Endotracheal Intubation (ETI)
ETI places a cuffed tube directly into the trachea, securing the airway completely. It allows continuous ventilation, protects against aspiration, and enables medication delivery. It is the definitive airway — but it requires skill and carries significant risks if done incorrectly.
Equipment
- Laryngoscope (direct or video) with working blade — Mac 3-4 for most adults
- ET tube: 7.5–8.0mm for adult males, 7.0–7.5mm for adult females
- 10 mL syringe to inflate the cuff
- Stylet — gives the tube shape; remove after tip passes cords
- BVM connected to oxygen for pre-oxygenation and backup
- Suction immediately available
- Waveform capnography — mandatory for confirmation
Landmarks
- The epiglottis is your guide — lift it with the blade to expose the vocal cords
- The vocal cords are white, triangular, and vertical. The tube goes between them.
- Pass the tube until the cuff is 2–3 cm past the cords (about 21–23 cm at the lip)
- Inflate the cuff with 5–10 mL air until no leak is felt during ventilation
Confirming Placement
- Waveform capnography: gold standard — consistent waveform + ETCO₂ 35–45 mmHg = tracheal placement
- Bilateral breath sounds and equal chest rise
- No gastric sounds over epigastrium
- SpO₂ improving or maintaining
- Fogging in the tube on exhalation (unreliable alone)
Absent or flat ETCO₂ waveform, gurgling over epigastrium, no chest rise, SpO₂ dropping, gastric distension. If you have ANY doubt — pull the tube immediately, ventilate with BVM, and reattempt. Never confirm placement by "feeling" resistance.
Rapid Sequence Intubation (RSI)
RSI uses a sedative + paralytic given in rapid sequence to facilitate intubation in a patient who is not deeply unconscious. It prevents the gag reflex, coughing, vomiting, and laryngospasm during laryngoscopy.
The RSI Sequence
- 1. Prepare: Equipment checked and ready, suction on, backup airway available, IV access confirmed
- 2. Pre-oxygenate: 100% O₂ via NRB or BVM for 3–5 minutes (flush nitrogen from lungs, buys you time)
- 3. Pre-treat: Lidocaine 1.5 mg/kg (reduces ICP spike with intubation — used for head injury patients)
- 4. Sedate: Give sedative — see options below
- 5. Paralyze: Give paralytic immediately after sedative
- 6. Intubate: When fasciculations stop (succinylcholine) or patient is flaccid (roc) — usually 45–60 seconds
- 7. Confirm: Waveform capnography, bilateral breath sounds, secure tube
- 8. Post-intubation care: Sedation for transport, target ETCO₂ 35–40 mmHg
Giving a paralytic without adequate sedation causes the patient to be fully conscious, paralyzed, and unable to communicate or breathe. This is a medical emergency and a devastating error. If you are unsure sedation has taken effect, do not give the paralytic.
RSI Medications
| Drug | Class | Dose | Notes |
|---|---|---|---|
| Etomidate | Sedative | 0.3 mg/kg IV | Hemodynamically neutral — preferred for most patients |
| Ketamine | Sedative | 1–2 mg/kg IV | Supports BP — preferred in shock. Also analgesic. Avoid in severe hypertension. |
| Midazolam | Sedative | 0.1–0.3 mg/kg IV | Alternative — causes vasodilation, can drop BP |
| Succinylcholine | Depolarizing NMB | 1.5 mg/kg IV | Onset 45s, duration 8–10 min. Causes fasciculations. Contraindicated: hyperkalemia, crush injury, burns >24h, pseudocholinesterase deficiency |
| Rocuronium | Non-depolarizing NMB | 1.2 mg/kg IV | Onset 60–90s, duration 45–60 min. Use when succinylcholine is contraindicated. Reversed by sugammadex. |
Supraglottic Airways (SGAs)
SGAs (King LT, iGel, LMA) sit above the glottis and create a seal around the larynx. They're easier to place than ETTs but don't protect the airway as well. Use when ETI has failed or isn't feasible.
- King LT: Dual-cuff, blind insertion. Size 4 for most adults (height-based). Inflate both cuffs with one syringe port.
- iGel: No cuff — gel-based seal. Faster and easier. Good for cardiac arrest.
- Both: Confirm with ETCO₂ waveform same as ETT
- SGAs in cardiac arrest: acceptable alternative to ETT per current ACLS guidelines
Waveform Capnography (ETCO₂)
ETCO₂ measures CO₂ in exhaled air. Normal: 35–45 mmHg. It's mandatory after intubation and provides continuous confirmation that the tube is in the trachea.
- ETCO₂ rising in cardiac arrest → ROSC may be occurring (CO₂ production increased as perfusion restores)
- ETCO₂ <10 mmHg in arrest despite good CPR → poor prognosis indicator
- Sudden drop in ETCO₂ in arrested patient → check tube placement, CPR quality, or pulmonary embolism
- Target post-intubation: 35–40 mmHg. Avoid hyperventilation (<35) — increases ICP and reduces cerebral perfusion.