What is the recommended rapid‑sequence induction regimen for endotracheal intubation in a pregnant patient to minimize maternal hypotension, uterine relaxation, and fetal drug exposure?

Rapid Sequence Induction for Pregnant Patients

Use propofol 2–2.5 mg/kg followed immediately by either rocuronium 1.0–1.2 mg/kg (with sugammadex backup) or succinylcholine 1.0 mg/kg, after completing 3 minutes of pre-oxygenation in a 20–30° head-up position with left uterine displacement. 1

Pre-Induction Positioning & Oxygenation

Positioning is critical and must be completed before any medication:

• Place the patient in 20–30° head-up position with left uterine displacement to prevent aortocaval compression, increase functional residual capacity, and extend safe apnea time. 2
• In obese patients, use "ramped" positioning (align external auditory meatus with suprasternal notch) rather than standard sniffing position to optimize laryngoscopic view. 2, 1
• Remove elaborate hair braids if present, as they restrict neck extension and worsen intubation difficulty. 2

Pre-oxygenation protocol:

• Perform tight-fitting mask pre-oxygenation for minimum 3 minutes using 100% oxygen at ≥10 L/min fresh gas flow. 2
• Target end-tidal oxygen fraction (FetO₂) ≥0.9 confirmed by capnography; breath-by-breath monitoring prevents erroneous readings from apparatus deadspace. 2
• Apply nasal cannulae at 5 L/min before starting pre-oxygenation to provide apneic oxygenation during laryngoscopy attempts. 2

Induction Agent Selection

Propofol is the preferred induction agent over thiopental:

• Administer propofol 2–2.5 mg/kg IV to ensure adequate depth of anesthesia and prevent awareness. 1
• Propofol suppresses airway reflexes more effectively than thiopental, which is advantageous if intubation fails and mask ventilation becomes necessary. 2
• The NAP5 audit identified inappropriately low thiopental doses (<4 mg/kg) as a major contributor to high awareness rates in obstetrics; adequate dosing of induction agent is mandatory. 2
• Have additional doses immediately available in case intubation difficulty is encountered. 2

Avoid ketamine as first-line in normotensive patients because retrospective evidence suggests it produces more hypotension than etomidate in shock states, though it remains acceptable when propofol is contraindicated. 3

Neuromuscular Blocker Selection

Two acceptable options exist:

Option 1: Succinylcholine (Traditional Standard)

• Administer succinylcholine 1.0 mg/kg IV immediately after propofol. 2
• Onset occurs in 45–60 seconds with spontaneous offset in approximately 9 minutes. 2
• Critical limitation: hypoxia occurs before neuromuscular recovery, so the presumed safety advantage of spontaneous ventilation return is illusory. 2
• Succinylcholine increases oxygen consumption through depolarization, causing earlier desaturation than rocuronium. 2

Option 2: Rocuronium with Sugammadex Backup (Preferred Alternative)

• Administer rocuronium 1.0–1.2 mg/kg IV immediately after propofol. 2, 1
• Onset occurs in 45–60 seconds, equivalent to succinylcholine at this dose. 2
• Sugammadex 16 mg/kg reverses rocuronium within 3 minutes, faster than the 9-minute spontaneous offset of succinylcholine. 2
• Pre-calculate sugammadex dose and have it immediately available for an assistant to draw up; anticipation is mandatory because preparation time delays reversal. 2
• Cost of sugammadex currently limits widespread adoption of this combination. 2

Cricoid Pressure Technique

• Apply 10 N force initially, then increase to 30 N after loss of consciousness. 2, 1
• Reduce force to 20 N if head-up position is used. 2
• Excessive force (>30 N or 44 N) causes airway obstruction; videolaryngoscopy allows the assistant to visualize and adjust pressure to optimize glottic view. 2
• Release or reduce cricoid pressure if intubation becomes difficult, as incorrectly applied pressure impairs laryngoscopy, tube insertion, and mask ventilation. 2

Ventilation Strategy During Apnea

• Avoid positive-pressure ventilation during rapid sequence induction to prevent gastric insufflation and aspiration risk. 2
• Gentle bag-mask ventilation (maximal inflation pressure <20 cmH₂O) is now recommended after induction drugs because it reduces oxygen desaturation without increasing aspiration risk when cricoid pressure is correctly applied. 2
• This gentle ventilation also estimates the likelihood of successful bag-mask ventilation if prolonged or failed intubation occurs. 2

Laryngoscopy & Intubation

• Perform intubation 45–60 seconds after neuromuscular blocker administration. 1
• A videolaryngoscope should be immediately available for all obstetric general anesthetics; it provides superior glottic views compared to direct laryngoscopy. 2
• Use size 7.0 tracheal tubes routinely to improve success rate and minimize trauma. 2
• If poor view is obtained, improve it by reducing/removing cricoid pressure, external laryngeal manipulation, and repositioning head/neck before attempting tube insertion. 2
• Use a bougie or stylet to facilitate tube insertion, but avoid repeated blind passage due to airway trauma risk. 2

Critical Pitfalls to Avoid

Awareness prevention:

• Never use inadequate induction doses; propofol must be dosed at 2–2.5 mg/kg, not lower. 1
• Administer propofol BEFORE paralytic, never reverse this sequence. 1

Hypoxemia prevention:

• Extended pre-oxygenation (≥3 minutes) is essential because obese pregnant patients desaturate rapidly during apnea. 1
• Nasal cannulae at 5 L/min provide apneic oxygenation during laryngoscopy attempts. 2

Aspiration prevention:

• Maintain cricoid pressure until airway is secured, but release it if intubation difficulty arises. 2, 1
• Confirm tube placement with capnography before surgical incision; never allow incision before airway security. 1

Hemodynamic stability:

• Propofol causes less hypotension than ketamine in normotensive patients; reserve ketamine for hypotensive patients. 3
• In preeclamptic patients, consider remifentanil 0.5–1 µg/kg (not fentanyl) to blunt hypertensive response to laryngoscopy. 1
• Magnesium sulfate potentiates neuromuscular blockers; reduce rocuronium dose if patient is receiving magnesium. 1

Post-Intubation Confirmation

• Confirm tube placement with capnography AND bilateral chest auscultation before any surgical steps. 1
• Release cricoid pressure after successful intubation to avoid airway trauma. 1
• Maintain quiet operating room environment during induction to reduce distraction and ensure team awareness. 2