ABSTRACT
This category of shock involves impedance to the flow of blood resulting in a decrease in cardiac filling. The causes involve mechanisms other than primary myocardial or valvular dysfunction. Etiologies include impaired diastolic filling (cardiac tamponade, constrictive pericarditis, pneumothorax), and an increase in right or left ventricular afterload (massive pulmonary embolism, acute pulmonary hypertension, aortic dissection). The differential diagnosis is extremely important in this shock state, as a physical intervention (surgery, pericardiocentesis, or chest tube insertion) may reverse the condition and can be life saving. Disorders that impede blood flow are often overlooked and must always be considered in appropriate settings. Maintenance of intravascular volume is extremely important in patients with obstructive shock. Fluid resuscitation may temporarily enhance the cardiac output and hypotension. Diuretics should be avoided in this type of shock. Inotropes and/or vasopressors probably have a minimal, often temporary role in the management of a patient with obstructive shock.
