Hypertonic Mannitol for the Prevention of Intradialytic Hypotension: A Randomized Controlled Trial

Rationale & Objective: Intradialytic hypotension (IDH) is a common complication at the initiation of hemodialysis (HD) therapy, is associated with greater mortality, and may be related to relatively rapid shifts in plasma osmolality. This study sought to evaluate the effect of an intervention to minimize intradialytic changes in plasma osmolality on the occurrence of IDH. Study Design: Double-blind, single-center, randomized, controlled trial. Setting & Participants: Individuals requiring initiation of HD for acute or chronic kidney disease. Intervention: Mannitol, 0.25 g/kg/h, versus a similar volume of 0.9% saline solution during the first 3 HD sessions. Outcomes: The primary end point was average decline in systolic blood pressure (SBP). The secondary end point was the proportion of total sessions complicated by IDH (defined as a decrease >= 20 mm Hg from the pre-HD SBP). Exploratory end points included biomarkers of cardiac and kidney injury. Results: 52 patients were randomly assigned and contributed to 156 study visits. There were no significant differences in average SBP decline between the mannitol and placebo groups (15 +/- 11 vs 19 +/- 16 mm Hg; P = 0.3). The proportion of total sessions complicated by IDH was lower in the mannitol group compared to placebo (25% vs 43%), with a nominally lower risk for developing an episode of IDH (OR, 0.38; 95% CI, 0.14-1.00), though this finding was of borderline statistical significance (P = 0.05). There were no consistent differences in cardiac and kidney injury biomarker levels between treatment groups. Limitations: Modest sample size and number of events. Conclusions: In this pilot randomized controlled trial studying patients requiring initiation of HD, we found no difference in absolute SBP decline between those who received mannitol and those who received saline solution. However, there were fewer overall IDH events and a nominally lower risk for dialysis sessions being complicated by IDH in the mannitol group. A larger multicenter randomized controlled trial is warranted.