[header] How to treat obstructive shock [title] Examine for signs of a massive pulmonary embolism. [step] A massive pulmonary embolism (blood clot in the lungs) may be a cause of obstructive shock. It presents with sudden onset chest pain, shortness of breath, and the ensuing signs of shock. 
A massive pe can be investigated for by getting a tee (transesophageal echocardiogram) or ct angio of the chest.. this is the fastest way to determine whether one is present and, if so, its exact location.