Control of Epistaxis With Surgiflo

This is a blind trial to test if Surgiflo is effective in posterior epistaxis. After the investigators see than anterior tamponade is not effective stopping epistaxis, the investigators try using Surgiflo and if it does not work the investigators continue with a nasal catheter. This is the usual way to stop nasal bleeding, but is painful and has serious after-effects in the nose. Surgiflo is a hemostatic matrix that can be put into the nose, painlessly and easily. So the investigators think it can be useful controlling nasal bleeding, so the investigators could avoid to put nasal catheters in these patients.