Introduction: Our recent study showed that maintaining a higher hemoglobin threshold after severe TBI offers no clinical benefit. The present study aimed to determine if a higher transfusion threshold was independently associated with an increased risk of progressive hemorrhagic injury (PHI), thereby contributing to higher rates of morbidity and mortality.
Methods: We performed a secondary analysis of data obtained from a recently performed randomized clinical trial studying the effects of erythropoietin and blood transfusions on neurological recovery after severe TBI. PHI was defined as the presence of new or enlarging intracranial hematomas on computerized tomography up to 24 hours after injury. A severe PHI was defined as an event that required an escalation of medical management or surgical intervention. Clinical, imaging parameters and transfusion thresholds (10g/dl vs 7g/l) were used in a multivariate Cox regression analysis to identify independent risk factors for PHI.
Results: Among 200 patients enrolled in the trial, PHI was detected in 61 patients (30.5%). The majority of patients had a new, delayed contusion (n=30, 49.2%) or an increased in contusion size (n=18, 29.5%). Severe PHI events were seen in 40 patients (65.6%). The mean time interval between injury and identification of PHI was 17.2±15.8 hours. Ninety-nine patients had a transfusion threshold of 7g/dl, and 101 patients had a transfusion threshold of 10g/dl. The risk of severe PHI was 2.3 times higher for patients with a transfusion trigger of 10gm/dl (95% CI 1.1-4.8, p=0.02). Surgery on admission and diffuse brain injury were associated with lower risk of severe PHI, while higher initial ICP was linked to an increased incidence of severe PHI.
Conclusions: Our analysis shows that a higher transfusion threshold of 10g/dl after severe TBI increased the risk of severe PHI events. These results indicate the potential adverse effect of using a higher transfusion threshold after severe TBI.
Patient Care: This study shows that maintaining a higher hemoglobin threshold of 10g/dl for patients with severe traumatic brain injury can increase the risk of progressive hemorrhagic injury. Our study has important implications for the management of severe traumatic brain injury. Our study identifies risk factors for progressive hemorrhagic injury and will guide physicians in determining when to transfuse patients with severe traumatic brain injury.
Learning Objectives: By the conclusion of this session, participants should be able to:
1) Describe the importance of transfusion thresholds in the management of severe traumatic brain injury
2) Understand risk factors for progression of hemorrhagic injury after severe traumatic brain injury
3) Identify ways to reduce secondary brain injury in patients with severe traumatic brain injury