Effect of Intravenous Tranexamic Acid on Visual Clarity During Shoulder Arthroscopy in the Beach Chair Position

The operating surgeon evaluated intraoperative visual clarity using the Visual Analog Scale for visibility (VAS-V), ranging from 0 (worst visual clarity) to 10 (best visual clarity), at 15-minute intervals during shoulder arthroscopy. At each assessment time point, the endoscope screen was simultaneously photographed. The surgeon was blinded to group allocation. Visual clarity assessments performed from skin incision up to 135 minutes of surgery were included in the analysis. For each participant, all intraoperative VAS-V measurements within this period were averaged to obtain a single mean intraoperative visibility score. Higher scores indicate better visual clarity.

Three blinded independent assessors evaluated standardized arthroscopic images projected on a screen using the Visual Analog Scale (VAS), ranging from 0 (no visibility) to 10 (optimal visibility). Images were obtained intraoperatively at predefined 15-minute time points during shoulder arthroscopy. Only images obtained from skin incision up to 135 minutes of surgery were included in the analysis. For each participant, visibility ratings from all assessors and time points within this period were averaged to obtain a single mean visibility score. Higher scores indicate better visibility.

Agreement among three blinded independent assessors evaluating standardized intraoperative arthroscopic images using the Visual Analog Scale (VAS), ranging from 0 (worst visual clarity) to 10 (best visual clarity), was assessed using Cronbach's alpha. Images obtained from skin incision up to 135 minutes of surgery were included in the analysis.

Mean arthroscopic visibility ratings assessed using the Visual Analog Scale (VAS), ranging from 0 (no visibility) to 10 (optimal visibility), were evaluated intraoperatively by the operating surgeon at 15-minute intervals during shoulder arthroscopy and by three blinded independent assessors using standardized intraoperative arthroscopic images. Only assessments obtained from skin incision up to 135 minutes of surgery were included in the analysis. For each participant, visibility ratings within this period were averaged to obtain a single mean visibility score, and mean visibility ratings were compared between the experimental and control groups.

Hemoglobin concentration was determined spectrophotometrically from homogenized waste irrigation fluid samples collected throughout shoulder arthroscopy. For each participant, a single hemoglobin concentration value was obtained from the total collected irrigation fluid during the intraoperative period.

The number of arthroscopic pump pressure-boost events, defined as transient increases in irrigation pressure of 20 mmHg sustained for a 2-minute period, was recorded throughout shoulder arthroscopy. For each participant, the total number of pressure-boost events occurring during the intraoperative period was recorded.

The total volume of irrigation fluid used during shoulder arthroscopy was recorded throughout the surgical procedure. For each participant, the cumulative irrigation fluid volume used during the intraoperative period was calculated and expressed in liters.

Mean arterial pressure (MAP) values were continuously recorded from the anesthesia machine throughout shoulder arthroscopy. For each participant, all intraoperative MAP measurements were averaged to obtain a single mean intraoperative MAP value, expressed in mmHg.

The duration of surgery was recorded for each participant as the time from skin incision to final suture and expressed in minutes.

Intraoperative blood loss was calculated for each participant based on hemoglobin concentration measured spectrophotometrically in homogenized waste irrigation fluid collected throughout shoulder arthroscopy, in combination with the total volume of irrigation fluid used during the intraoperative period. The result was expressed as total intraoperative blood loss in milliliters (mL).

Total perioperative blood loss was calculated using the Gross formula based on changes in hematocrit values from the preoperative baseline to postoperative day 2.

Postoperative (hidden) blood loss was calculated by subtracting the intraoperative blood loss from the total perioperative blood loss.

The perioperative decrease in hemoglobin concentration was calculated as the difference between the preoperative baseline value and the value measured on postoperative day 2.

Upper-arm circumference was measured using a measuring tape at three predefined anatomical points (A, B, and C) on the operated upper arm. Measurements were obtained preoperatively and on postoperative days 1 and 2. For each participant, measurements at points A, B, and C were averaged to obtain a single mean circumference value at each time point. Postoperative swelling was expressed as the change in mean upper-arm circumference from baseline to postoperative day 2.

Postoperative pain was assessed by the patient using the Visual Analog Scale (VAS), ranging from 0 (no pain) to 10 (worst pain). Pain intensity was recorded on postoperative day 1 and postoperative day 2. For each participant, pain scores from postoperative days 1 and 2 were averaged to obtain a single mean postoperative pain score. Higher scores indicate greater pain intensity.

Total postoperative analgesic consumption was calculated as the cumulative dose of all orally and intravenously administered analgesics, including paracetamol (acetaminophen), ketoprofen, tramadol, and metamizole, from the end of surgery until hospital discharge.

The length of hospital stay was recorded as the number of days each patient spent in the hospital following surgery until discharge.