Sickle cell trait and multisystem trauma: an unaddressed urgent knowledge gap

Sickle cell trait (SCT) has historically been considered a benign condition, but SCT-positive patients have increased baseline risk of venous thromboembolism and chronic kidney disease, as well as increased risk of sickled erythrocytes in settings of hypoxia, acidosis, and hypovolemia. Multisystem traumatic injuries are a common clinical scenario, in which hypoxia, acidosis, and hypovolemia occur; however, little is known about how SCT-positive status impacts outcomes in multisystem trauma. We conducted a scoping literature review to investigate what was known about SCT in the setting of multisystem trauma. In the 110+ years that sickle cell hemoglobinopathies have been known, only three studies have ever examined the relationship between SCT and multisystem traumas. All three articles were case reports. None of the articles intentionally measured the association between SCT and multisystem trauma outcomes; they only incidentally captured information on SCT. Our article then examines historical reasons why so little research has studied the pathophysiology of the multisystem trauma in patients with SCT. Among the reasons is that historical and logistical factors have long prevented patients from knowing their SCT-status: historical discriminations against SCT-positive patients in the 1960s and 1970s delayed federal mandating of SCT newborn screening until 2006, whereas difficulties communicating known SCT-status to afflicted children also contributed to lack of patient knowledge. In light of our findings, we offer specific calls to action for the trauma surgery research community: (1) consider testing for SCT in trauma patients that have unexpected complications, particularly venous thromboembolism, rhabdomyolysis, or renal failure and (2) support research to understand how SCT impacts multisystem trauma outcomes. We also offer specific guidelines about how to 'proceed with caution' in implementation of these goals in light of the troubled history of SCT testing and policy in the USA.