265 - Outcomes after Lumbar Spine Surgery in Patients with Preoperative Anem...

#265 Outcomes after Lumbar Spine Surgery in Patients with Preoperative Anemia

Epidemiology/Natural History

Poster Presented by: K. Singh

Author(s):

A.J. Marquez-Lara (1)
S.V. Nandyala (1)
S.J. Fineberg (1)
M. Noureldin (1)
K. Singh (1)

(1) Rush University Medical Center, Orthopaedic Surgery, Chicago, IL, United States

Abstract

Introduction: Anemia is thought to be an independent risk factor for postoperative complications following spine surgery. However, there is limited data in the literature describing the impact of a low hematocrit (Hct) in patients undergoing an elective lumbar spine surgery (LSS). The purpose of this study was to analyze a population-based database to determine the differences in patient demographics, preoperative conditions and surgical outcomes based upon the preoperative Hct level in patients undergoing a LSS.

Methods: The American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database was queried between 2006-2011. Patients who underwent an elective LSS were selected and divided into cohorts depending on their preoperative Hct level (Anemia= Males: Hct < 40.6g/dL, Females: < 36.1g/dL). Preoperative patient characteristics (demographics, comorbidities, preoperative lab values), surgery and hospital outcomes (e.g., operative time, length of stay (LOS), 30-day complication rates, and mortality) were compared between groups. SPSS v.20 was utilized for statistical analysis with independent t-tests and χ2-tests for continuous and categorical variables respectively. A p-value of≤ 0.001 was considered statistically significant. A multinomial regression analysis determined if a low Hct was an independent predictor of postoperative complications and mortality after controlling for demographics and comorbidities.

Results: A total of 20,280 LSS cases were identified between 2006-2011 of which 4,522 (22.3%) demonstrated a low Hct (36.12g/dL). Anemic patients were significantly older and demonstrated a greater number of comorbidities (p< 0.001). In addition, patients with anemia demonstrated greater ASA scores and underwent fewer outpatient procedures (p< 0.001). Anemic patients demonstrated a greater number of blood transfusions, operative time, postoperative complication rates, readmission rates and LOS than non-anemic patients (p< 0.001). However, the preoperative Hct level did not significantly affect the reoperation and mortality rates. Regression analysis demonstrated that a low preoperative Hct was an independent predictor for postoperative blood transfusions (p< 0.001).

Conclusion: Anemic patients undergoing a LSS demonstrated a greater comorbidity burden and higher ASA scores, which likely explained the greater postoperative complication rates, readmission rates and hospital LOS. Patients with a low Hct also demonstrated a greater number of intraoperative blood transfusions and a longer operative time than non-anemic patients. The results of this study demonstrate a logical association between preoperative anemia and the need for perioperative blood transfusions. However, further research is warranted to better characterize the association between a low Hct and the perioperative outcomes after a LSS.