The aim of this study is to investigate the effect of preoperative administration of intravenous or nebulized tranexamic acid on surgical field, blood loss, anesthetic consumption and hemodynamics of patients undergoing FESS.

Primary outcome Modena Bleeding Score (MBS) assessing surgical field Secondary outcome

1. Patient hemodynamics.
2. Anesthetic consumption, Extra doses of fentanyl and propofol and sevoflurane>2
3. Postoperative complications: including any adverse effects to TXA e.g.nausea, vomiting, any visual disturbances, fits, and any thrombotic manifestation.

Functional endoscopic sinus surgery (FESS) is the current standard treatment for a variety of conditions affecting the nasal cavity and the paranasal sinuses, such as chronic rhinosinusitis, benign and malignant tumors or cerebrospinal fluid leaks .Being mostly a one-handed technique, FESS does not allow simultaneous use of operative instruments and blood suction, thus endonasal bleeding control represents a challenging issue for the operating surgeon. Such narrow and highly vascularized cavities like the nasal fossae and paranasal spaces can be entirely filled with blood within few seconds, especially if the mucosa is severely inflamed as a consequence of rhinosinusitis. Bleeding is possibly the most relevant factor that could impair the quality of the surgical field during endoscopic procedures. It has been proven that uncontrolled bleeding during endoscopic sinus surgical procedures determines poor visualization of the anatomical landmarks, prolongs surgical time and carries a higher rate of complications .Several techniques to control intraoperative bleeding and improve surgical view during sinus surgery (e.g. topical vasoconstrictors, total intravenous anesthesia, controlled hypotension) have been described and analyzed to determine their efficacy .These types of studies, however, are complex and prone to bias, partially because standardized and validated methods of quantifying bleeding or grading the surgical field in endoscopic view are lacking.

Tranexamic acid functions as the competitive antagonist at the lysine site on plasminogen . During all surgical procedures, the tissue plasminogen activator is released due to tissue damage during surgery, which can convert tissue plasminogen to plasmin, promote fibrinolysis and activate the fibrinolytic system. Thus, tranexamic acid functions as an anti-fibrinolytic agent by inhibiting the tissue plasminogen activator. It can be applied topically or systemically with this mechanism in the coagulation cascade to reduce intraoperative bleeding .The results of several recent studies on endoscopic sinus surgery through topical administration of tranexamic acid are encouraging in terms of the efficacy of tranexamic acid for intraoperative bleeding and other pathological conditions .The purpose of this study is to analyze the efficacy of nebulized tranexamic acid and compare it with intravenous tranexamic acid to improve the surgeon and patient experiences of sinus surgery.

Inclusion Criteria:

1. Either sex
2. age 18-65 years
3. ASA I-II who are listed for elective functional endoscopic sinus surgery (FESS) under general anesthesia
4. normal accepted coagulation profile and hematocrit value ≥30

Exclusion Criteria:

• • chronic renal failure

  • liver cirrhosis
  • bleeding disorders
  • current anticoagulant therapy
  • pregnancy or breastfeeding
  • impaired color vision
  • severe vascular ischemia
  • history of venous thrombosis, pulmonary embolism
  • long term treatment with acetylsalicylic acid or non-steroidal anti-inflammatory drugs not discontinued before surgery
  • hemoglobin (HB) concentration <10 mg/dl _allergy to TXA.
  • BMI > 35 kg/ m2