Rapid-sequence induction and intubation

What it is

Rapid-sequence induction and intubation is the technique used when stomach contents may be regurgitated and inhaled, as in emergency surgery, bowel obstruction, late pregnancy, trauma or a patient who has not fasted. After thorough preoxygenation, an induction agent and a fast-acting neuromuscular blocker are given one straight after the other, and the trachea is intubated as soon as the muscles relax, so that the time between loss of airway reflexes and a cuffed tube is as short as possible. In the classic form no breaths are given by mask during that gap, to avoid blowing gas into the stomach, and cricoid pressure is applied to compress the upper oesophagus. Current practice is more flexible: gentle low-pressure mask ventilation is allowed in patients who would otherwise desaturate, and cricoid pressure, whose benefit is unproven, is released if it spoils the view or the ventilation. The induction agent is chosen for the patient's circulation (etomidate or ketamine are often preferred in shock), and the neuromuscular blocker is suxamethonium or a rocuronium intubating dose, which sugammadex can reverse.

Indications

• Patients who have not fasted or need emergency surgery.
• Bowel obstruction, ileus, upper gastrointestinal bleeding or a distended stomach.
• Pregnancy from mid-pregnancy onwards and the early postpartum period.
• Symptomatic reflux, hiatus hernia, gastroparesis (for example long-standing diabetes) or achalasia.
• Trauma, pain or opioids, which slow gastric emptying, and most emergency intubations outside the operating room.

Contraindications and precautions

• A predicted difficult airway where losing spontaneous breathing is dangerous: consider awake intubation instead.
• Suxamethonium contraindications: hyperkalaemia, burns, crush or denervation injury after the first day, neuromuscular disease, personal or family malignant hyperthermia.
• Shock: resuscitate before induction and have a vasopressor ready; reduce the induction agent and favour stable agents.
• Raised intracranial pressure or aortic disease: blunt the pressor response, for example with an opioid.
• Cricoid pressure: avoid with suspected cervical spine or laryngeal injury, and release it if the patient vomits.

Equipment and preparation

• Two working suction devices with a rigid sucker, the patient on a tilting trolley.
• Induction agent, neuromuscular blocker, vasopressor and sugammadex drawn up, labelled and checked.
• Laryngoscopes (direct and video), tubes, bougie, stylet and supraglottic airway for rescue.
• Full monitoring with waveform capnography, and a running intravenous line.
• A trained assistant for cricoid pressure and a spoken plan for failure.

Step by step (and why)

1. Prepare equipment, drugs and the team, and say the failed-intubation plan aloud — there is no time to improvise once the patient is apnoeic.
2. Empty the stomach with a nasogastric tube if obstructed — less fluid in the stomach means less to aspirate.
3. Preoxygenate head-up to an end-tidal oxygen of about 90%, with nasal oxygen — mask breaths are limited, so the store must be full.
4. Optimise the circulation with fluids and a vasopressor ready — induction and positive pressure drop blood pressure.
5. Apply cricoid pressure as the patient loses consciousness, if used — it aims to compress the oesophagus against the vertebra.
6. Give the induction agent and then at once the neuromuscular blocker — a short gap shortens the time with no protected airway.
7. Avoid mask breaths unless the saturation falls, then ventilate gently at low pressure — low pressure limits gas entering the stomach.
8. Intubate when relaxed, inflate the cuff and confirm with capnography — only then is the airway protected.
9. Release cricoid pressure after confirmation, then start sedation — paralysis outlasts the induction agent and can cause awareness.

The two neuromuscular blockers used in rapid-sequence induction

Complications

• Aspiration of gastric contents, leading to pneumonitis or pneumonia.
• Hypotension or cardiac arrest after induction, especially in shock, sepsis or hypovolaemia.
• Hypoxaemia and failed intubation, made worse by limited mask ventilation; follow the difficult-airway plan.
• Suxamethonium effects: hyperkalaemia, bradycardia (especially in children or with a repeat dose), muscle pains, malignant hyperthermia.
• Awareness under paralysis when sedation is delayed after a long-acting neuromuscular blocker.
• Cricoid pressure that distorts the larynx and worsens the view or ventilation.

Next step

• Start sedation and analgesia promptly after the tube is confirmed, and check the blood pressure often.
• Place a gastric tube to decompress the stomach if not already done.
• If aspiration happened, suction the trachea before ventilating, watch oxygenation and get a chest X-ray.
• Call for help at the first failed attempt; if oxygenation fails, wake the patient or move to rescue airway devices.
• Report adverse drug reactions and refer suspected malignant hyperthermia or anaphylaxis for testing.

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Elsewhere in DurgiPedia

• Bag-mask ventilation

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Educational content; it does not replace supervised training, your institution's protocols or the anaesthetist's or intensivist's decision. It contains no doses and no ventilator or infusion settings.

Sources: Tracheal Rapid Sequence Intubation (StatPearls (NCBI Bookshelf), 2022); Tracheal Intubation Medications (StatPearls (NCBI Bookshelf), 2023).

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Representative model, for educational purposes only.