Introduction to tracheal intubation

What tracheal intubation is (and why we do it)

• Tracheal intubation = placing a tube through the vocal cords into the trachea to secure the airway and allow controlled ventilation and oxygen delivery.
• Common reasons: protect the airway from aspiration, facilitate ventilation/oxygenation, allow delivery of inhalational anaesthesia, enable surgery requiring muscle relaxation or controlled ventilation.
• It is a high-stakes procedure: the main risks are hypoxia, oesophageal intubation, aspiration, and airway trauma—so preparation and confirmation are essential.

Core anatomy and key terms (plain language)

• Mouth → oropharynx → larynx (vocal cords) → trachea; oesophagus lies behind the trachea.
• Laryngoscopy = using a laryngoscope to see the larynx (vocal cords).
• Cormack–Lehane (CL) view = what you see at laryngoscopy (Grade 1 full cords; Grade 2 partial; Grade 3 epiglottis only; Grade 4 neither epiglottis nor cords).
• BURP/external laryngeal manipulation = gentle pressure on the larynx to improve the view (best done as ‘bimanual laryngoscopy’: you position the larynx, then an assistant holds).
• RSI (rapid sequence induction) = induction with planned no-mask-ventilation (or minimal ventilation) and early cuff inflation to reduce aspiration risk.

When to intubate (common new-starter scenarios)

• Elective GA: most major abdominal/thoracic surgery; procedures needing paralysis; prone/lateral positioning; long cases.
• High aspiration risk: full stomach, bowel obstruction, pregnancy >20 weeks, severe reflux, emergency surgery, reduced consciousness.
• Respiratory failure: need for controlled ventilation, severe hypoxia/hypercapnia, exhaustion.
• Airway protection: low GCS, seizures, major facial trauma, ongoing vomiting/bleeding into airway.
• If unsure: discuss early with your supervising anaesthetist—do not ‘press on’ with a plan you cannot safely execute.

Pre-intubation safety: the ‘set up’ that prevents harm

• Call for help early if you anticipate difficulty (difficult airway features, obesity, limited mouth opening, cervical spine issues, airway trauma/bleeding).
• Monitoring: ECG, NIBP, SpO2, capnography ready; suction on and working.
• IV access secured; drugs drawn up and clearly labelled.
• Positioning: aim for ‘sniffing’ position; in obesity use head-elevated laryngoscopy position (HELP) / ramping so ear-to-sternal notch is roughly level.
• Pre-oxygenation: tight mask seal, 100% oxygen; aim for end-tidal O2 as high as possible (if available) and SpO2 100% before induction when feasible.
• Airway plan: Plan A (intubation), Plan B (supraglottic airway), Plan C (mask ventilation), Plan D (front-of-neck access) aligned with local difficult airway guidance.

Equipment basics (what to check and why)

• Laryngoscope: correct blade size/type; light working; have a second laryngoscope available.
• Tracheal tube: appropriate size (typical adult: 7.0–7.5 mm ID female; 8.0–8.5 mm ID male—adjust to patient and surgery).
• Cuff check: inflate/deflate to ensure no leak; syringe attached and working.
• Bougie (introducer): have immediately available; know how to use it.
• Suction: Yankauer ready; consider soft suction catheter if secretions/blood.
• Capnography: must be available to confirm tracheal placement (continuous waveform).
• Rescue devices: appropriate supraglottic airway sizes; bag-valve-mask; oral/nasal airways; front-of-neck access kit as per local standard.

Step-by-step: a safe, standard intubation sequence

• Brief the team: roles, planned technique, backup plan, when you will stop and oxygenate.
• Pre-oxygenate; apply nasal cannula oxygen if used locally for apnoeic oxygenation.
• Induce anaesthesia; confirm you can ventilate with mask before giving neuromuscular blocker unless doing RSI.
• Laryngoscopy: insert blade carefully, sweep tongue left, lift along the handle axis (avoid levering on teeth).
• Identify landmarks: epiglottis then vocal cords; optimise view with positioning and external laryngeal manipulation.
• Pass tube through cords under direct vision; advance until cuff just beyond cords (avoid deep intubation).
• Inflate cuff; connect circuit; ventilate and confirm placement with continuous waveform capnography.
• Secure tube; set ventilator; reassess chest movement, breath sounds, and tube depth; document view and any adjuncts used.

Confirming correct placement (non-negotiables)

• Primary confirmation: continuous waveform capnography with consistent CO2 trace over several breaths.
• Also check: bilateral chest rise, misting in tube (not reliable alone), equal breath sounds, improving oxygenation, appropriate airway pressures.
• If no capnography trace (or it disappears): assume oesophageal intubation or disconnection until proven otherwise—remove tube and oxygenate if in doubt.
• Check tube depth: typical adult at teeth ~20–22 cm (varies with height/sex); reassess after moving the patient and after surgery positioning.

Common first-time problems and what to do

• Poor view: stop, oxygenate, reposition (head/neck, ramp), suction, use external laryngeal manipulation, change blade, use bougie, ask for help early.
• Cannot pass tube despite seeing cords: rotate tube 90 degrees, use smaller tube, use bougie, consider stylet if used locally and safely.
• Desaturation: stop attempts, ventilate with 100% O2, consider two-person mask technique, oral airway, PEEP; escalate to supraglottic airway if needed.
• Suspected oesophageal intubation: remove tube immediately, oxygenate, reattempt with improved plan and help.
• Right mainstem intubation: unilateral breath sounds/high airway pressures; withdraw tube 1–2 cm and reassess; confirm with capnography and auscultation.

Aspiration risk and RSI basics (intro level)

• Aim: minimise time between loss of airway reflexes and cuff inflation; avoid gastric insufflation and regurgitation.
• Preparation is key: suction ready, skilled assistant, clear plan for failed intubation.
• Cricoid pressure: follow local policy; if it worsens view or ventilation, it should be adjusted or released (communicate clearly).
• If intubation fails in RSI: prioritise oxygenation; move to mask ventilation (gentle) and/or supraglottic airway as per local difficult airway guidance; call for senior help early.

After intubation: immediate post-intubation checks

• Secure the tube well (tape/tube holder) and note depth at teeth/lips.
• Ensure capnography remains connected and displayed continuously.
• Set appropriate ventilation and alarms; reassess after any patient movement or change in position.
• Consider need for gastric tube, throat pack (if used), eye protection, and bite block if appropriate.
• Plan for extubation early: is this likely to be straightforward or high risk?