Relative decrease in hemoglobin and outcomes in patients undergoing kidney transplantation surgery: A retrospective cohort study.

Abstract Background Recent surgical literature suggests that a relative decrease in hemoglobin (ΔHb) is predictive of adverse outcomes regardless of the absolute level. We aimed to examine the association between perioperative ΔHb and kidney transplantation (KT) outcomes. Methods This was a retrospective cohort study of transplant recipients, where ΔHb =  [ Hb 0 –  Hb 1 Hb 0 ] x  100 (Hb0 = hemoglobin pre-KT and Hb1 = lowest hemoglobin 24-h post-KT). The main outcome of interest was immediate graft function (IGF). Results Of the 899 eligible patients, 38% experienced IGF, and ΔHb was associated with 36% lower odds of IGF. Also, ΔHb was associated with higher all-cause graft failure and longer length of stay but not death-censored graft failure or mortality. ΔHb ≥30% was the threshold beyond which the odds of IGF were significantly lower even if Hb1 was ≥7  g/dL. Conclusion ΔHb is associated with inferior outcomes independent of Hb1; whether it can be used to guide transfusion practices should be explored.