What are the 7 Ps of Rapid Sequence Intubation (RSI)?

The 7 Ps of Rapid Sequence Intubation

The traditional "7 Ps" mnemonic for RSI consists of: Preparation, Preoxygenation, Pretreatment, Paralysis with induction, Protection and positioning, Placement with proof, and Post-intubation management. However, modern evidence-based guidelines have evolved beyond this classic framework, with current best practices emphasizing positioning earlier in the sequence and de-emphasizing routine pretreatment 1, 2.

1. Preparation

• Ensure all necessary equipment is immediately available, including backup airway devices, to prevent "cannot intubate/cannot oxygenate" scenarios 2
• Have sugammadex readily available when planning to use rocuronium 2, 3
• Establish IV access and prepare medications in advance 1

2. Positioning

• The American College of Critical Care Medicine suggests using the semi-Fowler position (head and torso inclined) during RSI to reduce aspiration risk and potentially improve first-pass intubation success 1, 2
• This represents a shift from traditional supine positioning and should be implemented early in the sequence 1

3. Preoxygenation

• Standard preoxygenation is essential for all patients to extend the safe apnea time 1
• High-flow nasal oxygen (HFNO) is suggested when laryngoscopy is expected to be challenging 1, 2
• Noninvasive positive pressure ventilation (NIPPV) is recommended for patients with severe hypoxemia (PaO2/FiO2 < 150) 1, 2
• For agitated, delirious, or combative patients who cannot tolerate preoxygenation devices, medication-assisted preoxygenation (delayed sequence intubation) using ketamine is suggested, which can increase oxygen saturation by approximately 8.9% 1, 2

4. Pretreatment (Largely Abandoned)

• Modern guidelines have moved away from routine pretreatment with agents like fentanyl or lidocaine 1
• However, opioids may be administered to reduce the dosage requirements of hypnotic drugs and minimize side effects 4
• The focus has shifted to appropriate medication selection rather than routine pretreatment 1, 2

5. Paralysis with Induction

• A sedative-hypnotic induction agent must always be administered before a neuromuscular blocking agent to prevent awareness during paralysis 1, 2, 3

Induction Agent Selection:

• For hemodynamically unstable patients, etomidate (0.2-0.3 mg/kg) is preferred due to its minimal cardiovascular depression 2, 3
• Ketamine (1-2 mg/kg) is an alternative for unstable patients but may cause paradoxical hypotension in critically ill patients with depleted catecholamine stores 3
• No significant difference exists between etomidate and other induction agents (ketamine, midazolam, propofol) with respect to mortality or hypotension 1, 2
• Propofol (2 mg/kg) suppresses airway reflexes effectively but causes vasodilation and hypotension 1

Neuromuscular Blocking Agent Selection:

• The American College of Critical Care Medicine strongly recommends administering an NMBA when a sedative-hypnotic induction agent is used for intubation 1, 2, 3
• Either succinylcholine (1-1.5 mg/kg) or rocuronium (0.9-1.2 mg/kg) is suggested when there are no contraindications to succinylcholine 1, 2, 3
• Succinylcholine provides rapid onset and short duration, making it preferred for hemodynamically stable patients 3
• Rocuronium provides intubating conditions in median 1 minute with 31-67 minutes clinical duration depending on dose 1, 3

6. Protection and Placement with Proof

• Medications and neuromuscular blockade are administered in rapid succession with immediate endotracheal tube placement before assisted ventilation begins 2, 3
• This minimizes aspiration risk by avoiding the traditional period of mask ventilation 2
• Gastric tube decompression should be considered when the benefit outweighs the risk in patients at high risk of regurgitation 1
• If a gastric tube is already in place, it should be left in position and does not need to be removed 4
• Confirm tube placement immediately using multiple methods 1

7. Post-Intubation Management

• Apply PEEP of at least 5 cmH₂O after intubation of hypoxemic patients 1
• Perform a post-intubation recruitment maneuver in hypoxemic patients 1
• Include cardiovascular monitoring with defined parameters for fluid challenges and early vasopressor use to prevent hemodynamic instability 1
• Be aware that when using rocuronium, its longer duration may delay provision of post-intubation analgosedation, potentially increasing risk of awareness 1

Common Pitfalls to Avoid

• Inadequate preoxygenation increases desaturation risk—ensure proper technique and consider medication-assisted preoxygenation for uncooperative patients 1, 2
• Failure to administer a sedative-hypnotic agent before the neuromuscular blocker will result in awareness during paralysis 3
• Inappropriate medication selection can cause hemodynamic instability—choose etomidate for unstable patients 2, 3
• Not having sugammadex immediately available when using rocuronium can lead to prolonged paralysis in "cannot intubate/cannot oxygenate" scenarios 2, 3

Evidence Quality Note

The RSI framework is supported by multiple guidelines from the American College of Critical Care Medicine and Society of Critical Care Medicine, though much of the evidence is conditional with low to very low quality 1, 2. Despite this, RSI with neuromuscular blockade is independently associated with higher first-attempt success rates (OR 2.3,95% CI 1.8-2.9) without increased complications 5.