What is the maximum recommended dose of lidocaine for regional anesthesia in adults without and with epinephrine, respectively?

What is the maximum recommended dose of lidocaine for regional anesthesia in adults without and with epinephrine, respectively?

• A. 4.0 mg/kg without epinephrine; 6 mg/kg with epinephrine
• B. 5.0 mg/kg without epinephrine; 6 mg/kg with epinephrine
• C. Without epinephrine: 4.5 mg/kg; with epinephrine: up to 7 mg/kg
• D. 3.0 mg/kg without epinephrine; 5 mg/kg with epinephrine

Answer: (C)

The key idea is that adding a vasoconstrictor like epinephrine lets you use more local anesthetic safely because it reduces systemic absorption and keeps the drug near the nerve longer. That’s why the upper limit with epinephrine is higher than without. For lidocaine in adults, the maximum dose without epinephrine is 4.5 mg per kilogram of body weight. With epinephrine, you can push up to 7 mg per kilogram. In practice, clinicians also observe absolute caps (often around 300–500 mg total), but the per‑kilogram guidance above is the standard. So the correct interpretation is: without epinephrine, 4.5 mg/kg; with epinephrine, up to 7 mg/kg.

The key idea is that adding a vasoconstrictor like epinephrine lets you use more local anesthetic safely because it reduces systemic absorption and keeps the drug near the nerve longer. That’s why the upper limit with epinephrine is higher than without.

For lidocaine in adults, the maximum dose without epinephrine is 4.5 mg per kilogram of body weight. With epinephrine, you can push up to 7 mg per kilogram. In practice, clinicians also observe absolute caps (often around 300–500 mg total), but the per‑kilogram guidance above is the standard.

So the correct interpretation is: without epinephrine, 4.5 mg/kg; with epinephrine, up to 7 mg/kg.