Introduction: Lumbar laminectomy and fusion has been shown to be a highly successful procedure. However, blood loss can have a deleterious impact on complication rate and outcome. Predicting those that will have greater blood loss may allow for perioperative interventions that minimize blood loss.
Methods: 508 patients undergoing lumbar laminectomy and fusion of 3 or fewer levels were prospectively included in this study. Linear regression analysis evaluating the amount of blood loss during surgery was performed using age, BMI, ASA grade, preoperative hematocrit, length of surgery, primary vs. revision surgery, use of an interbody fusion, and the number of level fused as covariates.
Results: The average blood loss in our cohort was 555 ± 405 mL (range 50-3600 mL). Of the covariates analyzed above, length of surgery had the greatest association with blood loss (correlation coefficient 2.3, p<0.001). The number of levels undergoing arthrodesis and preoperative hematocrit were also significantly associated with blood loss (90.1, p<0.001 and -16.5, p<0.001, respectively). This translates into each additional minute of surgery increased blood loss by 2.3 mL, each additional level fused increased blood loss by 90.1 mL, and each 1 point decrease in pre-op hematocrit increased blood loss by 16.5 mL.
Conclusions: Our work suggests that patients with increased operating times, more levels fused, and lower hematocrit will suffer larger volumes of blood loss following lumbar laminectomy and fusion (=3 levels). Our model could potentially be used to guide surgeons on perioperative decisions in relation to blood loss such as the use of autologous transfusions vs. allogeneic transfusions and antifibrinolytics.
Patient Care: Lumbar laminectomy and fusion is one of the most commonly performed procedures by spine surgeons today. By knowing which factors preoperatively are most associated with blood loss during a procedure, the surgeon can plan and even predict an approximate blood loss to expect during a case. This is highly important because it can help prevent complications and guide surgeons in the use of perioperative decisions related to blood loss, such as the use of autologous transfusions vs. allogeneic transfusions.
Learning Objectives: The objective of this abstract is to show the factors that are associated with blood loss during lumbar laminectomy and fusion.