Hypovolemic Shock Complex in the Trauma Setting: A Pictorial Review

Hypovolemia is defined as the physiological state of Taylor et al [5] initially described the HSC or hyporeduced blood or, more specifically, reduced plasma volume. When volume loss is severe, many homeostatic mechanisms serve to maintain adequate tissue perfusion to critical organs, such as the brain and the heart. These compensatory mechanisms can result in a severe reduction of vascular perfusion and oxygen delivery to numerous other vital organs, such as the liver and the kidneys, which may ultimately lead to multiorgan failure. Key steps in the initial management of hypovolemic shock include determining the severity of volume loss, appropriate volume resuscitation, and accurate identification of the underlying cause. The severity of shock can be graded based on the scale of derangement in vital signs, such as heart rate and blood pressure, and by the presence and severity of clinical signs and symptoms, such as pallor, tachypnea, and a reduced level of consciousness. Classification schemes often use a 4or 6-point scale and have been shown to improve patient management and outcome [1e3]. The subgroups and major causes of hypovolemic shock are summarized in Table 1 [4]. In contemporary practice, patients with hypovolemic shock related to hemorrhagic traumatic causes are frequently evaluated by using computed tomography (CT). Although the primary aim of CT in patients with hemorrhagic traumatic shock is to identify the exact site of blood loss and to direct appropriate treatment of traumatic injuries, accurate recognition of a constellation of secondary CT findings termed the hypovolemic shock complex (HSC) also allows radiologists to contribute significantly towards the clinical grading of shock severity.