Hypotension is a common side effect of hemodialysis. 1 Intradialytic hypotension is a common adverse event that occurs in 20% to 50% of all dialysis treatments. 2,3 Dialysis hypotension usually presents in 1 of the 2 ways: as episodic hypotension (symptomatic hypotension), in which a sharp fall in blood pressure (usually late in dialysis) accompanied by signs and symptoms of hypotension are noted, and chronic persistent hypotension, in which systolic blood pressure is less than 90 to 100 mmHg at the onset of dialysis. Chronic persistent hypotension is estimated to occur in 3% to 5% of the dialysis population, whereas episodic hypotension occurs in between 15% and 25% of all dialysis encounters. 4 Chronic persistent hypotension is characterized by high circulating angiotensin II levels and maximal pre-dialysis vasoconstriction. 4,5 Symptomatic hypotension has multiple etiologies. Several studies have shown that a fall in plasma osmolality as ultrafi ltration proceeds compounds extracellular volume depletion because fl uid moves intracellularly. 6,7,8 This has led to the routine use of a higher sodium dialysate concentration with reported favorable outcomes. 9,10 Both of these conditions are therapeutic challenges because ultrafi ltration requirements are diffi cult to achieve in the context of hemodynamic instability. Patients who are frequently hypotensive often feel unwell and spend the interdialytic period "recovering" from the preceding dialysis. 11 Symptomatic hypotension can occur when the so-called dry weight of the patient is not attained. Dry weight cannot be determined exactly in hemodialysis. In practice, the choice of dry weight is most often based solely on clinical criteria. 12 Dialysis hypotension has a multifactorial etiology, including such disparate causes as autonomic dysfunction, 13 decreased plasma osmolality, 6,14,15 a decrease in extracellular fl uid volume with inadequate plasma, 5 decreased cardiac reserve, 16,17 impaired venous compliance, 18 and high plasma nitric oxide levels. 19 If there are no other reasons such as cardiac dysfunction or insuffi ciency of the autonomic nervous system, it is induced when ultrafi ltration exceeds refi lling of the intravascular compartment. 16,20 Intradialytic hypotension associated with declining plasma osmolality due to diffusion contributes to complications that decrease patient's well-being during dialysis. 21,22 Many strategies have been devised to decrease osmolality change through intravenous mannitol, 7 gradient/ramping sodium dialysate, 15,21,23-25 ultrafi ltration profi ling, 26,27 and used with gradient sodium and gradient ultrafi ltration. 7,9,22,28,29 It has been shown that limiting the reduction in plasma osmolality during hemodialysis by selecting a higher sodium concentration of the dialysate improves OBJECTIVE: This study aimed to investigate the effects of dialysate sodium profi ling and gradient ultrafi ltration on hypotension during hemodialysis.METHODS: In this study, a single-blinded, crossover design of 4 different dialysis proto...