While on pradaxa and after a hip replacement, i deveoped a massive pulmonary embolism. i haven't read anywhere that coagulation has ocurred while on pradaxa. are there any such cases known?

Possible: Although uncommon, I have heard of cases of Pradaxa (dabigatran) failure ( developing a blood clot while on treatment ). This is a relatively new drug and we are still learning potential down sides. The university of utah suggests some work up when this happens. See web page: http://healthcare.Utah.Edu/thrombosis/newagents/ts.Dabi_lab.Monitor.Pdf.

This is concerning: Prefaces used for prevention of blood clots with afib & was likely interrupted for surgery...Talk to your physician.

Yes: Deep vein thrombosis prophylaxis is not perfect. The use of medications, along with compression and ambulation, is designed to minimize the risk, but thrombosis can still occur. The use of an inferior vena caval filter is another aid to prevent pulmonary emboli, not dvt.