Is the Thrive protocol (rapid sequence intubation protocol) a suitable approach for intubation during a Cesarean section (C-section)?

THRIVE Protocol is NOT Appropriate for Cesarean Section Intubation

The THRIVE (Transnasal Humidified Rapid-Insufflation Ventilatory Exchange) protocol should not be used as the primary approach for intubation during cesarean section, as it is not mentioned in current obstetric airway guidelines and does not address the critical aspiration risk inherent to pregnant patients requiring rapid sequence induction. 1

Why THRIVE is Inappropriate for C-Section

Aspiration Risk Takes Priority

• Pregnant patients are at high risk for aspiration due to decreased lower esophageal sphincter tone from progesterone, delayed gastric emptying during labor, and increased intra-abdominal pressure 1
• Rapid sequence induction (RSI) with cricoid pressure remains the standard specifically to prevent aspiration during the vulnerable period between loss of consciousness and securing the airway 1, 2
• THRIVE involves passive oxygenation without airway protection, which directly contradicts the fundamental principle of aspiration prevention in obstetrics 1

What the Guidelines Actually Recommend

Pre-oxygenation technique (not THRIVE):

• Achieve end-tidal oxygen fraction (FetO2) ≥ 0.9 using tight-fitting facemask with fresh gas flow ≥ 10 L/min for 2-3 minutes 1
• Consider nasal cannulae at 5 L/min oxygen flow started before pre-oxygenation to provide apneic oxygenation during laryngoscopy attempts 1
• This apneic oxygenation via nasal cannulae is supplementary only and does not replace RSI 1

Standard RSI protocol for cesarean section:

• Propofol (preferred over thiopental) at adequate dosing to prevent awareness 1, 2
• Rocuronium 0.6-1.0 mg/kg or succinylcholine 1 mg/kg for neuromuscular blockade 1, 3, 4, 5
• Cricoid pressure (10 N initially, then 30 N after loss of consciousness) 1
• No positive pressure ventilation until airway is secured (unless "can't intubate, can't oxygenate" scenario) 1

The Correct Approach: Modified RSI with Apneic Oxygenation

Algorithm for obstetric intubation:

1. Pre-theatre preparation 1:

   • Airway assessment documented
   • Antacid prophylaxis (H2-blocker + sodium citrate immediately before induction)
   • Team briefing on "wake vs. proceed" decision if intubation fails

2. Positioning 1:

   • Head-up 15-30° (reduces aspiration risk and improves laryngoscopy view)
   • Ramped position in obese patients (external auditory meatus aligned with suprasternal notch)

3. Oxygenation strategy 1:

   • Apply nasal cannulae at 5 L/min oxygen
   • Pre-oxygenate with 100% oxygen via tight-fitting facemask for 2-3 minutes
   • Target FetO2 ≥ 0.9

4. Induction 1, 2:

   • Propofol 2-2.5 mg/kg (adequate dosing critical to prevent awareness)
   • Rocuronium 1 mg/kg (provides intubating conditions at 60 seconds comparable to succinylcholine) 4, 5
   • Apply cricoid pressure

5. Intubation 1:

   • Attempt at 60 seconds
   • Maximum 3 attempts before moving to failed intubation algorithm
   • Videolaryngoscopy preferred if available

Critical Pitfalls to Avoid

Common errors that increase morbidity:

• Inadequate induction agent dosing leading to awareness (documented as high-risk in obstetrics by NAP5 audit) 1
• Excessive cricoid pressure (>30 N) causing airway obstruction 1
• Failure to remove cricoid pressure when intubation becomes difficult 1
• Attempting positive pressure ventilation before airway is secured (increases aspiration risk) 1

When to deviate from standard RSI:

• If predicted extremely difficult airway identified antenatally, awake fiberoptic intubation should be planned instead 1
• If "can't intubate, can't oxygenate" occurs, proceed immediately to front-of-neck access 1

Why Simple Nasal Oxygen ≠ THRIVE Protocol

The guidelines mention nasal oxygen supplementation, but this is fundamentally different from THRIVE 1:

• Nasal cannulae at 5 L/min provide modest apneic oxygenation as a safety adjunct
• THRIVE uses high-flow humidified oxygen (30-70 L/min) as a primary oxygenation strategy
• THRIVE has only been studied in non-pregnant patients and is not validated for aspiration-risk scenarios 1

The obstetric patient requires immediate airway protection, not prolonged apneic oxygenation. 1, 2