Nocturnal versus conventional haemodialysis: some current issues

The burden of kidney disease continues to grow in the United States, and more patients are faced with the need for dialysis [1]. While haemodialysis is a life-saving form of renal replacement therapy, the long-term outlook for patients on the conventional dialysis regimen of 4 h per session three times per week is grim: mortality four times higher than the general population for dialysis patients under 30 and six times higher than the general population for dialysis patients over 65 [2]. The number of patients on home haemodialysis—both conventional haemodialysis (CHD) and nocturnal haemodialysis (NHD)—represents a small fraction of the end-stage renal disease population (ESRD) in the USA and Canada, ∼1500 in 2003, <0.4% of all dialysis patients in the USA [3]. A survey of dialysis machine manufacturers in 2007 estimated that ∼1% of ESRD patients in the USA were doing home dialysis [4]. Home haemodialysis enjoyed early success in the USA with ∼40% of all dialysis patients treated at home at one point [5]. Scribner and colleagues carried out the first nocturnal dialysis in Seattle in the 1960s, using a pumpless plate dialyser [6]. De Palma and colleagues undertook the earliest daily dialysis with a reusable coil dialyser and blood pump [7]. But their early experiment in daily and nocturnal dialysis failed because ‘economic considerations—not quality machinery and ergonomics—came first’ [4]. Others attributed the decline in home haemodialysis and NHD to the advent of continuous ambulatory peritoneal dialysis in the 1970s, improvements in cadaveric transplant survival with the advent of cyclosporine in the 1980s and increased use of living donor kidneys in the 1990s [3]. The USA initially funded home haemodialysis programmes to counter growing costs of in-centre dialysis, but home dialysis fell further out of popularity with passage of amendments to the Social Security act on dialysis payment in 1972 since in-centre dialysis was able to deliver minimum adequacy with three sessions per week [8]. Home NHD is now a little used modality. According to data from the US Renal Data System, only 0.2% of the incident ESRD patients in 2004 started on home haemodialysis of any sort. Of the 472 099 prevalent patients, only 0.4% were on home haemodialysis [9]. In 2005, 428 of 104 018 incident dialysis patients started on home haemodialysis, and 2105 of 340 057 prevalent dialysis patients were on home haemodialysis. In the USA, home haemodialysis patients are less likely to be African American and Hispanic than in-centre dialysis patients [10]. A survey of all known daily dialysis programmes in the USA found 13 centres in North America performing daily NHD as of January 2001, caring for 115 patients [11]. The International Quotidian Dialysis Registry in Ontario recorded 229 patients in 2007, up from 199 in 2006 [12]. Yet data have accumulated showing advantages to more frequent daily or nocturnal dialysis. Based on his experiences observing patients in the intensive care unit [13], Robert Uldall in Toronto initiated a 2-year pilot study with a grant from the government of Ontario to evaluate what he called simplified nocturnal home haemodialysis [14]. He reasoned that frequent long dialysis sessions produced fewer symptoms than short intermittent treatments; at-home dialysis was less expensive than in-centre dialysis; nocturnal dialysis was less disruptive than daytime dialysis. The programme started enrolling the first of 36 patients in 1994. The 30 patients enrolled at 5 years showed improvements in blood pressure, mineral metabolism and cognitive functioning. There was no difference in haemoglobin levels or erythropoietin use [15]. By 2003, the group had trained 90 patients and was dialysing 48 patients nightly and 5 every other night for a total experience of 230 patient-years [16].