Awake tracheal intubation involves placing an endotracheal tube in the trachea while the patient continues to spontaneously breathe. In this case the clinician does not take away the patient’s respirations or airway reflexes. This is different from rapid sequence intubation (RSI) or intubation under general anesthesia which involve induction and muscular relaxation (Schrader & Urits, 2022). Awake tracheal intubation is generally successful and safe. In the rare instances of failure, airway rescue strategies are needed (Ahmad et al., 2020). Intubation without general anesthesia is recommended in situations where an airway will likely be difficult to maintain.  

Difficult airway algorithms recommend an awake intubation if patients have at least one variable of a difficulty airway determined by factors such as mallampati classification, head and neck mobility, mouth opening, body weight, thyromental distance, and prognathism (Rosenstock, et al., 2012). For example, patients with an unstable cervical spine are good candidates for awake intubation. In the cases of intubation without general anesthesia, the patient will maintain their own airway until intubation is achieved. Instrumentation in the back of the throat may cause gagging and vomiting but the risk of clinically significant aspiration would, in these cases, be outweighed by the risk of airway loss when intubating with anesthesia. Patients who are at a high risk of vomiting are not strong candidates for an awake intubation (Ahmad et al., 2020). Absolute contraindications to awake intubation include patient refusal. Relative contraindications include airway bleeding, allergy to local anesthetic, and inexperience of clinician. Risk of aspiration is not a contraindication to awake intubation (Vora, Leslie, & Stacey, 2022).  

Video laryngoscopy and direct laryngoscopy are both used to facilitate awake tracheal intubation. Awake flexible fiberoptic intubation is the gold standard for management of difficult tracheal intubation. While it has been hypothesized that video laryngoscopy may be faster and safer to perform, there is no difference in time to intubation between awake flexible fiberoptic intubation and awake McGrath video laryngoscope intubation. However, video assisted intubation may be more useful for inexperienced operators (Rosenstock et al., 2012).  

Though awake intubation occurs without general anesthesia, other forms of anesthesia are still needed. The two arms of awake intubation are local anesthesia and systemic sedation. Local anesthetics are used to remove the sensation of pain. Sedating agents can also be used to help with patient tolerance of awake intubation. Notably, awake intubation can be completed solely with local anesthetic. Some drugs used for sedation during awake intubation include midazolam, remifentanil, propofol, and dexmedetomidine. More research is needed comparing the various drug regimens used for sedation during awake intubation (Leslie & Stacey, 2015). It is recommended that ECG, blood pressure, pulse oximetry, and continuous end-tidal carbon dioxide monitoring are used throughout awake tracheal intubation (Ahmad et al., 2020). Anti-sialagogues are also used to dry mucus membranes and decrease secretions, but these are not required for awake intubations. They may improve vision through a flexible bronchoscope, but the data demonstrating their utility in awake intubation is limited (Leslie & Stacey, 2015), (Ahmad et al., 2020).  

While intubation without general anesthesia can be a useful strategy to secure a patient’s airway, more high-quality evidence is needed to establish general guidelines and recommendations around its use. More research should be done to understand administration methods and drugs used in sedation or anesthesia (Ahmad et al., 2020). Still, it is a very promising technique that will benefit patients, especially those with difficult to manage airways.  

References 

1. Ahmad I, El-Boghdadly K, Bhagrath R, et al. Difficult Airway Society guidelines for awake tracheal intubation (ATI) in adults. Anaesthesia. 2020;75(4):509-528. doi:10.1111/anae.14904
2. Leslie D, Stacey M. Awake intubation, Continuing Education in Anaesthesia Critical Care & Pain. 2015:15(2):64–67.doi.org/10.1093/bjaceaccp/mku015
3. Rosenstock CV, Thøgersen B, Afshari A, Christensen AL, Eriksen C, Gätke MR. Awake fiberoptic or awake video laryngoscopic tracheal intubation in patients with anticipated difficult airway management: a randomized clinical trial. Anesthesiology. 2012;116(6):1210-1216. doi:10.1097/ALN.0b013e318254d085
4. Schrader M, Urits I. Tracheal Rapid Sequence Intubation. StatPearls. Published Jan 2022. https://www.ncbi.nlm.nih.gov/books/NBK560592/
5. Vora J, Leslie D, Stacey M. Awake tracheal intubation. British Journal of Anaesthesia Education. 2022;22(8):298-305. doi:10.1016/j.bjae.2022.03.006