The Effect of Preoperative Anemia on the Odds of Allogeneic Blood Transfusion and Patient Outcomes in Colorectal Neoplasm Patients.

Background: The optimal preoperative hemoglobin (Hb) value of colorectal neoplasm patients is still being debated. This study aimed at determining the effect of preoperative anemia on patient outcomes and allogeneic blood transfusion (ABT).

Methods: This retrospective cohort study enrolled colorectal neoplasm patients, that underwent surgery, from January 1, 2012, to December 31, 2021. The primary outcomes were the association between anemia and average length of stay (ALOS) and the odds of ABT. The secondary outcomes were the risk factors of the primary outcomes. Univariate and multivariate logistic regression analyses were applied to identify the association and risk factors.

Results: A total of 14,352 inpatients were included in the study, of whom 3,035 experienced (21.15%) mild anemia, 1,500 (10.45%) moderate anemia, and 104 (0.72%) severe anemia. Overall, 1,418 (9.88%) patients received ABT during the hospitalization, and 546 (3.80%) patients received perioperative ABT. In the multivariate logistic regression analysis, compared with the no anemic group, the odds ratio [OR] of ABT during the hospitalization for patients with mild/moderate/severe anemia were 5.915, 95% confidence interval [CI]: 4.717 - 7.418; 104.777, 95% CI: 84.345 - 130.160; and 13,361.442, 95% CI: 816.004 - 218,783.511, respectively, and the OR of periopera¬tive ABT were 4.332, 95% CI: 3.245 - 5.785; 27.492, 95% CI: 20.974 - 36.037; and 20.912, 95% CI: 11.832 - 36.959, respectively. Besides, the ALOS was longer, β were 0.619, 95% CI: 0.346 - 0.892; 1.188, 95% CI: 0.821 - 1.554; and 1.395, 95% CI: 0.107 - 2.684, respectively.

Conclusions: Anemia is a common phenomenon in colorectal neoplasm surgical patients, and even mild anemia could be a deleterious predictor on the outcomes of colorectal neoplasm patients that underwent surgery.