8.2 Ob/Gyn Emergencies and Emergency Delivery

Ob/Gyn Emergencies and Emergency Delivery

Critical care transport teams frequently encounter acute obstetrical emergencies that threaten both maternal and fetal lives. Rapid diagnostic differentiation, structured resuscitation, and decisive physical maneuvers during unexpected delivery are essential skills for the flight paramedic.

Obstetrical Hemorrhage: Placenta Previa vs. Placental Abruption

Maternal hemorrhage remains a leading cause of preventable maternal mortality. The transport clinician must rapidly differentiate between placenta previa and placental abruption (abruptio placentae) as their clinical courses and interventions differ.

[!WARNING] Never perform a digital vaginal examination on a pregnant patient presenting with third-trimester vaginal bleeding unless ultrasound has definitively ruled out placenta previa. Digitally disrupting a previa can cause catastrophic, fatal maternal hemorrhage.

Uterine Rupture

Uterine rupture is a catastrophic event occurring most commonly in patients with a history of prior Cesarean delivery or uterine surgery. It represents a complete tearing of the uterine wall, exposing the fetus and uterine contents to the peritoneal cavity.

Clinical Presentation

• Sudden, severe, sharp abdominal pain ("tearing" sensation) that may persist between contractions.
• Referred shoulder pain (Kehr's sign): Caused by blood accumulating under the diaphragm, irritating the phrenic nerve.
• Loss of fetal station: The presenting part of the fetus recedes back into the uterine cavity and is no longer palpable on vaginal exam.
• Cessation of uterine contractions: Active contractions stop abruptly.
• Signs of hypovolemic shock: Rapid maternal tachycardia, hypotension, and altered mental status.
• Fetal distress: Prolonged deceleration or bradycardia is the most common presenting sign.

Transport Management

Uterine rupture is a surgical emergency. Transport teams must focus on maintaining maternal perfusion with large-bore IV/IO access, initiating massive transfusion protocols (MTP) with uncrossed 1:1 packed red blood cells (PRBCs) and fresh frozen plasma (FFP), and maintaining left lateral tilt. Rapid transport to a surgical facility is the only definitive treatment.

Postpartum Hemorrhage (PPH)

Postpartum hemorrhage is traditionally defined as blood loss >500 mL after a vaginal delivery or >1000 mL after a Cesarean delivery, or any blood loss within 24 hours of delivery that leads to signs of hemodynamic instability.

The Four Ts of PPH

1. Tone (Uterine Atony): Accountable for approximately 70-80% of all PPH cases. The uterus fails to contract down after delivery to compress the spiral arteries.
2. Tissue: Retained placenta or membranes prevent the uterus from contracting.
3. Trauma: Lacerations of the cervix, vagina, or perineum; uterine inversion.
4. Thrombin: Pre-existing or acquired coagulopathies (e.g., DIC, hemophilia).

Clinical Management and Pharmacological Reference

If uterine atony is suspected, management must proceed in a rapid, stepwise fashion starting with uterine massage and bimanual compression, followed by targeted pharmacotherapy:

• Oxytocin (Pitocin): First-line agent for all patients. Causes rhythmic uterine contractions. Dose: 10 to 40 units diluted in 1000 mL of crystalloid, infused at 250 mL/hour, or 10 units intramuscularly (IM) if IV access is not yet established. Never give as a rapid IV bolus, as it can cause profound hypotension and cardiovascular collapse.
• Methylergonovine (Methergine): Ergot alkaloid that causes sustained tetanic uterine contraction. Dose: 0.2 mg IM (never IV due to severe vasoconstrictive risk). Contraindicated in hypertensive patients (preeclampsia, eclampsia, chronic hypertension) due to the risk of precipitating hypertensive crisis or stroke.
• Carboprost Tromethamine (Hemabate): Prostaglandin F2-alpha analogue. Dose: 250 mcg IM (may repeat every 15-90 minutes, max 8 doses). Contraindicated in patients with asthma due to the risk of severe bronchoconstriction.
• Misoprostol (Cytotec): Prostagroldin E1 analogue. Dose: 800 to 1000 mcg administered rectally (preferred in transport to avoid oral airway issues or vomiting). Safe in patients with hypertension and asthma.
• Tranexamic Acid (TXA): Antifibrinolytic. Dose: 1 g IV administered over 10 minutes. Must be given within 3 hours of delivery for maximal benefit. Can be repeated once if bleeding persists after 30 minutes.

Delivery Complications and Physical Maneuvers

When delivery occurs in the transport environment, the flight paramedic must be prepared to manage mechanical delivery complications.

1. Breech Delivery

Breech presentation occurs when the fetal buttocks or feet are the presenting part. The most significant risk is entrapment of the aftercoming fetal head, which can lead to asphyxia.

• Management: Allow the delivery to proceed spontaneously until the umbilicus is visible. Do not pull or traction the fetus.
• Mauriceau-Smellie-Veit Maneuver: Used to deliver the head. Place the index and middle finger of your non-dominant hand on the fetal maxilla (cheekbones) to flex the head. Support the fetal body along your dominant forearm, and place your index and middle fingers of the dominant hand over the fetal shoulders to apply gentle traction while flexing the neck.
• Airway Protection: If the head remains trapped, insert a gloved hand into the vagina, creating a "V" with your index and middle fingers on either side of the baby's nose and mouth to displace the vaginal wall and establish a patent airway. Do not remove your hand until delivery is complete or you arrive at the receiving facility.

2. Shoulder Dystocia

Shoulder dystocia occurs when the fetal anterior shoulder becomes impacted behind the maternal pubic symphysis, preventing delivery.

• Turtle Sign: The fetal head delivers but then immediately retracts tightly against the maternal perineum.
• McRoberts Maneuver: Hyperflex the mother's thighs tightly against her abdomen. This flattens the sacrum and rotates the pubic symphysis cephalad, opening the birth canal.
• Suprapubic Pressure: Apply downward, steady pressure over the maternal pubic symphysis (from the side of the fetal back) to displace the anterior shoulder under the pubic bone.
• CRITICAL WARNING: Never apply fundal pressure during shoulder dystocia. Fundal pressure further impacts the shoulder behind the pubic bone and can cause uterine rupture or severe fetal brachial plexus injury (Erb's palsy).

3. Prolapsed Umbilical Cord

A prolapsed cord occurs when the umbilical cord slips ahead of the presenting part, leading to compression of the cord between the fetus and the maternal pelvis during contractions.

• Management:
  1. Immediately insert a gloved hand into the vagina and apply upward pressure on the fetal presenting part (the head or breech) to lift it off the umbilical cord. Do not remove your hand until you are in the operating room and a surgeon takes over or performs a Cesarean section.
  2. Place the mother in the knee-chest position or extreme Trendelenburg position to use gravity to relieve pressure on the cord.
  3. Wrap the exposed, prolapsed cord in warm, moist, sterile saline gauze to prevent vasospasm.
  4. Do not attempt to push the cord back into the uterine cavity.