Blood loss estimation by Visual Assessment of stained surgical Gauze in Nakhonphanom hospital : An Experimental study

Abstract

Background: Accurate intraoperative blood loss estimation is essential for guiding fluid management and transfusion decisions. Underestimation may cause hypovolemia and hemodynamic instability, while overestimation can result in unnecessary transfusions and related complications. Visual estimation remains the most common technique due to its simplicity, but it is often inaccurate, particularly when blood is absorbed into surgical gauze.

Objective: To develop a visual analogue model for estimating blood loss absorbed by surgical gauze commonly used in Nakhon Phanom Hospital, in order to improve the accuracy of visual assessment.

Methods: This experimental study employed expired screened blood and surgical gauze of various sizes (4×4 inch, 3×18 inch, 12×12 inch, and 15×15 inch). Known blood volumes were applied and absorbed into the gauze. Photographs of stained surfaces were taken to construct visual reference models. The maximum absorption capacity of each gauze type was determined, and percentage stain coverage was correlated with blood volume.

Results: The maximum absorption capacity was 10 mL for 4×4 inch gauze, 100 mL for 3×18 inch swab, 200 mL for 12×12 inch swab, and 400 mL for 15×15 inch swab. A visual analogue scale was developed to assist clinicians in estimating intraoperative blood loss more accurately.

Conclusion: The gauze-based visual analogue model may improve the accuracy of intraoperative blood loss estimation, thereby reducing clinical errors related to under- or overestimation. Further validation in real surgical settings is recommended before clinical implementation.