What is the American Society of Anesthesiologists (ASA) standard of care for rapid sequence induction (RSI) in a patient with a full stomach?

ASA Standard of Care for Full Stomach RSI

The American Society of Anesthesiologists recommends rapid sequence intubation (RSI) for patients with a full stomach, consisting of semi-Fowler positioning, adequate preoxygenation (3-5 minutes), administration of a sedative-hypnotic agent followed immediately by a neuromuscular blocking agent (succinylcholine 1.5 mg/kg or rocuronium 1.0-1.2 mg/kg), and immediate endotracheal intubation before any assisted ventilation. 1, 2

Core RSI Protocol Components

Patient Positioning

• Place the patient in semi-Fowler position (head and torso inclined) to reduce aspiration risk and potentially improve first-pass intubation success 1, 2
• In patients with obesity (BMI >30 kg/m²), use ramped positioning combined with reverse Trendelenburg to extend the safe apnea period 1

Preoxygenation Strategy

• Deliver 3-5 minutes of preoxygenation using a well-fitted mask in a closed-circuit system with FiO₂ of 1.0 (target FetO₂ >0.9) and oxygen flow >10 L/min before administering the neuromuscular blocker 1, 3
• For patients with severe hypoxemia (PaO₂/FiO₂ <150), use noninvasive positive pressure ventilation (NIPPV) for preoxygenation 1, 2
• When difficult laryngoscopy is anticipated, apply high-flow nasal oxygen (HFNO) 1, 2
• For agitated, delirious, or combative patients who cannot tolerate preoxygenation devices, use medication-assisted preoxygenation (delayed sequence intubation) with ketamine 1-1.5 mg/kg IV, followed by 3 minutes of preoxygenation before administering the neuromuscular blocker 1, 2

Gastric Decompression

• Insert a nasogastric tube for decompression when the benefit outweighs the risk in patients at high risk of regurgitation of gastric contents 1
• The gastric tube should remain in place and be connected to suction during induction—do not withdraw it 4
• In patients with ileus, bowel obstruction, or passage disorders, gastric emptying with a nasogastric tube is mandatory before surgery 5, 3

Pharmacologic Management

Sedative-Hypnotic Induction Agents

• A sedative-hypnotic agent must be administered before any neuromuscular blocking agent to prevent awareness during paralysis 1, 6, 2
• For hemodynamically stable patients, use propofol 2 mg/kg IV, etomidate 0.2-0.3 mg/kg IV, or ketamine 1-2 mg/kg IV 1, 6
• For hemodynamically unstable patients, etomidate 0.2-0.3 mg/kg IV is preferred due to minimal cardiovascular depression 6, 2
• Ensure complete loss of consciousness before any airway manipulation to prevent coughing or awareness 1

Neuromuscular Blocking Agents

• Administer a neuromuscular blocking agent immediately after the sedative-hypnotic agent (strong recommendation) 1, 6, 2
• Succinylcholine 1.5 mg/kg IV is the preferred paralytic in hemodynamically stable patients because of its rapid onset (45-60 seconds) and brief duration of action 1, 6, 2
• Rocuronium 1.0-1.2 mg/kg IV is the alternative when succinylcholine is contraindicated, providing intubating conditions in approximately 1 minute but with longer duration (58-67 minutes) 1, 6, 2
• Sugammadex must be immediately available when rocuronium is used for potential "cannot intubate/cannot oxygenate" scenarios, allowing reversal in 3 minutes 1, 6, 2
• Wait at least 1 minute after neuromuscular blocker administration to allow full paralysis before attempting intubation 1

Airway Management Technique

Traditional vs. Modified RSI Decision Algorithm

• For patients with adequate oxygenation and high aspiration risk: Use traditional RSI (no ventilation between induction and intubation) 1
• For patients with severe hypoxemia despite optimal preoxygenation: Use modified RSI with gentle bag-mask ventilation or continuous positive airway pressure (CPAP) if a good mask seal is achieved 1
• For anticipated difficult or prolonged laryngoscopy: Use modified RSI permitting gentle ventilation 1

Ventilation Considerations

• If mask ventilation is required, use a two-person technique with VE-grip, a Guedel airway, minimal oxygen flow, and airway pressures consistent with safe ventilation 1
• After reliable loss of consciousness, gentle continuous positive airway pressure (CPAP) can be applied if a good mask seal is achieved 1

Cricoid Pressure

• Apply cricoid pressure (Sellick maneuver) only when a trained assistant is present 1
• Remove cricoid pressure immediately if it hinders intubation 1
• The effectiveness and routine use of cricoid pressure remains controversial, with recent evidence questioning its benefit 7, 5, 8

Equipment Verification

• Prior to induction, confirm functional intravenous access, continuous capnography, operative suction, a ventilator set to appropriate settings, and a complete airway cart that includes rescue devices 1
• In obese patients where the cricothyroid membrane is not palpable, locate it with ultrasound before induction 1

Special Population Considerations

Obesity (BMI >30 kg/m²)

• Patients with BMI >30 kg/m² have twice the risk of intubation-related complications (fourfold if BMI >40 kg/m²) due to rapid and severe desaturation 1
• Use ramped positioning combined with reverse Trendelenburg 1
• In failed intubation scenarios, avoid repeated attempts, supraglottic airway rescue, or prolonged mask ventilation—proceed promptly to surgical airway (FONA) using a scalpel with vertical incision 1

Cervical Spine Injury

• Perform early RSI with manual inline stabilization after removing at least the anterior portion of the cervical collar 1
• Use a bougie during direct laryngoscopy and maintain a low threshold for switching to video laryngoscopy 1

Burn Patients

• Avoid succinylcholine after the first 24 hours post-burn to prevent potentially fatal hyperkalemia 1
• Select an uncut (uncuffed) tracheal tube to accommodate anticipated facial swelling 1

Common Pitfalls and How to Avoid Them

• Inadequate preoxygenation: Ensure proper technique with 3-5 minutes of preoxygenation and consider medication-assisted preoxygenation for uncooperative patients 1, 2
• Failure to have backup airway equipment immediately available: This can lead to "cannot intubate/cannot oxygenate" scenarios 2
• Inappropriate medication selection or dosing: Can cause hemodynamic instability—use etomidate for unstable patients 6, 2
• Delayed post-intubation analgosedation: When using rocuronium, its longer duration (compared to succinylcholine) may delay provision of post-intubation analgosedation, potentially increasing risk of awareness 1, 2
• Premature intubation attempt: Wait at least 1 minute after neuromuscular blocker administration to ensure full paralysis 1
• Removing the gastric tube: If a gastric tube is in place, keep it connected to suction during induction rather than withdrawing it 4

Post-Intubation Management

• Apply PEEP of at least 5 cmH₂O after intubation of hypoxemic patients 1
• Use a post-intubation recruitment maneuver in hypoxemic patients 1
• Include a cardiovascular component in the protocol, defining conditions for fluid challenge and early administration of catecholamines to decrease cardiovascular complications 1

Evidence Quality Note

The 2023 Society of Critical Care Medicine guidelines acknowledge that modern RSI practice has evolved from strict "no-ventilation" dogma because preventing critical hypoxemia is now considered a higher priority than the theoretical aspiration risk associated with brief bag-mask ventilation 1. However, the guidelines do not issue a definitive recommendation for or against bag-mask ventilation during RSI due to insufficient high-quality evidence, classifying this as a "clinical uncertainty" 1. In clinical practice, the decision to use gentle ventilation should be based on the patient's oxygenation status and aspiration risk 1.