Study design: Retrospective cohort study.
Objective: To determine whether type of intraoperative blood transfusion used is associated with increased incidence of postoperative delirium after complex spine fusion involving five levels or greater.
Summary of background data: Postoperative delirium after spine surgery has been associated with age, cognitive status, and several comorbidities. Intraoperative allogenic blood transfusions have previously been linked to greater complication risks and length of hospital stay. However, whether type of intraoperative blood transfusion used increases the risk for postoperative delirium after complex spinal fusion remains relatively unknown.
Methods: The medical records of 130 adult (≥18 years old) spine deformity patients undergoing elective, primary complex spinal fusion (more than or equal to five levels) for deformity correction at a major academic institution from 2010 to 2015 were reviewed. We identified 104 patients who encountered an intraoperative blood transfusion. Of the 104, 15 (11.5%) had Allogenic-only, 23 (17.7%) had Autologous-only, and 66 (50.8%) had Combined transfusions. The primary outcome investigated was the rate of postoperative delirium.
Results: There were significant differences in estimated blood loss (Combined: 2155.5 ± 1900.7 mL vs. Autologous: 1396.5 ± 790.0 mL vs. Allogenic: 1071.3 ± 577.8 mL vs. None: 506.9 ± 427.3 mL, P < 0.0001) and amount transfused (Combined: 1739.7 ± 1127.6 mL vs. Autologous: 465.7 ± 289.7 mL vs. Allogenic: 986.9 ± 512.9 mL, P < 0.0001). The Allogenic cohort had a significantly higher proportion of patients experiencing delirium (Combined: 7.6% vs. Autologous: 17.4% vs. Allogenic: 46.7% vs. None: 11.5%, P = 0.002). In multivariate nominal-logistic regression analysis, Allogenic (odds ratio [OR]: 24.81, 95% confidence interval [CI] [3.930, 156.702], P = 0.0002) and Autologous (OR: 6.43, 95% CI [1.156, 35.772], P = 0.0335) transfusions were independently associated with postoperative delirium.
Conclusion: Our study suggests that there may be an independent association between intraoperative autologous and allogenic blood transfusions and postoperative delirium after complex spinal fusion. Further studies are necessary to identify the physiological effect of blood transfusions to better overall patient care and reduce healthcare expenditures.
Level of evidence: 3.