Certified Registered Nurse Anesthetist (CRNA) Practice Exam

What is the maximum safe dose of lidocaine for topical anesthesia of the airway?

1. 3.0 mg/kg

2. 4.5 mg/kg

3. 6.0 mg/kg

4. 5.0 mg/kg

The correct answer is: 4.5 mg/kg

The maximum safe dose of lidocaine for topical anesthesia of the airway is established based on the drug's pharmacological properties and the need to minimize the risk of systemic toxicity. This limit is particularly important in the context of airway anesthesia, where the potential for absorption into the circulation is higher due to the vascular nature of the mucosal tissues. A maximum dosing guideline of 4.5 mg/kg is supported by clinical evidence and safety standards, as it balances efficacy in achieving anesthesia while protecting against adverse effects such as central nervous system toxicity and cardiovascular complications. Exceeding this dose increases the risk of local toxicity that can manifest as symptoms ranging from confusion and seizures to more severe outcomes. Understanding these pharmacological principles ensures that CRNAs can apply safe practices in managing airway anesthesia effectively.