Dilutional coagulopathy in pediatric scoliosis surgery: A single center report

Abstract

Summary Background Children undergoing posterior spinal fusion experience high blood loss often necessitating transfusion. An appropriately activated coagulation system provides hemostasis during surgery, but pathologic dysregulation can cause progressive bleeding and increased transfusions. Despite receiving antifibrinolytics for clot stabilization, many patients still require transfusions. Aims We sought to examine the association of dilutional coagulopathy with blood loss and blood transfusion in posterior spinal fusion for pediatric scoliosis patients. Methods A retrospective, single institution study of children undergoing posterior spinal fusion >6 levels with a standardized, prospective anesthetic protocol utilizing antifibrinolytics. Blood loss was evaluated using a hematocrit‐based calculation. To evaluate transfusions, a normalized Blood Product Transfusion calculation was developed. Factors associated with blood loss and blood transfusions were determined by univariate analysis and multivariate regression modeling with multicollinearity and mediation analysis. Results Patients received 73.7 mL/kg (standard deviation ±30.8) of fluid poor in coagulation factors. Estimated blood loss was 42.6 mL/kg (standard deviation ±18.0). There was a significant association between estimated blood loss and total fluids delivered (Spearman's rho = 0.51, 95% confidence interval 0.33‐0.65, P < 0.001). Factors significantly associated with normalized Blood Product Transfusion in this cohort included age, weight, scoliosis type, levels fused, total osteotomies, pelvic fixation, total fluid, maximum prothrombin time, and minimum fibrinogen. Regression modeling showed the best combination of variables for modeling normalized Blood Product Transfusion included patient weight, number of levels fused, total fluid administered, and maximum prothrombin time. Conclusion Blood product transfusion remains a frustrating problem in pediatric scoliosis. Identifying and controlling dilutional coagulopathy in these patients may reduce blood loss and the need for blood transfusion.

Blood Loss and Transfusion in a Pediatric Scoliosis Surgery Cohort in the Antifibrinolytic Era

“…Univariate analysis of preoperative fibrinogen and association with intraoperative estimated blood loss was significant as demonstrated by the linear model [Intraoperative estimated blood loss (mL)=19.87−0.016×preoperative fibrinogen, P =0.042 for preoperative fibrinogen]. However, on multivariate analysis, when correcting for several factors known to be associated with blood loss in scoliosis surgery,2,7,27,28 this was no longer significant [intraoperative estimated blood loss (mL)=12.073+0.053×age−0.232×number of spinal levels fused+2.043×sex−0.136×weight at time of surgery−0.024×height at time of surgery+0.043×surgery time−0.009×preoperative fibrinogen, P =0.17 for preoperative fibrinogen]. None of the variables were significant predictors of clinically significant blood loss nor intraoperative or postoperative allogenic transfusion.…”

“…Coagulopathy in scoliosis surgery is multifactorial, stemming from significant effects on hemostasis because of the large and highly vascular surgical bed, dilutional coagulopathy, dysregulation of normal counterbalancing mechanisms, hyperfibrinolysis, and a systemic inflammatory response. 2,7,21,33 However, the specific mechanisms underlying coagulopathy in scoliosis surgery are not well defined. The complex interplay between the coagulation and inflammation systems may contribute to adverse outcomes in this population, particularly in patients with NMS, where differences in coagulation systemic activation have been proposed to contribute to adverse outcomes.…”

“…Coagulopathy in scoliosis surgery is multifactorial, stemming from significant effects on hemostasis because of the large and highly vascular surgical bed, dilutional coagulopathy, dysregulation of normal counterbalancing mechanisms, hyperfibrinolysis, and a systemic inflammatory response 2,7,21,33. However, the specific mechanisms underlying coagulopathy in scoliosis surgery are not well defined.…”

“…Age, number of spinal levels fused, surgical approach, and neuromuscular scoliosis (NMS) subtype are all known risk factors for increased blood loss in scoliosis surgery 1–3,6. However, the blood loss in scoliosis surgery has also been likened to a type of controlled traumatic coagulopathy, for which the exact mechanisms are not well understood 1,7–9. Efforts to improve our understanding of the mechanisms of this surgical-induced coagulopathy and intervention to decrease bleeding and transfusion are likely to improve outcomes for children undergoing surgical repair of scoliosis.…”