Video Laryngoscopy Limitation: Blood or Vomit in the Airway
The correct answer is C: effectiveness is diminished with blood or vomit in the airway. This is a well-recognized practical limitation of video laryngoscopy explicitly stated in major airway management guidelines 1.
Why Blood or Vomit Limits VL Effectiveness
The British Journal of Anaesthesia guidelines for tracheal intubation in critically ill adults specifically identify that "blood, secretions and vomitus in the airway hamper both fibreoptic visualization and video-laryngoscopy" 1. This occurs because:
- The camera lens on video laryngoscopes becomes obscured by blood or secretions, degrading the video image quality 1
- Unlike direct laryngoscopy where the operator can directly visualize around blood/secretions, VL relies entirely on the camera view 1
- This limitation is particularly problematic in critically ill patients where awake intubation techniques may be needed but contaminated airways make VL less reliable 1
Why the Other Options Are Incorrect
Option A: "Cannot be used by trainees" - FALSE
- Video laryngoscopy is actually superior for novice operators compared to direct laryngoscopy 2
- A 2022 meta-analysis of 1,730 intubations showed novices had higher initial success rates and faster intubation times with VL versus DL 2
- Medical students specifically showed improved success rates when using VL rather than DL 2
- The shared screen view facilitates superior teaching and training, as the entire team can assess progress in real time 3, 4
Option B: "More prone to causing hypoxic events than DL" - FALSE
- A 2025 meta-analysis of 15 RCTs (4,582 intubations) found no significant difference in hypoxemia between VL and DL 5
- VL actually reduces oxygen desaturation in some studies by improving first-pass success 3
- The 2017 Cochrane Review demonstrated statistically significantly fewer failed intubations with VL, which would reduce hypoxic events 1, 6
Option D: "Ineffective in patients with difficult airway" - FALSE
- This is the opposite of reality—VL is specifically recommended for difficult airways 6, 7
- The 2017 Cochrane Review stated "there were fewer failed intubations in those with an anticipated difficult airway when using a videolaryngoscope" 1, 6
- A 2014 ED study showed VL maintained higher first-pass success even with three or more difficult airway characteristics (68.9% vs 54.1% for DL) 7
- The American Society of Anesthesiologists recommends VL for patients with predicted difficult airways (Category A1-B evidence) 6
Clinical Context and Practical Implications
When encountering a contaminated airway with blood or vomit:
- Consider direct laryngoscopy with immediate suction availability as an alternative 1
- Have aggressive suction prepared before attempting VL in patients at risk for aspiration 1
- In critically ill patients with upper GI bleeding, awake fiberoptic intubation or DL may be more appropriate than VL 6
The key distinction is that while VL excels in most difficult airway scenarios, the specific presence of airway contamination represents its primary practical limitation 1.