Cardiogenic shock of the obstructive type impairs diastolic ventricular filling and can result from cardiac tamponade, tension pneumothorax, massive pulmonary embolism, or severe aortic stenosis. Treatment involves addressing the underlying cause through interventions such as drainage of tamponade, insertion of a chest tube, dissolving lung blood clots, or repairing or replacing a stenotic valve.
Like the management of pump failure cardiogenic shock, obstructive failure can include the use of inotropes (such as dobutamine, dopamine, and milrinone) to increase cardiac output and decrease systemic vascular resistance, along with oxygen therapy and reduction of myocardial oxygen demand. Since the problem in these cases is not fluid deficits, care should be taken not to give excessive fluids.
| Type | Core problem | Treatment emphasis |
|---|---|---|
| Hemorrhagic / hypovolemic | Loss of circulating blood volume, with decreased filling pressures and reduced cardiac output | Fluid or blood resuscitation |
| Relative hypovolemia | Normal intravascular volume but vessel dilation from spinal cord trauma, anaphylaxis, sepsis, or neurogenic shock | Fluid or blood resuscitation |
| Anaphylactic | Mast-cell mediators produce arterial dilation, hypotension, and airway edema | Stop or slow absorption of the agent, secure the airway, epinephrine, H1 and H2 blockers, racemic epinephrine for airway edema, hydrocortisone IV, fluid resuscitation |
| Septic | Endotoxin-driven vasodilation with blood pooling and cardio-depression despite adequate volume | Fluids and early antibiotics; norepinephrine first line, then vasopressin and if needed epinephrine; corticosteroids |
| Neurogenic | Autonomic disruption causing inappropriate vasodilation and low systemic vascular resistance | Fluid resuscitation and vasopressors; atropine for bradycardia |
| Cardiogenic — pump failure | Heart muscle cannot maintain cardiac output; systemic vascular resistance rises in compensation | Inotropes (dobutamine, dopamine, milrinone), oxygen, reduced myocardial oxygen demand, antiarrhythmics — not large fluid volumes |
| Cardiogenic — obstructive | Impaired diastolic ventricular filling from tamponade, tension pneumothorax, massive pulmonary embolism, or severe aortic stenosis | Relieve the obstruction (drainage, chest tube, clot lysis, valve repair or replacement); inotropes and oxygen; avoid excessive fluids |
