Guidelines for Nebulized Lidocaine Use in Awake Intubation

Dosage Recommendations

For adult awake intubation, administer 200 mg of 4 % lidocaine via nebulizer (5 mL) combined with spray‑as‑you‑go technique, ensuring the total topical dose does not exceed 9 mg/kg lean body weight. The Difficult Airway Society recommends this upper limit. 1
The Difficult Airway Society explicitly advises a maximum total topical dose of 9 mg/kg lean body weight for awake tracheal intubation. 1
British Thoracic Society data indicate that doses up to 15.4 mg/kg are generally well‑tolerated, although subjective toxicity (e.g., dizziness, euphoria) may appear at ≥ 9.6 mg/kg. 2
Cardiac and neurological toxicity are typically observed when serum lidocaine concentrations exceed 5 mg/L or when topical doses exceed 7 mg/kg. 2
In pediatric patients, the maximum recommended dose is 5 mg/kg ideal body weight for procedures lasting up to 2 hours. 3
For infants younger than 6 months, underweight children, or those with hepatic disease, the dose should be reduced to 4 mg/kg ideal body weight. 4
In children weighing less than 10 kg, use 1 % or 2 % lidocaine solutions to provide an adequate volume for topicalization. 4
Concentrations greater than 4 % must never be used in children. 3

Combining nebulized lidocaine with the spray‑as‑you‑go technique yields superior airway anesthesia compared with nebulization alone. 2

Early warning signs of lidocaine systemic toxicity include circumoral numbness, facial tingling, metallic taste, dizziness, and euphoria; their appearance should prompt immediate cessation of further lidocaine administration. 2
After topicalization, patients should be observed for 30–60 minutes to detect delayed systemic absorption. 4
Patients with congestive heart failure have an increased risk of cardiac toxicity from lidocaine. 2
Hepatic dysfunction prolongs lidocaine elimination half‑life and heightens toxicity risk. 4
Infants younger than 6 months possess immature hepatic enzymes, necessitating dose reduction as noted above. 4

Document the total lidocaine dose clearly in the patient record. 4
Conduct a pre‑operative team brief when both anesthetist and surgeon plan to use lidocaine, to avoid cumulative overdose. 4
20 % intravenous lipid emulsion must be immediately available in any location where lidocaine topicalization is performed. 3
Do not use lidocaine solutions containing vasoconstrictors (e.g., epinephrine) in children, due to the risk of hypertensive crises and cardiac arrest. 4
Sedation must not replace inadequate topical anesthesia; effective airway anesthesia must be established first. 1
Limit the number of intubation attempts to three, with a possible fourth attempt by a more experienced operator, even when adequate topicalization is achieved. 1
General anesthesia must not be induced until the tracheal tube position is confirmed by both visual inspection and capnography. 1

Patients should fast for at least 1 hour after airway topicalization; fasting time should be extended for those at high aspiration risk. 3
The anesthetic effect of lidocaine lasts approximately 30–60 minutes, while oral mucosal anesthesia may resolve in less than 15 minutes. 4
Post‑procedure recovery should be managed by staff trained to recognize signs of aspiration and local anesthetic systemic toxicity. 4