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. 2019 Jan 16;2019(1):CD011204. doi: 10.1002/14651858.CD011204.pub2

Liu 2016.

Methods

  • Study design: parallel, open‐label RCT

  • Duration of study: not reported

  • Duration of follow‐up: 12 months
Participants

  • Country: China

  • Setting: single centre

  • Prevalent patients on HD (age criteria not reported) with a time on dialysis of > 6 months at enrolment, treated previously with standard dialysate [Na+] 138 mM, hypertensive (defined as a mean ambulatory BP of > 135/85 and < 160/100), on stable antihypertensive medication (no adjustments in the month prior to enrolment), left ventricular ejection fraction > 40%, serum albumin > 30 g/L, average predialysis serum [Na+] over the last 12 months > 138 mM

  • Number (randomised/analysed): treatment group (32/28); control group (32/29)

  • Mean age ± SD (years): treatment group (59 ± 10); control group (57 ± 11)

  • Sex (M/F): treatment group (16/12); control group (15/14)

  • Mean time on dialysis; IQR (months): treatment group (61; 8 to 91); control group (68; 13 to 108)

  • Measured characteristics and comorbidities otherwise balanced

  • Exclusion criteria: stroke, MI, or limb ischaemia in the previous 6 months; residual daily urine output > 200 mL/d; hypotension‐prone (not otherwise defined)
Interventions HD regimen

  • 3 times/week, 4 hours/session

  • Low‐flux polysulfone dialyser

  • Bicarbonate buffer

  • QB 200 to 300 mL/min, QD 500 mL/min


Treatment group

  • Dialysate [Na+]: 136 mM


Control group

  • Dialysate [Na+] 138 mM


Duration

  • 12 months (4524 sessions in control group, 4368 in treatment group)
Outcomes

  • Outcomes were assessed at baseline and 12 months, with the exception of predialysis BP, IDWG, cramps and intradialytic hypotension which were assessed over the entire period of observation:

    • Interdialytic ambulatory SBP (midweek, 44 hours)

    • Interdialytic ambulatory DBP (midweek, 44 hour)

    • Home SBP (3 times/day, 7 days/week, one week/month)

    • Home DBP (3 times/day, 7 days/week, one week/month)

    • Intradialytic hypotension ‐ "decrease in systolic BP by 20 mm Hg or a decrease in mean arterial pressure by 10 mm Hg associated with clinical events and need for nursing interventions"

    • Intradialytic cramps ‐ "symptoms that required emergency medical attention or saline infusion without a reduction in BP"

    • IDWG

    • Predialysis serum [Na+] (monthly)

    • Postdialysis serum [Na+] (monthly)

    • Types and numbers and doses of antihypertensives

    • Postdialysis extracellular fluid volume status: multipolar bioimpedance analysis (monthly)

    • Dietary salt intake ‐ 3 day food diary (monthly)

    • Pulse wave velocity (single operator, blinded to allocation)

    • Pulse wave velocity (single operator, blinded to allocation)

    • LVMI, EDD, ESD, SWT, PWT by echocardiography (single operator, blinded to allocation)

    • Other biochemical measurements
Notes

  • Funding source: Beijing High‐Level Talents in Health Care System Funding 2014‐3‐021.

  • Postdialysis extracellular fluid volume status not reported
Risk of bias
Bias Authors' judgement Support for judgement
Random sequence generation (selection bias) Low risk Randomisation clearly stated in published article, along with mechanism of randomisation
Allocation concealment (selection bias) Unclear risk Insufficient information to permit judgement
Blinding of participants and personnel (performance bias) 
 All outcomes High risk Open‐label
Blinding of outcome assessment (detection bias) 
 All outcomes Low risk Blinding included outcomes assessors
Incomplete outcome data (attrition bias) 
 All outcomes Unclear risk 7/64 patients were removed from the study, 5 because of death, 2 because of transplantation, and 1 because of loss to follow‐up. These serious adverse events are not otherwise reported. The study is not analysed as intention to treat, and data from those who dropped out is omitted from analysis. The reasons for dropout might be related to the treatment, and there is a risk of attrition bias. In addition, dropouts may have affected balance of patient characteristics by arm, although they are only a small number
Selective reporting (reporting bias) Low risk The study appears to be free of reporting bias
Other bias High risk PWV and echocardiography performed by a single, albeit blinded assessor. There is potential for ascertainment bias, and also potential for drift with respect to the echocardiography, which was assessed 12 months apart