DOI: https://doi.org/10.21203/rs.3.rs-1464362/v1
Background: Ingestion of alkaline substances can cause mucosal damage and upper airway obstruction. This is a serious and potentially fatal complication that occurs within the first few hours after ingestion. There has been no established algorithm for emergent airway management in these situations. We present a case of difficult airway management in a patient with upper airway obstruction caused by alkali ingestion, wherein we opted for intubation with video laryngoscopy and successfully treated the patient.
Case presentation: An 80-year-old patient accidentally ingested a small amount of alkaline liquid and presented to our hospital with complaints of burning sensation in the throat. Within two hours of arrival at the hospital, the edema in the epiglottis rapidly worsened, resulting in upper airway obstruction. Assuming that intubation and ventilation would be difficult in this situation, we attempted to intubate the patient using fiberoptic bronchoscopy, but it was difficult. Finally, after two unsuccessful attempts, we successfully intubated the patient using a video laryngoscope.
Conclusions: The patient in our case had acute upper airway obstruction due to alkali ingestion, which caused difficulty in tracheal intubation. Our experience, in this case, would likely help emergency physicians to intubate more safely in patients with emergent upper airway obstruction due to alkali ingestion. For intubation in such situations, it would be a reasonable option to use video laryngoscopy.
Ingestion of corrosive substances such as alkalis, acids, and metals can cause mucosal damage, leading to airway obstruction, which sometimes requires emergency airway interventions (1). According to Struck (2), intubation was necessary in half (14/28, 50%) of the patients with corrosive esophagitis in their study. Among them, Three (21%) of the patients had difficult airways. However, there is no effective algorithm for emergency airway management in such situations.
Herein, we present a case study where we attempted to intubate the patient for upper airway obstruction using fiberoptic bronchoscopy (FOB) but were unsuccessful. We then performed a video laryngoscopy (VL) and successfully intubated the patient. In addition, we also discuss the optimal method for intubating patients with upper airway obstruction caused by alkali ingestion.
An 80-year-old woman presented to the emergency department (ED) complaining of a burning sensation in her throat. Two hours before admission, she had ingested a liquid from a beverage can at home. She immediately felt a tingling sensation in her mouth and spat out the liquid. She had ingested only a small amount, which was later estimated to be less than 50 mL. Following this, she experienced a burning sensation in her throat and arrived at the ED. She had no respiratory distress, nausea, or vomiting. Initially, the contents of the can were unknown, but after admission, the liquid was identified to be an exfoliant with pH 12.3.
The patient’s height was 156 cm and her body weight was 52 kg. Upon arrival, she was alert and conscious. Her vital signs were determined as follows: heart rate, 97 beats/min; blood pressure, 138/89 mmHg; respiratory rate, 18 breaths/min; oxygen saturation (SpO2), 99% (room air); and body temperature, 36.8°C. Her voice was muffled, and her tongue had erosions along with bleeding. She did not display any stridor or abdominal tenderness.
We considered the possibility of upper airway obstruction and performed an FOB. Her SpO2 levels were stable. The FOB revealed erosion and edema of the middle pharynx and epiglottis. Due to the presence of edema in the epiglottis, we expected further airway obstruction and decided to intubate the patient. At this point, 3 hours had passed since the accidental ingestion.
We considered the risk of a failed intubation and prepared for surgical airway management (e.g., cricothyrotomy) along with a bougie, VL, and FOB. Because the ED was crowded, we could only intubate the patient 4 hours after alkali ingestion. At this time, there was still no decrease in her SpO2 levels or stridor; therefore, we chose to intubate her orally with the FOB. A skilled emergency physician performed the initial intubation. We administered 30 mg of propofol and tried to intubate the patient while she was awake and breathed spontaneously. She had a lot of secretion in pharynx, which resulted in poor visualization, and the edema of the epiglottis was prominent (Figure 1). Intubation was interrupted at 2 min 50 s because her SpO2 levels dropped to 70%. After her SpO2 levels improved, intubation was performed again using the same approach. As observed during the first attempt of intubation, clear visibility could not be obtained, and her SpO2 levels dropped once again; therefore, intubation was stopped at 4 min 50 s. We decided to perform VL instead because it could provide a direct view and the secretions prevented clear visualization with the FOB. After her SpO2 levels improved, we successfully intubated the patient with the VL despite poor visualization due to secretion and edema. At this point, 37 min had passed since the first intubation attempt.
The patient was then admitted to the intensive care unit. Upper gastrointestinal endoscopy was performed on the first day after admission. A diagnosis of corrosive esophagitis was made, with Zargar classification grade 3 (3). On the 14th day of hospitalization, the upper airway was assessed again using nasal laryngoscopy. The edema in the upper airway had not receded; therefore, we performed tracheostomy. On the 30th day of hospitalization, the patient could speak with the aid of a tracheostomy tube containing a speaking valve. On the 38th day of hospitalization, the tracheostomy incision was sutured, and the patient was discharged without any decline in activities of daily living.
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
FOB, fiberoptic bronchoscopy; VL, video laryngoscopy; ED, emergency department
Ethics approval and consent to participate
Ethics committee approval was obtained from the Ethics and Research Committee of Shonan Kamakura General Hospital. (SKEC-21-25)
Consent for publication
Written informed consent was obtained from the patient for the publication of this case report and accompanying image.
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Authors’ contributions
AT and KF examined and treated the patient. AT wrote the manuscript and made the figure. KF revised the manuscript. HY supervised the manuscript. HY and IS commented on the draft respectively. All authors have read and approved the final manuscript.
Acknowledgements
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