Conditions that Complicate Intubation

Intubation is a critical procedure to maintain a patient’s airway and allow breathing that can be complicated by various conditions. The success rate of intubation depends on striking a balance between airway patency and cardiorespiratory stability, especially in the face of anatomically and physiologically challenging airways. A difficult airway can be identified according to the visibility of the uvula. High visibility is associated with easier intubation. Respiratory distress, such as that experienced in a COVID-19 patient, leads to inflammation that causes swelling around the uvula, leading to a difficult airway and a complicated intubation. [1,2] Several other conditions can complicate intubation as well.

Damage to the larynx and trachea could be caused by the COVID-19 virus or a downstream inflammatory response to the virus. Complicated intubation has been associated with COVID-19 patients due to their need for prolonged intubation. They need to be oxygenated for longer periods of time. [2] Other conditions that narrow the airway or lead to abnormal anatomy in the airway can similarly complicate intubation.

In the case studies published by Sandu et al., chronic renal disease, hypertension, obesity, ischemic heart disease, sleep apnea and diabetes mellitus were comorbidities associated with complications after intubation. For example, a 53-year-old male with severe COVID-19 and a history of hypertension was intubated for five weeks and following discharge, developed a significant tracheal obstruction which needed surgical intervention to correct. Similarly, a 68-year-old man diagnosed with COVID-19 who presented with comorbidities such as chronic renal disease and hypertension was intubated for 27 days. Post-discharge, he developed progressive breathlessness due to mild tracheal stenosis and a granuloma, which was surgically removed, resulting in symptom relief and no subsequent respiratory issues. In general, several factors impact the extent and severity of stenosis, a complication that arises from intubation. These factors include intubation time, the diameter of the tracheal tube, sedation level, patient health, underlying high risk conditions such as cardiovascular diseases, diabetes, and obesity, as well as the presence of local infections. [3]

All patients admitted to the ICU are experiencing hemodynamic and respiratory instability from their underlying conditions that complicate intubation. The incidence of complications during ICU intubations is up to 30-40%, and hypotension during intubation is linked to elevated mortality rates. Infusing 500ml of crystalloids prior to intubation, the early use of vasopressors, and the application of induction agents like ketamine or ‘ketofol’ have all been shown to reduce the likelihood of hypotension during the intubation process. This has been shown to reduce patient mortality during recovery. [4]

During the COVID-19 pandemic, video laryngoscopy and neuromuscular blockade usage increased significantly. This led to a higher rate of first-pass success in intubations. Even with a higher first-rate pass, the complications associated with intubation were still rising. More research is needed to determine how best to apply these techniques to reduce complications, but Nauka et al. were able to demonstrate that trainee physicians benefitted from this combination of video laryngoscopy and neuromuscular blockade. Complications were visibly reduced among their patient cohort. [5]

References

1. R, Natesh Prabu, et al. “Compliance With Intubation Bundle and Complications in Critically Ill Patients: A Need to Revisit the Bundle Components!” Trends in Anaesthesia and Critical Care, vol. 42, Feb. 2022, pp. 26–33, doi:10.1016/j.tacc.2021.10.001.

2. Shrestha, Sushmita, et al. “Upper Airway Complications in COVID-19: A Case Series.” Cureus, Apr. 2023, doi:10.7759/cureus.37163.

3. Sandu, Kishore. “Laryngotracheal Complications in Intubated COVID-19 Patients.” Clinical Medicine Insights: Case Reports, vol. 14, Jan. 2021, p. 117954762110205,

doi:10.1177/11795476211020590.

4. M, Taboada, et al. “Complications and degree of difficulty of orotracheal intubation in the Intensive Care Unit before and after the establishment of an intubation protocol for critically ill patients: a prospective, observational study” Revista Española de Anestesiología y Reanimación vol. 1539, July 2023, pp. 1–11, doi.org/10.1016/j.redare.2023.12.004

5. Nauka, Peter, et al. “Practice, Outcomes, and Complications of Emergent Endotracheal Intubation by Critical Care Practitioners During the COVID-19 Pandemic.” Chest, vol. 160, no. 6, Dec. 2021, pp. 2112–22, doi:10.1016/j.chest.2021.06.008.