Methods of Quantifying Intraoperative Blood Loss in Orthopaedic Trauma Surgery: A Systematic Review.

Objectives: To collect and present the recently published methods of quantifying blood loss (BL) in orthopaedic trauma.

Data Sources: A systematic review of English-language literature in PubMed, Cochrane Library, and Scopus databases was conducted according to the PRISMA guidelines on articles describing the methods of determining BL in orthopaedic trauma published since 2010.

Study Selection: English, full-text, peer-reviewed articles documenting intraoperative BL in an adult patient population undergoing orthopaedic trauma surgery were eligible for inclusion.

Data Extraction: Two authors independently extracted data from the included studies. Articles were assessed for quality and risk of bias using the Cochrane Collaboration's tool for assessing risk of bias and ROBINS-I.

Data Synthesis: The included studies proved to be heterogeneous in nature with insufficient data to make data pooling and analysis feasible.

Conclusions: Eleven methods were identified: 6 unique formulas with multiple variations, changes in hemoglobin and hematocrit levels, measured suction volume and weighed surgical gauze, transfusion quantification, cell salvage volumes, and hematoma evacuation frequency. Formulas included those of Gross, Mercuriali, Lisander, Sehat, Foss, and Stahl, with Gross being the most common (25%). All formulas used blood volume estimation, determined by equations from Nadler (94%) or Moore (6%), and measure change in preoperative and postoperative blood counts. This systematic review highlights the variability in BL estimation methods published in current orthopaedic trauma literature. Methods of quantifying BL should be taken into consideration when designing and evaluating research.