Endobronchial bleeding is a relatively common complication of diagnostic bronchoscopy. Both tranexamic acid and adrenaline are used topically for the control of endobronchial bleeding. The aim of this study is to compare the efficacy of tranexamic acid with adrenaline in controlling iatrogenic endobronchial bleeding after diagnostic bronchoscopy.

Inclusion Criteria:

• patients with endobronchial bleeding during diagnostic bronchoscopy that was not successfully controlled with cold (4°C) normal saline (3 aliquots of 5ml during 60sec)

Exclusion Criteria:

• Any patient with a contraindication for diagnostic flexible bronchoscopy
• Coagulopathy (PV INR >1.3)
• Thrombocytopenia (<50x10^9) or anemia (hgb <80 g/L)
• Direct oral anticoagulant, low molecular weight heparin or antiplatelet drug therapy
• Thrombophilia, history of pulmonary embolism or deep vein thrombosis
• Contraindication for endobronchial application of adrenaline
• Coronary heart disease, cerebrovascular disease, history of tachyarrhythmia
• Uncontrolled pulmonary hypertension
• Cardiovascular decompensation
• Severe hypoxia (PaO2 <60mmHg, SaO2 <90% with an FiO2 >=60%)