Vasopressors in Trauma: A Never Event?

Abstract

Vasopressor use in severely injured trauma patients is discouraged due to concerns that vasoconstriction will worsen organ perfusion and result in increased mortality and organ failure in hypotensive trauma patients. Hypotensive resuscitation is advocated based on limited data that lower systolic blood pressure and mean arterial pressure will result in improved mortality. It is classically taught that hypotension and hypovolemia in trauma are associated with peripheral vasoconstriction. However, the pathophysiology of traumatic shock is complex and involves multiple neurohormonal interactions that are ultimately manifested by an initial sympathoexcitatory phase that attempts to compensate for acute blood loss and is characterized by vasoconstriction, tachycardia, and preserved mean arterial blood pressure. The subsequent hypotension observed in hemorrhagic shock reflects a sympathoinhibitory vasodilation phase. The objectives of hemodynamic resuscitation in hypotensive trauma patients are restoring adequate intravascular volume with a balanced ratio of blood products, correcting pathologic coagulopathy, and maintaining organ perfusion. Persistent hypotension and hypoperfusion are associated with worse coagulopathy and organ function. The practice of hypotensive resuscitation would appear counterintuitive to the goals of traumatic shock resuscitation and is not supported by consistent clinical data. In addition, excessive volume resuscitation is associated with adverse clinical outcomes. Therefore, in the resuscitation of traumatic shock, it is necessary to target an appropriate balance with intravascular volume and vascular tone. It would appear logical that vasopressors may be useful in traumatic shock resuscitation to counteract vasodilation in hemorrhage as well as other clinical conditions such as traumatic brain injury, spinal cord injury, multiple organ dysfunction syndrome, and vasodilation of general anesthetics. The purpose of this article is to discuss the controversy of vasopressors in hypotensive trauma patients and advocate for a nuanced approach to vasopressor administration in the resuscitation of traumatic shock.