TY - CHAP M1 - Book, Section TI - Management of Obstetrical Hemorrhage A1 - Cunningham, F. Gary A1 - Leveno, Kenneth J. A1 - Dashe, Jodi S. A1 - Hoffman, Barbara L. A1 - Spong, Catherine Y. A1 - Casey, Brian M. Y1 - 2022 N1 - T2 - Williams Obstetrics, 26e AB - Recognition of obstetrical hemorrhage severity is crucial to its management. However, visual estimates, especially when blood losses are excessive, are notoriously inaccurate. In many cases, true volume losses are often two to three times the clinical estimate. Moreover, in obstetrics, part and sometimes even all of the lost blood may be concealed. Estimation is further complicated in that peripartum hemorrhage also includes the pregnancy-augmented blood volume. After pregnancy hypervolemia is lost at delivery, blood loss can be estimated by calculating 500 mL loss for each 3 volume percent drop in hematocrit. Its nadir depends on the speed of resuscitation with intravenous crystalloids and blood products. With ongoing blood loss, the real-time hematocrit is at its maximum whenever measured in the delivery, operating, or recovery room. SN - PB - McGraw Hill CY - New York, NY Y2 - 2024/03/29 UR - obgyn.mhmedical.com/content.aspx?aid=1190763437 ER -