Anemia increases risk in colorectal surgery

Does Preoperative Anemia Adversely Affect Colon and Rectal Surgery Outcomes?

Leichtle SW, Mouawad NJ, Lampman R, Singal B, Cleary RK
J Am Coll Surg. 2011;212:187-194
Summary

The authors obtained information from the National Surgical Quality Improvement Program database on 23,348 patients treated in 251 hospitals to determine whether preoperative anemia is a risk factor for postoperative adverse events, including complications, hospital length of stay, and death. Approximately half of the study group had preoperative anemia. When adjusted for multiple variables (ie, age, body mass index, race, sex, and preexisting disease), severe preoperative anemia increased the risk for any adverse outcome by approximately 80% (odds ratio = 1.83, 95% confidence interval = 1.05-3.2); mild anemia increased the risk by about 50% (odds ratio = 1.49, 95% confidence interval = 1.2-1.9).
Viewpoint

This large study confirms that even after adjusting for many potentially confounding variables, anemia confers a significant risk for unfavorable outcomes after colorectal surgery. It is somewhat surprising that excess risk did not seem to change much with increased levels of anemia. This study did not find a critical level of anemia that would alert the surgeon to a potentially adverse patient outcome. Still to be answered is the important question: Should patients with anemia receive preoperative therapy designed to improve their anemia?

Abstract