnal hemodialysis on nutrition.

The dose of daily multivitamin preparation is increased to two tablets daily. However, there has been no definite evidence of vitamin deficiency [84].

FERTILITY/PREGNANCY — Females undergoing conventional hemodialysis have markedly decreased fertility. When pregnancy does occur, intrauterine growth retardation and miscarriage can occur unless dialysis frequency is increased to five to six times per week. (See "Pregnancy in patients on dialysis", section on 'Obstetric outcomes'.)

A paucity of data exists concerning the effect of nocturnal hemodialysis on fertility and pregnancy:

●In a small cohort study, five females undergoing frequent nocturnal hemodialysis had seven pregnancies, resulting in six live infants [85]. Although less common or severe than in historic controls, complications included intrauterine growth restriction or small for gestational age (two infants), delivery before 32 weeks (one), and shortened cervix threatening labor (one). Thus, nocturnal hemodialysis may be associated with improved fertility. However, these findings are limited given the study's small size and observational design. Whether it is the increased frequency, greater dose, or better-timed average concentration of urea that produces a greater success rate requires further prospective studies.

●A study compared the pregnancy outcomes from 22 pregnancies in the Toronto Pregnancy and Kidney Disease Clinic and Registry (2000 to 2013), including mostly women on intensive hemodialysis, with outcomes from 70 pregnancies in the American Registry for Pregnancy in Dialysis Patients (1990 to 2011). The live birth rate in the Toronto cohort was significantly higher than the rate in the American cohort (86.4 versus 61.4 percent, respectively) [86]. A dose response between dialysis intensity and pregnancy outcomes was shown, with live birth rates of 48 percent in women dialyzed ≤20 hours per week and 85 percent in women dialyzed >36 hours per week.

A more detailed discussion of pregnancy in patients on dialysis is presented separately. (See "Pregnancy in patients on dialysis".)

COGNITION — Nocturnal hemodialysis may be associated with improved general cognitive efficiency as measured by psychomotor efficiency and increased attention and working memory [87], although this has not been shown in all studies [27,88].

COST — Due to the frequent schedule with daily nocturnal hemodialysis, the cost of consumables is higher than on conventional hemodialysis and is similar to the cost of short daily hemodialysis. On the other hand, the personnel cost of nocturnal hemodialysis at home is lower than with in-center hemodialysis regimens [89].

Depending upon the consumable/personnel cost ratio in different countries, nocturnal hemodialysis can be less or more expensive than in-center conventional hemodialysis. In addition, the cost of medications, possibly including erythropoietin (EPO; not confirmed in randomized, controlled studies), antihypertensive agents, and phosphate binders, is lower with nocturnal hemodialysis. It also appears that hospitalization expenses may be lower [40,90].

Two prospective, nonrandomized, controlled studies evaluated the costs associated with home nocturnal versus conventional in-center hemodialysis in Canada [90,91]. The overall treatment cost of patients on nocturnal hemodialysis was 20 percent lower than those on conventional hemodialysis, similar to the observations in a study in the United States [40].

The combination of improved quality of life and lower cost lead to higher cost utility for nocturnal hemodialysis when compared with conventional hemodialysis [92,93]. A decision analysis that compared nocturnal with conventional hemodialysis based upon a Markov state transition model reported similar findings [94].

POSSIBLE NEGATIVE EFFECTS

Vascular access complications — There may be more vascular access complications associated with frequent nocturnal hemodialysis compared with conventional three-times-weekly dialysis, as shown in the Frequent Hemodialysis Network (FHN) Nocturnal trial [27]. This may be the result of more frequent arteriovenous access cannulation, although other causes need to be investigated further.

Residual kidney function — There may be more rapid decline in residual kidney function in patients on nocturnal hemodialysis compared with conventional three-times-weekly dialysis [95]. This may be the result of decrements in kidney perfusion arising from enhanced fluid removal, although other causes need to be investigated further.

Caregiver burden — There may be a higher degree of caregiver burden associated with nocturnal hemodialysis compared with conventional three-times-weekly hemodialysis [96].

ROLE FOR NOCTURNAL HEMODIALYSIS — In view of the positive clinical results, acceptance by patients, and favorable financial profile in some jurisdictions, nocturnal home hemodialysis should be considered for patients capable of performing home hemodialysis, and in-center nocturnal hemodialysis should be considered for patients who have access to such programs. Patients with significant metabolic needs including hyperphosphatemia, fluid gains, cardiac dysfunction, resistant hypertension, as well as pregnancy are particularly well suited.

Patients who would prefer night dialysis to improve quality of life and/or pursue daytime employment or vocational rehabilitation should be considered as well.

Nocturnal home hemodialysis along with short daily hemodialysis will hopefully increase the use of home hemodialysis. (See "Choosing home hemodialysis for end-stage kidney disease".)

Obstacles to adoption of nocturnal hemodialysis are unfamiliarity with home hemodialysis, the financial impact of the high frequency of dialysis, and the lack of in-center nocturnal programs in some regions. With most current reimbursement schemes, the dialysis provider does not benefit from the savings realized from the decreased cost of medications, hospitalization, and transportation but is burdened by the increased cost of providing dialysis at increased frequency [18]. Thus, changes in the reimbursement schemes are needed. The barriers to nocturnal hemodialysis are largely similar to the barriers to home hemodialysis in general [97-100]. Efforts in the form of the Kidney Health Initiative and the Advancing American Kidney Health Initiative in the United States will have a positive effect on the adoption of home dialysis in general [101-104].

SUMMARY AND RECOMMENDATIONS

●Outcomes with nocturnal hemodialysis – Nocturnal hemodialysis appears to be associated with benefits compared with conventional hemodialysis regimens. Some of the benefits with the technique have been clearly shown, while others require further analysis.

•Solute clearance – Clearance of urea, phosphate, and beta2-microglobulin are enhanced with nocturnal hemodialysis. (See 'Solute clearance' above.)

•Survival – Studies evaluating patient survival on nocturnal hemodialysis have yielded conflicting results. While several observational studies have shown a possible survival benefit compared with conventional hemodialysis, other studies including one randomized trial have not confirmed these findings. (See 'Survival' above.)

•Quality of life – Limited data suggest that quality of life may be improved, although this has not been confirmed by randomized, controlled trials. (See 'Quality of life' above.)

•Cardiovascular effects – Excellent blood pressure control is achieved by nocturnal hemodialysis, with many patients no longer requiring antihypertensive medications. Increasing evidence also suggests that nocturnal hemodialysis is associated with regression of left ventricular hypertrophy. (See 'Cardiovascular effects' above.)

•Sleep and nutrition – Sleep disturbance is minimal during home nocturnal hemodialysis, and sleep architecture appears to improve. Nocturnal hemodialysis usually allows patients to liberalize their dietary intake. Most patients on nocturnal hemodialysis can be maintained on a free diet, including the unrestricted intake of salt, water, potassium, phosphate, and protein. (See 'Sleep' above and 'Nutrition' above.)

•Cost – Depending upon the consumable/personnel cost ratio in different countries, nocturnal hemodialysis can be less or more expensive than in-center conventional hemodialysis. (See 'Cost' above.)

•Possible negative effects – Possible negative effects of frequent nocturnal hemodialysis include increased vascular access complications associated with the higher dialysis frequency, accelerated decline in residual kidney function, and increased caregiver burden. (See 'Possible negative effects' above.)

●Role for nocturnal hemodialysis – In view of the clinical results, acceptance by patients, and favorable financial profile in some jurisdictions, nocturnal hemodialysis should be considered as an attractive option for patients who have access to centers equipped to deliver nocturnal hemodialysis via either home or in-center programs. Obstacles to adoption of nocturnal hemodialysis are unfamiliarity with home hemodialysis, the financial impact of the high frequency of dialysis, and the lack of in-center nocturnal programs in some regions. (See 'Role for nocturnal hemodialysis' above.)

ACKNOWLEDGMENT — We are saddened by the death of Andreas Pierratos, MD, FRCPC, who passed away in November 2022. UpToDate acknowledges Dr. Pierratos's past work as an author for this topic.