What are the recommended steps for performing rapid sequence intubation, including pre‑oxygenation, induction medication selection, paralytic choice, and post‑intubation sedation and analgesia?

Rapid Sequence Intubation: Evidence-Based Protocol

Pre-Oxygenation and Positioning

Position the patient in semi-Fowler position (head and torso elevated 20-30 degrees) during RSI to reduce aspiration risk and improve first-pass intubation success. 1

• Pre-oxygenate with 100% oxygen for 3-5 minutes in cooperative patients to maximize oxygen reserves and delay desaturation during apnea 2, 1
• For agitated or combative patients unable to tolerate pre-oxygenation, initiate medication-assisted pre-oxygenation with ketamine (1-2 mg/kg IV) to achieve dissociation while maintaining spontaneous respiration 2, 1
• In high-risk aspiration patients (e.g., bowel obstruction), insert a large-bore nasogastric tube before induction to decompress the stomach 3
• Point-of-care gastric ultrasound can assess gastric volume and guide risk stratification, as 6-16% of appropriately fasted patients still have gastric content 1

Induction Agent Selection

For hemodynamically unstable patients (shock, sepsis, severe hypotension), use etomidate (0.2-0.3 mg/kg IV) as the first-line induction agent because it produces minimal cardiovascular depression. 2

• The 2023 Society of Critical Care Medicine guidelines found no difference in mortality or vasopressor use between etomidate and other agents, supporting its safety in critically ill patients 2
• Retrospective evidence suggests etomidate may produce less hypotension than ketamine in patients presenting with shock or sepsis 4
• Ketamine (1-2 mg/kg IV) is the preferred alternative for agitated or combative patients, as it preserves spontaneous respiration and stimulates catecholamine release 2
• Avoid ketamine in patients with severe catecholamine depletion (e.g., septic or cardiogenic shock) because it may cause paradoxical hypotension and cardiac arrest 2
• Propofol (2-2.5 mg/kg IV) should be limited to hemodynamically stable adults, as it causes marked venodilation-related hypotension 2

Neuromuscular Blocking Agent Selection

The Society of Critical Care Medicine issues a Class I strong recommendation that an NMBA be administered immediately after a sedative-hypnotic to prevent awareness during paralysis. 2, 1

• Succinylcholine (1-1.5 mg/kg IV) provides the fastest onset (45-60 seconds) and shortest duration (5-10 minutes) and is preferred when no contraindications exist 2
• Contraindications to succinylcholine include hyperkalemia risk (burns >24 hours old, crush injuries, denervation injuries, prolonged immobilization), malignant hyperthermia history, and known neuromuscular disorders 5
• Succinylcholine was given to 67% of patients with baseline bradycardia in one study and was significantly associated with post-RSI bradycardia (RR=1.81), highlighting the importance of checking for contraindications 5
• Rocuronium (0.9-1.2 mg/kg IV for RSI) is an acceptable alternative when succinylcholine is contraindicated; at this high dose its onset (≈1 minute) is comparable to succinylcholine, though its duration is longer (58-67 minutes) 2
• The 2023 Society of Critical Care Medicine guidelines report no outcome differences between succinylcholine and rocuronium in stable patients 2
• Have sugammadex immediately available when using rocuronium for reversal in "cannot intubate/cannot oxygenate" scenarios 1

Pretreatment Analgesia (Optional)

• Fentanyl (2-5 µg/kg IV administered 3 minutes before induction) can blunt the sympathetic response to laryngoscopy in adults with cardiovascular disease or elevated intracranial pressure, reducing peri-intubation hypertension and tachycardia 2
• However, fentanyl may increase the risk of apnea and should be used cautiously 2
• Use of pretreatment medications (atropine, lidocaine, fentanyl) has fallen out of favor in clinical practice as there is limited evidence for their use outside of select clinical scenarios 4

Evidence-Based Selection Algorithm

For unstable patients: Use etomidate (0.2-0.3 mg/kg) plus succinylcholine (1-1.5 mg/kg) to achieve rapid intubation with minimal hemodynamic impact 2

For stable patients: Either etomidate or ketamine may be used for induction, combined with either succinylcholine or high-dose rocuronium (0.9-1.2 mg/kg); the Society of Critical Care Medicine guidelines find no significant differences in outcomes among these options 2

For agitated/combative patients unable to tolerate pre-oxygenation: Begin with ketamine (1-2 mg/kg IV) for medication-assisted pre-oxygenation, then proceed with the chosen NMBA once adequate dissociation is achieved 2

Critical Timing and Administration

• Administer sedative-hypnotic and NMBA in rapid succession with immediate endotracheal tube placement before assisted ventilation begins to minimize aspiration risk 2, 1
• Have video laryngoscopy, supraglottic airways, and surgical airway equipment immediately available 1
• If intubation fails after maximum three attempts, immediately move to failed intubation plan 1, 3
• Do NOT persist with cricoid pressure if it impairs laryngoscopy 1
• Do NOT avoid gentle ventilation if hypoxemia develops during induction, as the risk-benefit calculation favors preventing critical hypoxemia 1

Post-Intubation Sedation and Analgesia

Immediately initiate continuous sedation and analgesia after successful intubation to prevent awareness during paralysis, particularly when using rocuronium. 6

• Use of rocuronium for RSI was associated with reduced likelihood of timely post-RSI sedation and analgesia, with median time to first sedation dose of 12 minutes (vs 10 minutes with succinylcholine) 6
• Coupled with low initial sedative dosing (median propofol infusion rate of only 20 µg/kg/min), patients intubated with rocuronium are at increased risk of being awake during paralysis 6
• Post-intubation hypotension (nadir systolic blood pressure <100 mm Hg in the first hour) was predictive of decreased sedation administration (aHR=0.67), requiring careful hemodynamic monitoring 6
• Bedside presence of an emergency department pharmacist was associated with improved sedation administration (aHR=1.14), suggesting the value of multidisciplinary involvement 6

Critical Pitfalls to Avoid

• Do NOT use inadequate NMBA doses: full RSI doses are succinylcholine 1-2 mg/kg or rocuronium 0.9-1.2 mg/kg 1, 3
• Do NOT delay post-intubation sedation and analgesia, especially when using rocuronium, as the longer duration of paralysis increases risk of awareness 6
• Do NOT use ketamine in severely catecholamine-depleted patients (septic or cardiogenic shock) due to risk of paradoxical hypotension 2
• Do NOT give succinylcholine to patients with contraindications (hyperkalemia risk, malignant hyperthermia history, neuromuscular disorders) 5