What is the proper procedure for intubation?

Proper Procedure for Endotracheal Intubation

The proper procedure for intubation requires a systematic approach including optimal positioning, adequate preoxygenation, appropriate medication selection, and proper technique with confirmation of tube placement to minimize complications and maximize patient safety. 1

Pre-Intubation Assessment and Preparation

Patient Positioning

• Position patient in "sniffing position" with head extended on the neck so the face is horizontal
• For obese patients, use "ramping" position (external auditory meatus level with sternal notch)
• Ensure bed mattress is firm to optimize cricoid pressure application and access to cricothyroid membrane 1

Equipment Preparation

• Verify all necessary equipment is available:
  • Laryngoscope (direct or video)
  • Appropriately sized endotracheal tube (ETT)
  • Stylet/bougie
  • Suction
  • Bag-valve-mask with PEEP valve
  • Waveform capnography
  • Backup airway devices (supraglottic airway)
  • Emergency cricothyrotomy equipment 1, 2

Monitoring

• Apply standard monitoring before intubation:
  • Pulse oximetry
  • Waveform capnography
  • Blood pressure
  • Heart rate
  • ECG
  • End-tidal oxygen concentration (if available) 1

Preoxygenation

Standard Preoxygenation

• Use tight-fitting facemask with 10-15 L/min of 100% oxygen for 3 minutes
• Target end-tidal oxygen concentration >85% to confirm adequate preoxygenation
• Use two-handed technique to minimize mask leak 1, 3

Preoxygenation in High-Risk Patients

• For hypoxemic patients, use CPAP (5-10 cmH₂O) or NIV with supported breaths
• Consider high-flow nasal oxygen (HFNO) at 30-70 L/min in appropriate patients
• For agitated patients who cannot tolerate preoxygenation, consider delayed sequence induction with small doses of ketamine to facilitate preoxygenation 1, 4
• For obese patients, use 25° head-up position with positive pressure ventilation 5

Medication Administration

Induction Agents

• Select appropriate hypnotic agent based on patient condition:
  • Etomidate: 0.3 mg/kg (hemodynamically unstable patients)
  • Ketamine: 1-2 mg/kg (septic or asthmatic patients)
  • Propofol: 1-2 mg/kg (hemodynamically stable patients) 1

Neuromuscular Blocking Agents

• For rapid sequence intubation:
  • Succinylcholine: 1-1.5 mg/kg (first-line if no contraindications)
  • Rocuronium: 1.0-1.2 mg/kg (if succinylcholine contraindicated)
  • Have sugammadex available when using rocuronium 1, 6

Intubation Procedure

Direct Laryngoscopy Technique

1. Hold laryngoscope in left hand
2. Insert blade into right side of mouth, sweep tongue to left
3. Advance blade to vallecula (curved blade) or posterior to epiglottis (straight blade)
4. Lift forward and upward (not using teeth as fulcrum)
5. Visualize vocal cords
6. Insert ETT through cords with right hand
7. Advance until cuff passes cords by 1-2 cm
8. Inflate cuff and confirm placement 1, 7

Confirmation of Placement

• Primary confirmation: Waveform capnography (most reliable method)
• Secondary confirmation:
  • Chest rise and fall
  • Bilateral breath sounds
  • Absence of gastric sounds
  • Misting in tube 1

Tube Fixation

• Secure tube firmly after confirming correct placement
• Document depth at teeth/lips
• Consider post-intubation chest X-ray 1

Difficult Airway Management

MACOCHA Score Assessment

Assess difficulty using MACOCHA score (0-12 points):

• Mallampati III/IV: 5 points
• Obstructive sleep apnea: 2 points
• Cervical spine limitation: 1 point
• Opening mouth <3 cm: 1 point
• Coma: 1 point
• Hypoxemia (SpO₂ <80%): 1 point
• Non-anesthetist operator: 1 point 1

Failed Intubation

If intubation fails after maximum of three attempts:

1. Return to bag-mask ventilation with CPAP
2. Consider supraglottic airway device (LMA)
3. If ventilation impossible ("can't intubate, can't ventilate"), proceed to emergency front-of-neck access 1

Emergency Front-of-Neck Access

For "can't intubate, can't ventilate" scenario:

1. Identify cricothyroid membrane using laryngeal handshake
2. Make transverse stab incision through membrane
3. Rotate blade 90° (sharp edge toward feet)
4. Slide bougie along blade into trachea
5. Railroad lubricated cuffed tube (5.0-6.0 mm) into trachea
6. Confirm placement with capnography 1

Common Pitfalls and Caveats

• Failure to adequately preoxygenate leads to rapid desaturation during intubation attempts
• Multiple laryngoscopy attempts increase risk of trauma and hypoxemia
• Esophageal intubation not recognized promptly can be fatal - always confirm with waveform capnography
• Inappropriate tube size or depth can lead to single lung ventilation or accidental extubation
• Failure to recognize difficult airway in advance leads to poor preparation
• Inadequate sedation/paralysis can result in patient movement and failed intubation 1, 7

By following this structured approach to intubation, clinicians can maximize success rates while minimizing complications that could lead to increased morbidity and mortality.