Shock — Types and Mechanisms

Which of the following best describes the primary pathophysiological mechanism in cardiogenic shock?

A 58-year-old man with a 10-year history of poorly controlled hypertension presents to the emergency department with acute onset chest pain radiating to the back. On examination, blood pressure is 180/110 mmHg (right arm) and 140/90 mmHg (left arm), heart rate 110/min, respiratory rate 24/min. Cardiac auscultation reveals an early diastolic murmur. Chest X-ray shows a widened mediastinum. Despite aggressive fluid resuscitation and vasopressor support, the patient develops hypotension (BP 85/55 mmHg), cool extremities, oliguria, and altered mental status. Which type of shock is this patient most likely experiencing?

A 42-year-old woman with a history of rheumatoid arthritis (on methotrexate) presents to the emergency department with a 3-day history of fever, cough, and dyspnea. On examination: temperature 39.8°C, BP 92/58 mmHg, heart rate 128/min, respiratory rate 28/min, oxygen saturation 88% on room air. Lung auscultation reveals bilateral crackles. Blood cultures are pending. Lactate is 4.2 mmol/L (normal <2). Chest X-ray shows bilateral infiltrates. The patient is started on broad-spectrum antibiotics and fluid resuscitation. Despite 2 liters of normal saline, the BP remains 90/55 mmHg, urine output is 0.3 mL/kg/hr, and extremities remain warm. Which type of shock is this patient experiencing, and what is the underlying pathophysiologic mechanism?

A 42-year-old woman with sepsis secondary to urosepsis (E. coli) presents with BP 92/58 mmHg, HR 132/min, RR 32/min, warm extremities, and normal mental status. Lactate is 3.2 mmol/L (normal <2). She has received 2 L of crystalloid fluid in the past 2 hours. What is the most appropriate next step in management?

A 42-year-old man with acute myocardial infarction presents with hypotension, elevated jugular venous pressure, and pulmonary edema. A 38-year-old woman with sepsis from pneumonia presents with hypotension, warm extremities, and low CVP. Which single feature best distinguishes cardiogenic shock from septic shock in these two patients?