How much local anesthesia is contained in 4 cartridges of 2% Lidocaine 1:50,000?

To determine the amount of local anesthesia in 4 cartridges of 2% Lidocaine with a concentration of 1:50,000, it is essential to first understand the concentration of Lidocaine in one cartridge.

A standard dental cartridge typically holds 1.8 mL of solution. The concentration of 2% Lidocaine means there are 2 grams of Lidocaine per 100 mL of solution. To convert this to a milligram amount, you have:

2 grams = 2000 mg in 100 mL, which is equivalent to 20 mg/mL.

Now, for one cartridge of 2% Lidocaine:

• Each cartridge contains 1.8 mL

• Thus, the amount of Lidocaine in one cartridge is: 20 mg/mL * 1.8 mL = 36 mg.

When considering 4 cartridges, you multiply the amount of Lidocaine per cartridge by 4:

36 mg * 4 = 144 mg.

This calculation leads to the total amount of local anesthesia contained in 4 cartridges of 2% Lidocaine 1:50,000, which is 144 mg. Therefore, this is why the correct answer is what it is; the computation reflects