Q: What is pseudo-pulmonary embolus syndrome?


Answer: The clinical scenario of collapse, shortly after an intravenous heparin bolus, most likely to be one of HIT type II is called ‘pseudo pulmonary embolus’. This is not due to a major pulmonary embolus, but is thought to be due to an endothelial injury, with sudden augmented release of IL-6, von Willebrand factor, and other adhesion molecules, resulting in an acute adult-type respiratory distress syndrome as a result of sudden vascular leak with hypoxia and hypotension.