Diagnostics & Procedures · Topic 7 of 16

Airway Management & Rapid Sequence Intubation

Procedures · emergency airway

Airway Management & Rapid Sequence Intubation

Predict the difficult airway, preoxygenate, resuscitate before induction, and confirm the tube with waveform capnography — every time.

Key numbers

Preoxygenate 3–5 minutes, head up100% O₂ × 3–5 min

Confirm placement with waveform capnographyETCO₂ waveform

Keep cuff pressure below 30 cm H₂Ocuff < 30 cm H₂O

01 · DoPreoxygenate 3–5 minutes, head up

Preoxygenate with high-concentration oxygen for 3–5 minutes, head elevated 20–45°; in hypoxemic patients use noninvasive ventilation, which halved peri-intubation hypoxemia versus an oxygen mask (9.1% vs 18.5%, PREOXI).

02 · GiveRSI: induction agent plus paralytic together

Rapid sequence intubation gives an induction agent (etomidate 0.3 mg/kg or ketamine 1–2 mg/kg) immediately followed by a paralytic (succinylcholine 1.5 mg/kg or rocuronium up to 1.2 mg/kg); paralysis improves first-pass success.

03 · WatchConfirm placement with waveform capnography

Continuous waveform capnography is the standard for confirming and monitoring tube placement — a sustained ETCO₂ trace over several breaths; chest rise, auscultation and the chest radiograph are supplements, not substitutes.

Causes & risk factors

Why it happens

Predict difficulty: LEMON and MOANS must knowScreen for a difficult laryngoscopy with LEMON (Look externally, Evaluate 3-3-2, Mallampati, Obstruction, Neck mobility) and difficult bag-mask ventilation with MOANS (Mask seal, Obesity/obstruction, Age > 55, No teeth, Snoring).

Physiologically difficult airway: hypoxemia, shock, acidosisNormal anatomy does not mean a safe intubation: severe hypoxemia, shock, metabolic acidosis or right ventricular failure cause rapid desaturation or cardiovascular collapse during the apneic period.

Diagnosis & monitoring

Work-up

Adult tube ≥ 8 mm, 21–23 cmUse an endotracheal tube of 8 mm internal diameter or larger in most adults (lower resistance, easier suctioning and bronchoscopy), at about 21–23 cm at the teeth; an overadvanced tube enters the right mainstem.

Keep cuff pressure below 30 cm H₂OMeasure cuff pressure with a manometer at least every 8 hours and keep it below 30 cm H₂O; higher pressures cause ischemic tracheal erosion, stenosis and fistula.

Intubate to oxygenate, ventilate or protectIndications: failure to oxygenate or ventilate (including failed noninvasive ventilation), inability to protect the airway (deep coma, status epilepticus), threatened airway (edema, burns, trauma), and cardiopulmonary arrest.

Do right now

In this order

First moves

Predict difficulty: LEMON and MOANS

→

Preoxygenate 3–5 minutes, head up100% O₂ × 3–5 min

→

Resuscitate shock before induction

→

RSI: induction agent plus paralytic together

→

Confirm placement with waveform capnographyETCO₂ waveform

Why each step

Predict difficulty: LEMON and MOANSScreen for a difficult laryngoscopy with LEMON (Look externally, Evaluate 3-3-2, Mallampati, Obstruction, Neck mobility) and difficult bag-mask ventilation with MOANS (Mask seal, Obesity/obstruction, Age > 55, No teeth, Snoring).

Preoxygenate 3–5 minutes, head upPreoxygenate with high-concentration oxygen for 3–5 minutes, head elevated 20–45°; in hypoxemic patients use noninvasive ventilation, which halved peri-intubation hypoxemia versus an oxygen mask (9.1% vs 18.5%, PREOXI).

Resuscitate shock before inductionShock before intubation predicts cardiovascular collapse during it: resuscitate first (volume, or blood in hemorrhage), have a vasopressor ready or running, and lower the induction dose; ATLS 11 makes RSI follow initial resuscitation.

RSI: induction agent plus paralytic togetherRapid sequence intubation gives an induction agent (etomidate 0.3 mg/kg or ketamine 1–2 mg/kg) immediately followed by a paralytic (succinylcholine 1.5 mg/kg or rocuronium up to 1.2 mg/kg); paralysis improves first-pass success.

Confirm placement with waveform capnographyContinuous waveform capnography is the standard for confirming and monitoring tube placement — a sustained ETCO₂ trace over several breaths; chest rise, auscultation and the chest radiograph are supplements, not substitutes.

Management

Orders

Can't intubate, can't oxygenate: cricothyrotomyIf intubation fails, oxygenate with a supraglottic airway or bag-mask; if neither works (cannot intubate, cannot oxygenate), perform an emergency scalpel–bougie cricothyrotomy and place a 6.0 tube.

Video laryngoscopy improves first-pass successVideo laryngoscopy raised first-attempt success in critically ill adults (85.1% vs 70.8% with direct laryngoscopy, DEVICE trial) and is suggested as the first device, particularly for a predicted difficult airway.

Use a bougie for a partial viewWhen only the epiglottis or arytenoids are visible, pass a bougie under the epiglottis (tracheal rings felt as clicks) and railroad the tube over it; a first-attempt bougie improved first-pass success in difficult airways.

Post-intubation: film, light sedation, watch BPAfter intubation, secure the tube, get a chest radiograph, and start analgesia-first light sedation (propofol or dexmedetomidine over benzodiazepines); expect hypotension from positive pressure and sedatives.

Cricoid pressure is optional, release if obstructiveCricoid pressure (Sellick) is no longer routine: it may not prevent aspiration and can worsen the laryngeal view, so release it if it hinders laryngoscopy or tube passage.

Red flags & don'ts

Avoid harm

Avoid succinylcholine when hyperkalemia risk avoidAvoid succinylcholine in burns or crush injuries older than 1–2 days, spinal cord injury, neuromuscular disease and malignant hyperthermia risk; use rocuronium, reversible with sugammadex.

The rules

Know these

Awake intubation for predicted difficult airwayThe 2022 ASA guideline recommends awake intubation when laryngoscopy is predicted difficult plus any of: difficult mask or supraglottic ventilation, high aspiration risk, poor apnea tolerance, or a difficult emergency surgical airway.

Limit laryngoscopy attempts and reoxygenateLimit intubation attempts (about 3, plus 1 by the most experienced operator), call for help early and reoxygenate between attempts; 3 or more laryngoscopies sharply raise hypoxemia, aspiration and cardiac arrest.

More detail

Reference

Show 6 reference facts

In the 2026 RSI trial, ketamine and etomidate had similar 28-day mortality (28.1% vs 29.1%), but cardiovascular collapse during intubation was more common with ketamine (22.1% vs 17.0%).

Apneic oxygenation (nasal cannula 15 L/min left on during laryngoscopy) is low risk and widely used, though the FELLOW trial showed no significant reduction in hypoxemia.

Nasotracheal intubation is absolutely contraindicated with midface or suspected basal skull fractures; it causes epistaxis and near-universal sinusitis after 3 days and rarely accepts a tube ≥ 8 mm.

In prolonged cardiac arrest ETCO₂ may be absent despite tracheal placement; an esophageal detector device (bulb or syringe) can help, since the rigid trachea does not collapse under suction.

Severe obesity shortens safe apnea time and makes laryngoscopy harder: position ramped or head-elevated before induction and preoxygenate with positive pressure.

Any translaryngeal tube injures the vocal folds to some degree; subglottic stenosis can appear 3–4 weeks later, and absent left breath sounds after intubation are usually right mainstem placement rather than pneumothorax.

Pearl

No trace, wrong place: without a sustained ETCO₂ waveform, assume the tube is in the esophagus.

Sources · Merck Manual Professional — Tracheal Intubation (Sankari A, rev. Jun 2026) · Merck Manual Professional — Medications to Aid Intubation (Sankari A, rev. Jun 2026; cites the 2023 SCCM RSI guideline) · Liaqat T, Amjad MA, Cherian SV. Difficult Airway Management in the Intensive Care Unit: A Narrative Review of Algorithms and Strategies. J Clin Med 2025 (PMC12295989) · Gibbs KW et al. Noninvasive Ventilation for Preoxygenation during Emergency Intubation (PREOXI). N Engl J Med 2024;390:2165–2177 (abstract via Europe PMC) · Rosboch GL et al. Towards a universal, holistic, evidence-based consensus on difficult airway management: the new ASA guidelines. Ann Transl Med 2022 (PMC9708469) · Apfelbaum JL et al. 2022 American Society of Anesthesiologists Practice Guidelines for Management of the Difficult Airway. Anesthesiology 2022;136:31–81 · JournalFeed — New ATLS update: what you need to know (summary of the ATLS 11th edition review, Injury 2026) · Prekker ME et al. Video versus Direct Laryngoscopy for Tracheal Intubation of Critically Ill Adults (DEVICE). N Engl J Med 2023;389:418–429 (PMC11075576) · Rocuronium bromide injection prescribing information — DailyMed (RSI 0.6–1.2 mg/kg) · Casey JD et al. Ketamine or Etomidate for Tracheal Intubation of Critically Ill Adults (RSI trial). N Engl J Med 2026;394:1608–1620 (abstract via Europe PMC) · Merck Manual Professional — Surgical Airway (rev. Jun 2026) · Merck Manual Professional — Airway Establishment and Control (Situations Requiring Airway Control; rev. Jun 2026) · Starter sheet built from the verified AGACNP fact map (facts reviewed 2026-10-15).