The guidelines given by The American Society of Anesthesiologists recommend several methods of intubation, including an FOB, for patients with anticipated difficult airways. The approach for patients with upper airway obstruction is not specifically defined and fiberoptic intubation is described as an option (4). However, as seen in our case, emergency intubation with an FOB might be more difficult than intubation with a VL for the ingestion of corrosive substances. This could be explained by three reasons.
First, alkali ingestion can cause upper airway obstruction with a lot of secretion. To the best of our knowledge, this has not been reported previously. Although FOB is used occasionally for upper airway obstruction, the presence of secretions may make visualization difficult. The presence of excessive secretion and blood can be factors for failed intubation (5). This is also a disadvantage for VL (6). In our case, the secretion was due to mucosal injury from ingesting an alkali substance; therefore, it was difficult to obtain clear visibility, as in the case of airway bleeding. According to Struck (2), emergency physicians did not use an FOB for patients with caustic ingestion but instead used a direct laryngoscope in all cases and succeeded in fewer than two attempts. This fact also encouraged us to attempt intubation with direct or VL.
Second, it is difficult to perform an advanced procedure such as fiberoptic intubation in an emergency. According to Jiang et al (7), physicians require more experience (25 times vs. fewer than 5 times) for a fiberoptic intubation to achieve a success rate of more than 90% within 3 min than for VL. Even for experienced physicians, regular practice is required to maintain their skills (8). In our case, the physician who performed intubation had insufficient experience according to the above data. Without training or experience, it might not be safe to perform an FOB.
Finally, a fiberoptic intubation was inferior to a VL in terms of intubation time. Alhomar et al (9) reported that the time taken to successfully perform a VL was shorter than an FOB. Fiberoptic intubation is time-consuming and difficult to perform in patients prone to hypoxemia. A study showed that the average time for a successful intubation with an FOB was 2 min whereas intubations that took longer than 3 min failed (10). Our attempt of intubating the patient with an FOB for more than 3 min also failed. Hypoxia could be avoided by stopping the intubation procedure after 3 min. It is better to avoid the use of an FOB in high-risk cases of hypoxia.
Our case study has two limitations. First, the emergency physician who performed the intubation was inexperienced. A successful intubation with an FOB is highly dependent on the skill of a physician. Second, we failed to administer atropine to reduce the secretions, which would have made intubation easier. Nevertheless, emergency physicians should be aware of difficulty of intubation for airway obstruction by alkali ingestion.
The patient had rapidly developed upper airway obstruction due to accidental ingestion of a small amount of alkaline substance. We successfully rescued her by intubation with VL after our attempts with fiberoptic intubation failed. The discussion of our failed experience might help emergency physicians intubate patients more safely with emergent upper airway obstruction due to alkali ingestion.
In conclusion, emergency intubation for upper airway obstruction due to alkali ingestion can be difficult in terms of airway management. It would be a reasonable option to use video laryngoscopy in such situations. In our case, intubation with FOB proved to be difficult; however, we managed to intubate the patient with a VL instead. We hope that our experience would help emergency physicians to intubate piatients of alkali ingestion more safely