Local Anesthetic Safety Calculator

Calculate maximum allowable volume for various local anesthetics based on weight, concentration, and epinephrine use.

Maximum Dose

Max mg/kg

4.50 mg/kg

LidocaineWithout epinephrine.

Max volume

31.5 mL

Max total 315 mg at 10 mg/mL.

These are theoretical maximums. Use the least amount necessary. Adjust for frailty, hepatic disease, pregnancy, pediatrics, or combining multiple anesthetics.

How to Use This Calculator

1

Select anesthetic and concentration

Choose the percentage solution being used (e.g., 1%, 2%). The calculator converts to mg/mL.

2

Specify epinephrine use

Safe doses increase with epinephrine due to reduced systemic absorption.

3

Compare with planned volume

Ensure total injected volume stays below the maximum. Consider cumulative doses when combining agents.

Formula

Max total (mg) = weight (kg) × max mg/kg.

Derived from FDA labeling, dental anesthesia guidelines, and ASRA recommendations.

Frequently Asked Questions

How to convert percent to mg/mL?

1% solution = 10 mg/mL. Multiply % by 10 to get mg/mL.

What if I mix local anesthetics?

Sum the fractions of each maximum dose. For example, 50% of max lidocaine + 50% of max bupivacaine equals full combined dose.

How to adjust for pediatric patients?

Use pediatric-specific guidelines. Max doses per kg may differ; consult pediatric anesthesia references.

What are signs of local anesthetic systemic toxicity (LAST)?

Perioral numbness, tinnitus, metallic taste, seizures, arrhythmias. Initiate lipid resuscitation immediately.

Can I exceed max dose for tumescent anesthesia?

Special tumescent protocols allow higher doses under strict monitoring. Use dedicated calculators.