Blackwell Publishing AsiaMelbourne, AustraliaNEPNephrology1320-5358© 2006 The Authors; Journal compilation © 2006 Asian Pacific Society of Nephrology2006115413418Original ArticleTwo schedules of nocturnal home haemodialysisK Mahadevan et al.
NEPHROLOGY 2006; 11, 413–418
doi:10.1111/j.1440-1797.2006.00670.x
Original Article
Comparison of biochemical, haematological and volume parameters in two treatment schedules of nocturnal home haemodialysis KUMAR MAHADEVAN,1 REBECCA PELLICANO,2 ALISTAIR REID,1 PETER KERR,2 KEVAN POLKINGHORNE2 and JOHN AGAR1 1
Department of Nephrology, Geelong Hospital, Geelong, and 2Department of Nephrology, Monash Medical Centre, Melbourne, Victoria, Australia SUMMARY: Background: The biochemical, haemodynamic, clinical and nutritional benefits of nocturnal home haemodialysis (NHHD) compared with 4 h, three times per week conventional haemodialysis are well known and accrue by increasing dialysis time and frequency either for 8 h alternate night per week (NHHD3.5) or for 8 h six nights per week (NHHD6). However, there are little data comparing NHHD3.5 with NHHD6. Method and Results: Thirteen patients on NHHD6 were compared with 21 patients on NHHD3.5, all with similar demographic profiles. Pre- and post-dialysis phosphate (PO4) control was ideal between the groups. However, all NHHD6 needed PO4 supplementation compared with 4/21 (19%) NHHD3.5. In the present study, 8/21 (38%) NHHD3.5 needed PO4 binders whereas none was required with NHHD6. The pre-haemoglobin (Hb) 122.8 g/L (NHHD6) versus 124.9 g/L (NHHD3.5) and the pre-albumin 38.31 g/L (NHHD6) versus 37.71 g/L (NHHD3.5) were not significantly different. NHHD6 had significantly lower pre-blood urea and creatinine (10.16 vs 19.54 mmol/L and 437.0 vs 812.3 µmol/L, respectively). Less interdialytic urea and creatinine fluctuation were also noted in NHHD6. Of major significance was the significantly lower ultra filtration rate and intradialytic weight gains (mean ± SEM) of NHHD6 (249 ± 76 mL/h and 2.0 ± 0.65 kg) versus NHHD3.5 (425 ± 168 mL/h and 2.9 ± 1.2 kg). Conclusion: The authors conclude that NHHD6 offers the optimum biochemical, volume and clinical outcome, but NHHD3.5 has additional appeal to providers seeking home-based therapy cost advantages and consumable expenditure control. A flexible dialysis programme should offer all the time and frequency options of NHHD but in particular, should support NHHD at a frequency sympathetic to the clinical rehabilitation and lifestyle aspirations of individual patients. KEY WORDS: comparison, differing frequency, haemodialysis, home, nocturnal.
Conventional haemodialysis (CHD) is the most widely used modality of renal replacement therapy. Typically, it implies a three times weekly dialysis schedule with between 3 and 5 h dialysis each session, either in-centre or at a satellite dialysis centre. As a result of the long interdialytic interval and the rapid fluid removal needed during each dialysis session, the side-effects of CHD are numerous and can be severe. Consequently, morbidity and mortality rates remain unacceptably high for end-stage renal disease patients on CHD with cardiovascular disease being the most common Correspondence: Dr Kumar Mahadevan, Department of Renal Medicine, Queen Elizabeth Hospital, 11 Woodville Road, Woodville, Adelaide, SA 5000, Australia. Email:
[email protected] Accepted for publication 23 June 2006. © 2006 The Authors Journal compilation © 2006 Asian Pacific Society of Nephrology
cause of death.1 As a result, there has been renewed interest in the improved outcomes that have been reported with more intensive dialysis regimens. Nocturnal home haemodialysis (NHHD) as first described by Uldall et al.2 and Pierratos et al.,3 allows for an increase treatment duration and, potentially, an increase in sessional frequency of haemodialysis. The majority of studies thus far have reported NHHD where dialysis has been performed for 8 h, six nights per week. This reduces the interval between dialysis treatments to 16 h compared with the usual 44 h (midweek) or 68 h (weekend) commonly associated with 4 h per treatment CHD. This reduction in the interdialytic interval has been reported to virtually eliminate the frequently encountered conventional dialysisrelated problems of hypotension, nausea, vomiting, cramps, lethargy, post-dialysis headaches and prolonged recovery time. NHHD has not only been shown to be safe4,5 but also to result in improved dialysis adequacy, better haemody-
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namic control, improved nutrition, quality of life and biochemical parameters and enhanced rehabilitation when compared with CHD.6–8 Less requirement for antihypertensive medications has been documented9–11 as has an approximately 50% reduction in erythropoietin dose in NHHD patients.12 Furthermore, given the longer dialysis duration of NHHD, the removal of time-dependent solutes such as phosphate is increased and larger molecular weight, slowdiffusion substances like homocysteine and β2-microglobulin is more effectively accomplished when using high flux membranes. Although the advantage of longer dialysis time of NHHD appears unquestionable, there remains debate regarding the ideal or optimum frequency of the longer treatment sessions. Although earlier work favoured nightly therapy, studies comparing the comparative costs of NHHD six nights per week with CHD three times per week demonstrated that NHHD was the cheaper modality.13–15 This was despite the one-on-one equipment requirements and a doubled consumable expenditure. Interest subsequently intensified in an even more cost-effective NHHD regimen, not at the original frequency of six nights/week but using an alternate night regimen where treatment duration was sustained but the treatment frequency was diminished from 12 to seven nights/fortnight (3.5 nights/week) yet still achieving the abolition of the ‘long break’ of CHD. Alternate night NHHD soon formed an increasingly popular subset of NHHD patients yet, to date, no studies have compared the different treatment schedules of NHHD. The present study has aimed to compare the various biochemical parameters between two groups of patients with end-stage renal disease on different NHHD treatment schedules: (i) a schedule of eight dialysis hours on six nights per week (NHHD6) and (ii) a schedule of eight dialysis hours on alternate nights (NHHD3.5). METHOD Subjects A retrospective cohort study was conducted comparing 13 patients (mean age 52 years) from the six nights/week (NHHD6) programme at the Geelong Hospital with 21 patients (mean age 45 years) from the alternate night (NHHD3.5) programme at Monash Medical Centre. Only patients stable on NHHD for 3 months or longer were included. All patients in both groups dialysed for a mean of 8 h/night, and all patients dialysed in a supine posture. The initial patient selection for NHHD at both centres was based mainly on individual patient preference.
Study design The study measured various biochemical parameters prior to and post dialysis including serum urea (Ur), creatinine (Cr), corrected calcium (Ca) and phosphate (PO4). Haemoglobin (Hb), albumin (Alb) and parathyroid hormone (PTH) levels were only taken prior to dialysis. Total homocysteine (Hcy) levels were taken post dialysis. Both centres recorded these above measurements from serum collected between 3 and 6 months after patients had commenced NHHD as most patients from Monash Medical Centre had only been on NHHD for less than a
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year. Baseline PTH levels were also collected prior to conversion from CHD to NHHD in the two groups. Patients on NHHD collected their own specimens. Pre-dialysis bloods were taken from the arterial line prior to introduction of any saline or heparin. Post-dialysis bloods were taken from the arterial line after the pump was stopped but prior to reinfusion. The use of blood pressure medications, calcitriol (Rocaltrol, Roche Diagnostics P/L, Castle Hill, New South Wales, Australia) and phosphate binders comprising of either calcium carbonate (Caltrate, Whitehall Consumer Healthcare P/L, Baulkham Hills, New South Wales, Australia) and/or aluminium hydroxide (Alutabs, 3M Pharmaceuticals P/L, Thornleigh, New South Wales, Australia), were compared between the two groups. Data were also collected and compared for erythropoietin (EPO) dose (Eprex, Janssen-Cilag P/L, North Ryde, New South Wales, Australia) and Fleet enema packs containing sodium phosphate monobasic 2.4 g and dibasic 0.9 g per 5 mL (C.B Fleet Co., Braeside, Victoria, Australia) for phosphate supplementation. Finally, volume parameters such as the average ultrafiltration rate (UFR) per session and interdialysis weight gain were also compared between the groups. Both groups had similar dialysis prescriptions with a dialysate sodium concentration of 140 mmol/L, a bicarbonate concentration 32 mmol/L, a calcium concentration 1.5 mmol/L and a dextrose concentration 5 mmol/L. The dialysate flow rate was 300 mL/min for both groups. Blood flow rates were 250 mL/min (NHHD6) and 225 mL/min (NHHD3.5). The NHHD6 group used low flux polysulphone Fresenius HPS dialysers (Fresenius Medical Care (Australia), Milsons Point, New South Wales, Australia). The effective surface area of these dialysers ranged from 1.6 m2 (F7 HPS) to 1.8 m2 (F8 HPS) as determined by the treating physician for each individual patient. The NHHD3.5 group only used high flux polysulphone (Fresenius) dialysers with a surface area of 1.8 m2. Both centres had fairly similar iron replacement protocols with the administration of 100 mg of iron in the form of iron polymaltose compound (Ferrosig, Sigma Pharmacuticals P/L, Clayton, Victoria, Australia) at weekly, fortnightly or monthly intervals as determined by serum ferritin levels of less than 300 µg/L, 301–500 µg/L or 501–650 µg/L, respectively. Serum ferritin levels were measured at 2 monthly intervals and iron administration was held if serum ferritin was greater than 650 µg/L. Vitamin C supplementation in the form of ascorbic acid was only used in the NHHD3.5 group if serum ferritin was greater than 650 µg/L and transferrin saturation less than 20%. Patients on NHHD6 were not commonly placed on vitamin C supplementation. Pre-dialysis circuit water treatment consisted of two in series 10 inch filters (one a 5 µm particle filter and the other a 5 µm carbon filter) prior to the reverse osmosis unit (Gambro WRO, Baulkham Hills Au, New South Wales, Australia). In areas of known high chlorine and/or chloramines exposure, an extra carbon tank was also installed at the patient’s home.
Statistical analysis Biochemical parameters were analysed using unpaired t-tests (twotailed) for parametric data and Mann–Whitney tests for non-parametric data with Prism 4 (GraphPad Software Inc., San Diego, USA). A result was reported as statistically significant if P < 0.05. Results are presented as mean ± standard deviation or median (range).
RESULTS Baseline characteristics of the two groups are presented in Table 1. Although the Geelong NHHD patients were slightly older, the two groups were otherwise comparable in terms of primary renal disease, comorbidities, body mass index and length of time on renal replacement therapy. © 2006 The Authors Journal compilation © 2006 Asian Pacific Society of Nephrology
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Two schedules of nocturnal home haemodialysis
Mean pre-urea levels (10.16 ± 2.08 mmol/L) and post-urea levels (2.32 ± 1.3 mmol/L) in the NHHD6 group were significantly lower than mean pre-urea levels (19.54 ± 7.06 mmol/L) and post-urea levels (4.35 ± 2.10 mmol/L) in Table 1 Comparison of baseline characteristics between NHHD6 and NHHD3.5 Characteristics Age (years) Gender (male : female) Aetiology of renal disease Diabetes GN APCKD Other Comorbidities Diabetes IHD Smoking Body mass index Length of RRT (months) Previous transplantation (n) Parathyroidectomy (n)
NHHD6 (n = 13) 52 (25–70) 13:0
NHHD3.5 (n = 21) 45 (28–64) 18:3
2 5 1 5
1 15 3 2
2 3 1 26.4 (19.8–35.4) 29 (8–312)
1 3 1 29.9 (18.4–39.4) 33 (3–290)
5
6
3
5
APCKD, adult polycystic kidney disease; GN, glomerulonephritis; IHD, ischaemic heart disease; NHHD3.5, nocturnal home haemodialysis alternate night per week; NHHD6, nocturnal home haemodialysis six nights per week; RRT, renal replacement therapy.
the NHHD3.5 group (P < 0.001 and P = 0.0031, respectively). Similarly, mean pre-Cr levels (437.0 ± 73.6 µmol/ L) and post-Cr levels (139.8 ± 50.26 µmol/L) in the NHHD6 group were significantly lower than mean pre-Cr levels (812.3 ± 203.7 µmol/L) and post-Cr levels (274.6 ± 83.53 µmol/L) in the NHHD3.5 group (P < 0.001 for both) (Table 2). Mean pre-Ca levels in the NHHD6 group (2.57 ± 0.14 mmol/L) were statistically higher than mean pre-Ca in the NHHD3.5 group (2.36 ± 0.19 mmol/L); P < 0.002. No significant difference was found for post-Ca levels (2.60 ± 0.10 NHHD6 vs 2.51 ± 0.15 mmol/L NHHD3.5; P = 0.06; Table 2). Although the NHHD6 group had slightly lower mean pre-PO4 levels (1.64 ± 0.36 mmol/ L) than NHHD3.5 group (1.88 ± 0.55 mmol/L), this difference was not statistically significant (P = 0.18). Similarly, the difference between mean post-PO4 levels (0.86 ± 0.16 NHHD6 vs 0.88 ± 0.19 mmol/L NHHD3.5) was not significant (P = 0.72; Table 2). None of the NHHD6 group required the use of phosphate binders whereas 8/21 (38%) in the NHHD3.5 group still required phosphate binder medication (Table 3). Mann–Whitney test for independent samples found no statistically significant difference between the groups for PTH prior to starting NHHD (14.3 pmol/L (0.8–132.0) for NHHD6 vs 31.10 pmol/L (4.7–102.0) for NHHD3.5). After 3 months of NHHD, the NHHD6 group (12.8 pmol/L (0.9– 96.8)) had significantly lower median PTH levels compared with the NHHD3.5 group (30.7 pmol/L (4.8–192.0); P = 0.006; Table 2). Calcitriol use was higher in the NHHD6 group compared with the NHHD3.5 group (11/13 (84%) vs 11/21 (52%); Table 3).
Table 2 Comparison of biochemical and volume parameters between NHHD6 and NHHD3.5 Parameters Urea (mmol/L) Pre Post Creatinine (µmol/L) Pre Post Phosphate (mmol/L) Pre Post Calcium (mmol/L) Pre Post PTH (pmol/L) Pre-NHHD 3/12 NHHD† Haemoglobin (g/L) Albumin (g/L) Homocysteine (mmol/L) UFR (mL/min) Weight gain (kg)
NHHD6
NHHD3.5
P-value
10.16 ± 2.08 2.32 ± 1.13
19.54 ± 7.06 4.35 ± 2.10
