Hemorrhagic Shock in Orthopedic Fractures

Trauma remains a leading cause of mortality worldwide, particularly among young adults, with hemorrhage accounting for a significant proportion of early preventable deaths . Hemorrhagic shock is a form of hypovolemic shock resulting from acute blood loss leading to inadequate tissue perfusion and oxygen delivery to meet cellular metabolic demands.

hemorrhagic shock occurs when systolic blood pressure (SBP) \< 90 mmHg , Shock index ≥ 0.9 , serum lactate level ≥ 2 mmol/L or need for massive transfusion .

hemorrhagic shock is a critical complication of traumatic injuries associated with high morbidity and mortality if not promptly recognized and managed. Among traumatic injuries, fractures of long bones and the pelvis are particularly important due to their potential for substantial internal blood loss.

The Shock Index is calculated as:

Shock Index (SI) = Heart Rate (HR) ÷ Systolic Blood Pressure (SBP) Normal SI: 0.5 - 0.7 Early concern SI: ≥ 0.9 Indicative of hemorrhagic shock SI ≥ 1.0 . Long bone fractures, especially femoral fractures, can result in significant hemorrhage due to disruption of intramedullary vessels and surrounding soft tissues \[4\]. When multiple long bones are involved, the cumulative blood loss may be considerable and can contribute to the development of hypovolemic shock. Pelvic fractures, however, are even more concerning, as they are often associated with high-energy trauma and complex vascular injuries. The pelvis contains extensive venous plexuses and major arterial branches, making it a major source of life-threatening hemorrhage. It is estimated that venous bleeding accounts for approximately 80% of hemorrhage in pelvic fractures, primarily from the presacral and prevesical venous plexuses .

Patients with pelvic fractures frequently present with hemodynamic instability and may rapidly deteriorate into hemorrhagic shock. These injuries are associated with significant mortality, particularly when shock is present. Studies have shown that pelvic fractures complicated by hemorrhagic shock carry mortality rates of up to 30%, highlighting their severity and the need for early recognition and intervention . Furthermore, pelvic injuries are strongly associated with trauma-induced coagulopathy, which further exacerbates bleeding and worsens outcomes .

Early identification of patients at risk of hemorrhagic shock is crucial in the emergency department (ED) setting. Several clinical and laboratory parameters have been investigated as potential predictors. Variables such as shock index, lactate level, base deficit, and Glasgow Coma Scale (GCS) have been shown to correlate with severity and outcomes in trauma patients . In patients with pelvic fractures, factors such as elevated lactate, hypothermia, and unstable fracture patterns (e.g., type B and C injuries) have been identified as predictors of significant hemorrhage and the need for intervention . Additionally, parameters including shock index, mean arterial pressure, lactate, and fibrinogen levels have demonstrated strong predictive value for mortality in patients with pelvic fractures complicated by shock .

• Blood transfusion requirements [Time frame: 1st hour]