Peripartum hemorrhage

Published on 07/02/2015 by admin

Filed under Anesthesiology

Last modified 07/02/2015

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Peripartum hemorrhage

K.A. Kelly McQueen, MD, MPH

Despite advances in obstetric care and improved diagnostic testing, peripartum hemorrhage remains a leading cause of maternal morbidity and death. Severe bleeding is most common in the third trimester of pregnancy and near the time of delivery.

Antepartum hemorrhage

Causes of antepartum hemorrhage

Severe antepartum hemorrhage is most commonly associated with placenta previa, abruptio placentae, and uterine rupture.

Placenta previa

Placenta previa is defined as abnormal implantation of the placenta on the lower uterine segment with partial to complete occlusion of the internal cervical os. It occurs in 1 in 200 to 1 in 250 deliveries and is associated with maternal mortality rate of up to 0.9%. The multiparous patient and the older patient are at increased risk for developing placenta previa, as are patients undergoing repeat cesarean section (C/S). The chance of recurrence in a subsequent pregnancy is approximately 5%.

Abruptio placentae

Abruptio placentae results from separation of a normally implanted placenta after 20 weeks of gestation and before birth. It occurs in 1 in 75 to 1 in 226 deliveries. Maternal mortality rate is 1.8% to 2.8%, and fetal mortality rate may be as high as 50%. Risk factors include hypertensive disorders, high parity, uterine abnormalities, trauma, intravenous drug use, and history of previous abruption. Bleeding may be apparent (external) or concealed (internal) and varies in severity from mild (<100 mL) to severe (>500 mL).

The type of delivery and the timing will depend on the severity of hemorrhage. With limited blood loss, vaginal delivery is often possible. If the mother or fetus is in distress, then rapid delivery by C/S is required. In mild or moderate abruptions with fetal death, maternal coagulation must be evaluated before regional anesthetic is administered because disseminated intravascular coagulation may occur within 8 h of fetal demise.

Uterine rupture

Uterine rupture is a rare but serious cause of hemorrhage occurring in 0.1% to 0.3% of pregnancies. Risk factors include previous uterine surgery, past history of uterine rupture, abnormal fetal presentation, operative vaginal delivery, use of uterotonic agents, and uterine distention. Maternal mortality rate approaches 5%, and fetal mortality rate is as high as 50%. Presenting signs and symptoms include atypical abdominal pain, shoulder pain, vaginal bleeding, uterine tenderness, hypotension, tachycardia, and shock.

Anesthetic management of antepartum hemorrhage

Anesthetic management includes ensuring the availability of blood and blood products and securing adequate venous access through placement of large-bore central cannulas, peripheral cannulas, or both. If an emergency C/S is required, general anesthesia is usually recommended because of maternal intravascular hypovolemia, coagulopathy, positioning problems during regional anesthetic administration, and surgical urgency.

When possible, before a C/S is undertaken, all efforts should be made to stabilize the mother while maintaining uterine perfusion pressure (uterine arterial pressure minus uterine venous pressure) and maximizing oxygenation. If time permits, maternal laboratory evaluation, including platelet concentration, prothrombin time, activated partial thromboplastin time, fibrinogen level, and hemoglobin concentration, should be ordered. If maternal hemodynamic status is stable and coagulation status is normal, then regional anesthesia can be used for the urgent C/S.

Postpartum hemorrhage

The vast majority of cases of severe postpartum hemorrhage occur within a few minutes after delivery. Postpartum hemorrhage is the most common hemorrhagic condition in obstetrics and is typically defined as a blood loss of 500 mL or more within 24 h of delivery. Postpartum hemorrhage can be massive and sudden and may require aggressive therapy. The three most common causes of postpartum hemorrhage are retained placenta and membranes, uterine atony, and genital tract disruption (Box 189-1).

Box 189-1 Etiology of Antepartum and Postpartum Hemorrhage

Antepartum hemorrhage

Abruptio placentae

Placenta previa

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