Evaluation of a Novel Method of Surgical Blood Loss Determination During Cesarean Delivery in Predicting Postoperative Hemoglobin – A Prospective Observational Study
Abstract Number: T-23
Abstract Type: Original Research
Introduction: Visual estimation and gravimetric methods are commonly used to quantify the volume of blood loss (BL) during cesarean delivery (CD). A new device, Triton™ (Gauss Surgical Inc., Los Altos, CA) measures BL using “Feature Extraction Technology” from iPad-derived images of surgical material contaminated with blood. The aim of the study was to evaluate the association between BL, evaluated by a gravimetric approach (gBL), visual estimation and Triton System™ (tBL), and post-CD hemoglobin (Hb).
Methods: After obtaining IRB approval, we performed a prospective study of 61 women undergoing CD to assess the relations between post-CD Hb and BL measured using 4 modalities: gBL, visual estimations by a blinded obstetrician (oBL) and anesthesiologist (aBL), and tBL. Hb was measured preoperatively and at 15 min post-CD. gBL was quantified from blood volume in a suction canister plus the weight of blood-soaked sponges. To obtain aBL and oBL, the anesthesiologist and obstetrician were each asked to estimate the total BL at the end of surgery. tBL was measured with the Triton System™ by photographing blood-soaked sponges and suction canister contents. To assess the relation between each BL measurement with post-CD Hb, we performed uni- and multivariable linear regression adjusting for baseline Hb, patient BMI, and oxytocin dose.
Results: Mean preoperative Hb was 12 g/dL and post-CD Hb was 11.3 g/dL. Only 1 patient had a post-CD Hb<9 g/dl. Median [IQR] qBL, oBL, aBL, and tBL values were 672 ml [266-970], 700 ml [600-800], 750 ml [600-1000], and 496 ml [374-729], respectively. Univariable analyses revealed statistically significant associations between qBL, aBL, tBL with post-CD Hb, respectively (Table). However, after additional adjustment, only aBL was independently associated with post-CD Hb (P<0.05) (Table). Similar associations, albeit non-significant, were found between oBL and tBL with post-CD Hb.
Conclusion: Although only BL estimated by the anesthesiologist was independently associated with post-CD Hb, the magnitude and direction of change was similar for the associations between aBL, oBL, and tBL with post-CD Hb. As the majority of women did not experience large amounts of intraoperative blood loss and were not severely anemic post-CD, larger studies are needed to determine which BL measuring technique best predicts severe postoperative anemia.