Comparison of citrate anticoagulation strategies in hemodialysis patients at high risk of bleeding: a prospective observational cohort study.

Optimal regional citrate anticoagulation (RCA) for hemodialysis (HD) in high-bleeding-risk patients remains undefined. This prospective observational cohort study included 195 high-bleeding-risk patients (481 HD sessions) allocated to three RCA groups: RCA-one (prefilter citrate only, 141 patients/337 sessions), RCA-two (pre- and post-filter citrate, 51 patients/133 sessions), and RCA+saline (prefilter citrate + post-filter saline, 3 patients/11 sessions). Primary outcome: circuit survival time; secondary outcomes: complete dialysis rate, clotting scores, and adverse events. RCA-two had the highest complete dialysis rate (99.7% vs. 97.0% [RCA-one], 97.7% [RCA+saline]; p = .037) and lowest venous expansion chamber serious clotting (score = 3: 5.4% vs. 16.9%, 30.0%; p < .001). Non-severe venous clotting (score < 3) was highest in RCA-two (94.6% vs. 83.1%, 70%; p < .001), with no intergroup differences in dialyzer clotting (score < 3: 96.1% vs. 95.3%, 90%; p = .83). RCA-two had the lowest adverse event rate (1.8% vs. 10.8%, 11.1%; p = .001), including less hypotension (0.9% vs. 7.6%, 2.0%; p = .023) and no muscle cramps. Venous pretreatment calcium in RCA-two decreased at 2 h (p = .03) without serious electrolyte/acid-base imbalances. Circuit survival time did not differ among groups (p > .05). RCA is safe and effective for high-bleeding-risk HD patients. RCA-two (pre- and post-filter citrate) offers advantages in venous anticoagulation and safety but requires confirmation in large randomized trials.