Anaesthetic Management of Ruptured Ectopic Pregnancy

1. Preoperative Assessment & Immediate Priorities

Haemodynamic Classification

Concurrent Actions

• Two large-bore IV cannulae (14–16G) immediately
• Send urgent bloods: FBC, coagulation (PT, aPTT, fibrinogen), U&E, LFT, crossmatch (4 units pRBC minimum), β-hCG
• Activate massive haemorrhage protocol (MHP) early — do not wait for labs
• Foley catheter for urine output monitoring
• Anaesthetist, surgeon, scrub nurse, and blood bank all notified simultaneously
• Blood warmer and rapid infusion device (e.g. Level 1, Belmont) set up
• Intraoperative cell salvage: consider if available, though some centres avoid it in suspected infection

2. Resuscitation Strategy

Permissive Hypotension (Damage Control Resuscitation)

• Target MAP 50–65 mmHg (systolic ~80–90 mmHg) — sufficient for cerebral and coronary perfusion without worsening ongoing haemorrhage
• Avoid aggressive crystalloid resuscitation — dilutes clotting factors, worsens hypothermia, and causes abdominal compartment syndrome
• Balanced haemostatic resuscitation: pRBC : FFP : platelets in a 1:1:1 ratio
• Tranexamic acid (TXA) 1 g IV over 10 min — give as early as possible (within 3 hours of bleeding onset); repeat dose of 1 g if bleeding continues after 30 min

Vasopressors

• Vasopressin or noradrenaline can temporise BP to allow induction if the patient is moribund
• Use cautiously — may mask ongoing haemorrhage severity

3. Choice of Anaesthetic Technique

General Anaesthesia is Almost Always Required

• Sympathetic block causes catastrophic hypotension in a volume-depleted patient
• High intraabdominal blood may cause raised diaphragm — spinal block level unpredictable
• Patient cooperation and immobility cannot be guaranteed
• Surgical access for laparoscopy or laparotomy requires muscle relaxation

4. Rapid Sequence Induction (RSI)

Pre-oxygenation

• High-flow O₂ for 3–5 min (8 breaths ETF protocol acceptable in extremis)
• Head-up 20–30° if tolerated (reduces risk of passive regurgitation)
• Apnoeic oxygenation via nasal cannulae at 15 L/min during laryngoscopy

Induction Agents — Modified for Haemorrhagic Shock

Suxamethonium vs Rocuronium for Muscle Relaxation

Cricoid Pressure (Sellick's Manoeuvre)

• Apply 10 N awake, increase to 30 N at loss of consciousness
• Release if: active vomiting, laryngoscopy difficult, or airway cannot be secured
• Controversial but remains standard practice in RSI for full-stomach patients

5. Airway Management

• Video laryngoscopy preferred (improved glottic view, less force required)
• Cuffed ETT — secure and confirm position before releasing cricoid pressure
• Have a difficult airway trolley immediately available
• Bougie on the laryngoscope blade as a routine
• If cannot intubate / cannot oxygenate: follow Difficult Airway Society (DAS) failed intubation guidelines; ultimately, surgical airway

6. Intraoperative Anaesthetic Maintenance

Volatile vs TIVA

• Volatile agents (isoflurane, sevoflurane) cause dose-dependent vasodilation — use low MAC (0.5–0.8) initially, supplement with opioids
• TIVA with ketamine ± midazolam (0.05 mg/kg) is an alternative — ketamine 1–2 mg/kg/h infusion maintains haemodynamics
• Avoid high-dose volatile until surgical haemostasis is achieved and volume is being restored

Opioids

• Fentanyl 1–3 mcg/kg at induction (cautiously)
• Titrate morphine or fentanyl intraoperatively according to haemodynamic response
• Remifentanil infusion useful if concerns about awareness (reduced volatile dose)

Nitrous Oxide

• Generally avoided in emergency abdominal surgery (bowel distension, haemoperitoneum)

Monitoring

• ETCO₂ — mandatory; hypocapnia increases myocardial oxygen demand
• Invasive arterial line (A-line): radial artery — ideally pre-induction if time permits; non-invasive monitoring acceptable in extremis until access obtained
• Central venous catheter: not mandatory in acute setting; may defer until after haemostasis
• Temperature monitoring — active warming with forced-air warmer (hypothermia worsens coagulopathy — the lethal triad with acidosis and coagulopathy)
• Urinary catheter — target urine output >0.5 mL/kg/h

7. Blood Product Management & Coagulopathy

The Lethal Triad

Transfusion Targets

• Hb: maintain ≥7–8 g/dL (higher if ischaemic heart disease)
• Platelets: ≥75 × 10⁹/L (≥100 × 10⁹/L if TBI co-exists)
• Fibrinogen: ≥1.5–2.0 g/L (cryoprecipitate or fibrinogen concentrate)
• INR: ≤1.5 (FFP 15 mL/kg)
• Point-of-care coagulation testing (ROTEM/TEG) greatly assists targeted therapy

Tranexamic Acid

• Give 1 g IV as soon as massive haemorrhage recognised
• Repeat 1 g at 30 min if ongoing haemorrhage
• Evidence from WOMAN trial (postpartum haemorrhage) supports early TXA reducing mortality — extrapolated to ruptured ectopic

8. Surgical Approach & Anaesthetic Implications

• CO₂ insufflation → ↑ PaCO₂ → increase minute ventilation
• Trendelenburg position → ↑ airway pressure, ↓ FRC
• Monitor for CO₂ embolism

9. Special Considerations

Awareness Under Anaesthesia

• High risk in haemorrhagic shock — reduced MAC due to hypovolaemia, reduced cardiac output
• Use BIS monitoring if available; target BIS 40–60
• Low-dose benzodiazepine (midazolam 1–2 mg) or scopolamine (hyoscine) reduces awareness risk without significant haemodynamic effect
• Inform the patient postoperatively and document

Hypothermia Prevention

• Theatre temperature ≥22°C
• All IV fluids warmed (fluid warmer mandatory)
• Forced-air warming device (Bair Hugger)
• Warm humidified gases

Postoperative Care

• HDU/ICU admission for haemodynamically compromised patients
• Continue blood product therapy guided by lab values and ROTEM/TEG
• Monitor for: re-bleeding, acute kidney injury (from hypoperfusion), ARDS (from massive transfusion), DIC
• Pain management: multimodal — regular paracetamol, NSAIDs (once haemostasis assured), opioids PRN; consider wound infiltration with local anaesthetic

10. Summary Algorithm

RUPTURED ECTOPIC → Haemorrhagic Shock
        ↓
Simultaneous: 2× large-bore IV | Bloods + XM | Activate MHP | Ketamine RSI prep
        ↓
RESUSCITATION: TXA 1g IV | 1:1:1 pRBC:FFP:PLT | Permissive hypotension (MAP 50–65)
        ↓
RSI: Ketamine 0.5–1 mg/kg + Suxamethonium 1.5 mg/kg | Cricoid pressure | Cuffed ETT
        ↓
MAINTENANCE: Low volatile (0.5–0.8 MAC) or ketamine TIVA | Active warming | A-line
        ↓
SURGERY: Laparotomy (preferred if unstable) or laparoscopy (stable)
        ↓
HAEMOSTASIS → Restore volume → Correct lethal triad → HDU/ICU

Key Points

1. Don't delay surgery — haemostasis is the definitive treatment; anaesthesia facilitates, not delays it.
2. Ketamine is the induction agent of choice in haemorrhagic shock.
3. Permissive hypotension until haemostasis; then resuscitate fully.
4. TXA early — within 3 hours; evidence strongly supports mortality reduction.
5. Regional anaesthesia is contraindicated in haemorrhagic shock.
6. The lethal triad (hypothermia, acidosis, coagulopathy) must be actively prevented and treated.
7. Awareness risk is high — use BIS monitoring and acknowledge the risk explicitly.