Blood loss quantification during major abdominal surgery: prospective observational cohort study

Area of Science:

• Surgical Oncology
• Anesthesiology
• Medical Devices

Background:

• Accurate blood loss quantification is vital for evaluating strategies to reduce perioperative bleeding during major abdominal surgery.
• Current methods for measuring blood loss are often unreliable and inaccurate.
• This study addresses the need for precise blood loss measurement in surgical settings.

Purpose of the Study:

• To compare the accuracy of different blood loss quantification methods during major abdominal surgery.
• To evaluate visual estimation (surgeon and anesthesiologist), gravimetric method, and calculation method against spectrophotometric measurement.
• To determine the most reliable method for assessing perioperative blood loss.

Main Methods:

• Prospective observational cohort single-center study involving 61 patients undergoing elective liver or pancreatic resection.
• Blood loss was assessed using visual estimation, gravimetric method, calculation formula (López-Picado), and spectrophotometric analysis.
• Statistical comparison included paired t-test, Wilcoxon test, and Bland-Altman analysis.

Main Results:

• All tested methods (visual estimation, gravimetric, calculation) significantly differed from spectrophotometric measurement (p < 0.05).
• All methods consistently overestimated blood loss compared to spectrophotometric measurement.
• Surgeon's visual estimate was the closest to spectrophotometric measurement, with a mean difference of 68.7 ml.

Conclusions:

• Visual estimation, gravimetric, and calculation methods for blood loss are significantly inaccurate in clinical practice.
• The common assumption that surgeons underestimate blood loss was not confirmed in this study.
• Spectrophotometric measurement is the most accurate method for quantifying blood loss in major abdominal surgery.