Table 1. Blood loss determinations.
| Method | Extraction Assay | Visual EBL | QBLGrav (adjusted)a | Colorimetric | |
|---|---|---|---|---|---|
| Sponge (mL) | Mean ± SD | 280 ± 222 | 759 ± 317 | 332 ± 255 | |
| Median (IQR) | 203 (138) | 695 (426) | 251 (181) | ||
| Bias (95% CI) | 480 (428–531) | 52 (32–71) | |||
| p Value | < 0.001 | < 0.001 | |||
| Canister (mL) | Mean ± SD | 190 ± 133 | 63 ± 335 | 240 ± 137 | |
| Median (IQR) | 142 (173) | −13 (285) | 199 (202) | ||
| Bias (95% CI) | −127 (−228 to −26) | 50 (26–74) | |||
| p Value | 0.014 | < 0.001 | |||
| Total blood loss per procedure (mL) | Mean ± SD | 470 ± 296 | 928 ± 261 | 822 ± 489 | 572 ± 334 |
| Median (IQR) | 384 (296) | 800 (200) | 651 (475) | 481 (332) | |
| Bias (95% CI) | 458 (396–520) | 352 (237–467) | 102 (72–132) | ||
| p Value | < 0.001 | < 0.001 | < 0.001 |
Abbreviations: CI, confidence interval; EBL, estimated blood loss; IQR, interquartile range; QBLGrav, quantitative blood loss; SD, standard deviation.
a
Adjusted by subtracting the measured amniotic fluid volume and irrigation volume.
Note: p Values reflect the statistical significance level of paired t-tests comparing each method with the extraction assay (reference standard).