Comparison of four methods of blood loss estimation after cesarean delivery

To assess agreement between four different methods of blood loss estimation after lower-segment cesarean delivery (LSCD).

A secondary analysis was undertaken of a randomized controlled trial of three timings of cord clamping during LSCD performed at a center in Sri Lanka between January 21 and April 30, 2013. Eligible women underwent prepartum LSCD at 37-39weeks of pregnancy. Estimated blood loss (EBL) was assessed by a combined method (direct measurements of spilled blood and sucker bottle volumes, and weighing of surgical towels and drapes before and after use), according to visual assessments by the surgeon and by anesthesiologists, and by measurement of preoperative and postoperative hemoglobin levels.

Among 156 participants, mean EBL was 502mL (95% CI 370-618) from the combined method, 506mL (412-643) calculated from hemoglobin levels, 484mL (367-621) by the surgeon's estimation, and 491mL (361-612) by anesthesiologists' estimation (P=0.32). Visual assessment of EBL by anesthesiologists had the best intraclass correlation (0.713) and limits of agreement with the combined method. There were no significant differences between the proportion of cases in which anesthesiologists and the surgeon underestimated or overestimated the EBL when compared with the combined method.

EBL should be ideally obtained by the combined method.