OB Emergencies in the ED: Ectopic Pregnancy, Pre-eclampsia, Post-partum Haemorrhage

OB Emergencies in the ED: Ectopic Pregnancy, Pre-eclampsia, Post-partum Haemorrhage

A high-density, practical guide for emergency clinicians

What Is This?

This guide covers three life-threatening obstetric (OB) emergencies that present to the emergency department (ED):
1. Ectopic pregnancy – A pregnancy implanted outside the uterus, most commonly in the fallopian tube, risking rupture and haemorrhage.
2. Pre-eclampsia – A hypertensive disorder of pregnancy (after 20 weeks) with multisystem involvement, progressing to eclampsia (seizures) or HELLP syndrome (haemolysis, elevated liver enzymes, low platelets).
3. Post-partum haemorrhage (PPH) – Excessive bleeding (>500 mL vaginal, >1000 mL caesarean) within 24 hours of delivery, leading to hypovolaemic shock.

Why it matters today: These conditions kill pregnant or recently pregnant patients globally. The ED is often the first point of contact, and delays in recognition or management directly increase mortality.

Why It Matters

• Ectopic pregnancy is the leading cause of maternal death in the first trimester (1–2% of pregnancies, but 10% of pregnancy-related deaths).
• Pre-eclampsia affects 2–8% of pregnancies and causes 14% of maternal deaths worldwide. It can progress to eclampsia (seizures) or stroke.
• PPH accounts for 25% of maternal deaths globally. In the UK, it’s the third leading direct cause of maternal mortality.

Key problem solved: Rapid identification and stabilisation of these patients in the ED prevents decompensation before definitive OB/gynaecology (OBGYN) or surgical intervention.

Core Concepts

1. Ectopic Pregnancy

• Definition: Implantation of a fertilised ovum outside the uterine cavity (95% in fallopian tubes).
• Classic triad: Amenorrhoea + vaginal bleeding + abdominal pain (but only 50% present with all three).
• Rupture risk: Tubal rupture causes haemoperitoneum, hypovolaemic shock, and death.
• Diagnostic tools:
• ?-hCG: >1500 IU/L (discriminatory zone) should show intrauterine pregnancy (IUP) on transvaginal ultrasound (TVUS). If no IUP + ?-hCG >1500-suspect ectopic.
• TVUS: Look for adnexal mass, free fluid, or "ring of fire" sign (hypervascular lesion on Doppler).
• Laparoscopy: Gold standard for diagnosis and treatment (salpingectomy or salpingostomy).

2. Pre-eclampsia

• Definition: New-onset hypertension (BP ?140/90 mmHg) after 20 weeks’ gestation + proteinuria (?0.3 g/24h) or end-organ dysfunction (e.g., renal/liver impairment, thrombocytopenia, pulmonary oedema).
• Severe features (admit immediately):
• BP ?160/110 mmHg
• Platelets <100 × 10?/L
• AST/ALT >2× upper limit of normal
• Creatinine >90 ?mol/L
• Headache, visual disturbances, epigastric pain
• Eclampsia: Seizures in a pre-eclamptic patient (can occur antepartum, intrapartum, or postpartum).
• HELLP syndrome: Haemolysis, Elevated Liver enzymes, Low Platelets (a variant of severe pre-eclampsia).

3. Post-partum Haemorrhage (PPH)

• Definition: Blood loss >500 mL (vaginal) or >1000 mL (caesarean) within 24 hours of delivery.
• Primary causes (4 Ts):
• Tone (uterine atony – 70% of cases)
• Trauma (cervical/vaginal lacerations, uterine rupture)
• Tissue (retained placenta or clots)
• Thrombin (coagulopathy, e.g., DIC)
• Stabilisation priorities:
• ABCs: Oxygen, IV access (2 large-bore cannulas), fluid resuscitation.
• Uterotonics: Oxytocin (first-line), ergometrine, misoprostol, carboprost.
• Mechanical tamponade: Bakri balloon, uterine packing.
• Surgical intervention: B-Lynch suture, uterine artery embolisation, hysterectomy (last resort).

How It Works: ED Management Workflow

1. Ectopic Pregnancy

Step 1: Recognise the patient at risk - History: Amenorrhoea, vaginal bleeding, abdominal pain, shoulder tip pain (referred from diaphragmatic irritation), syncope. - Risk factors: Previous ectopic, PID, tubal surgery, IVF, IUD in situ.

Step 2: Stabilise - ABCs: If hypotensive (SBP <90 mmHg), give 1–2 L crystalloid bolus. Type and crossmatch blood. - IV access: 2 large-bore cannulas. - Analgesia: Morphine or fentanyl (avoid NSAIDs if bleeding risk).

Step 3: Diagnose - ?-hCG: If >1500 IU/L and no IUP on TVUS-assume ectopic until proven otherwise. - TVUS: Look for: - Empty uterus - Adnexal mass (tubal ring sign) - Free fluid in pouch of Douglas (haemoperitoneum) - If unstable: Proceed to laparoscopy/laparotomy without waiting for imaging.

Step 4: Definitive management - Stable patient: Methotrexate (if ?-hCG <5000 IU/L, no fetal heartbeat, no rupture). - Unstable patient: Emergency laparoscopy/laparotomy + salpingectomy.

2. Pre-eclampsia / Eclampsia

Step 1: Identify hypertension - BP measurement: Use correct cuff size, patient seated, repeat after 15 mins if elevated. - Severe hypertension (BP ?160/110 mmHg): Treat within 30–60 mins to prevent stroke.

Step 2: Assess for severe features - Symptoms: Headache, visual disturbances, epigastric/RUQ pain, nausea/vomiting. - Signs: Hyperreflexia, clonus, oedema (not diagnostic alone). - Labs: FBC (platelets), LFTs (AST/ALT), U&Es (creatinine), urinalysis (proteinuria).

Step 3: Stabilise - Seizure prophylaxis: Magnesium sulphate (4 g IV loading dose over 15 mins, then 1 g/h infusion). - BP control: - First-line: Labetalol (20 mg IV, repeat every 10 mins up to 300 mg total). - Second-line: Hydralazine (5 mg IV, repeat every 20 mins) or nifedipine (10 mg PO, repeat in 30 mins). - Avoid: ACE inhibitors, ARBs, diuretics (teratogenic/unsafe in pregnancy).

Step 4: Deliver the baby (definitive treatment) - ?37 weeks: Induce labour or caesarean. - <34 weeks: Steroids (betamethasone) for fetal lung maturity, then deliver if severe features persist.

3. Post-partum Haemorrhage (PPH)

Step 1: Recognise PPH - Signs: Heavy vaginal bleeding, boggy uterus, tachycardia, hypotension, oliguria. - Quantify blood loss: Weigh pads (1 g = 1 mL blood).

Step 2: Call for help - Activate massive transfusion protocol (MTP) if bleeding uncontrolled. - OBGYN, anaesthetics, haematology, theatre team.

Step 3: Resuscitate - ABCs: High-flow oxygen, 2 large-bore IVs, warm fluids/blood. - Uterotonics (in order): 1. Oxytocin: 5–10 IU IV/IM, then 40 IU in 500 mL saline over 4 hours. 2. Ergometrine: 500 mcg IV/IM (avoid in hypertension). 3. Misoprostol: 800–1000 mcg PR. 4. Carboprost: 250 mcg IM (repeat every 15 mins, max 8 doses; avoid in asthma).

Step 4: Identify and treat the cause | Cause | Action | |-----------------|----------------------------------------------------------------------------| | Uterine atony | Bimanual uterine massage, Bakri balloon, B-Lynch suture. | | Trauma | Inspect cervix/vagina for lacerations, repair surgically. | | Retained tissue | Manual removal of placenta/clots, curettage. | | Coagulopathy | FFP, cryoprecipitate, platelets, tranexamic acid (1 g IV). |

Step 5: Escalate if bleeding persists - Uterine artery embolisation (interventional radiology). - Hysterectomy (last resort).

Hands-On: ED Management Checklists

Ectopic Pregnancy

1. Assess stability:
2. SBP <90 mmHg-activate MTP, call OBGYN/surgery.
3. Stable-proceed to imaging.
4. Order:
5. ?-hCG (quantitative)
6. TVUS (if ?-hCG >1500 IU/L and no IUP-assume ectopic)
7. If unstable:
8. 2 large-bore IVs, O-negative blood, laparotomy.
9. If stable:
10. Methotrexate (if ?-hCG <5000 IU/L, no fetal heartbeat, no rupture).
11. Follow-up ?-hCG in 48 hours (should drop by 15%).

Pre-eclampsia

1. Check BP:
2. ?160/110 mmHg-treat within 30 mins (labetalol/hydralazine).
3. Assess for severe features:
4. Headache, visual disturbances, epigastric pain, hyperreflexia.
5. Labs:
6. FBC, LFTs, U&Es, urinalysis (proteinuria).
7. If severe features:
8. Magnesium sulphate (4 g IV loading dose, then 1 g/h infusion).
9. Deliver baby (induction/caesarean).
10. If eclampsia (seizures):
11. ABCs, magnesium sulphate, deliver ASAP.

Post-partum Haemorrhage

1. Call for help (OBGYN, anaesthetics, haematology).
2. ABCs:
3. Oxygen, 2 large-bore IVs, warm fluids/blood.
4. Uterotonics:
5. Oxytocin-ergometrine-misoprostol-carboprost.
6. Bimanual uterine massage.
7. Identify cause (4 Ts):
8. Tone: Bakri balloon, B-Lynch suture.
9. Trauma: Repair lacerations.
10. Tissue: Manual removal/curettage.
11. Thrombin: FFP, cryoprecipitate, tranexamic acid.
12. If bleeding persists:
13. Uterine artery embolisation or hysterectomy.

Common Pitfalls & Mistakes

Ectopic Pregnancy

1. Assuming ?-hCG <1500 IU/L rules out ectopic.
2. Why it’s wrong: Ectopics can have low ?-hCG. Repeat in 48 hours if no IUP on TVUS.

3. Fix: If ?-hCG is rising <50% in 48 hours, suspect ectopic.

4. Discharging a patient with pain + bleeding + positive pregnancy test.

5. Why it’s wrong: 50% of ectopics present atypically (e.g., no bleeding).

6. Fix: Never discharge without TVUS or OBGYN review.

7. Delaying surgery in an unstable patient for imaging.

8. Why it’s wrong: Ruptured ectopic-haemorrhagic shock-death.
9. Fix: If hypotensive + positive pregnancy test-laparotomy now.

Pre-eclampsia

1. Ignoring "mild" hypertension (BP 140–159/90–109 mmHg).
2. Why it’s wrong: Can progress to eclampsia or stroke.

3. Fix: Admit all pre-eclamptic patients for monitoring.

4. Using magnesium sulphate for BP control.

5. Why it’s wrong: Magnesium prevents seizures, not hypertension.

6. Fix: Use labetalol/hydralazine for BP, magnesium for seizure prophylaxis.

7. Stopping magnesium sulphate after delivery.

8. Why it’s wrong: 25% of eclampsia cases occur postpartum.
9. Fix: Continue magnesium for 24 hours postpartum.

Post-partum Haemorrhage

1. Underestimating blood loss.
2. Why it’s wrong: PPH is often concealed (e.g., intra-abdominal bleeding).

3. Fix: Weigh pads, check vitals (tachycardia/hypotension = late signs).

4. Not calling for help early.

5. Why it’s wrong: PPH can escalate to DIC in minutes.

6. Fix: Activate MTP at first sign of uncontrolled bleeding.

7. Relying on oxytocin alone for uterine atony.

8. Why it’s wrong: Oxytocin receptors saturate quickly.
9. Fix: Escalate to ergometrine/misoprostol/carboprost early.

Best Practices

Ectopic Pregnancy

• Always consider ectopic in any woman of reproductive age with abdominal pain or vaginal bleeding.
• If ?-hCG >1500 IU/L and no IUP on TVUS-assume ectopic.
• Never discharge a patient with a positive pregnancy test without OBGYN review.

Pre-eclampsia

• Treat BP ?160/110 mmHg within 30–60 mins to prevent stroke.
• Magnesium sulphate is for seizure prophylaxis, not BP control.
• Deliver the baby if severe features persist (even if preterm).

Post-partum Haemorrhage

• Use the "4 Ts" to identify the cause.
• Call for help early (OBGYN, anaesthetics, haematology).
• Start uterotonics in order (oxytocin-ergometrine-misoprostol-carboprost).

Tools & Frameworks

Real-World Use Cases

1. Ectopic Pregnancy: Ruptured Tubal Ectopic

• Scenario: A 28-year-old woman presents with sudden-onset severe lower abdominal pain, syncope, and shoulder tip pain. BP 80/50 mmHg, HR 120 bpm.
• ED actions:
• 2 large-bore IVs, O-negative blood, call OBGYN/surgery.
• No imaging needed (unstable-straight to laparotomy).
• Outcome: Salpingectomy, 4 units PRBCs, stable post-op.

2. Pre-eclampsia: Eclampsia in the ED

• Scenario: A 32-year-old at 36 weeks’ gestation has a tonic-clonic seizure in the ED. BP 180/110 mmHg, proteinuria 3+.
• ED actions:
• ABCs, left lateral tilt, magnesium sulphate (4 g IV loading dose).
• Labetalol