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A New Method for Reproducibly Quantifying Surgical Wound Bleeding

Spotnitz, William D. MD, MBA∗,†; Zielske, Dirk MD; Centis, Valerie PhD; Hoffman, Rachel BSE; Gillen, Daniel L. PhD§; Wittmann, Catherine PhD; Guyot, Vincent MSE; Campos, Doris M. PhD; Forest, Patricia PhD; Pearson, Alan PhD; McAfee, Paul C. MD, MBA||

doi: 10.1097/BRS.0000000000002447

Study Design. Benchtop model with prospective surgeon video testing.

Objective. To create a surface bleeding severity scale, the SPOT GRADE (SG), for quantitative assessment of target bleeding site (TBS) blood loss. This is of particular interest for spinal surgery due to epidural bleeding and an inability to use diathermy and radiofrequency cautery close to nerve roots.

Summary of Background Data. A novel apparatus perfusable at known flow rates and simulating different sized wounds was used to create movies to educate surgeons on specific degrees of bleeding.

Methods. Training (36) and testing (108) videos were created using a benchtop apparatus employing different bleeding severities based on the six-level SG (none, minimal, mild, moderate, severe, and extreme) and TBS sizes (1, 10, and 50 cm2). Fourteen surgeons in four specialties (cardiothoracic, abdominal, spine, and orthopedic lower extremity) were trained and tested to evaluate SG characteristics including inter-rater and intrarater reliability.

Results. The interclass correlation coefficient was estimated to be 0.89840 (95% confidence interval [CI]: 0.85771, 1), whereas the intraclass correlation coefficient was estimated to be 0.93673 (95% CI: 0.89603, 1). In 98% of cases (95% CI: 0.9736, 0.9927), surgeons correctly identified eligible bleeds for a future clinical trial (scores = 1, 2, or 3) and in 91% of cases (95% CI: 0.8895, 0.9344), surgeons correctly identified noneligible bleeds (scores = 4 or 5). In 98.6% of cases (95% CI: 0.9777, 0.9945), physicians correctly identified true hemostasis (score = 0). Based upon these data the probability of a physician rating a bleed incorrectly as hemostasis (score = 0) is estimated to be 1.51% (95% CI: 0.0061, 0.0363).

Conclusion. This SG is reproducible and reliable providing a basis for educating surgeons on TBS blood loss. It appears to be a new standard for evaluating wound blood loss.

Level of Evidence: 2

Department of Surgery, University of Virginia, Charlottesville, VA

Biom’up, SA, Saint-Priest, France

North American Science Associates, Inc, Minneapolis, MN

§Department of Statistics, University of California, Irvine, CA

Origin Product Design, Ltd, Broughton, Cambs, UK

||Scoliosis and Spine Center, University of Maryland, Towson, MD.

Address correspondence and reprint requests to William D. Spotnitz, MD, MBA, Department of Surgery, University of Virginia, 2738 SW 92nd Dr, Gainesville, FL 32608; E-mail:

Received 4 May, 2017

Revised 3 September, 2017

Accepted 29 September, 2017

The manuscript submitted does not contain information about medical device(s)/drug(s).

Biom’up (Lyon, France) funds were received in support of this work.

Relevant financial activities outside the submitted work: consultancy, employment, travel/accommodations/meeting expenses.

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