Preparation for Awake Intubation
Ralph L. Slepian
1 Describe in detail the device or technique.
The technique of “awake intubation” may be misnamed. Dr. Andranick Ovassapian, the founder of the Society for Airway Management, commented that the patient undergoing awake intubation should appear to sleep, but be aroused by verbal or other nonnoxious stimulation. Some authors have preferred to call the state “aware.” The patient should be comfortable, but should be able to obey commands and maintain oxygenation and ventilation and protect their own airway. Additionally, sufficient analgesia of the upper airway must be achieved to allow examination and instrumentation by an oral or nasal route (when not contraindicated).
Awake intubation is not synonymous with flexible scope intubation. Virtually any device used to manage the airway of a patient under general anesthesia can be used in the awake patient.
Planning is an essential part of the technique—the anesthesia provider should have a predetermined plan for patient preparation and contingency plans for each step of preparation as well as airway management.
Psychological Preparation: Most patients expect to be asleep or unconscious when the surgical procedure calls for general anesthesia. A frank discussion, including the reason awake intubation has been chosen, and assurances go a long way toward engendering a cooperative patient. Patient positioning can help reduce apprehension. Patients with airway pathology typically prefer a semi-upright position (using wedges, pillows, or the maneuverability of the OR table). Not only will this often improve their breathing comfort, but it may also reduce the effects of gravity on the anesthesia provider’s ability to access the airway.
Desiccation: When not contraindicated by glaucoma or a compromising atrial arrhythmia, early IM or IV application of a drying agent will increase the effectiveness of topical anesthetics and reduce obscuring secretions in the airway. Glycopyrolate, 0.2 to 0.4 mg, is often chosen. Topical anesthesia of the upper airway (excluding the nose) should not be started until the patient subjectively feels drying. The dose may be repeated.
Sedation/Analgesia: Intravenous analgesia may be used judiciously: small, repeated doses of midazolam (1-2 mg in an average adult) and fentanyl (e.g., 50-100 µg) or remifentanil or dexmedetomidine infusions. Following the principles enumerated above, it is better to undersedate and “add,” than to lose the patient’s cooperation and airway maintenance. Avoid compensating for poor analgesic block technique with oversedation.
Topical/Local Analgesia: Many techniques have been described to anesthetize the nares, oral pharynx, and upper airway, including topical anesthetics and nerve blocks. If a nasal approach is planned, the nasal passages will additionally need to be prepared with a vasoconstrictor (e.g., oxymetazoline).