This proposal will measure the effects of mannitol administration versus placebo in hypotensive-prone, adult, maintenance hemodialysis patients with respect to changes in patient symptoms and blood pressure stability.

A randomized crossover trial of hypertonic mannitol vs. placebo in IDH-prone participants will be performed over a 4-week period to determine the effect on:

• Patient symptoms
• The magnitude of intra-dialytic hypotension

The hypothesis to be tested is that the use of hypertonic mannitol will result in fewer adverse symptoms and less decline in intra-dialytic BP, compared with the use of placebo.

Inclusion Criteria:

• Maintenance HD (>90 days)
• Age ≥18y
• Thrice-weekly HD
• IDH-prone (defined as nadir intra-dialytic SBP <100 mmHg in ≥30% of sessions in the prior 4 weeks)
• Hematocrit>21%
• Written informed consent

Exclusion Criteria:

• Acute myocardial infarction or stroke within one month
• Pre-HD serum potassium >6.5 mmol/L in last 4 weeks
• Pregnancy
• Institutionalized individuals
• Life expectancy <2 months
• Planned renal transplant within 2 months
• Active enrollment in another interventional trial
• Known allergy to mannitol

Modest sized single-center study with no plan to share individual participant data