1477. Analysis of Transfusion Requirement Rates by Common Elective Spine Surgery Cases Adjusted for Operative Time and Pre-Operative Anemia

Authors: Yaroslav Gelfand, MD; Jonathan Nakhla, MD; Rafael De la Garza, MD; David Kramer, MD; Merritt Kinon, MD; Reza Yassari, MD (Bronx, NY)

Introduction: Perioperative blood loss and transfusions are linked to increased length of hospital stay and perioperative complications. We conducted a retrospective review of a largest patient sample to analyze the risk of transfusions associated with elective spine procedures. Methods: Patients undergoing elective spine surgery were identified in the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database from 2006 to 2016. Those with disseminated cancer, spine metastasis, and epidural abscess were excluded from the analysis. Thirteen distinct groups were developed based on spinal procedure performed. Preoperative anemia was defined as hematocrit < 40% in males, and < 36% in females. Significant anemia was defined as hematocrit ≤ 29%. Age, gender, BMI, preoperative hematocrit/anemia, operative time, and percent of patients transfused were compared between the groups. Multivariate analysis was used to compare transfusion requirements adjusted for pre-operative anemia and operative times between the groups. Results: 201,718 patients met inclusion criteria. Transfusions were required in 7.5% of all procedures. 21.8% of patients had preoperative anemia, and 2.2% had significant preoperative anemia. Transfusion risk was increased for patients with preoperative anemia in all surgical groups. The patients undergoing any osteotomy had the highest risk of transfusion overall adjusted for preoperative anemia. On multivariate analysis both pre-operative anemia and type of surgery significantly predicted the transfusion risks. The contribution of anemia and surgery type to the transfusion risk differed between the procedure types. Conclusion: this is the first large (over 200,000 patients) sample analysis of transfusion requirements across multiple surgical spine procedures. Although further studies are needed, given a significant contribution of both surgery type and pre-operative anemia on transfusion risk, better pre-operative optimization of patients may be helpful in reducing overall transfusion requirements and improving outcomes.