What does RSI stand for in anesthesia?: A Guide to Rapid Sequence Intubation

October 11, 2025 •

4 min read

According to a multi-center study published in the journal Academic Emergency Medicine, Rapid Sequence Intubation (RSI) was the initial method of choice in 78% of emergency intubations. When addressing the question of what does RSI stand for in anesthesia?, it refers to this specific, high-stakes procedure for securing a patient's airway quickly in emergent situations.

Quick Summary

Rapid Sequence Intubation (RSI) is a critical procedure for securing an emergency airway, involving the near-simultaneous administration of a potent sedative and a muscle relaxant. This technique rapidly induces unconsciousness and paralysis to facilitate intubation and minimize the risk of pulmonary aspiration in patients at high risk.

Key Points

RSI Defined: RSI stands for Rapid Sequence Intubation, an emergency airway procedure involving the rapid administration of sedation and paralysis to facilitate intubation.
High-Risk Patient Focus: The technique is specifically designed for patients at high risk of aspirating gastric contents, including those who have not fasted or have impaired airway reflexes.
Coordinated Procedure: A structured approach, often following the "Seven P's" mnemonic (Preparation, Pre-oxygenation, Pretreatment, etc.), is used to ensure a swift and safe process.
Pharmacology: Key medications include fast-acting induction agents (e.g., Etomidate, Ketamine) and paralytics (e.g., Succinylcholine, Rocuronium).
Key Difference from Standard Intubation: A critical distinction is the avoidance of manual ventilation before intubation to prevent stomach inflation and aspiration risk.
Managed by Experts: Due to its complexity and potential risks, RSI is performed by highly trained professionals, such as anesthesiologists and emergency physicians.
Not Universal: RSI is not appropriate for all intubation scenarios, particularly for patients with a known difficult airway where a more controlled approach may be necessary.

Understanding Rapid Sequence Intubation (RSI)

Rapid Sequence Intubation, or RSI, is a critical airway management technique used primarily in emergency and critical care settings. It involves a specific, time-sensitive process to secure a patient's airway with an endotracheal tube (ETT). The technique is differentiated from standard intubation by the simultaneous and rapid administration of a sedative and a paralytic agent, without manual bag-mask ventilation, to prevent gastric insufflation and subsequent aspiration. This is particularly crucial for patients with a high risk of pulmonary aspiration, such as those with a "full stomach" (having recently eaten or with delayed gastric emptying) or compromised airway protective reflexes due to trauma, altered mental status, or illness. RSI requires a highly coordinated, skilled team and careful patient assessment to ensure a safe and successful outcome.

The Seven P's of RSI

To standardize and streamline the process, many practitioners follow a mnemonic known as the "Seven P's" of RSI. This structured approach helps ensure all necessary steps are completed methodically, even under pressure.

Preparation: Before starting, all necessary equipment is gathered and checked. This includes the laryngoscope, endotracheal tubes of various sizes, suction, and monitoring devices like a pulse oximeter and end-tidal CO2 detector. Medications are drawn up and clearly labeled.
Pre-oxygenation: The patient is given 100% oxygen, typically via a non-rebreather mask or high-flow nasal cannula, for several minutes. The goal is to fill the lungs with oxygen and create a reserve, extending the safe apnea time before oxygen saturation drops.
Pretreatment: In some cases, specific medications (e.g., Fentanyl, Lidocaine) are given to blunt the physiological responses to intubation, such as increased heart rate or intracranial pressure, especially in high-risk patients.
Paralysis with Induction: This is the core of the RSI procedure. A potent sedative (induction agent) and a fast-acting muscle relaxant (paralytic) are administered rapidly, one after the other. This quickly renders the patient unconscious and motionless, allowing for intubation.
Protection and Positioning: The patient is placed in the "sniffing" position (head extended, neck flexed) to align the airway axes, unless a cervical spine injury is suspected. Historically, cricoid pressure (Sellick's maneuver) was also applied to occlude the esophagus and reduce aspiration risk, though its routine use is now debated.
Placement of the Tube: The clinician performs laryngoscopy to visualize the glottis and inserts the endotracheal tube. The cuff at the end of the tube is then inflated immediately to protect the airway.
Post-intubation Management: Once the ETT is secured, placement is confirmed using end-tidal CO2 detection, along with auscultation of breath sounds and visual chest rise. The patient is then connected to a mechanical ventilator, and continuous sedation is initiated.

Key Medications in RSI Pharmacology

Induction Agents:

Etomidate: Known for its cardiovascular stability, making it a preferred choice for hemodynamically unstable patients.
Ketamine: Can increase heart rate and blood pressure, making it useful for hypotensive patients, but can increase secretions.
Propofol: A fast-acting hypnotic that can cause significant hypotension, particularly in volume-depleted or elderly patients.

Paralytic Agents (Neuromuscular Blockers):

Succinylcholine: A depolarizing paralytic with a very rapid onset and short duration of action. It has several contraindications, including hyperkalemia and burns.
Rocuronium: A non-depolarizing paralytic with a rapid onset (especially at higher doses) and a longer duration. It has fewer contraindications than succinylcholine, and its effects can be quickly reversed by the agent Sugammadex.

RSI vs. Standard Anesthetic Induction


Feature	Rapid Sequence Intubation (RSI)	Standard Anesthetic Induction
Speed of Action	Extremely fast: Sedative and paralytic given almost simultaneously.	Slower: Gradual administration of drugs with optional ventilation before paralysis.
Ventilation (BVM)	Avoided before intubation to prevent gastric insufflation.	Often performed with a bag-valve mask (BVM) before intubation.
Aspiration Risk	High risk, so technique focuses on minimizing the unprotected airway time.	Lower risk, as patient is typically fasting and has intact airway reflexes.
Patient Population	Used for emergencies and high-risk patients with a "full stomach."	Used for elective surgery and patients who have been fasting.

Potential Risks and Complications of RSI

Despite its life-saving potential, RSI carries several risks that require careful management by an experienced team. These include:

Pulmonary Aspiration: The primary risk that RSI is designed to prevent, but can still occur if the process is not performed correctly or if cricoid pressure is ineffective.
Hemodynamic Instability: The rapid administration of induction drugs can cause a sharp drop in blood pressure (hypotension) or increase (hypertension) in susceptible patients.
Hypoxia: If the intubation attempt fails or is significantly delayed, the patient can become hypoxic, a potentially life-threatening complication.
Esophageal Intubation: Incorrect placement of the ETT into the esophagus instead of the trachea can be fatal if not quickly recognized and corrected.
Difficult Airway: If a patient has an anatomical difficult airway, RSI can be more challenging and should only be performed with backup plans readily available.
Drug-Related Complications: Specific medications, like succinylcholine, have associated side effects that need to be considered.

Conclusion

What does RSI stand for in anesthesia? The answer, Rapid Sequence Intubation, signifies a time-critical, advanced procedure for securing a patient's airway and preventing dangerous pulmonary aspiration in emergency contexts. It is a cornerstone of advanced airway management, relying on swift pharmacological induction and paralysis to facilitate endotracheal tube placement. The structured approach, adherence to protocols, and the skill of the medical team are paramount for minimizing risks and ensuring the best possible outcome for critically ill patients. While powerful and effective, RSI is not without risk and necessitates a high level of expertise and preparation to be performed safely. For further information, the National Center for Biotechnology Information (NCBI) offers comprehensive resources on the procedure: National Institutes of Health (NIH) | (.gov).

Frequently Asked Questions

In medical terms, RSI stands for Rapid Sequence Intubation, a procedure for emergency airway management.

RSI is used in emergencies to secure a patient's airway quickly and efficiently when they are at a high risk of aspirating stomach contents into their lungs.

The primary goal is to minimize the time between the loss of consciousness and the securing of the airway with a cuffed endotracheal tube, protecting the patient from aspiration.

The main difference is the speed and sequence of drug administration. In RSI, a sedative and a paralytic are given almost simultaneously, and manual bag-mask ventilation is typically avoided before intubation to prevent gastric distention and aspiration.

The procedure uses two main types of medications: induction agents (potent sedatives like Etomidate or Ketamine) and paralytic agents (neuromuscular blocking agents like Succinylcholine or Rocuronium).

RSI is an advanced procedure that should only be performed by experienced and highly trained clinicians, including anesthesiologists, emergency physicians, and intensivists.

Potential risks include pulmonary aspiration, hemodynamic instability (hypotension/hypertension), hypoxia due to a failed intubation attempt, and unintended esophageal intubation.

Yes, RSI is contraindicated in cases where a difficult airway is known or suspected. In these situations, alternative airway management techniques are used to avoid a "cannot intubate, cannot ventilate" scenario.