Short daily or nocturnal hemodialysis improves nutrition better than conventional hemodialysis.
Despite advances in conventional thrice-weekly hemodialysis (HD), high morbidity rates and malnutrition remain ongoing concerns. With evidence accumulating regarding the potential health benefits of short daily or nocturnal HD, these treatment modalities are receiving new attention.
The availability of newer portable home HD equipment and an increase in the number of in-center programs offering nocturnal dialysis are making these options more accessible to patients.
The beneficial nutritional impact of short daily HD (2-2.5 hours, six times per week for a mean of 39 months) was demonstrated in a study of 17 patients who switched from conventional dialysis (four- to five-hour treatments thrice weekly for a mean of 9.6 years). The researchers observed significant improvements in nutrition-related parameters, including higher protein and calorie intakes as reflected by improved serum albumin and body weight (Semin Dial. 2004;17:104-108).
Fluid status was better managed, with average interdialytic weight gains (IDWGs) about half those seen with conventional dialysis. Serum phosphorus decreased and patients required fewer phosphate binders. The authors noted that “nutritional improvement appeared rapidly and was sustained throughout the study” and concluded that “short daily hemodialysis appears to be a suitable method to improve nutritional status in dialysis patients.”
Quality of life (QOL) may also impact nutrition, and frequent nocturnal HD has been examined for possible benefits in this area. A six-month randomized controlled trial involving 52 patients (JAMA. 2007;298:1291-1299) compared frequent nocturnal HD (six hours or more, five to six nights a week) with conventional HD in terms of their effects on left ventricular mass and QOL.
Regarding QOL, the authors reported that nocturnal HD yielded statistically significant improvement in the “effects of kidney disease” and “burden of kidney disease” domains. Left ventricular mass, the primary outcome, was significantly better for this group, along with a decreased need for antihypertensive medication.
The investigators also monitored mineral metabolism and found that, compared with conventional HD, “nocturnal hemodialysis was more effective at lowering serum phosphorus, calcium-phosphate product, and parathyroid hormone levels.” Moreover, “a reduction or discontinuation of oral phosphate binders occurred in 19 of 26 patients,” compared with only three of 25 patients on conventional HD.
A recent review provides additional evidence of improved phosphorus balance with daily dialysis (Semin Dial. 2007;20:342-345). Nocturnal HD appears to be more effective in phosphorus removal than short daily dialysis since phosphorus “equilibrates slowly from the intracellular pools to the extracellular pools during hemodialysis.”
Not surprisingly, the contrast in efficiency of phosphorus removal is greatest when nocturnal HD is compared with conventional dialysis. In support of this, the author cited results of a study (Kidney Int. 1998;1399-1404) indicating that “total weekly phosphate removal with nocturnal hemodialysis was more than twice that removed by conventional hemodialysis with significantly lower average serum phosphorus levels in the nocturnal hemodialysis group.”
For people with stage 5 CKD, maintaining fluid balance is a challenge, especially with conventional HD. An 18-week study that enrolled 32 patients compared center-based vs. home-based daily HD (2.3-3.2 hours, six days per week) with respect to safety and clinical outcomes, specifically BP and related medications, and IDWG (Hemodial Int. 2007;11:468-477).
The study demonstrated improved fluid control as reflected by lower mid-week IDWG compared with previous conventional HD, as well as significantly improved BP and decreased use of antihypertensive medications. Based on the experience of study subjects, the authors concluded that daily home HD “is a safe and viable option for select end-stage renal disease patients capable of home/self-care dialysis.”
To assist patients who may be considering home HD as a treatment option, the National Institute of Diabetes and Digestive and Kidney Diseases has developed an educational tool called “Home Hemodialysis”. The publication details practical aspects of home HD, along with an explanation of potential risks, benefits, and possible barriers. “Points to remember” are summarized as:
- New, smaller dialysis machines are making home HD more practical;
- Training for home HD takes three to eight weeks;
- Patients performing home HD can choose between shorter daily treatments or longer nightly treatments;
- Patients who perform home HD say it improves their quality of life;
- Patients should talk with their insurance provider or clinic social worker about whether payments for daily home HD will be covered.
Ms. Blair is a renal dietitian working on her doctorate in clinical nutrition at the University of Medicine and Dentistry of New Jersey in location in Stratford, N.J.