18.1 Obstetric Trauma and Medical Emergencies

After 20 weeks the uterus is a venous tourniquet if you leave the patient flat. Domain 5.A of the August 2026 Board of Certification for Emergency Nursing (BCEN) Certified Flight Registered Nurse (CFRN) outline tests obstetrical trauma and medical emergencies because one stretcher holds two patients and because aortocaval compression will steal cardiac output if you ignore the first. Pharmacology, delivery, and postpartum care continue in section 18.2.

Two patients, one circulation

The fetus lives on maternal cardiac output. Oxygenate, ventilate, and perfuse the mother first. A handheld Doppler tone on the ramp does not excuse a hypotensive, hypoxic, or supine mother. Maternal resuscitation is fetal resuscitation. Do not delay maternal advanced cardiac life support (ACLS) to hunt a fetal heart rate while the aircraft turns.

Document gestational age, number of fetuses, prenatal complications, Rh status if available, contractions, rupture of membranes, vaginal bleeding, and fetal movement. Continuous electronic fetal monitoring is a sending or receiving skill. You will not produce a reliable tracing in a vibrating cabin. Hand off what you have and fly.

Aortocaval compression and left uterine displacement

After about 20 weeks—when the fundus is near the umbilicus—the gravid uterus compresses the inferior vena cava (IVC) and can compress the aorta when the patient is supine. Venous return, stroke volume, and placental perfusion fall. She may look only dizzy, or she may crash when you strap her flat for takeoff.

Left uterine displacement (LUD) is the flight intervention:

• Manual LUD: displace the uterus left off the cava while you work the airway or chest.
• Tilt: 15–30 degrees of left lateral tilt with blankets or a backboard wedge if spinal motion restriction allows.
• Full left lateral decubitus if she is not a spinal precaution and the cabin allows.

Do not accept a perfectly supine packaged photo after 20 weeks. If you must be more supine for intubation or compressions, someone owns continuous LUD.

Dalton's law still applies. Pregnant patients have higher oxygen consumption and a lower functional residual capacity (FRC). Raise fraction of inspired oxygen (FiO2) early. Request a lower cabin if she is already borderline on the pad.

Trauma: belt, abruption, rupture, previa

The lap belt sits under the belly across the iliac crests; the shoulder strap runs between the breasts and lateral to the uterus. A belt high on the fundus is a lever on the placenta.

Abruption, rupture, and previa

Placental abruption is premature placental separation after trauma, cocaine, hypertension, or sudden deceleration. Painful bleeding is classic, but bleeding can be concealed. The uterus can be rigid and tender. Shock can outrun visible blood. Disseminated intravascular coagulation (DIC) can follow. Treat maternal shock, keep LUD, give blood per program (Chapter 8), and fly to a hospital that can operate on a pregnant abdomen and resuscitate a neonate.

Uterine rupture follows a prior cesarean scar, trauma, or obstructed labor. Pain may be tearing. Contractions can stop. Fetal parts may be felt outside the expected contour. Shock is often out of proportion. This is an operating-room destination, not a community labor hold.

Placenta previa presents as painless bright red bleeding when the placenta covers the cervix. Do not perform a digital vaginal exam. Do not pack the vagina. Support volume and go to a capable obstetric operating room.

Hypertensive disease, HELLP, and amniotic fluid embolism

Preeclampsia is new hypertension after 20 weeks plus proteinuria or end-organ signs. Severe-range blood pressure is commonly taught as 160/110 mm Hg or higher. Headache, visual change, pulmonary edema, right-upper-quadrant (RUQ) pain, thrombocytopenia, and rising liver enzymes are not ramp-and-wait findings. Eclampsia is the seizure. Magnesium sulfate is the anticonvulsant (toxicity and calcium live in 18.2). Destination can deliver, run a neonatal intensive care unit (NICU) matched to gestational age, and treat stroke-range blood pressure. Watch the face and the end-tidal carbon dioxide (ETCO2) waveform; rotor noise can hide a brief convulsion.

HELLP syndrome is Hemolysis, Elevated Liver enzymes, and Low Platelets. The liver can infarct or rupture. Palpate gently. Treat as a combined obstetric and surgical emergency, not as gastritis at cruise.

Amniotic fluid embolism (AFE) is sudden collapse around labor, delivery, or immediately postpartum: hypoxia, hypotension or arrest, and often explosive DIC. Think AFE when a delivering or just-delivered patient codes without another obvious cause. Support and blood—not a single antidote.

Arrest, the four-minute clock, and what you will not do in cruise

If a pregnant patient arrests and the uterus is at or above the umbilicus, high-quality maternal cardiopulmonary resuscitation (CPR) with continuous LUD is the first job. Emptying the uterus can restore maternal venous return. Classic teaching starts a perimortem cesarean—also called resuscitative hysterotomy—at about 4 minutes of unsuccessful resuscitation. That operation is a physician procedure in a place that can open an abdomen. Do not invent that you will perform a cesarean in a helicopter. Say the time of arrest out loud. Divert to the nearest capable facility. Keep ACLS and LUD going.

Kleihauer-Betke testing for fetal-maternal hemorrhage and Rho(D) immune globulin (RhoGAM) for the Rh-negative mother are receiving interventions. Document Rh status if known, the mechanism, and any vaginal bleeding. Do not delay lift for a Kleihauer-Betke result.

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