What is the proper procedure for intubating a patient on the ground with a potential difficult airway?

Ground Intubation Technique

When intubating a patient on the ground, position yourself in the left lateral decubitus position (lying on your left side) rather than kneeling, as this provides superior glottic visualization, faster intubation times, and reduced complications. 1, 2

Operator Positioning

• Adopt the left lateral decubitus position (lying on your left side next to the patient) as your primary approach, which achieves complete glottic visualization in 87% of cases versus only 33% when kneeling 1
• This position reduces intubation time to a median of 10.5 seconds compared to 14.6 seconds when kneeling (P < 0.001) 1
• The left lateral decubitus position significantly reduces laryngoscopic difficulty (11.1% vs 26.9% when kneeling, P < 0.01) and requires fewer intubation attempts 2
• If kneeling is necessary due to space constraints or operator preference, expect more difficult laryngoscopy and plan accordingly 1, 2

Patient Positioning and Preparation

• Position the patient's head in the "sniffing position" with slight head extension and neck flexion to optimize the laryngeal view 3
• If spinal injury is suspected, remove the front of the hard collar and head blocks after establishing manual in-line stabilization, but maintain cervical spine protection throughout 3
• Pre-oxygenate aggressively with high-flow oxygen through a facemask with reservoir bag, targeting maximum oxygen reserves 3, 4
• For hypoxemic patients (SaO2 < 90%) or those with poor respiratory effort, provide gentle bag-mask ventilation while keeping pressures below 25 cmH2O to minimize gastric distension and aspiration risk 3
• Consider apneic oxygenation via nasal cannulae to prolong time to desaturation, though evidence is limited 3

Intubation Technique

• Use an intubating bougie (Eschmann introducer) routinely as your first-line adjunct, as it significantly improves success rates when the laryngeal view is suboptimal 3
• Apply optimum external laryngeal manipulation (OELM) or BURP (backward, upward, rightward pressure) with your right hand during the first laryngoscopy attempt 3
• Limit intubation attempts to a maximum of three, with the most experienced operator performing the attempts 3
• Between each attempt, ventilate with bag-mask or supraglottic airway to maintain oxygenation 3
• If cricoid pressure impedes laryngoscopy or causes airway obstruction, have a low threshold to reduce or remove it 3

Bougie Technique Specifics

• Keep the laryngoscope in the mouth while passing the bougie blindly toward the laryngeal inlet 3
• Advance the bougie gently to a maximum of 45 cm, feeling for tracheal clicks or distal hold-up (resistance indicating bronchial tree engagement) 3
• Once the bougie is confirmed in the trachea, railroad the endotracheal tube over it while keeping the laryngoscope in place 3
• Rotate the tube 90° anticlockwise if resistance is encountered during railroading 3

Difficult Airway Considerations

• Anticipate difficult intubation in all ground-based scenarios and ensure every effort is made for successful first-pass intubation 3
• If intubation fails after three attempts, immediately implement your failed intubation plan using a second-generation supraglottic airway device 3
• Have clear indications and equipment ready for surgical cricothyroidotomy as the definitive rescue technique 3
• Avoid needle cricothyroidotomy due to high complication and failure rates requiring conversion to surgical cricothyroidotomy 3

Confirmation and Securing

• Confirm correct tube placement immediately with waveform capnography and standard clinical assessment 3, 4
• Reconfirm tube position each time the patient is moved 3
• For head-injured patients, secure the tube with self-adhesive tape rather than circumferential ties to avoid impairing venous drainage 3
• Connect the breathing system using an in-line heat and moisture exchange filter 3

Common Pitfalls

• Attempting too many intubation attempts leads to progressive laryngeal edema and hemorrhage, potentially converting a "can intubate, can ventilate" situation into "cannot intubate, cannot ventilate" 3, 5, 6
• Kneeling position significantly worsens glottic visualization and should be avoided when possible 1, 2
• Failing to remove the front of the cervical collar before intubation limits jaw opening and restricts laryngoscopic view 3
• Not having a clear failed intubation plan rehearsed before starting leads to delayed rescue interventions 3