Rosh Internal Medicine Boost Practice Exam

What is the most likely cause of hemodynamic instability in a patient presenting with a stab wound and vital signs indicating shock?

1. Hypovolemic shock

2. Neurogenic shock

3. Obstructive shock

4. Spinal shock

The correct answer is: Hypovolemic shock

In assessing a patient who presents with a stab wound and displays signs of shock, hypovolemic shock is the most likely cause of hemodynamic instability. This type of shock occurs due to a significant loss of blood volume, which can result from penetrating trauma like a stab wound. In this scenario, the stab wound could potentially lead to bleeding from major blood vessels or organ systems, leading to inadequate circulating blood volume and subsequent shock. The vital signs indicative of shock, such as hypotension and tachycardia, are typical presentations in hypovolemic shock as the body attempts to compensate for the decreased blood volume. The administration of fluids and blood products is essential in these cases to restore hemodynamic stability. Other forms of shock, such as neurogenic, obstructive, and spinal shock, generally are associated with different mechanisms. Neurogenic shock is characterized by loss of vascular tone due to spinal cord injury, obstructive shock relates to physical obstruction of blood flow, such as in cases of tension pneumothorax or cardiac tamponade, and spinal shock refers to the immediate loss of reflexes below a spinal cord injury. In this context, the direct cause of hypovolemia due to trauma makes hypovolemic shock the most