Obstetric and Gynecologic Emergencies

1

What are the typical expected physiologic/anatomic changes in pregnancy?

A number of changes occur. Average weight gain is 25–35 lbs (11.5–16 kg). Most weight gain is from the enlarged uterus/fetus, blood volume, breast tissue, and extracellular fluid. Physiologic changes include 1500 mL increase in blood volume, heart rate increases of 15 to 20 bpm, increased cardiac output (30%–50% above baseline), and a trend toward lower mean arterial pressure. Functional residual capacity (FRC) also decreases in pregnancy, up to 10% to 25% depending on gestational age, due to uterine enlargement resulting in an upward movement toward the diaphragm and elevating. Minute ventilation with a subsequent respiratory alkalosis and increased oxygen consumption are the leading reasons for increased hypoxemia in a pregnant patient with decreased or absent respirations.

Case: A 23-year-old female calls EMS for sudden-onset lower abdominal pain. She was running and felt a sudden “pain.” She is nauseated and reports vaginal bleeding that started today. Her friend reports a possible syncopal episode. She denies trauma and reports her period is 3 weeks late. She denies sexual activity. Vital signs (VS): blood pressure (BP), 83/45; heart rate (HR), 123; respiratory rate (RR), 16; temperature (T), 100.4 (oral); and 100% room air (RA).

2

What diagnoses are included in her differential and what actions need to be taken?

The differential for this patient is wide, including ovarian torsion, ectopic pregnancy, appendicitis, tuboovarian abscess (TOA), pelvic inflammatory disease (PID), and threatened miscarriage. Maintaining a high index of suspicion is key for not missing these diagnoses in female patients. The patient is hypotensive, tachycardic, febrile, and in pain. Given the sudden onset of pain, ovarian torsion and ruptured ectopic are higher on the differential. The delay in her normal menstrual period also leads toward an ectopic. The patient should receive intravenous (IV) fluids and pain medication and be transported to a facility where an obstetrician/gynecologist or general surgeon with surgical capabilities can evaluate her. Prompt transport and further evaluation can decrease morbidity as well as mortality in these cases.

3

What is an ectopic pregnancy?

Any pregnancy implanted outside the endometrial cavity, occurring in 1.5% to 2.6% of pregnancies, with an increased risk if there is a history of PID.

Case: A 35-year-old female 35 weeks pregnant with twins calls EMS for sudden-onset central abdominal pain. She was sitting at home and her 3-year-old child jumped on her stomach. She is nauseated and reports vaginal bleeding that started after he jumped on her. She reports chronic hypertension, and her first delivery was by cesarean section. VS: BP, 142/82; HR, 123; RR, 22; T, afebrile; 100% RA. The patient smokes socially.

4

What are risk factors for placental abruption?

Placental abruption is premature separation of the placenta from the uterine wall and accounts for upward of 30% of second trimester bleeding. Abdominal pain and vaginal bleeding should lead you to concerns for abruption, but vaginal bleeding can be absent with a concealed hemorrhage. Risk factors include chronic hypertension with or without preeclampsia, smoking, multiple gestation pregnancies, trauma, and cocaine/drug use.

5

What if the patient in the case had a more severe trauma mechanism? Does this change your concerns?

Uterine rupture can occur in late-term pregnancies or those with multiple gestations due to a thinning uterine wall and increased intrauterine volume. Loss of fundal height or a fetal presenting part that is easily palpable through the abdominal can occur. Vaginal bleeding, VS instability, and fetal heart rate abnormalities (bradycardia) are common.

6

What if the patient has painless vaginal bleeding and no trauma? Does this change your concerns?

Yes, painless vaginal bleeding can be seen in the setting of a vase/placenta previa occurring in the second half of pregnancy. In previa, the placenta or umbilical cord (vasa) overlies the internal cervical os. Digital cervical examinations are contraindicated; any further examination should be deferred to the treating facility. Large-bore IV above the diaphragm access should be obtained.

Case: A 43-year-old female who is 39 weeks pregnant with twins calls EMS for sudden-onset blurred vision and headache. She is nauseated, reports good fetal movement, and denies vaginal bleeding or loss of fluid. She has 2+ pitting edema in her lower extremities. Past medical history (PMH): chronic hypertension. Past surgical history (PSH): cesarean section. VS: BP, 172/112; HR, 98; RR, 18; T, afebrile; 100% RA. Repeat BP 5 minutes later is 175/110.