pseudo-pulmonary embolus syndrome

Q: What is pseudo-pulmonary embolus syndrome?

Answer: Shortly after an intravenous heparin bolus, the clinical scenario of collapse 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 the sudden augmented release of IL-6, von Willebrand factor, and other adhesion molecules, resulting in an acute adult-type respiratory distress syndrome as result of a sudden vascular leak with hypoxia and hypotension.

It is observed in patients with underlying heparin-induced thrombocytopenia (HIT).

#pulmonary

#vascular

#hemodynamic

References:

1. Hartman V, Malbrain M, Daelemans R, Meersman P, Zachée P. Pseudo-pulmonary embolism as a sign of acute heparin-induced thrombocytopenia in hemodialysis patients: safety of resuming heparin after disappearance of HIT antibodies. Nephron Clin Pract. 2006;104(4):c143-8. doi: 10.1159/000094959. Epub 2006 Aug 10. PMID: 16902310.

2. Salomon O, Leshem Y, Gluck I, Grossman E, Apter S, Konen E. Pseudo pulmonary embolism in cancer patients: a new clinical syndrome. Blood Coagul Fibrinolysis. 2014 Dec;25(8):871-5. doi: 10.1097/MBC.0000000000000174. PMID: 25022841.

3. Popov D, Zarrabi MH, Foda H, Graber M. Pseudopulmonary embolism: acute respiratory distress in the syndrome of heparin-induced thrombocytopenia. Am J Kidney Dis. 1997 Mar;29(3):449-52. doi: 10.1016/s0272-6386(97)90208-0. PMID: 9041223.