This patient is in a shock state caused by left-sided pyelonephritis.

Shock is an emergency medical state characterized by cardiovascular or circulatory failure.  Shock prevents peripheral tissues from receiving adequate perfusion, resulting in organ dysfunction and failure.  Shock can be categorized as hypovolemic, distributive, obstructive, or cardiogenic.  The different categories of shock are defined by their underlying cause (i.e., sepsis, hemorrhage, pulmonary embolism, etc.) and their hemodynamics which sometimes overlap.  The diagnosis of shock is largely clinical and supported by the history, vital signs, and physical exam.  Additional studies, such as laboratory investigations, bedside ultrasound, and imaging tests help narrow down the type of shock, potential triggers, and guide management.  The chart below details the categories of shock, each category’s hemodynamics, potential causes, and treatments.   

The patient’s signs, symptoms, physical exam, and urine studies point towards an infectious etiology.  This patient is in septic shock, which is considered a type of distributive shock (Choice B).  Hypovolemic shock (Choice A), obstructive shock (Choice C), and cardiogenic shock (Choice D) are caused by other conditions reflected in the above table.