Rapid Sequence Intubation (RSI) Notes for Ronnie

Rapid Sequence Intubation (RSI) – Study Notes

Why RSI is important

• RSI is one of the most exciting but also riskiest procedures in emergency and critical care medicine.

• It involves sedating and paralyzing a patient, removing all airway reflexes, and securing the airway rapidly.

• Main fear: patient cannot breathe on their own while paralyzed and airway may be difficult.

Case example

• Angioedema patient → airway nearly impossible with laryngoscope.

• Ultimately required cricothyrotomy.

• Lesson: successful preoxygenation provided critical extra time before desaturation.

Concepts in RSI

RSI vs Traditional Intubation

• Traditional anesthesia approach: sedative → paralytic → intubate healthy, stable patients.

• RSI was developed for critically ill patients at risk of aspiration, with full stomachs, poor reserves.

• Key feature: sedative and paralytic given in quick sequence, no bagging unless severely hypoxic.

Preoxygenation and Denitrogenation

• Crucial step: maximizes “safe apnea time” (time until desaturation after paralysis).

• Room air → <60 seconds safe apnea time.

• Proper preoxygenation replaces nitrogen in lungs with oxygen, creating reservoir.

• Goal: achieve near 100% saturation before RSI.

Apneic Oxygenation

• Use nasal cannula at 15 L/min during intubation.

• Provides continuous oxygen diffusion even when patient is apneic.

• Can be used under NRB mask or BVM during preoxygenation.

• Mnemonic: NO DESAT (Nasal Oxygenation During Efforts Securing A Tube).

Delayed Sequence Intubation (DSI)

• Used when patients cannot tolerate preoxygenation (agitated, altered, pulling off O2).

• Give dissociative dose of ketamine (1 mg/kg, then 0.5 mg/kg as needed).

• Patient remains breathing, can be preoxygenated effectively.

• Once adequately preoxygenated → give paralytic → intubate.

Preoxygenation Strategies

Risk Stratification (Levitan & Weingart)

• Low-risk patients (SpO₂ 96–100):

  • Use NRB mask ± nasal cannula at max O₂ flow (crank wall O₂ >15 L/min).

  • True NRB gives FiO₂ closer to 60–90%, not 100%.

• High-risk/hypoxemic patients (SpO₂ <95):

  • Require positive pressure (CPAP, BVM with PEEP).

  • Goal: recruit alveoli and increase oxygen reserve.

Paralytics

• Succinylcholine

  • Dose: 1.5 mg/kg IV.

  • Onset: ~45 sec. Duration: 5–10 min.

  • Contraindications: hyperkalemia, severe burns, neuromuscular disease, malignant hyperthermia.

• Rocuronium

  • Dose: 1 mg/kg IV (0.6–1.2 mg/kg range).

  • Onset: ~60 sec. Duration: 45 min.

  • Fewer contraindications, safer in many populations.

  • Study: Rocuronium associated with less desaturation than succinylcholine.

Induction Agents

• Etomidate (0.3 mg/kg): rapid onset, minimal hemodynamic effects, no analgesia.

• Propofol (1.5–2.5 mg/kg): rapid, strong sedative, causes hypotension and respiratory depression, no analgesia.

• Ketamine (1–2 mg/kg): dissociative, provides analgesia, maintains BP, good in trauma/shock.

Positioning and Airway Maneuvers

• Ramping and elevating head 20–30° improves view for all patients (not just obese).

• Cricoid pressure: no longer recommended, obstructs view, not effective at preventing aspiration.

• Bimanual laryngoscopy: operator adjusts trachea with free hand to improve view, then assistant holds.

Post-Intubation Management

• Sedation and analgesia are critical:

  • Etomidate/propofol/ketamine wear off within minutes.

  • Rocuronium paralysis lasts 45 min → patients may be awake but paralyzed if not sedated.

• Under-sedation leads to awareness, pain, fear, tachycardia, hypertension, and even tears in paralyzed patients.

• Always reassess sedation and analgesia immediately post-intubation.

Confirmation of Tube Placement

• End-tidal CO₂ capnography = gold standard.

• Chest rise, condensation, and CXR are not definitive.

The Takeaways

• Preoxygenation is the single most important step in RSI.

• Apneic oxygenation extends safe apnea time.

• DSI allows safe preoxygenation in uncooperative patients.

• Rocuronium is generally safer and more reliable than succinylcholine.

• Always provide post-intubation sedation and analgesia.

• Confirm tube with capnography.