Video Laryngoscopy and Difficult Airway Rescue

Video Laryngoscopy and Difficult Airway Rescue

Why Video Laryngoscopy Matters

Direct laryngoscopy (DL) relies on aligning the oral, pharyngeal, and laryngeal axes so the provider can see the glottis with an unobstructed line of sight. In patients with limited neck mobility, large tongue, obesity, facial trauma, or distorted anatomy, that line of sight may be impossible to achieve. Video laryngoscopy (VL) routes the view through a small camera mounted near the blade tip, displaying the image on a screen. Because the camera rounds the anatomical corner, VL typically provides a better glottic view even when DL fails — making it a cornerstone of the modern difficult airway toolkit.

Video Laryngoscope Setup and Screen Interpretation

Before approaching the patient, verify the device is charged or connected to power, the screen is clean and displaying correctly, and the blade size is appropriate for the patient. Anti-fog solution or a brief warm rinse prevents lens fogging during insertion. Select an endotracheal (ET) tube one-half size smaller than you might use for DL, because the more acute glottic angle often requires a pre-loaded stylet bent to match the blade's curve.

During insertion, advance the blade midline along the tongue toward the vallecula (for a Macintosh-style VL blade) or beyond (for a hyperangulated blade, depending on the device). Watch the screen — not the patient's mouth — once the blade tip is past the tongue. Center the glottis on the screen before attempting tube delivery. A common error is obtaining a perfect camera view but then looking away from the screen to pass the tube; this causes the tube tip to miss the glottis. Keep your eyes on the screen throughout tube delivery.

The Difficult Airway Algorithm

The American Society of Anesthesiologists (ASA) and the Difficult Airway Society both publish stepwise algorithms that guide providers through escalating interventions. As a respiratory therapist you must know and be able to execute this sequence in collaboration with the team.

Step 1 — Recognize and communicate. If DL fails after an optimal attempt (best head position, external laryngeal manipulation, best blade choice), declare the situation clearly: "Direct laryngoscopy has failed. I am moving to video laryngoscopy." Announce to the team and call for additional help early — not as a last resort.

Step 2 — Attempt VL. Apply video laryngoscopy as described above. Limit intubation attempts to preserve airway tissue and avoid bleeding that worsens the view. Most guidelines recommend no more than two to three total laryngoscopy attempts before moving to a rescue airway.

Step 3 — Supraglottic airway (SGA). If VL does not succeed or is unavailable, insert a supraglottic airway (e.g., laryngeal mask airway, LMA) to restore oxygenation and ventilation. Oxygenation takes priority over a definitive tube. Confirm ventilation by bilateral chest rise, equal breath sounds, and end-tidal CO₂ waveform.

Step 4 — Wake the patient or accept SGA ventilation if the procedure is elective and the patient can be safely awakened. For an emergency or when the patient cannot be awakened, continue down the algorithm.

Step 5 — Cannot Intubate, Cannot Oxygenate (CICO). This is the most critical decision point. CICO is defined as a situation in which no supraglottic technique is providing adequate oxygenation (SpO₂ falling despite best efforts, cyanosis, bradycardia) and intubation has failed. CICO demands an emergency surgical airway.

Cricothyrotomy: The Rescue of Last Resort

Cricothyrotomy creates a direct opening through the cricothyroid membrane to bypass upper airway obstruction entirely. Clinical indicators for cricothyrotomy include confirmed CICO with deteriorating SpO₂, failed SGA ventilation, and absence of any other rapidly available rescue option.

Preparatory steps on a task trainer:

1. Position the patient supine with neck extended (place a roll under the shoulders if possible).

2. Locate the cricothyroid membrane by palpating the laryngeal prominence (Adam's apple), then sliding caudally to the soft indentation between the thyroid and cricoid cartilages.

3. Stabilize the larynx with the non-dominant hand using the "laryngeal handshake" (thumb and middle finger on the thyroid cartilage, index finger palpating the membrane).

4. Make the incision or insert the needle/device per the specific technique being used (open surgical, modified Seldinger, or commercial kit) — exact technique depends on what your institution stocks and your clinical role.

5. Confirm ventilation and oxygenation once the airway is established.

Safety Principles

• Oxygenation always comes first. A bag-valve mask (BVM) and supraglottic airway buy time; pursue those before escalating.
• Limit attempts. Each laryngoscopy attempt risks trauma, bleeding, and swelling that make the next attempt harder.
• Call for help early. The difficult airway algorithm explicitly emphasizes early activation of additional skilled personnel.
• Scope of practice. Know your state's RT practice act. Cricothyrotomy may or may not be within an RT's independent scope; always act under physician direction and institutional protocol. Never attempt a procedure you are not credentialed and authorized to perform in your clinical setting.
• Know your equipment. Device-specific technique varies; read the training manual for every VL device you will use.
• Document and debrief. After any difficult airway event, document the interventions, airway grades, and devices used, and participate in team debriefing to improve future responses.