The state of systemic oxygen transport depending on the hematocrit and hemoglobin values in an intrapartum hemorrhage

Background. Massive obstetric hemorrhage (MOH) is the most common cause of maternal mortality worldwide. There are currently a lot of national guidelines for MOH mana­gement, but the guidelines provided do not grant reasonable guidance on the minimum acceptable hemoglobin (Hb) level, which ensures the minimum acceptable oxygen delivery (IDO2). The work was aimed to assess the state of systemic oxygen transport depending on hematocrit and Hb in terms of blood loss, and to determine the minimum acceptable level of Hb, which provides an adequate relationship between systemic oxygen transport and oxygen needs in the development of MOH. Materials and methods. The study included 113 mothers in whom childbirth was complicated by blood loss. The mean age of parturient women was 32.5 ± 6.4 years, mean weight — 76.5 ± 12.4, mean gestational age — 39.5 ± 1.5 weeks. The dominant causes of MOH were uterine atony (52.14 %), ute­rine inversion (15.38 %), and amniotic fluid embolism (10.26 %). Less frequently, blood loss was observed due to uterine rupture (5.98 %), placental abruption (5.98 %), placenta previa (5.98 %), and delayed placental abruption (4.27 %). Postpartum blood loss ave­raged 1830.5 ± 622.7 ml (1200 to 2500 ml). The bleeding in all cases was stopped according to current protocols. Results. With Ht values ranging from 20.0 to 28.9 %, and Hb 45.1–68.9 g/l and the same FiO2 accounted for 100 %, the deviation of IDO2 was 2–3 times lower than the normal state of the gas transport blood function and only in patients with Ht 29.0–30.0 % and Hb 70.1–79.9 g/l, IDO2 values were close to the physiological norm. At Ht levels of 20.0–22.9 %, and Hb 45.1–50.4 g/l, the systemic oxygen consumption index was twice less than the generally accepted physiological norms, and in patients with the level of Ht 29.0–30.0 %, and Hb 70.1–79.9 g/l, the values of this indicator were within normal li­mits. At Ht levels ranged from 20.0 to 25.9 %, and Hb 45.1–60.2 g/l, tissue oxygen extraction rates were 1.5–2 times higher than gene­rally accepted physiological norms, and in patients with Ht 29.0–30.0 %, and Hb 70.1–79.9 g/l, its values were within normal limits. When calculating the minimum accep­table value of Hb in parturient women in the conditions of blood loss by linear regression with the calculation of coefficients by the method of the least squares, the obtained Hb values of 82.5365 g/l were consi­dered minimally acceptable when functional heart state and oxygen exchange are