THREAT helps to identify epistaxis patients requiring blood transfusions.

Objective: To analyze the characteristics of patients who needed a blood transfusion due to epistaxis-caused anemia and to define potential risk factors.

Design: Retrospective cohort study.

Setting: A total cohort of 591 epistaxis patients, prospectively included between March 2007 and April 2008 at the ENT department of the University Hospital of Zurich, was evaluated concerning the need for blood transfusions.

Methods: The clinical charts and medical histories of these patients were evaluated.

Main Outcome Measures: Common parameters that increase the risk for severe anemia due to epistaxis.

Results: Twenty-two patients required blood transfusions due to their medical condition. 22.7% suffered from traumatic nosebleeds. Another 27.3% had a known medical condition with an increased bleeding tendency. These proportions were significantly higher than in the group of patients without need of blood transfusion. The odds ratio for receiving a blood transfusion was 14.0 in patients with hematologic disorders, 4.3 in traumatic epistaxis and 7.7 in posterior bleeders. The transfusion-dependent epistaxis patients suffered significantly more often from severe posterior nosebleeds with the need for a surgical therapeutic approach.

Conclusions: Patients with severe nosebleeds either from the posterior part of the nose or with known hematologic disorders or traumatic epistaxis should be closely monitored by blood parameter analyses to evaluate the indication for hemotransfusion. The acronym THREAT (Trauma, Hematologic disorder, and REAr origin of bleeding → Transfusion) helps to remember and identify the factors associated with an increased risk of receiving blood transfusion.