Emergency Obstetric Anesthesia

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Pregnant Patient Physiology & Risks - Code Red Mama

  • Cardiovascular: ↑CO (30-50%), ↑HR. Supine hypotension (aortocaval compression) - LUD crucial.
  • Respiratory: ↑O₂ demand, ↑MV, ↓FRC (20-30%) → rapid desaturation. Airway edema → difficult intubation risk.
  • Gastrointestinal: ↓LES tone, delayed gastric emptying → ↑aspiration risk.
  • Nervous System: ↓MAC (up to 30%). ↓Epidural/spinal volume.
  • Key Risks:
    • Difficult airway
    • Aspiration (Mendelson's)
    • Rapid O₂ desaturation
    • Supine hypotension
    • ↑Drug sensitivity 📌 "HERO" for High-Risk Obstetric Patient: Hypotension (supine), Emptying (gastric delayed), Respiratory (↓FRC, edema), Oxygen (desaturation fast).

    ⭐ Aortocaval compression by the gravid uterus causes supine hypotension. Prevent with left uterine displacement (LUD) of at least 15°. Aortocaval compression and left uterine displacement

Airway & RSI in Obstetrics - Can't Breathe, Baby!

  • Airway Challenges:
    • ↑ Airway edema, friability (bleeding risk).
    • ↓ FRC, ↑ O2 consumption → rapid desaturation.
    • Mallampati score often ↑.
  • RSI (Assume Full Stomach):
    • Pre-oxygenation: 3-5 min 100% O2 or 4-8 vital capacity breaths.
    • Cricoid pressure (Sellick’s).
    • Drugs:
      • Induction: Propofol (1.5-2.5 mg/kg), Ketamine (1-2 mg/kg).
      • Paralysis: Succinylcholine (1-1.5 mg/kg).
    • ETT size: 6.0-7.0 mm.
  • Difficult Airway Plan:
    • Anticipate (LEMON).
    • SADs, AFOI, surgical airway ready.

⭐ Due to ↓FRC and ↑O2 consumption, pregnant patients desaturate very rapidly (within 2-3 min) after apnea.

Pregnant Patient Airway Intubation Challenges

Anesthesia for Emergency C-Section - Speedy Delivery Anesthesia

  • Goal: Rapid, safe anesthesia for mother & fetus.
  • Choice: General Anesthesia (GA) vs. Regional (Spinal).
  • GA Indications:
    • Extreme urgency (e.g., fetal distress, hemorrhage).
    • Regional contraindicated/failed.
    • Maternal refusal.
  • Spinal Anesthesia: Preferred if time permits (>10-15 min to incision) & no contraindications. Faster onset than epidural.
  • GA Technique (RSI - Rapid Sequence Intubation):
    • Preoxygenation: 100% O2 for 3-5 min.
    • Induction: Propofol or Ketamine (if hemodynamically unstable).
    • Muscle Relaxant: Succinylcholine or Rocuronium.
    • Maintain: Volatiles (0.5-0.75 MAC till delivery), then ↑.
  • Aspiration Prophylaxis: Crucial (e.g., Ranitidine, Sodium Citrate).
  • Left Uterine Displacement (LUD): Essential.

⭐ Maintain left uterine displacement (LUD) of at least 15 degrees or manual displacement until delivery to prevent aortocaval compression.

Managing Obstetric Crises - Mayday! Mayday! Mama Needs Help!

  • General Approach:
  • Key Crises & Anesthetic Pointers:
    • Amniotic Fluid Embolism (AFE): Sudden CV collapse, hypoxia, coagulopathy. Rx: Aggressive supportive care (ABC, O2, intubation, vasopressors, blood products), ICU. 📌 A-OK (Atropine, Ondansetron, Ketorolac) - controversial.
    • Major Obstetric Hemorrhage (MOH):
      • Causes: 4Ts (Tone, Trauma, Tissue, Thrombin). Atony common.
      • Rx: Call for help (MTP!), ABCs. Uterotonics (Oxytocin etc.), surgical control. GA.

      ⭐ Activate Massive Transfusion Protocol (MTP) early: PRBC:FFP:Platelets in 1:1:1 ratio.

    • Eclampsia: Seizures + preeclampsia. Rx: Magnesium sulfate (4-6g IV load, 1-2g/hr). Airway, O2. Avoid Ketamine.
    • Uterine Rupture: Fetal distress, maternal shock. Rx: Emergency laparotomy. RSI + GA. Aggressive resuscitation.
    • Placental Abruption: Painful bleed, fetal distress. Rx: Emergency CS. GA. Prepare for DIC. Multidisciplinary team training for obstetric emergency

High‑Yield Points - ⚡ Biggest Takeaways

  • Aspiration prophylaxis (e.g., ranitidine, sodium citrate) is crucial before any anesthetic.
  • Higher risk of difficult airway in parturients; always be prepared.
  • Rapid Sequence Intubation (RSI) is the technique of choice for General Anesthesia (GA).
  • Maintain left uterine displacement continuously to prevent aortocaval compression.
  • Proactively manage maternal hypotension following neuraxial or general anesthesia.
  • Anticipate and manage Postpartum Hemorrhage (PPH) with uterotonics.
  • GA is preferred for Category 1 (most urgent) C-sections due to speed of onset.

Practice Questions: Emergency Obstetric Anesthesia

Test your understanding with these related questions

A 29-year-old G3P2 woman at 34 weeks' gestation is involved in a serious car accident, loses consciousness briefly, and presents to the emergency department awake and alert with a severe headache, abdominal, and pelvic pain. Her vital signs include a blood pressure of 150/90 mm Hg, heart rate of 120/min, temperature of 37.4°C (99.3°F), and respiratory rate of 22/min. Fetal heart rate is 155/min. Physical examination reveals minor bruises on the abdomen and limbs, blood in the vault upon vaginal inspection, and strong, frequent uterine contractions. Which of the following is most likely a complication of her current condition?

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Flashcards: Emergency Obstetric Anesthesia

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Preoxygenation with tidal volume breathing of _____ mins is required before tracheal intubation

TAP TO REVEAL ANSWER

Preoxygenation with tidal volume breathing of _____ mins is required before tracheal intubation

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