Endotracheal Intubation

Intubation is time-critical once oxygenation is falling. Agree the attempt limit, abort threshold and rescue plan before the first attempt.

Endotracheal intubation (ETI) is the placement of a cuffed endotracheal tube (ETT) through the mouth or nose and into the trachea. The tube protects the airway. It also gives you control over oxygenation and ventilation.

How It Works

• Isolates the airway: the inflated cuff cuts down aspiration of stomach contents, blood and secretions.
• Controls ventilation: you push air in under positive pressure. That delivers oxygen, a set tidal volume and PEEP.
• Allows suction: the tube is a straight line to the lower airway. Suction goes straight down it to clear secretions.
• Requires proof: sight doesn't prove it. Breath sounds don't either, and neither does fogging. Waveform capnography does.

Where It Fits

Intubation is Plan A of a three-plan approach. Plan B is a supraglottic airway (SGA) to oxygenate if the tube fails. Plan C is a surgical airway (cricothyrotomy), for when oxygenation is failing and neither of the first two works (CICO). Say the plan out loud before induction. The drug-assisted sequence lives on the RSI page.

Indications

• Failure to oxygenate or ventilate despite BVM and non-invasive support (NIV, HFNC).
• Inability to protect the airway: GCS ≤ 8, loss of protective reflexes, or persistent vomiting.
• Predicted deterioration: airway burns, angioedema, expanding neck hematoma, or progressive shock.
• Respiratory failure with exhaustion: hypercarbia with pH below 7.20 and rising PaCO₂, despite maximal support.
• Cardiac or respiratory arrest: see Cardiac Arrest below.

Cardiac Arrest

During CPR, you may consider bag-mask ventilation or an advanced airway. It depends on the scene and the professional's skill set (2025 AHA Guidelines for CPR and ECC, Part 9, COR 2b, LOE B-R). Intubating in arrest takes frequent practice or retraining (COR 1, LOE B-NR). Interrupting compressions? Hold the tube until the patient fails initial CPR and defibrillation or achieves ROSC (COR 1, LOE C-LD). Continuous waveform capnography is the recommended way to confirm and monitor placement (COR 1, LOE C-LD). In small studies it was 100% specific for tube position during arrest. Here's the catch: sensitivity drops after a long arrest. So a low or absent EtCO₂ during CPR can reflect low cardiac output. Get the tube checked by direct view or video laryngoscopy where you can. AHA doesn't name a method. In OHCA, a supraglottic airway is acceptable when ETT success is low or training is minimal. Where success is high, either device can be used (2025 AHA Guidelines for CPR and ECC, Part 9, COR 2a, LOE B-R). EMS systems that intubate in arrest need ongoing quality improvement. The aim is fewer complications and better tracking of SGA and ETT placement success (COR 1, LOE C-EO).

Watch for a sudden EtCO₂ jump during compressions or at a rhythm check. It can flag ROSC (COR 2b, LOE B-NR). A rise above 10 mmHg may indicate ROSC. In an intubated adult, an EtCO₂ still at or below 10 mmHg by waveform capnography, after 20 minutes of ALS resuscitation, may be one input to a multimodal decision to end resuscitation (COR 2b, LOE C-LD). It is strongly, but not perfectly, predictive of futility. Don't lean on it alone.

Absolute Contraindications

No absolute contraindication exists when intubation is truly indicated.

Relative Contraindications & Cautions

• Suspected epiglottitis or upper airway obstruction: manipulation can make it worse. Prepare for awake or surgical options.
• Coagulopathy or anticoagulation: bleeding risk is higher. Have hemostatic plans ready.
• Unstable cervical spine: hold manual in-line stabilization the whole time.
• Do-not-intubate orders or goals of care: confirm them with medical direction before induction.

Consider an Alternative

Start with NIV, HFNC or BVM if they can bridge the patient safely. Awake intubation with topical anesthesia can be considered for a cooperative patient with a predicted difficult airway (planned link: awake-intubation).

Abort / Stop Criteria

• SpO₂ falls below 90% during an attempt.
• An attempt exceeds the time limit or makes no progress.
• Three attempts have failed.
• Hemodynamic collapse develops during laryngoscopy.

Team Roles During the Procedure

• Operator: performs laryngoscopy and tube placement; calls the attempt and the abort.
• Airway/oxygen manager: runs BVM, PEEP valve and apneic oxygenation.
• Medication clinician: prepares and gives drugs, reads back doses and weights.
• Monitor and recorder: watches SpO₂, ECG and EtCO₂, times the attempt and documents.

Ask two questions before the first attempt. Can the tube go in? That's structural difficulty. Can the patient tolerate the attempt? That's physiologic difficulty.

Anatomic Difficulty

Physiologic Risk

• Hypotension: SBP < 90 mmHg or shock index above about 0.8–0.9 before induction (protocol-dependent).
• Hypoxemia: SpO₂ < 93% before laryngoscopy is a typical risk marker. It shortens the safe apnea time.
• Acidosis: severe metabolic acidosis (typical marker: pH < 7.20) means the patient loses respiratory compensation during apnea.
• Low reserve: pregnancy, obesity, sepsis, low hemoglobin or large-volume bleeding.

These thresholds are common risk markers from peri-intubation studies. They aren't guideline cut-offs. Use your protocol values.

Site / Device Check

Confirm SpO₂, ECG, blood pressure and EtCO₂ monitoring are all running. Know where the SGA and the surgical airway kit are. Know who will use them.

Equipment

Sizing

Laryngoscope Blades

Video Laryngoscope (VL)

• Evidence: in the DEVICE trial of critically ill adults, video laryngoscopy reached 85.1% first-attempt success, against 70.8% for direct laryngoscopy.
• Platforms: GlideScope, C-MAC, McGrath and King Vision are the common ones. Standard and hyperangulated blades differ in geometry. Learn the one you carry.
• Limitations: blood or secretions can cloud the camera. Keep your direct laryngoscopy skills and switch when the view is poor.

Stylet and Bougie

• Stylet: shape it to the blade. Direct laryngoscopy takes a gentle hockey-stick bend. Video laryngoscopy often needs more curve. Keep the tip short of the ETT tip.
• Bougie: use it when only the arytenoids or epiglottis are visible. Feel for tracheal clicks. A hold-up at the carina confirms the bougie is in the trachea.
• Evidence: in BOUGIE, the bougie did not beat the stylet on first-attempt success in critically ill adults. It was 80.4% against 83.0% with a stylet, and the difference was not significant. Use it for a limited view, not as a routine upgrade.
• Railroading: load the tube over the bougie. If the tube catches on the arytenoids, rotate it 90° counterclockwise while you advance.

Adjuncts and Backup Devices

• Suction: rigid Yankauer for the mouth, large-bore catheter for the tube. In heavily soiled airways, suction continuously during laryngoscopy (suction-assisted laryngoscopy and airway decontamination, SALAD).
• Supraglottic airways (SGA): the rescue device when intubation fails but ventilation is still possible. Some (Air-Q, intubating LMA) let a tube pass. They protect the airway less well than an ETT.

Patient Positioning & Preparation

Ramp until the ear lines up with the sternal notch. A pillow or a ramp device will do it, or you can reverse Trendelenburg on a stretcher. Ramping pays off most in obesity and pregnancy, where it improves the view.

Preoxygenation

• Spontaneous breathing: a tight non-rebreather at flush rate (at least 15 L/min) or high-flow nasal oxygen. Preoxygenate for 3 minutes of tidal breathing or 8 vital-capacity breaths when time allows.
• Apneic or hypoventilating patient: BVM with a PEEP valve (5–10 cm H₂O) and two-hand seal. Avoid hyperventilation.
• Evidence: in PREOXI, noninvasive ventilation for preoxygenation reduced hypoxemia to 9.1%, against 18.5% with a face mask.
• Apneic oxygenation: nasal cannula at 15 L/min during every attempt, and after the mask comes off (protocol).

Doses here are typical adult and pediatric references. Verify them against local protocol and current drug labeling. Doses vary by protocol; follow local protocols and medical direction.

Induction Agent Choice

A 2026 trial compared ketamine with etomidate in critically ill adults, across 14 US emergency departments and ICUs. It did not include prehospital care. 28-day death was 28.1% with ketamine and 29.1% with etomidate. That gap was not significant. Cardiovascular collapse during intubation was more frequent with ketamine (22.1% vs 17.0%). With more collapse on ketamine, reduce the induction dose, resuscitate first, and have a vasopressor ready when shock index is high or the patient is hypotensive, per protocol. Here's the key distinction: protocol and the hemodynamic picture pick the agent. A belief that one drug is safer doesn't.

After Intubation

Start analgosedation once the tube is confirmed, per protocol. Opioid and sedative choices live on the drug pages (for example, fentanyl). Analgosedation as a topic is a planned link.

Phase 1: Prepare

1. Brief the team: assign roles, state Plan A, B and C, and agree the abort threshold and time limit.
2. Check equipment: suction tested, BVM with PEEP valve, oxygen flowing, blade light on, ETT and backup ready, SGA and surgical kit at the bedside.
3. Preoxygenate: non-rebreather or high-flow oxygen with BVM as needed; ramp the patient to ear-to-sternal-notch.
4. Start apneic oxygenation: nasal cannula at 15 L/min before induction (protocol).
5. Give induction and paralytic: per Medications & Settings and the RSI page, with weight and doses read back.

Phase 2: Perform

4. Insert the blade: from the right side of the mouth, sweep the tongue left, and advance to the vallecula (Macintosh) or past the epiglottis (Miller).
5. Expose the cords: lift along the handle axis, not toward the teeth. Suction blood or secretions; use external laryngeal manipulation if it helps.
6. Pass the tube or bougie: pass the tube through the cords under view. With only partial view, pass the bougie first and railroad the tube over it.

Phase 3: Confirm & Secure

7. Inflate the cuff: to 20–30 cm H₂O, then start ventilation.
8. Confirm placement: sustained waveform EtCO₂ over 5–6 breaths, with chest rise and breath sounds (see Confirmation & Monitoring).
9. Secure the tube: commercial holder or tape; record the depth at the teeth; add a bite block if needed.
10. Reassess after every move: recheck waveform, depth and breath sounds after transfer, repositioning or transport.

Alternative Technique: Video Laryngoscopy First

Reach for a video laryngoscope first when you have one. The screen often shows the cords above the tongue, so you see more. Abort limits and confirmation steps don't change. Load the bougie with the tube first.

Alternative Technique: Bougie-Assisted Intubation

When any glottic structure is visible, pass the bougie and feel for clicks. Load the tube onto it. Catch? Rotate it 90° counterclockwise. The bougie comes out only after the tube is seated and confirmed.

Primary Confirmation

Waveform capnography is the one objective test that proves tracheal placement. Look for a sustained square wave over at least 5–6 breaths. In a perfusing patient, EtCO₂ is typically 35–45 mmHg. Record the time, the value and the waveform.

Secondary Confirmation

• Bilateral chest rise with ventilation.
• Symmetric breath sounds in both axillae; listen high to avoid transmitted sounds.
• No epigastric sounds or gurgling.
• Improving SpO₂ in a hypoxemic patient.
• Fogging in the tube is unreliable, especially in hypothermia.

Capnography Waveform

• Phase 0 and I: the baseline stays near zero through inspiration and dead space.
• Phase II: the waveform climbs fast as alveolar gas reaches the sensor.
• Phase III: the alveolar plateau. You read EtCO₂ at the end of this phase.

Waveform Loss: DOPE Check

Capnography Devices

Mainstream and sidestream sensors give you a waveform EtCO₂. A nasal cannula sensor measures during ventilation. A colorimetric detector changes color with exhaled CO₂. It's a backup only, and it's less reliable in low perfusion.

Ongoing Monitoring

• Continuous: waveform EtCO₂, SpO₂, ECG and trend of each.
• Blood pressure: continuous or every 1–2 minutes for the first 10–15 minutes after induction, then per protocol.
• Tube position: depth and breath sounds after every move, and after any new device.
• Blood gas: 30–60 minutes after intubation and after major ventilator changes.

Pediatrics

Size the ETT and depth with a length-based tape or the pediatric protocol. Two pages cover this: equipment sizing and pediatric airway. With a perfusing rhythm, confirm the tube with exhaled CO₂ (colorimetric detector or capnography) (2025 AHA Guidelines for CPR and ECC, Part 8, COR 1, LOE C-LD). Low cardiac output or arrest can make exhaled CO₂ unreliable.

• Paralytics: succinylcholine 2 mg/kg for infants and small children; 1 mg/kg for older children, per label.
• Induction: etomidate is labeled for age 10 and older. Younger children need a specialist protocol.
• Surgical airway: cricothyrotomy is generally not used below about 8 years. Teaching differs for 8–12 years, so follow local protocol and the cricothyrotomy page. Below the cut-off, use needle or tracheotomy techniques.
• Cuffed ETT size: age in years ÷ 4 + 3.5 is standard airway teaching. AHA 2025 doesn't state it, so check it against the length-based tape. Cuffed tubes are reasonable (2025 AHA Guidelines for CPR and ECC, Part 8, COR 2a, LOE B-NR). When you use one, attend to size, position and cuff pressure, usually below 20–25 cm H₂O (COR 1, LOE C-EO). Depth at the teeth is about 3 times the ETT internal diameter. That's standard teaching. Confirm it with EtCO₂ and auscultation.
• Desaturation and bradycardia: kids desaturate faster. Vagal bradycardia can occur with laryngoscopy. Atropine is recommended for bradycardia with cardiopulmonary compromise from increased vagal tone or atrioventricular conduction block, not from hypoxia (2025 AHA Guidelines for CPR and ECC, Part 8, COR 1, LOE C-LD). Correct oxygenation and ventilation first. If heart rate stays below 60/min with compromise despite effective ventilation with oxygen, start CPR (Part 8, Management of Bradycardia, rec 2, COR 1, LOE C-EO). As premedication for emergency intubation, 0.02 mg/kg with no minimum dose may be considered (COR 2b, LOE C-LD). The maximum single dose is the adult dose, per the NASEMSO Universal Care Guideline, p. 13. The AHA does not state a cap. Preoxygenate fully.
• Anatomy: a big occiput and a floppy epiglottis point you to a straight blade and a shoulder roll, per protocol.
• Neonates: follow the neonatal resuscitation guideline. This page doesn't cover neonatal tube depth.

Obesity

• Ramp the patient and use high-flow oxygen. Safe apnea time is shorter.
• Video laryngoscopy is often the first device. In DEVICE, it raised first-attempt success across critically ill adults.

Pregnancy

• Oxygen reserve is lower. Preoxygenate thoroughly and expect faster desaturation.
• Expect airway edema and higher aspiration risk. Have a smaller tube (about 6.0–7.0 mm) ready, and use video laryngoscopy where available.
• Consider a left uterine displacement and early use of a difficult-airway plan.

Physiologically Difficult Patients

• Severe ARDS, right heart failure and profound shock don't tolerate induction well. Consider DSI or awake intubation.
• Have vasopressors drawn and running before induction. If the patient is unstable, reduce PEEP and tidal volume during the attempt.

Trauma and Cervical Spine

• Maintain manual in-line stabilization. Remove the anterior collar only when the view requires it.
• Expect bleeding and vomit. Suction early.

Traumatic Brain Injury

• Avoid hypoxemia and hypotension. Resuscitate before or while you induce. Aim for normocapnia rather than prophylactic hyperventilation. The BTF 4th edition advises against profound hypocapnia (PaCO₂ below 25 mmHg). Use brief hyperventilation only for signs of herniation.
• Avoid high PEEP. It impedes venous return and raises intracranial pressure.

Immediate Aftercare

• Confirm the tube again: waveform EtCO₂, breath sounds, depth at teeth.
• Start analgosedation per protocol, then reassess paralysis and sedation.
• Obtain chest X-ray per protocol to confirm tip position.
• Place an orogastric tube per protocol to decompress the stomach, after confirming tube position.

Ongoing Maintenance

• Cuff pressure 20–30 cm H₂O; recheck after each move and per protocol.
• Keep the tube secured; check the holder and the bite block.
• Suction as needed; use a closed suction system where available.

Transport Considerations

• Reassess the tube after every move: stretcher, ambulance, elevator and stairs.
• Altitude and temperature change cuff pressure. Recheck it on climbs and descents.
• In noise and vibration, rely on EtCO₂ and your monitors. A sensor alarm means check the tube.
• Carry a backup ETT, suction, BVM and the surgical airway kit in the same compartment.

Initial Ventilator Settings

Ideal body weight (Devine): male 50 + 0.91 × (height in cm − 152.4) kg; female 45.5 + 0.91 × (height in cm − 152.4) kg.

Pearls

• Plan out loud: state Plan A, B and C before the first attempt.
• Waveform, not sight: sight doesn't prove tracheal placement. Only a sustained EtCO₂ waveform does.
• Limit the attempt: every attempt has a time limit. Desaturation ends it.
• Video first when available: in critically ill adults (DEVICE), it improved first-attempt success.
• Bougie for a limited view: it helps only if some glottic structure shows.

Common Pitfalls

• Pitfall: continuing attempts through desaturation → fix: abort at SpO₂ 90% and reoxygenate.
• Pitfall: trusting breath sounds alone → fix: confirm with waveform EtCO₂.
• Pitfall: paralyzing without a sedation and analgesia plan → fix: start analgosedation as soon as the tube is confirmed. Paralysis hides distress. It doesn't prevent awareness.
• Pitfall: forgetting the tube moves → fix: reassess after every transfer.

Skill Maintenance

• Practice on a manikin with the full team, including the abort and rescue steps.
• Use a checklist for every attempt, including the equipment and abort threshold.
• Debrief every intubation, successful or not, with the team.
• Cross-train on every video laryngoscope and SGA in your system.