Introduction
Rapid Sequence Intubation is a rapid airway management technique used to control the airway in patients as a precautionary measure to reduce the risk of regurgitation and aspiration of gastric contents. Rapid Sequence Intubation (RSI) is done in emergencies with a risk to the airway. It is only done in patients with preserved airway reflexes; on the other hand, in arrested or completely obtunded patients endotracheal tube is placed without using medications.
The technique is used by doctors of various specialties, including anesthesiologists, emergency medical professionals, and critical care physicians. The technique requires all the necessary equipment and supplies at the bedside, including alternative options for securing the airway in case of procedure failure.
What Are the Indications for RSI?
RSI is carried out in those patients who need endotracheal intubation and are at increased risk of gastric reflux and aspiration of gastric contents.
The indications for RSI include the following:
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In patients with acute respiratory failure due to inadequate oxygenation or ventilation.
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Patients with acute upper gastrointestinal bleeding increase the aspiration risk.
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In patients with altered mental status for airway maintenance.
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In patients with gastroesophageal reflux (due to conditions like hiatus hernia).
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In case of trauma patients or emergency surgery cases where the patient's fasting status is unknown.
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Patients with delayed gastric emptying due to conditions like autonomic gastroparesis.
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In pregnancy from the second trimester.
What Are the Contraindications for RSI?
The contraindications for RSI include the following:
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Complete obstruction of the upper airway.
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Anatomic abnormalities.
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Injury to the airway.
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Total loss of oropharyngeal or facial landmarks.
What Is the Preparation Needed for the RSI Procedure?
The preparation of the RSI procedure involves the preparation of the patient, preparation of the equipment, preparation of team members, and preparation for a difficult airway.
The steps involved in preparation are explained as follows:
1. Patient Preparation: Patient preparation involves educating the patient about the procedure, including cricoid pressure. Patient cooperation is essential for effective preoxygenation. If the patient is alert, a non-particulate antacid is given to the patient before the procedure.
2. Equipment Preparation: The equipment required for the procedure includes the following:
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Monitoring equipment like pulse oximeter, blood pressure cuff and sphygmomanometer, electrocardiograph, and waveform capnography.
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Suction equipment.
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Oxygen supply machine.
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Oxygen delivery devices like a self-inflating bag.
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Standard airway equipment includes face masks, laryngoscope blades of various ranges, handles, and endotracheal tube tape.
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Supraglottic rescue device.
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Difficult airway equipment includes a bougie (tracheal tube inducer), video laryngoscope, and nasopharyngeal airway.
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Drugs include induction agents, emergency drugs, drugs for maintaining anesthesia, and neuromuscular blocking agents.
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IV access.
3. Preparation of the Team: The preparation of team members is also an important part of RSI. The tasks which have to be done during the technique involve the following:
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Pre-oxygenation.
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Drug administration.
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Intubation.
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Cricoid pressure application if needed.
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Assisting incubator for passing equipment.
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Manual in-line stabilization if required.
A minimum of two or three medical professionals are required for airway management using RSI.
What Are the Drugs Required for the RSI Procedure?
The drugs required for the RSI procedure include the following:
1. Hypnotics: The drugs which are usually used to induce anesthesia include the following:
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Ketamine - It is used in unstable patients in a prehospital setting. It causes an increase in secretions, so suctioning or premedication with an anti-sialagogue may be required.
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Propofol - Propofol is used in hemodynamically stable patients in the operating theatre.
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Thiopentone - Thiopentone has the most predictable and quick effect.
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Midazolam - Midazolam is used in obtunded patients who require amnesia.
2. Nueromuscular Blockers: Succinylcholine (Suxamethonium) is the most commonly used neuromuscular blocker for RSI. It is reliable and easily available. Adverse effects are rare, with myalgia being the most common side effect. It can also cause bradycardia, anaphylaxis, hyperkalemia, and malignant hyperthermia. Rocuronium is an alternative drug. In high doses, it produces profound relaxation. There is a possibility for anaphylaxis, but other adverse effects of Succinylcholine, like myalgia, are avoided.
3. Other Drugs:
- Opioids, including rapid-acting opioids like Fentanyl and Remifentanil, are used in RSI.
- Lidocaine is used for reducing bronchospasm and cough.
How Is the RSI Procedure Carried Out?
After the preparation steps, the induction agents are administered to the patient. The patient is appropriately positioned for the intubation procedure. An intravenous cannula is placed to maximize drug delivery. Preoxygenation is performed as completely as possible. After adequate preoxygenation is achieved, the required medications are administered. Cricoid pressure (force application to cricoid cartilage) should be increased if consciousness is lost.
After the paralytic agents take effect, the patient’s mouth is opened using the scissoring technique. In this technique, the right thumb is placed on the right middle finger, and the right hand is inserted into the patient’s mouth. The physician then opens the patient’s mouth, and the laryngoscope is inserted from right to left with a sweeping motion.
The physician locates the epiglottis and places the laryngoscope in the vallecula. Suctioning helps in clearing debris, better visualization, and applying pressure to the thyroid cartilage to manipulate the glottis into view. After locating the glottis, the endotracheal tube is passed through the vocal cords. After advancing the tube to an adequate distance, the cuff is inflated. A chest X-ray is used to assess adequate placement.
What to Consider in Specific Clinical Situations?
The following should be considered in specific clinical situations:
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Pregnancy: Aspiration risk is higher during the second and third trimesters of pregnancy due to anatomic and physiological changes. Intubation is difficult in such patients. If RSI is to be given to such patients, special care should be given to patient positioning, preoxygenation, expertise, and difficult airway equipment availability. The patient should be positioned with a left tilt using a tilted table.
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Cervical Spine Injury: A laryngoscopy is done with minimal cervical spine movement, or an awake fiber-optic technique is used in unstable cervical spine injury patients.
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Pediatrics: Children and infants desaturate rapidly, and their vagal response to laryngoscopy is more pronounced. The required drug doses may be higher than for adults due to the greater volume of distribution.
Conclusion
Rapid Sequence Intubation is a rapid airway management technique used to control the airway in patients as a precautionary measure to reduce the risk of pulmonary aspiration. The lead physician directs the healthcare team; delineating roles is important for the procedure's success.
